0001628280-22-006926 | 10-K | XBRL Viewer

Print Document View Excel Document

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
Statements of Cash Flows - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (26,851)	$ (16,687)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	948	546
Amortization of debt discount and debt issuance costs	279	274
Non-cash interest expense	540	531
Deferred income taxes	148	(106)
Stock-based compensation	4,728	2,694
Changes in assets and liabilities:
Accounts receivable, net	(744)	(3,195)
Prepaid expenses and other current assets	521	(708)
Other assets	(167)	(15)
Accounts payable	(655)	986
Accrued and other current liabilities	984	1,596
Net cash used in operating activities	(20,269)	(14,084)
Cash flows from investing activities:
Purchases of property and equipment	(2,370)	(455)
Purchase of other assets	(50)	0
Net cash used in investing activities	(2,420)	(455)
Cash flows from financing activities:
Proceeds from exercise of stock options	89	13
Proceeds from common stock issued under Employee Stock Purchase Plan	390	142
Proceeds from exercise of common stock warrants	32	18
Principal payment on capital lease obligations	(525)	(249)
Proceeds from Paycheck Protection Program loan	0	2,865
Repayment of Paycheck Protection Program loan	0	(2,865)
Proceeds from the issuance of common stock in public offering, gross	69,144	0
Net cash provided by (used in) financing activities	64,683	(97)
Net change in cash, cash equivalents and restricted cash	41,994	(14,636)
Cash, cash equivalents and restricted cash, beginning of period	57,548	72,184
Cash, cash equivalents and restricted cash, end of period	99,542	57,548
Supplemental disclosure of cash flow information:
Cash paid for interest expense	1,815	1,758
Supplemental disclosure of non-cash items:
Equipment purchased under capital lease obligations	1,111	260
Costs incurred, but not paid, in connection with capital expenditures	685	553
Deferred offering costs included in accounts payable and accrued and other current liabilities	0	40
Deferred offering costs reclassified to equity	28	0
Public Offering
Cash flows from financing activities:
Payment of issuance costs related to public offering	(4,407)	0
Other Offering
Cash flows from financing activities:
Payment of issuance costs related to public offering	$ (40)	$ (21)

Statements of Stockholders' Equity (Parenthetical) $ in Thousands	Dec. 31, 2021 USD ($)
Statement of Financial Position [Abstract]
Stock issuance costs	$ 4,435

Stock Option Plan (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Schedule of Stock Option Activity

Stock option activity under the Company's 2019 Plan is set forth below:


	Number of Options	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding, December 31, 2020	1,975,761	$	11.81	8.71	$	6,750
Granted	229,850	$	16.79
Exercised	(11,950)	$	7.40
Forfeited	(128,665)	$	14.44
Expired	(50,666)	$	17.18
Outstanding, December 31, 2021	2,014,330	$	12.10	7.87	$	5,428
Vested and expected to vest, December 31, 2021	2,014,330	$	12.10	7.87	$	5,428
Options exercisable, December 31, 2021	1,050,036	$	10.17	7.53	$	4,262

Schedule of Share-based Payment Arrangement, Restricted Stock Unit, Activity

Restricted stock unit activity under the Company's 2019 Plan is set forth below:


	Number of Shares	Weighted- Average Grant Date Fair Value		Aggregate Intrinsic Value
Outstanding, December 31, 2020	—	$	—	$	—
Awards granted	449,000	$	16.51
Awards released	—	$	—
Awards canceled	(33,675)	$	16.24
Outstanding, December 31, 2021	415,325	$	16.54	$	4,830

Schedule of Fair Value Assumptions, Stock Options

The fair value of employee stock options was estimated using the following assumptions to determine the fair value of stock options granted:


	Years Ended December 31,
		2021	2020
Expected volatility		56%-60%	47%-53%
Risk-free interest rate		0.8%-1.1%	0.4%-1.7%
Dividend yield		—	—
Expected term (in years)		5.50-6.08	5.5-6.08

The following assumptions were used to calculate the stock-based compensation for each stock purchase right granted under the ESPP:


	Years Ended December 31,
		2021	2020
Expected volatility		45%-60%	58.0%-83.0%
Risk-free interest rate		0.1%	0.1%-1.1%
Dividend yield		—	—
Expected term (in years)		0.5	0.5

Stock-based compensation expense related to the ESPP for the years ended December 31, 2021 and 2020 was $0.2 million and less than $0.1 million, respectively. As of December 31, 2021, total unrecognized compensation cost related to stock purchase rights granted under the ESPP was less than $0.1 million, which is expected to be recognized over a remaining weighted-average vesting period of 0.2 years.

Schedule of Non-cash Stock-based Compensation Expense

Total non-cash stock-based compensation expense recorded related to options granted, restricted stock units granted and stock purchase rights granted under the ESPP in the statement of operations is as follows (in thousands):


	Years Ended December 31,
		2021		2020
Cost of revenue		$	164	$	33
Selling, general and administrative		3,943		2,419
Research and development		621		242
Total		$	4,728	$	2,694

Schedule of Common Stock Reserved For Future Issuance

Common stock reserved for future issuance consists of the following at December 31, 2021:


Warrants to purchase common stock						1,214,059
Common stock option grants issued and outstanding						2,014,330
Common stock reserved for issuance upon vesting of outstanding restricted stock units						415,325
Common shares available for grant under the 2019 Plan						1,179,571
Common shares available for future issuance under ESPP						327,516
Total						5,150,801

Stock Option Plan - Common Stock Reserved For Future Issuance (Details)	Dec. 31, 2021 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	5,150,801
Warrants to purchase common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	1,214,059
Common stock option grants issued and outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	2,014,330
Common stock reserved for issuance upon vesting of outstanding restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	415,325
Common shares available for grant under the 2019 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	1,179,571
Common shares available for future issuance under ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	327,516

Summary of Significant Accounting Policies - Revenue by Major Payers (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Medicare \| Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk percentage	19.00%	20.00%
Medicare Advantage \| Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk percentage	13.00%	11.00%
Blue Shield \| Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk percentage	12.00%	11.00%
Blue Shield \| Accounts Receivable
Disaggregation of Revenue [Line Items]
Concentration risk percentage	19.00%	11.00%
Janssen (SIMPONI) \| Revenue Benchmark
Disaggregation of Revenue [Line Items]
Concentration risk percentage		12.00%
Janssen (SIMPONI) \| Accounts Receivable
Disaggregation of Revenue [Line Items]
Concentration risk percentage	0.00%	35.00%
United Healthcare \| Accounts Receivable
Disaggregation of Revenue [Line Items]
Concentration risk percentage	18.00%

Commitment and Contingencies - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Nov. 30, 2021	May 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Rent expense			$ 900	$ 600
Period for royalties to begin	18 months
Purchase obligation, due in next twelve months			3,700
Purchase obligation, due in second year			$ 6,000
Annual increase in purchase commitments			15.00%
AHN Collaboration
Loss Contingencies [Line Items]
Collaboration agreement, collaboration expenses			$ 300
Minimum \| Licensing Agreements
Loss Contingencies [Line Items]
Royalty obligation, percent of net sales			1.50%
Maximum \| Licensing Agreements
Loss Contingencies [Line Items]
Royalty obligation, percent of net sales			7.00%
Prometheus Laboratories
Loss Contingencies [Line Items]
Payments to acquire intellectual property			$ 100
Future minimum royalty commitment			1,200
Advance royalties payment			$ 100
Prometheus Laboratories \| Minimum
Loss Contingencies [Line Items]
Royalty obligation, percent of net sales			2.50%
Allegheny Health Network Research Institute
Loss Contingencies [Line Items]
Collaboration fee		$ 400
Allegheny Health Network Research Institute \| Licensing Agreements
Loss Contingencies [Line Items]
Initial license fee		$ 400
Queen Mary University Of London \| Licensing Agreements
Loss Contingencies [Line Items]
Initial license fee	$ 400
One time payment	$ 100
Office and Laboratory
Loss Contingencies [Line Items]
Operating leases, renewal term			5 years
Office
Loss Contingencies [Line Items]
Operating leases, renewal term			5 years

Fair Value Measures and Disclosures (Tables)

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Financial Instrument Measured on a Recurring Basis

The following table sets forth the Company's financial instruments that were measured at fair value on a recurring basis within the fair value hierarchy (in thousands):


	December 31, 2021
	Total		Level 1		Level 2		Level 3
Assets:
Money market funds, included in cash and cash equivalents	$	95,761	$	95,761	$	—	$	—


	December 31, 2020
	Total		Level 1		Level 2		Level 3
Assets:
Money market funds, included in cash and cash equivalents	$	34,507	$	34,507	$	—	$	—

Borrowings - Narrative (Details)		1 Months Ended		12 Months Ended
Borrowings - Narrative (Details)	Dec. 07, 2018 USD ($)	Nov. 30, 2021 USD ($) installment	Sep. 30, 2017 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Loan payable \| Capital Royalty Partners II LP
Debt Instrument [Line Items]
Loan repayment			$ 17,800,000
2017 Term loan \| Loan payable \| Innovatus Life Sciences Lending Fund
Debt Instrument [Line Items]
Term loan borrowings	$ 5,000,000		$ 20,000,000	$ 0
Term loan, interest rate		8.00%
Term loan, paid in-kind, interest rate		2.00%
Term loan, effective interest rate		8.50%
Number of monthly installments \| installment		24
Term loan, fee incurred upon payment of final installment				$ 1,000,000
Term loan, prepayment premium percentage		3.00%
Term loan, annual reduction in prepayment penalty percentage		1.00%
Term loan, covenant, revenue performance period				12 months
Term loan, covenant, number of days to cure covenant if performance measure is not met				60 days
Term loan covenant, minimum unrestricted cash balance		$ 2,000,000.0
Term loan covenant, increase to interest rate				4.00%
2017 Term loan \| Paid in-kind note \| Innovatus Life Sciences Lending Fund
Debt Instrument [Line Items]
Term loan, paid in-kind loans issued				$ 500,000	$ 500,000

Other Financial Information - Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 8,656	$ 5,043
Less: accumulated depreciation and amortization	(3,884)	(2,941)
Property and equipment, net	4,772	2,102
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	83	64
Laboratory equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	4,361	2,679
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment	1,206	927
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	1,151	1,072
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 1,855	$ 301

Other Financial Information

12 Months Ended

Dec. 31, 2021

Other Financial Information [Abstract]

Other Financial Information

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following (in thousands):


	December 31,
	2021		2020
Diagnostic testing supplies	$	1,091	$	1,203
Prepaid product royalties	49		68
Prepaid maintenance and insurance contracts	2,008		2,229
Other prepaid and other current assets	490		659
Prepaid and other current assets	$	3,638	$	4,159

Property and Equipment

Property and equipment consist of the following (in thousands):


	December 31,
	2021		2020
Furniture and fixtures	$	83	$	64
Laboratory equipment	4,361		2,679
Computer equipment and software	1,206		927
Leasehold improvements	1,151		1,072
Construction in progress	1,855		301
Total property and equipment	8,656		5,043
Less: accumulated depreciation and amortization	(3,884)		(2,941)
Property and equipment, net	$	4,772	$	2,102

Depreciation and amortization expense for the years ended December 31, 2021 and 2020, was approximately $0.9 million and $0.5 million, respectively. At December 31, 2021 and December 31, 2020, the gross book value of assets under capital lease was $2.5 million and $1.2 million, respectively, and is classified in "Laboratory equipment" in the table above. At December 31, 2021, $1.5 million relates to leasehold improvements in connection

with the conversion of the Company's warehouse space into additional clinical laboratory space and research and development facility space, which is expected to be placed in service in calendar year 2022.

Accrued and Other Current Liabilities

Accrued and other current liabilities consist of the following (in thousands):


	December 31,
	2021		2020
Accrued payroll and related expenses	$	4,048	$	3,589

Accrued interest	139		147
Accrued purchases of goods and services	510		311
Accrued royalties	180		221
Accrued clinical study activity	254		228
Capital lease obligations, current portion	587		308
Other accrued liabilities	1,108		953
Accrued and other current liabilities	$	6,826	$	5,757

Stock Option Plan - Restricted Stock Units (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding, December 31, 2020 (in dollars per share)	$ 13.20
Outstanding, December 31, 2021 (in dollars per share)	$ 11.63
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding, December 31, 2020 (in shares)	0
Awards granted (in shares)	449,000
Awards released (in shares)	0
Awards canceled (in shares)	(33,675)
Outstanding, December 31, 2021 (in shares)	415,325
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding, December 31, 2020 (in dollars per share)	$ 0
Awards granted, Weighted-Average Grant Date Fair Value (in dollars per share)	16.51
Awards released, Weighted-Average Grant Date Fair Value (in dollars per share)	0
Awards canceled, Weighted-Average Grant Date Fair Value (in dollars per share)	16.24
Outstanding, December 31, 2021 (in dollars per share)	$ 16.54
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value [Abstract]
Outstanding, Aggregate Intrinsic Value	$ 4,830	$ 0

Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2019		12,560,990
Beginning balance at Dec. 31, 2019	$ 55,659	$ 13	$ 220,248	$ (164,602)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)		47,549
Exercise of stock options	13		13
Issuance of stock under Employee Stock Purchase Plan (in shares)		11,649
Issuance of stock under Employee Stock Purchase Plan	142		142
Stock-based compensation	2,694		2,694
Exercise of common stock warrants (in shares)		32,120
Exercise of common stock warrants	18		18
Net loss	$ (16,687)			(16,687)
Ending balance (in shares) at Dec. 31, 2020	12,652,308	12,652,308
Ending balance at Dec. 31, 2020	$ 41,839	$ 13	223,115	(181,289)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock in public offering, net of issuance costs of $4,435 (in shares)		4,255,000
Issuance of stock in public offering, net of issuance costs of $4,435	64,709	$ 4	64,705
Retirement of common stock in exchange for common stock warrant (in shares)		(804,951)
Retirement of common stock in exchange for common stock warrant	(12,775)	$ (1)	(12,774)
Issuance of common stock warrant in exchange for retirement of common stock	$ 12,775		12,775
Exercise of stock options (in shares)	11,950	11,950
Exercise of stock options	$ 89		89
Issuance of stock under Employee Stock Purchase Plan (in shares)		32,968
Issuance of stock under Employee Stock Purchase Plan	390		390
Stock-based compensation	$ 4,728		4,728
Exercise of common stock warrants (in shares)	17,719	17,719
Exercise of common stock warrants	$ 32		32
Net loss	$ (26,851)			(26,851)
Ending balance (in shares) at Dec. 31, 2021	16,164,994	16,164,994
Ending balance at Dec. 31, 2021	$ 84,936	$ 16	$ 293,060	$ (208,140)

Other Financial Information - Prepaid Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Other Financial Information [Abstract]
Diagnostic testing supplies	$ 1,091	$ 1,203
Prepaid product royalties	49	68
Prepaid maintenance and insurance contracts	2,008	2,229
Other prepaid and other current assets	490	659
Prepaid and other current assets	$ 3,638	$ 4,159

Income Taxes - Narrative (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal net operating loss carryforwards	$ 89,400,000	$ 70,600,000
State net operating loss carryforwards	61,000,000.0	48,900,000
Federal tax loss carryforwards, subject to expiration	43,500,000
Federal net operating loss carryforwards, carryforward indefinitely	45,900,000
Tax attribute carryforwards cannot be utilized under IRC Section 382			$ 61,800,000
Unrecognized tax benefits	$ 0	$ 0

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit)

The provision for income taxes consists of the following (in thousands):


	Years Ended December 31,
	2021		2020
Current:
Federal	$	—	$	—
State	27		27
Total current	27		27
Deferred:
Federal	137		(117)
State	11		11
Total deferred	148		(106)
Provision (benefit) for income tax	$	175	$	(79)

Schedule of Effective Income Tax Rate Reconciliation

The effective tax rate of our provision for income taxes differs from the federal statutory rate as follows:


	Years Ended December 31,
	2021		2020
Federal statutory tax rate	(21.0)	%	(21.0)	%
State income taxes, net of federal tax benefits	(3.8)	%	(3.9)	%
Research and development tax credits	(1.2)	%	(0.5)	%
Stock compensation	0.9	%	1.0	%
Non-deductible expenses	1.1	%	1.1	%

Change in valuation allowance	24.6	%	22.6	%

Other	—	%	0.2	%
Effective tax rate	0.6	%	(0.5)	%

Schedule of Deferred Tax Assets and Liabilities

If the Company’s judgment changes and it is determined that the Company will be able to realize these deferred tax assets, the tax benefits relating to any reversal of the valuation allowance on deferred tax assets will be accounted for as a reduction to income tax expense (in thousands).


	December 31,
	2021		2020
Deferred tax assets:
Net operating loss carryforwards	$	22,365	$	17,733
Research and development tax credits	1,102		629
Accruals, reserves and other	1,055		920
Interest expense	1,953		1,306
Basis differences in fixed and intangible assets	—		117
Stock compensation	1,407		528
Total gross deferred tax assets	27,882		21,233
Less: valuation allowance	(27,158)		(20,596)
Deferred tax assets, net	724		637
Deferred tax liabilities:
Financing and acquisition-related liabilities	(335)		(336)
Indefinite lived assets	(521)		(459)
Basis differences in fixed and intangible assets	(175)		—
Deferred tax liabilities, net	(1,031)		(795)
Net deferred tax liabilities	$	(307)	$	(158)

Summary of Valuation Allowance

Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2021 and 2020, which related primarily to increases in net operating loss (NOL) carryforwards, accrued revenue and accruals and reserves were as follows (in thousands):


	December 31,
	2021		2020
Valuation allowance at the beginning of the year	$	20,596	$	16,797
Decreases recorded as benefits to income tax provision	—		—
Increases recorded to income tax provision	6,562		3,799
Valuation allowance at the end of the year	$	27,158	$	20,596

Commitment and Contingencies (Tables)

12 Months Ended

Dec. 31, 2021

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Rental Payments for Capital Leases

Minimum annual lease payments under non-cancelable lease arrangements at December 31, 2021 are as follows (in thousands):


Years Ending December 31,	Capital Leases		Operating Leases
2022	$	641	$	1,337
2023	566		1,445
2024	313		1,489
2025	66		1,533
2026	—		1,584
Thereafter	—		539
Total minimum lease payments	1,586		$	7,927
Less: amount representing interest	(116)
Present value of future minimum lease payments	1,470
Less: current portion	(587)
Long-term capital lease obligations	$	883

Schedule of Future Minimum Rental Payments for Operating Leases

Minimum annual lease payments under non-cancelable lease arrangements at December 31, 2021 are as follows (in thousands):


Years Ending December 31,	Capital Leases		Operating Leases
2022	$	641	$	1,337
2023	566		1,445
2024	313		1,489
2025	66		1,533
2026	—		1,584
Thereafter	—		539
Total minimum lease payments	1,586		$	7,927
Less: amount representing interest	(116)
Present value of future minimum lease payments	1,470
Less: current portion	(587)
Long-term capital lease obligations	$	883

Stockholders' Equity (Details)	12 Months Ended
Stockholders' Equity (Details)	Dec. 31, 2021 $ / shares shares
Class of Stock [Line Items]
Warrants issued to purchase redeemable convertible preferred stock (in shares)	1,214,059
Exercise of common stock warrants (in shares)	17,719
Warrant expiration January 19, 2026
Class of Stock [Line Items]
Warrants issued to purchase redeemable convertible preferred stock (in shares)	237,169
Class of warrant or right, exercise price of warrants or rights (in dollars per share) \| $ / shares	$ 1.84
Warrant expiration March 31, 2026
Class of Stock [Line Items]
Warrants issued to purchase redeemable convertible preferred stock (in shares)	67,086
Class of warrant or right, exercise price of warrants or rights (in dollars per share) \| $ / shares	$ 1.84
Warrant expiration April 1, 2026
Class of Stock [Line Items]
Warrants issued to purchase redeemable convertible preferred stock (in shares)	131
Class of warrant or right, exercise price of warrants or rights (in dollars per share) \| $ / shares	$ 1.84
Warrant expiration September 7, 2024
Class of Stock [Line Items]
Warrants issued to purchase redeemable convertible preferred stock (in shares)	83,778
Class of warrant or right, exercise price of warrants or rights (in dollars per share) \| $ / shares	$ 14.32
Warrant expiration December 7, 2025
Class of Stock [Line Items]
Warrants issued to purchase redeemable convertible preferred stock (in shares)	20,944
Class of warrant or right, exercise price of warrants or rights (in dollars per share) \| $ / shares	$ 14.32
No expiration
Class of Stock [Line Items]
Warrants issued to purchase redeemable convertible preferred stock (in shares)	804,951
Class of warrant or right, exercise price of warrants or rights (in dollars per share) \| $ / shares	$ 0.001

Other Financial Information - Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Other Financial Information [Abstract]
Accrued payroll and related expenses	$ 4,048	$ 3,589
Accrued interest	139	147
Accrued purchases of goods and services	510	311
Accrued royalties	180	221
Accrued clinical study activity	254	228
Capital lease obligations, current portion	587	308
Other accrued liabilities	1,108	953
Accrued and other current liabilities	$ 6,826	$ 5,757

Summary of Significant Accounting Policies - (Policies)	12 Months Ended
Summary of Significant Accounting Policies - (Policies)	Dec. 31, 2021
Accounting Policies [Abstract]
Concentration of Credit Risk and Other Risk and Uncertainties	Concentration of Credit Risk and Other Risk and Uncertainties Financial instruments that potentially subject the Company to credit risk consist principally of cash, cash equivalents, and accounts receivable. Substantially all the Company's cash and cash equivalents are held at one financial institution that management believes is of high credit quality. Such deposits may, at times, exceed federally insured limits.
Fair Value Measurements	Fair Value Measurements The carrying value of the Company's cash and cash equivalents approximate fair value due to the short-term nature of these items. The estimated fair value of the Company's long-term borrowings are determined by Level 2 inputs and is based primarily on quoted market prices for the same or similar issues. The recorded value of the Company's long-term borrowings approximates the current fair value as the interest rate and other terms are that which are currently available to the Company. Fair value is defined as the exchange price that would be received for an asset or an exit price paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy defines a three-level valuation hierarchy for disclosure of fair value measurements as follows: Level 1 - Unadjusted quoted prices in active markets for identical assets or liabilities; Level 2 - Inputs other than quoted prices included within Level I that are observable, unadjusted quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and Level 3 - Unobservable inputs that are supported by little or no market activity for the related assets or liabilities. The categorization of a financial instrument within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash The Company considers all highly-liquid investments purchased with a remaining maturity date upon acquisition of three months or less to be cash equivalents and are stated at cost, which approximates fair value.
Property and Equipment	Property and EquipmentProperty and equipment are stated at cost, net of depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, generally between three and five years. Leasehold improvements are amortized on a straight-line basis over the lesser of the estimated useful life or the remaining term of the related lease. Maintenance and repairs are charged to expense as incurred, and improvements and betterments are capitalized. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the balance sheet and any resulting gain or loss is reflected in other income or expense in the statements of operations in the period realized.
Long-lived Assets	Long-lived Assets The Company’s long-lived assets are comprised principally of its property and equipment, finite lived intangible assets, and goodwill. If the Company identifies a change in the circumstances related to its long-lived assets, such as property and equipment and intangible assets (other than goodwill), that indicates the carrying value of any such asset may not be recoverable, the Company will perform an impairment analysis. A long-lived asset (other than goodwill) is deemed to be impaired when the undiscounted cash flows expected to be generated by the asset (or asset group) are less than the asset’s carrying amount. Any required impairment loss would be measured as the amount by which the asset’s carrying value exceeds its fair value, and would be recorded as a reduction in the carrying value of the related asset and a charge to operating expense. Goodwill is reviewed for impairment annually (during the fourth quarter) or more frequently if indicators of impairment exist. As the Company operates in a single operating segment and reporting unit, the Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of the reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform a quantitative assessment. If, after assessing qualitative factors, the Company determines it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing a quantitative assessment is unnecessary. If deemed necessary, a quantitative assessment compares the fair value of the reporting unit with its carrying amount, including goodwill. If the fair value of the reporting unit exceeds its carrying amount, goodwill is not considered impaired; otherwise, an impairment loss is recorded. No impairment was recognized for any of the periods presented.
Clinical Studies	Clinical StudiesFrom time to time, the Company engages in efforts to scientifically measure and document the application and efficacy of its various testing products. These arrangements typically require the Company to pay a fee to a third-party scientific investigator (usually a physician or research institution) for each subject enrolled in a clinical study, and the Company accrues expenses associated with these efforts as subjects are enrolled in each study. Payments made prior to the completion of clinical study services are capitalized until the services are rendered. Expenses associated with clinical study activities are recorded in research and development expenses in the accompanying statement of operations.
Revenue Recognition	Revenue Recognition Substantially all of the Company's revenue has been derived from sales of its testing products and is primarily comprised of a high volume of relatively low-dollar transactions. The Company primarily markets its testing products to rheumatologists and their physician assistants in the United States. The healthcare professionals who order the Company's testing products and to whom test results are reported are generally not responsible for payment for these products. The parties that pay for these services (each, a payors) consist of healthcare insurers, government payors (primarily Medicare and Medicaid), client payors (i.e., hospitals, other laboratories, etc.), and patient self-pay. The Company's service is a single performance obligation that is completed upon the delivery of test results to the prescribing physician which triggers revenue recognition. Payors are billed at the Company's list price. Net revenues recognized consist of amounts billed net of allowances for differences between amounts billed and the estimated consideration the Company expects to receive from such payors. The process for estimating revenues and the ultimate collection of accounts receivable involves significant judgment and estimation. The Company follows a standard process, which considers historical denial and collection experience, insurance reimbursement policies and other factors, to estimate allowances and implicit price concessions, recording adjustments in the current period as changes in estimates occur. Further adjustments to the allowances, based on actual receipts, are recorded upon settlement. The transaction price is estimated using an expected value method on a portfolio basis. The Company's portfolios are grouped per payor (i.e. each individual third-party insurance, Medicare, client payors, patient self-pay, etc.) and per test basis. Collection of the Company's net revenues from payors is normally a function of providing complete and correct billing information to the healthcare insurers and generally occurs within 30 to 90 days of billing. Contracts do not contain significant financing components based on the typical period of time between performance of services and collection of consideration. Revenue recognized during the years ended December 31, 2021 and 2020 related to performance obligations satisfied in previous periods was approximately $0.7 million and $0.8 million, respectively, which relates to a change in estimate of the transaction price.
Research and Development	Research and Development Costs associated with research and development activities are expensed as incurred and include, but are not limited to, personnel-related expenses, including stock-based compensation expense, materials, laboratory supplies, consulting costs, costs associated with setting up and conducting clinical studies and allocated overhead including rent and utilities.
Advertising and Marketing Costs	Advertising and Marketing Costs Costs associated with advertising and marketing activities are expensed as incurred. Total advertising and marketing costs were approximately $1.7 million and $1.3 million for the years ended December 31, 2021 and 2020, respectively, and are included in selling, general and administrative expenses in the accompanying statements of operations.
Stock-Based Compensation	Stock-Based Compensation The Company recognizes compensation expense for all stock-based awards to employees and directors based on the grant-date estimated fair values over the requisite service period of the awards (usually the vesting period) on a straight-line basis. The fair value of stock options and purchases under the Company's 2019 Employee Stock Purchase Plan (ESPP) rights is determined using the Black-Scholes-Merton (BSM) option pricing model, which requires management to make certain assumptions regarding a number of complex and subjective variables. Equity award forfeitures are recorded as they occur. The BSM option pricing model incorporates various estimates, including the fair value of the Company's common stock, expected volatility, expected term and risk-free interest rates. The weighted-average expected term of options was calculated using the simplified method. The risk-free interest rate for periods within the contractual term of the option is based on the U.S. Treasury yield in effect at the time of grant. The dividend yield was zero, as the Company has never declared or paid dividends and has no plans to do so in the foreseeable future. The fair value of each restricted stock unit is determined on the grant date using the closing price of the Company's common stock on the grant date and generally vest from the grant date in four equal annual installments subject to the holder's continued service with the Company. The Company issues new shares to satisfy restricted stock units upon vesting. The fair value of the Company's common stock is determined by using the closing price of its common stock on the corresponding date.
Comprehensive Loss	Comprehensive Loss Comprehensive loss is defined as a change in equity of a business enterprise during a period, resulting from transactions from nonowner sources. There have been no items qualifying as other comprehensive loss and, therefore, for all periods presented, the Company's comprehensive loss was the same as its reported net loss.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their net recorded amount, management would adjust the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions on the basis of a two-step process whereby (i) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (ii) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50% likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability.
Net Loss Per Share	Net Loss Per Share Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. The weighted-average number of shares in 2021 used to compute basic and diluted shares includes shares issuable upon the exercise of pre-funded warrants at a nominal price. Potentially dilutive common stock equivalents are comprised of warrants for the purchase of common stock, options and restricted stock units outstanding under the Company's 2019 Incentive Award Plan (the 2019 Plan) and shares of the Company's common stock pursuant to the ESPP. For the years ended December 31, 2021 and 2020, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as the inclusion of the potentially dilutive securities would be antidilutive.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations as, and manages its business in, one operating segment.
Recent Accounting Pronouncements Not Yet Adopted, Recently Adopted Accounting Standards	Recent Accounting Pronouncements Not Yet Adopted From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB), or other standard setting bodies and adopted by the Company as of the specified effective date. Under the Jumpstart Our Business Startups Act of 2012 (JOBS Act), the Company meets the definition of an emerging growth company. The Company has elected to use the extended transition period for complying with new or revised accounting standards pursuant to Section 107(b) of the JOBS Act. Unless otherwise discussed, the impact of recently issued standards that are not yet effective will not have a material impact on the Company's financial position or results of operations upon adoption. In February 2016, the FASB issued Accounting Standards Update (ASU) 2016-02, Leases (Topic 842). The new topic supersedes Topic 840, Leases, and increases transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requires disclosures of key information about leasing arrangements. In July 2018, the FASB issued ASU 2018-10, Codification Improvements to Topic 842, which provides narrow amendments to clarify how to apply certain aspects of the new lease standard, and ASU 2018-11, Leases: Targeted Improvements, which was issued to provide relief to companies from restating comparative periods. Pursuant to this ASU, in the period of adoption the Company will not restate comparative periods presented in its financial statements. The effective date of this guidance for public companies is for reporting periods beginning after December 15, 2018. In June 2020, the FASB issued ASU 2020-05, which delays the adoption of ASU 2016-02 for non-public entities to fiscal years beginning after December 15, 2021, and interim periods beginning after December 15, 2022. As an emerging growth company as defined in the JOBS Act, the Company has elected to early adopt this ASU as of January 1, 2022. Topic 842 mandates a modified retrospective transition method. The Company intends to adopt the new lease standard using a cumulative effect to accumulated deficit and will elect the package of practical expedients, which among other things will allow the Company to carry forward its historical lease classification. The Company is in the process of completing its evaluation of the effect that the adoption of this ASU will have on its financial statements. The Company currently believes the most significant change will be related to the recognition of a new right-of-use asset and lease liability at January 1, 2022 on the Company's balance sheet for its office and laboratory space operating leases. Recently Adopted Accounting Standards In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes. The new guidance removes certain exceptions to the general principles of ASC 740 in order to simplify the complexities of its application. These changes include eliminations to the exceptions for intraperiod tax allocation, recognizing deferred tax liabilities related to outside basis differences, and year-to-date losses in interim periods, among others. The effective date of this guidance for public companies is for fiscal years, and interim period within those fiscal years, beginning after December 15, 2020. The Company adopted this guidance on January 1, 2021, and the adoption did not have a material impact on its financial statements. In November 2021, the FASB issued ASU 2021-10, Government Assistance (Topic 832). The update requires certain annual disclosures about transactions with a government that are accounted for by applying a grant or contribution model by analogy. The amendments in this update are effective for fiscal years beginning after December 15, 2021. Early application of the amendments is permitted. The Company early adopted these disclosure requirements and applied them to its disclosure of the funding received as part of the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) in 2020.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Basis of Presentation and Use of Estimates

The Company's financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). The preparation of the accompanying financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities as of the date of the financial statements, and the reported amounts of revenue and expenses during the reporting period. Actual results could materially differ from those estimates.

Significant estimates and assumptions made in the accompanying financial statements include, but are not limited to revenue recognition, the fair value of financial instruments measured at fair value, the recoverability of its long-lived assets (including goodwill) and net deferred tax assets (and related valuation allowance). The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates.

Concentration of Credit Risk and Other Risk and Uncertainties

Financial instruments that potentially subject the Company to credit risk consist principally of cash, cash equivalents, and accounts receivable. Substantially all the Company's cash and cash equivalents are held at one financial institution that management believes is of high credit quality. Such deposits may, at times, exceed federally insured limits.

Significant payors and customers are those which represent more than 10% of the Company's total revenue or accounts receivable balance at each respective balance sheet date. For each significant payor and customer, revenue as a percentage of total revenue and accounts receivable as a percentage of total accounts receivable are as follows:


		Revenue
	Years Ended December 31,
			2021		2020
Medicare			19	%	20	%
Medicare Advantage			13	%	11	%
Blue Shield			12	%	11	%
Janssen (SIMPONI®)			*		12	%



*						Less than 10%.


	Accounts Receivable
	December 31,
	2021		2020
Blue Shield	19	%	11	%
United Healthcare	18	%	*
Janssen (SIMPONI®)	—	%	35	%



*						Less than 10%.

For the years ended December 31, 2021 and 2020, approximately 81% and 70% of the Company's revenue was related to the AVISE® CTD test, respectively.

The Company is dependent on key suppliers for certain laboratory materials. For each of the years ended December 31, 2021 and 2020, approximately 97% of the Company's diagnostic testing supplies were purchased from two suppliers. An interruption in the supply of these materials would impact the Company's ability to perform testing services.

Disaggregation of Revenue

The following table includes the Company's revenues as disaggregated by payor and customer category (in thousands):


	Years Ended December 31,
		2021		2020
Revenue:
Healthcare insurers		$	27,499	$	22,456
Government		9,221		8,446
Client(1)		9,288		5,109
Other(2)		1,091		836
Janssen (SIMPONI®)		1,200		5,128
Total revenue		$	48,299	$	41,975

(1)Includes hospitals, other laboratories, etc.

(2)Includes patient self-pay.

Fair Value Measurements

The carrying value of the Company's cash and cash equivalents approximate fair value due to the short-term nature of these items. The estimated fair value of the Company's long-term borrowings are determined by Level 2 inputs and is based primarily on quoted market prices for the same or similar issues. The recorded value of the Company's

long-term borrowings approximates the current fair value as the interest rate and other terms are that which are currently available to the Company.

Fair value is defined as the exchange price that would be received for an asset or an exit price paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs.

The fair value hierarchy defines a three-level valuation hierarchy for disclosure of fair value measurements as follows:

Level 1 - Unadjusted quoted prices in active markets for identical assets or liabilities;

Level 2 - Inputs other than quoted prices included within Level I that are observable, unadjusted quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and

Level 3 - Unobservable inputs that are supported by little or no market activity for the related assets or liabilities.

The categorization of a financial instrument within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement.

Cash, Cash Equivalents and Restricted Cash

The Company considers all highly-liquid investments purchased with a remaining maturity date upon acquisition of three months or less to be cash equivalents and are stated at cost, which approximates fair value.

The Company has an arrangement with a financial institution with which it has an existing banking relationship whereby in exchange for the issuance of corporate credit cards, the Company agreed to obtain a $0.1 million certificate of deposit with this financial institution as collateral for the balances borrowed on these credit cards. The Company has classified the value of this certificate of deposit (including all interest earned thereon) within other assets in the accompanying balance sheets. The Company has the right to terminate the credit card program at any time. Upon termination of the credit card program and repayment of all outstanding balances owed, the Company may redeem the certificate of deposit (and all interest earned thereon).

Cash, cash equivalents and restricted cash presented in the accompanying statements of cash flows consist of the following (in thousands):


		December 31,
	2021	2020
Cash and cash equivalents		$	99,442	$	57,448
Restricted cash		100		100
		$	99,542	$	57,548

Property and Equipment

Property and equipment are stated at cost, net of depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, generally between three and five years. Leasehold improvements are amortized on a straight-line basis over the lesser of the estimated useful life or the remaining term of the related lease. Maintenance and repairs are charged to expense as incurred, and improvements and betterments are capitalized. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the balance sheet and any resulting gain or loss is reflected in other income or expense in the statements of operations in the period realized.

Long-lived Assets

The Company’s long-lived assets are comprised principally of its property and equipment, finite lived intangible assets, and goodwill.

If the Company identifies a change in the circumstances related to its long-lived assets, such as property and equipment and intangible assets (other than goodwill), that indicates the carrying value of any such asset may not be recoverable, the Company will perform an impairment analysis. A long-lived asset (other than goodwill) is deemed to be impaired when the undiscounted cash flows expected to be generated by the asset (or asset group) are less than the asset’s carrying amount. Any required impairment loss would be measured as the amount by which the asset’s carrying value exceeds its fair value, and would be recorded as a reduction in the carrying value of the related asset and a charge to operating expense.

Goodwill is reviewed for impairment annually (during the fourth quarter) or more frequently if indicators of impairment exist. As the Company operates in a single operating segment and reporting unit, the Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of the reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform a quantitative assessment. If, after assessing qualitative factors, the Company determines it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing a quantitative assessment is unnecessary. If deemed necessary, a quantitative assessment compares the fair value of the reporting unit with its carrying amount, including goodwill. If the fair value of the reporting unit exceeds its carrying amount, goodwill is not considered impaired; otherwise, an impairment loss is recorded. No impairment was recognized for any of the periods presented.

Clinical Studies

From time to time, the Company engages in efforts to scientifically measure and document the application and efficacy of its various testing products. These arrangements typically require the Company to pay a fee to a third-party scientific investigator (usually a physician or research institution) for each subject enrolled in a clinical study, and the Company accrues expenses associated with these efforts as subjects are enrolled in each study. Payments made prior to the completion of clinical study services are capitalized until the services are rendered. Expenses associated with clinical study activities are recorded in research and development expenses in the accompanying statement of operations.

Revenue Recognition

Substantially all of the Company's revenue has been derived from sales of its testing products and is primarily comprised of a high volume of relatively low-dollar transactions. The Company primarily markets its testing products to rheumatologists and their physician assistants in the United States. The healthcare professionals who order the Company's testing products and to whom test results are reported are generally not responsible for payment for these products. The parties that pay for these services (each, a payors) consist of healthcare insurers, government payors (primarily Medicare and Medicaid), client payors (i.e., hospitals, other laboratories, etc.), and patient self-pay. The Company's service is a single performance obligation that is completed upon the delivery of test results to the prescribing physician which triggers revenue recognition.

Payors are billed at the Company's list price. Net revenues recognized consist of amounts billed net of allowances for differences between amounts billed and the estimated consideration the Company expects to receive from such payors. The process for estimating revenues and the ultimate collection of accounts receivable involves significant judgment and estimation. The Company follows a standard process, which considers historical denial and collection experience, insurance reimbursement policies and other factors, to estimate allowances and implicit price concessions, recording adjustments in the current period as changes in estimates occur. Further adjustments to the allowances, based on actual receipts, are recorded upon settlement. The transaction price is estimated using an expected value method on a portfolio basis. The Company's portfolios are grouped per payor (i.e. each individual third-party insurance, Medicare, client payors, patient self-pay, etc.) and per test basis.

Collection of the Company's net revenues from payors is normally a function of providing complete and correct billing information to the healthcare insurers and generally occurs within 30 to 90 days of billing. Contracts do not contain significant financing components based on the typical period of time between performance of services and collection of consideration. Revenue recognized during the years ended December 31, 2021 and 2020 related to performance obligations satisfied in previous periods was approximately $0.7 million and $0.8 million, respectively, which relates to a change in estimate of the transaction price.

Janssen Promotion Agreement

In December 2018, the Company entered into a co-promotion agreement (as amended from time to time, the Janssen Agreement) with Janssen Biotech, Inc. (Janssen) to co-promote SIMPONI® in the United States. In August 2021, the Company and Janssen mutually agreed to terminate the Janssen Agreement effective on August 31, 2021.

Pursuant to the Janssen Agreement, the Company was responsible for the costs associated with its sales force over the course of such co-promotion. Janssen was responsible for all other aspects of the commercialization of SIMPONI® under the Janssen Agreement. In exchange for the Company's sales and co-promotional services, the Company was entitled to a quarterly tiered promotion fee based on the incremental increase in total prescribed units of SIMPONI® for that quarter over a predetermined baseline. For the year ended December 31, 2020, the tiered promotion fee ranged from $750 to $1,250 per prescription over a predetermined baseline. Due in part to COVID-19, in June 2020, the Janssen Agreement was amended to adjust the predetermined average baseline for the third and fourth quarters of 2020. The Janssen Agreement was further amended in June 2020 and December 2020 to adjust the predetermined average baseline for prescribed units for the quarters ending December 31, 2020 and March 31, 2021 and was subject to further adjustment under certain circumstances. In June 2021, the Janssen Agreement was again amended to proportionally increase the baseline for prescribed units for the quarter ended June 30, 2021 to reflect the addition of certain geographies to the sales territories covered by the Janssen Agreement. For the first and second quarters of 2021, the Company earned the minimum promotion fee of $0.3 million.

Upon the termination of the Janssen Agreement on August 31, 2021, the Company became entitled to receive an aggregate of $0.6 million in consideration, which was earned in the year ended December 31, 2021. Pursuant to the terms of the termination, the Company is restricted from promoting any other biologic or Janus kinase inhibitor used for treatment of indications covered by the Janssen Agreement without first obtaining Janssen's written consent until May 31, 2022.

The Company's obligations relating to sales and co-promotion services for SIMPONI® were a series of single performance obligations since Janssen simultaneously received and consumed benefits provided by the Company's sales and co-promotional services. The method for measuring progress towards satisfying the performance obligations was based on prescribed units in excess of the contractual baseline at the contractual rate earned per unit since the Amended Janssen Agreement was cancelable. The Company recognized co-promotion revenue of approximately $1.2 million and $5.1 million during the years ended December 31, 2021 and 2020, respectively. The related expenses for marketing SIMPONI® are included in selling, general and administrative expenses and are expensed as incurred.

Research and Development

Costs associated with research and development activities are expensed as incurred and include, but are not limited to, personnel-related expenses, including stock-based compensation expense, materials, laboratory supplies, consulting costs, costs associated with setting up and conducting clinical studies and allocated overhead including rent and utilities.

Advertising and Marketing Costs

Costs associated with advertising and marketing activities are expensed as incurred. Total advertising and marketing costs were approximately $1.7 million and $1.3 million for the years ended December 31, 2021 and 2020, respectively, and are included in selling, general and administrative expenses in the accompanying statements of operations.

Shipping and Handling Costs

Costs incurred for shipping and handling are included in costs of revenue in the accompanying statements of operations and totaled approximately $2.1 million and $1.4 million, for the years ended December 31, 2021 and 2020, respectively.

Stock-Based Compensation

The Company recognizes compensation expense for all stock-based awards to employees and directors based on the grant-date estimated fair values over the requisite service period of the awards (usually the vesting period) on a

straight-line basis. The fair value of stock options and purchases under the Company's 2019 Employee Stock Purchase Plan (ESPP) rights is determined using the Black-Scholes-Merton (BSM) option pricing model, which requires management to make certain assumptions regarding a number of complex and subjective variables. Equity award forfeitures are recorded as they occur.

The BSM option pricing model incorporates various estimates, including the fair value of the Company's common stock, expected volatility, expected term and risk-free interest rates. The weighted-average expected term of options was calculated using the simplified method. The risk-free interest rate for periods within the contractual term of the option is based on the U.S. Treasury yield in effect at the time of grant. The dividend yield was zero, as the Company has never declared or paid dividends and has no plans to do so in the foreseeable future.

The fair value of each restricted stock unit is determined on the grant date using the closing price of the Company's common stock on the grant date and generally vest from the grant date in four equal annual installments subject to the holder's continued service with the Company. The Company issues new shares to satisfy restricted stock units upon vesting.

The fair value of the Company's common stock is determined by using the closing price of its common stock on the corresponding date.

Comprehensive Loss

Comprehensive loss is defined as a change in equity of a business enterprise during a period, resulting from transactions from nonowner sources. There have been no items qualifying as other comprehensive loss and, therefore, for all periods presented, the Company's comprehensive loss was the same as its reported net loss.

Income Taxes

The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date.

The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their net recorded amount, management would adjust the deferred tax asset valuation allowance, which would reduce the provision for income taxes.

The Company records uncertain tax positions on the basis of a two-step process whereby (i) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (ii) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50% likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability.

Net Loss Per Share

Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. The weighted-average number of shares in 2021 used to compute basic and diluted shares includes shares issuable upon the exercise of pre-funded warrants at a nominal price. Potentially dilutive common stock equivalents are comprised of warrants for the purchase of common stock, options and restricted stock units outstanding under the Company's 2019 Incentive Award Plan (the 2019 Plan) and shares of the Company's common stock pursuant to the ESPP. For the years ended December 31, 2021 and 2020,

there is no difference in the number of shares used to calculate basic and diluted shares outstanding as the inclusion of the potentially dilutive securities would be antidilutive.

Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common stock equivalent shares):


	Years Ended December 31,
		2021	2020


Warrants to purchase common stock		409,108	426,827
Common stock options		2,014,330	1,975,761
Restricted stock units		415,325	—
Employee stock purchase plan		20,193	11,640
Total		2,858,956	2,414,228

Government Assistance Grant Income

Absent authoritative accounting standards, interpretive guidance issued and commonly applied by financial statement preparers allows for the selection of accounting policies amongst acceptable alternatives. Based on the facts and circumstances of the government assistance received by the Company as discussed in Note 11, the Company determined it most appropriate to account for the transaction by analogy to International Accounting Standards 20 (IAS 20), Accounting for Government Grants and Disclosure of Government Assistance. IAS 20 permits for the recognition in earnings either separately under a general heading such as other income, or as a reduction of the related expenses.

Segment Reporting

Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations as, and manages its business in, one operating segment.

Recent Accounting Pronouncements Not Yet Adopted

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB), or other standard setting bodies and adopted by the Company as of the specified effective date. Under the Jumpstart Our Business Startups Act of 2012 (JOBS Act), the Company meets the definition of an emerging growth company. The Company has elected to use the extended transition period for complying with new or revised accounting standards pursuant to Section 107(b) of the JOBS Act. Unless otherwise discussed, the impact of recently issued standards that are not yet effective will not have a material impact on the Company's financial position or results of operations upon adoption.

In February 2016, the FASB issued Accounting Standards Update (ASU) 2016-02, Leases (Topic 842). The new topic supersedes Topic 840, Leases, and increases transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requires disclosures of key information about leasing arrangements. In July 2018, the FASB issued ASU 2018-10, Codification Improvements to Topic 842, which provides narrow amendments to clarify how to apply certain aspects of the new lease standard, and ASU 2018-11, Leases: Targeted Improvements, which was issued to provide relief to companies from restating comparative periods. Pursuant to this ASU, in the period of adoption the Company will not restate comparative periods presented in its financial statements. The effective date of this guidance for public companies is for reporting periods beginning after December 15, 2018. In June 2020, the FASB issued ASU 2020-05, which delays the adoption of ASU 2016-02 for non-public entities to fiscal years beginning after December 15, 2021, and interim periods beginning after December 15, 2022. As an emerging growth company as defined in the JOBS Act, the Company has elected to early adopt this ASU as of January 1, 2022. Topic 842 mandates a modified retrospective transition method. The Company intends to adopt the new lease standard using a cumulative effect to accumulated deficit and will elect the package of practical expedients, which among other things will allow the Company to carry forward its historical lease classification. The Company is in the process of completing its evaluation of the effect that the adoption of this ASU will have on its financial statements. The Company currently believes the most significant change will be

related to the recognition of a new right-of-use asset and lease liability at January 1, 2022 on the Company's balance sheet for its office and laboratory space operating leases.

Recently Adopted Accounting Standards

In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes. The new guidance removes certain exceptions to the general principles of ASC 740 in order to simplify the complexities of its application. These changes include eliminations to the exceptions for intraperiod tax allocation, recognizing deferred tax liabilities related to outside basis differences, and year-to-date losses in interim periods, among others. The effective date of this guidance for public companies is for fiscal years, and interim period within those fiscal years, beginning after December 15, 2020. The Company adopted this guidance on January 1, 2021, and the adoption did not have a material impact on its financial statements.

In November 2021, the FASB issued ASU 2021-10, Government Assistance (Topic 832). The update requires certain annual disclosures about transactions with a government that are accounted for by applying a grant or contribution model by analogy. The amendments in this update are effective for fiscal years beginning after December 15, 2021. Early application of the amendments is permitted. The Company early adopted these disclosure requirements and applied them to its disclosure of the funding received as part of the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) in 2020.

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Schedule of Outstanding Warrants

The following equity classified warrants to purchase common stock were outstanding as of December 31, 2021:

Exercise Price

Issuance date

Expiration date

Common stock warrants

237,169

1.84

January 19, 2016

January 19, 2026

Common stock warrants

67,086

1.84

March 31, 2016

March 31, 2026

Common stock warrants

131

1.84

April 1, 2016

April 1, 2026

Common stock warrants

83,778

14.32

September 7, 2017

September 7, 2024

Common stock warrants

20,944

14.32

December 7, 2018

December 7, 2025

Common stock warrants (Exchange Warrants)

804,951

0.001

June 22, 2021

None

1,214,059

Income Taxes - Reconciliation of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 22,365	$ 17,733
Research and development tax credits	1,102	629
Accruals, reserves and other	1,055	920
Interest expense	1,953	1,306
Basis differences in fixed and intangible assets	0	117
Stock compensation	1,407	528
Total gross deferred tax assets	27,882	21,233
Less: valuation allowance	(27,158)	(20,596)	$ (16,797)
Deferred tax assets, net	724	637
Deferred tax liabilities:
Financing and acquisition-related liabilities	(335)	(336)
Indefinite lived assets	(521)	(459)
Basis differences in fixed and intangible assets	(175)	0
Deferred tax liabilities, net	(1,031)	(795)
Net deferred tax liabilities	$ (307)	$ (158)

Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 48,299	$ 41,975
Healthcare insurers
Disaggregation of Revenue [Line Items]
Revenue	27,499	22,456
Government
Disaggregation of Revenue [Line Items]
Revenue	9,221	8,446
Client
Disaggregation of Revenue [Line Items]
Revenue	9,288	5,109
Other
Disaggregation of Revenue [Line Items]
Revenue	1,091	836
Janssen (SIMPONI)
Disaggregation of Revenue [Line Items]
Revenue	$ 1,200	$ 5,128

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 40
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9031-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130543-203045

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130545-203045

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 924
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

+ Details

Stock Option Plan - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 4,728	$ 2,694
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	164	33
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3,943	2,419
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 621	$ 242

Stockholders' Equity

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Stockholders' Equity

Stockholders' EquityCommon Stock

On November 10, 2020, the Company filed a registration statement on Form S-3 (the Shelf Registration Statement), covering the offering, from time to time, of up to $150.0 million of common stock, preferred stock, debt securities, warrants and units, which Shelf Registration Statement became effective on November 19, 2020.

On March 25, 2021, the Company completed a public offering of 4,255,000 shares of its common stock at a public offering price of $16.25 per share. Net proceeds from the offering were approximately $64.7 million, after deducting underwriting discounts, commissions and other offering expenses of $4.4 million. The shares were registered pursuant to the Company's Shelf Registration Statement discussed above.

Exchange Agreement

On June 22, 2021, the Company entered into an exchange agreement (the Exchange Agreement) with an Investor and its affiliates (the Exchanging Stockholders), pursuant to which the Company exchanged an aggregate of 804,951 shares of the Company's common stock owned by the Exchanging Stockholders for pre-funded warrants (the Exchange Warrants) to purchase an aggregate of 804,951 shares of common stock (subject to adjustment in the event of any stock dividends and splits, reverse stock split, recapitalization, reorganization or similar transaction, as described in the Exchange Warrants), with an exercise price of $0.001 per share. The Exchange Warrants do not expire and are exercisable at any time except that the Exchange Warrants cannot be exercised by the Exchanging Stockholders if, after giving effect thereto, the Exchanging Stockholders would beneficially own more than 4.99% of the Company's common stock, which percentage may change at the Exchanging Stockholder's election to any other percentage upon 61 days' notice to the Company. The Company recorded the retirement of common stock exchanged as a reduction of common shares outstanding and additional paid-in-capital at the fair value of the Exchange Warrants on the issuance date. The Exchange Warrants are classified as equity and the fair value of the Exchange Warrants was recorded as an increase to additional paid-in-capital and is not subject to remeasurement. The Company determined that the fair value of the Exchange Warrants is substantially similar to the fair value of the retired shares on the issuance date due to the negligible exercise price for the Exchange Warrants. As of December 31, 2021, none of the Exchange Warrants have been exercised.

Outstanding Warrants

The following equity classified warrants to purchase common stock were outstanding as of December 31, 2021:

Exercise Price

Issuance date

Expiration date

Common stock warrants

237,169

1.84

January 19, 2016

January 19, 2026

Common stock warrants

67,086

1.84

March 31, 2016

March 31, 2026

Common stock warrants

131

1.84

April 1, 2016

April 1, 2026

Common stock warrants

83,778

14.32

September 7, 2017

September 7, 2024

Common stock warrants

20,944

14.32

December 7, 2018

December 7, 2025

Common stock warrants (Exchange Warrants)

804,951

0.001

June 22, 2021

None

1,214,059

During the year ended December 31, 2021, warrants to purchase common stock were exercised resulting in the issuance of 17,719 shares of the Company's common stock and cash proceeds of an immaterial amount.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-URI http://asc.fasb.org/topic&trid=2208762

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 16
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496180-112644

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

401(k) Plan	12 Months Ended
401(k) Plan	Dec. 31, 2021
Retirement Benefits [Abstract]
401(k) Plan	401(k) PlanThe Company sponsors an employee savings plan that qualifies as a deferred salary arrangement under Section 401(k) of the Code. Participating employees may defer up to the Internal Revenue Service annual contribution limit. Additionally, the Company may elect to make contributions into the savings plan at its sole discretion. For each of the years ended December 31, 2021 and 2020, the Company made contributions to the Plan at 3% of qualified employee compensation, which totaled approximately $0.5 million. Effective January 1, 2022, the Company will make contributions to the Plan at 4% of qualified employee compensation.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section S99
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=21916913&loc=d3e273930-122802

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (o)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (p)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-URI http://asc.fasb.org/topic&trid=2235017

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 60
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6414203&loc=d3e39689-114964

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(03)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (q)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (r)(1)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iii)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (l)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

+ Details

Organization - (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 99,442	$ 57,448
Accumulated deficit	$ 208,140	$ 181,289

- Definition

The cumulative amount of the reporting entity's undistributed earnings or deficit.

+ References + Details

Commitment and Contingencies

12 Months Ended

Dec. 31, 2021

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Leases

As of December 31, 2021, the Company leases office and laboratory space in Vista, California, under leases that expire in April 2027, with an option to extend a portion of the lease for an additional 5-year period. The Company also leases additional office space in Vista, California, under a lease that expires in April 2027 with an option to extend the lease for an additional 5-year period. The Company's lease payments under each of these leases are subject to escalation clauses. In addition, effective on August 23, 2021, the Company entered into a sub-lease agreement for an additional office space in Carlsbad, California. The sub-lease commended in October 2021 and expires in April 2027.

Minimum annual lease payments under non-cancelable lease arrangements at December 31, 2021 are as follows (in thousands):


Years Ending December 31,	Capital Leases		Operating Leases
2022	$	641	$	1,337
2023	566		1,445
2024	313		1,489
2025	66		1,533
2026	—		1,584
Thereafter	—		539
Total minimum lease payments	1,586		$	7,927
Less: amount representing interest	(116)
Present value of future minimum lease payments	1,470
Less: current portion	(587)
Long-term capital lease obligations	$	883

For the years ended December 31, 2021 and 2020, rent expense was $0.9 million and $0.6 million, respectively.

Acquisition-related liabilities

In connection with the acquisition of the medical diagnostics division of Cypress Bioscience, Inc. in 2010, the Company was required to pay certain amounts in the event that certain revenue milestones were achieved and upon the first commercial sale of a product associated with this acquisition. The acquisition also included amounts that may be due under several licensing agreements. One such license agreement, the license agreement, dated September 13, 2007, between the Company and Prometheus Laboratories, Inc. (the Prometheus License), was terminated by mutual agreement on September 28, 2021. In consideration for terminating the Prometheus License, including with respect to the remaining potential milestone payments thereunder, the Company agreed to pay Prometheus Laboratories, Inc. a fee of approximately $0.1 million and acquired the intellectual property previously licensed to the Company pursuant to the Prometheus Agreement.

The Company has ongoing royalty payment obligations of 2.5% on net sales of products which incorporate certain acquired technologies. Future royalties payable under these arrangements are limited to the lesser of (i) an aggregate of $1.2 million (including an upfront payment of $100,000) and (ii) the total royalties earned through January 1, 2024.

Licensing Agreements

The Company has licensed technology for use in its diagnostic tests. In addition to the milestone payments required by these agreements as described above, individual license agreements generally provide for ongoing royalty payments ranging from 1.5% to 7.0% on net sales of products which incorporate licensed technology, as defined in such agreements. Royalties are accrued when earned and recorded in costs of revenue in the accompanying statement of operations.

In May 2021, the Company entered into an exclusive license agreement with Allegheny Health Network Research Institute, or AHN, to obtain an exclusive license to AHN's patent rights in certain inventions, pursuant to which the Company paid AHN an initial license fee of $0.4 million. In addition, under the terms of the exclusive license agreement, the Company is required to pay the greater of royalties in the low single digits on net sales of diagnostic tests using the assigned patents or a flat annual minimum royalty amount, pending approvals and commercialization.

In November 2021, the Company entered into an exclusive license agreement with Queen Mary University of London, or QMUL, to obtain an exclusive license to QMUL's patent rights in certain inventions, pursuant to which the Company is required to pay QMUL an initial license fee of $0.4 million. The Company is obligated to make a one-time payment of $0.1 million relating to the first commercial sale of the licensed products. In addition, after the first 18 months of commercial sales under the terms of the exclusive license agreement, the Company is required to

pay royalties in the high single-digits on net sales of testing products using the assigned patents, pending approvals and commercialization.

Supply Agreement

In December 2021, the Company entered into an amended supply agreement with one supplier for reagents which includes minimum annual purchase commitments of $3.7 million and $6.0 million for the years ended December 31, 2021 and 2022, respectively, with a 15% annual increase thereafter for unconditional minimum purchase commitments through the year ended December 31, 2025.

Collaboration Obligations

In May 2021, the Company entered into a master research collaboration agreement with AHN, pursuant to which the Company is required to pay AHN a collaboration fee of $0.4 million for each year during the initial term of the agreement. Collaboration expenses under the master research collaboration agreement were $0.3 million for the year ended December 31, 2021. Collaboration expenses under the AHN collaboration are included in research and development expenses.

Contingencies

In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for general indemnifications; including subpoenas and other civil investigative demands, from governmental agencies, Medicare or Medicaid payors and managed care organizations reviewing billing practices or requesting comment on allegations of billing irregularities that are brought to their attention through billing audits or third parties. The Company's exposure under these agreements is unknown because it involves claims that may be made against the Company in the future, but have not yet been made or that the Company believes to be immaterial. The Company accrues a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated.

Litigation

From time to time, the Company may be subject to various legal proceedings that arise in the ordinary course of business activities.

Fair Value Measurements

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

Fair Value Measurements

The following table sets forth the Company's financial instruments that were measured at fair value on a recurring basis within the fair value hierarchy (in thousands):


	December 31, 2021
	Total		Level 1		Level 2		Level 3
Assets:
Money market funds, included in cash and cash equivalents	$	95,761	$	95,761	$	—	$	—


	December 31, 2020
	Total		Level 1		Level 2		Level 3
Assets:
Money market funds, included in cash and cash equivalents	$	34,507	$	34,507	$	—	$	—

The fair value of the Company's money market funds is based on quoted market prices.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 99,442	$ 57,448
Accounts receivable, net	9,654	8,910
Prepaid expenses and other current assets	3,638	4,159
Total current assets	112,734	70,517
Property and equipment, net	4,772	2,102
Goodwill	5,506	5,506
Other assets	433	250
Total assets	123,445	78,375
Current liabilities:
Accounts payable	2,492	3,014
Accrued and other current liabilities	6,826	5,757
Total current liabilities	9,318	8,771
Borrowings-non-current portion, net of discounts and debt issuance costs	27,478	26,659
Deferred tax liabilities	306	158
Other non-current liabilities	1,407	948
Total liabilities	38,509	36,536
Commitments and contingencies (Note 5)
Stockholders' equity:
Preferred stock, $0.001 par value; 10,000,000 shares authorized, no shares issued or outstanding at December 31, 2021 and December 31, 2020	0	0
Common stock, $0.001 par value; 200,000,000 shares authorized at December 31, 2021 and December 31, 2020; 16,164,994 and 12,652,308 shares issued and outstanding at December 31, 2021 and December 31, 2020, respectively	16	13
Additional paid-in capital	293,060	223,115
Accumulated deficit	(208,140)	(181,289)
Total stockholders' equity	84,936	41,839
Total liabilities and stockholders' equity	$ 123,445	$ 78,375

Income Taxes - Reconciliation of Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Federal statutory tax rate	(21.00%)	(21.00%)
State income taxes, net of federal tax benefits	(3.80%)	(3.90%)
Research and development tax credits	(1.20%)	(0.50%)
Stock compensation	0.90%	1.00%
Non-deductible expenses	1.10%	1.10%
Change in valuation allowance	24.60%	22.60%
Other	0.00%	0.20%
Effective tax rate	0.60%	(0.50%)

Income Taxes - Change In Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Changes In The Valuation Allowance For Deferred Tax Assets [Roll Forward]
Valuation allowance at the beginning of the year	$ 20,596	$ 16,797
Decreases recorded as benefits to income tax provision	0	0
Increases recorded to income tax provision	6,562	3,799
Valuation allowance at the end of the year	$ 27,158	$ 20,596

Balance Sheets - (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Preferred stock
Par value (in dollars per share)	$ 0.001	$ 0.001
Shares authorized (in shares)	10,000,000	10,000,000
Shares issued (in shares)	0	0
Shares outstanding (in shares)	0	0
Common stock
Par value (in dollars per share)	$ 0.001	$ 0.001
Shares authorized (in shares)	200,000,000	200,000,000
Shares issued (in shares)	16,164,994	12,652,308
Shares outstanding (in shares)	16,164,994	12,652,308

Statements of Operations - USD ($) $ in Thousands	12 Months Ended
Statements of Operations - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Revenue	$ 48,299	$ 41,975
Operating expenses:
Costs of revenue	20,588	16,559
Selling, general and administrative expenses	44,541	37,033
Research and development expenses	7,237	3,568
Total operating expenses	72,366	57,160
Loss from operations	(24,067)	(15,185)
Interest expense	(2,625)	(2,565)
Other income, net	16	984
Loss before income taxes	(26,676)	(16,766)
Income tax (expense) benefit	(175)	79
Net loss	$ (26,851)	$ (16,687)
Net loss per share, basic (in dollars per share)	$ (1.68)	$ (1.32)
Net loss per share, diluted (in dollars per share)	$ (1.68)	$ (1.32)
Weighted-average number of shares used to compute net loss per share, basic (in shares)	15,972,256	12,632,780
Weighted-average number of shares used to compute net loss per share, diluted (in shares)	15,972,256	12,632,780

Covid-19	12 Months Ended
Covid-19	Dec. 31, 2021
Reorganizations [Abstract]
Covid-19	COVID-19 During 2020, due to the worldwide COVID-19 pandemic, the Company experienced a reduction in patient test volumes, delays in patient enrollment in ongoing and planned clinical studies, and delays in the procurement of its testing supplies. In response to the pandemic, the Company has curtailed non-essential employee travel, equipped employees with the ability to work remotely with the exception of clinical laboratory employees, and reduced marketing spend and employee headcount. The full extent to which the COVID-19 pandemic will directly or indirectly continue to impact the Company's business, results of operations and financial condition, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19 and the actions taken to contain or treat COVID-19, including, the success of ongoing vaccination efforts, the emergence and prevalence of variant strains of COVID-19, the institution or reinstitution of shutdowns, "stay-at-home-orders" and other public health measures as well as the related economic impact of these matters on local, regional and international markets. On March 27, 2020, the CARES Act was enacted in response to the COVID-19 pandemic. The CARES Act, among other things, permits NOL carryovers and carrybacks to offset 100% of taxable income for taxable years beginning before 2021. The CARES Act did not have a material impact on the Company's effective tax rate or income tax provision for the year ended December 31, 2020. Under the Tax Cuts and Jobs Act (TCJA), NOLs generated post TCJA were allowed to be carried forward indefinitely but were only allowed to offset 80% of taxable income. As a result of the CARES Act and the change to permit NOLs generated in taxable years 2018, 2019 and 2020 to offset 100% of taxable income, the Company released valuation allowance against its deferred tax assets in the amount of $0.1 million. The release of valuation allowance resulted in a discrete tax benefit of $0.1 million for the year ended December 31, 2020. As of the year ended December 31, 2021, some tax benefits under the CARES Act have expired including the ability to use certain NOLs to offset 100% of taxable income. Accordingly, the Company increased its valuation allowance that resulted in a tax expense of $0.1 million for the year ended December 31, 2021. In April 2020, the Company received $0.7 million of funding under the CARES Act Provider Relief Fund, subject to the Company's agreement to comply with the Department of Health & Human Services' (HHS) standard terms and conditions. The CARES Act Provider Relief Fund is a federal fund allocated for general distributions to Medicare facilities and providers impacted by the COVID-19 pandemic and is intended to support COVID-related expenses or lost revenue attributable to COVID-19. The funding received is considered a government grant which is recognized when there is reasonable assurance that the grant will be received and that conditions attached to the grant have been met. The Company accepted the terms and conditions of the grant in May 2020. For the year ended December 31, 2020, the Company recognized $0.7 million due to lost revenue attributable to COVID-19, which is reflected in other income, net, on its statements of operations and as an operating activity in the statement of cash flows. On April 16, 2020, the Company entered into a promissory note (the Note) with BOKF, NA dba Bank of Oklahoma (BofO), the lender, evidencing an unsecured loan pursuant to the U.S. Small Business Administration (SBA) Paycheck Protection Program (PPP) of the CARES Act of approximately $2.9 million (the PPP Loan). The Company applied for and received the PPP Loan pursuant to the then published PPP qualification and certification requirements. On April 23, 2020, the SBA, in consultation with the Department of Treasury, issued new guidance that created uncertainty regarding the qualification requirements for the PPP Loan (the New Guidance). In light of the New Guidance, on May 11, 2020, the Company paid off in full the principal and interest on the PPP Loan, resulting in the termination of the Note. On December 27, 2020, the Consolidated Appropriations Act, 2021 was signed into law. It provides additional COVID-19 focused relief and extends certain provisions of the CARES Act. The Consolidated Appropriations Act, 2021 did not have a material impact on the Company's financial statements.

Fair Value Measurements (Details) - Recurring - Money market funds, included in cash and cash equivalents - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets:
Money market funds, included in cash and cash equivalents	$ 95,761	$ 34,507
Level 1
Assets:
Money market funds, included in cash and cash equivalents	95,761	34,507
Level 2
Assets:
Money market funds, included in cash and cash equivalents	0	0
Level 3
Assets:
Money market funds, included in cash and cash equivalents	$ 0	$ 0

Summary of Significant Accounting Policies - (Tables)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Schedule of Concentration of Risk, by Risk Factor and Significant Payer

For each significant payor and customer, revenue as a percentage of total revenue and accounts receivable as a percentage of total accounts receivable are as follows:


		Revenue
	Years Ended December 31,
			2021		2020
Medicare			19	%	20	%
Medicare Advantage			13	%	11	%
Blue Shield			12	%	11	%
Janssen (SIMPONI®)			*		12	%



*						Less than 10%.


	Accounts Receivable
	December 31,
	2021		2020
Blue Shield	19	%	11	%
United Healthcare	18	%	*
Janssen (SIMPONI®)	—	%	35	%



*						Less than 10%.

Disaggregation of Revenue

The following table includes the Company's revenues as disaggregated by payor and customer category (in thousands):


	Years Ended December 31,
		2021		2020
Revenue:
Healthcare insurers		$	27,499	$	22,456
Government		9,221		8,446
Client(1)		9,288		5,109
Other(2)		1,091		836
Janssen (SIMPONI®)		1,200		5,128
Total revenue		$	48,299	$	41,975

(1)Includes hospitals, other laboratories, etc.

(2)Includes patient self-pay.

Schedule of Restricted Cash and Cash Equivalents

Cash, cash equivalents and restricted cash presented in the accompanying statements of cash flows consist of the following (in thousands):


		December 31,
	2021	2020
Cash and cash equivalents		$	99,442	$	57,448
Restricted cash		100		100
		$	99,542	$	57,548

Schedule of Cash and Cash Equivalents

Cash, cash equivalents and restricted cash presented in the accompanying statements of cash flows consist of the following (in thousands):


		December 31,
	2021	2020
Cash and cash equivalents		$	99,442	$	57,448
Restricted cash		100		100
		$	99,542	$	57,548

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common stock equivalent shares):


	Years Ended December 31,
		2021	2020


Warrants to purchase common stock		409,108	426,827
Common stock options		2,014,330	1,975,761
Restricted stock units		415,325	—
Employee stock purchase plan		20,193	11,640
Total		2,858,956	2,414,228

Summary of Significant Accounting Policies - Securities (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Anti-dilutive securities excluded from computation (in shares)	2,858,956	2,414,228
Warrants to purchase common stock
Class of Stock [Line Items]
Anti-dilutive securities excluded from computation (in shares)	409,108	426,827
Common stock options
Class of Stock [Line Items]
Anti-dilutive securities excluded from computation (in shares)	2,014,330	1,975,761
Restricted stock units
Class of Stock [Line Items]
Anti-dilutive securities excluded from computation (in shares)	415,325	0
Employee stock purchase plan
Class of Stock [Line Items]
Anti-dilutive securities excluded from computation (in shares)	20,193	11,640

Borrowings - Future minimum payments (Details) $ in Thousands	Dec. 31, 2021 USD ($)
Debt Disclosure [Abstract]
2022	$ 1,653
2023	1,686
2024	2,980
2025	16,152
2026	14,786
Total	37,257
Unamortized debt discount and issuance costs	(208)
Interest	(9,571)
Total borrowings, net of discounts and debt issuance costs	$ 27,478

Stockholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 22, 2021	Mar. 25, 2021	Nov. 10, 2020	Dec. 31, 2021
Subsidiary, Sale of Stock [Line Items]
Estimated offering expenses for aggregate expenses				$ 4,435
Exchanging Stockholders
Subsidiary, Sale of Stock [Line Items]
Number of shares exchanged for warrants (in shares)	804,951
Class of warrant or right, exercise price of warrants or rights (in dollars per share)	$ 0.001
Sale of stock, percentage of ownership after transaction	4.99%
Number of warrants exercised (in shares)				0
Common Stock
Subsidiary, Sale of Stock [Line Items]
Number of shares authorized to be sold in offering (in shares)			150,000,000.0
Number of shares issued in transaction (in shares)		4,255,000
Shares issued in public offering, price per share (in dollars per share)		$ 16.25
Proceeds from public offering, net		$ 64,700
Estimated offering expenses for aggregate expenses		$ 4,400

Stock Option Plan - Fair Value Assumptions (Details)	12 Months Ended
Stock Option Plan - Fair Value Assumptions (Details)	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility rate, minimum	56.00%	47.00%
Expected volatility rate, maximum	60.00%	53.00%
Risk-free interest rate, minimum	0.80%	0.40%
Risk-free interest rate, maximum	1.10%	1.70%
Dividend yield	0.00%	0.00%
Stock options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	5 years 6 months	5 years 6 months
Stock options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 29 days	6 years 29 days
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility rate, minimum	45.00%	58.00%
Expected volatility rate, maximum	60.00%	83.00%
Risk-free interest rate, minimum	0.10%	0.10%
Risk-free interest rate, maximum		1.10%
Dividend yield	0.00%	0.00%
Expected term (in years)	6 months	6 months

Other Financial Information - (Tables)

12 Months Ended

Dec. 31, 2021

Other Financial Information [Abstract]

Prepaid Expenses Table

Prepaid expenses and other current assets consist of the following (in thousands):


	December 31,
	2021		2020
Diagnostic testing supplies	$	1,091	$	1,203
Prepaid product royalties	49		68
Prepaid maintenance and insurance contracts	2,008		2,229
Other prepaid and other current assets	490		659
Prepaid and other current assets	$	3,638	$	4,159

Property and Equipment

Property and equipment consist of the following (in thousands):


	December 31,
	2021		2020
Furniture and fixtures	$	83	$	64
Laboratory equipment	4,361		2,679
Computer equipment and software	1,206		927
Leasehold improvements	1,151		1,072
Construction in progress	1,855		301
Total property and equipment	8,656		5,043
Less: accumulated depreciation and amortization	(3,884)		(2,941)
Property and equipment, net	$	4,772	$	2,102

Accrued and Other Current Liabilities

Accrued and other current liabilities consist of the following (in thousands):


	December 31,
	2021		2020
Accrued payroll and related expenses	$	4,048	$	3,589

Accrued interest	139		147
Accrued purchases of goods and services	510		311
Accrued royalties	180		221
Accrued clinical study activity	254		228
Capital lease obligations, current portion	587		308
Other accrued liabilities	1,108		953
Accrued and other current liabilities	$	6,826	$	5,757

401(k) Plan (Details) - USD ($) $ in Millions		12 Months Ended
401(k) Plan (Details) - USD ($) $ in Millions	Jan. 01, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Contribution Plan Disclosure [Line Items]
Qualified employee compensation, employer matching contribution, percent of employees' gross pay		3.00%	3.00%
Qualified employee compensation contribution, amount		$ 0.5	$ 0.5
Subsequent Event
Defined Contribution Plan Disclosure [Line Items]
Qualified employee compensation, employer matching contribution, percent of employees' gross pay	4.00%

Borrowings - (Tables)

12 Months Ended

Dec. 31, 2021

Debt Disclosure [Abstract]

Schedule of Future Minimum Aggregate Payments for Outstanding Borrowings

As of December 31, 2021, future minimum aggregate payments, including interest, for outstanding borrowings under the Loan Amendment are as follows (in thousands):


	Years Ending December 31,


2022	$	1,653
2023	1,686
2024	2,980
2025	16,152
2026	14,786
Total	37,257
Less:
Unamortized debt discount and issuance costs	(208)
Interest	(9,571)
Total borrowings, net of discounts and debt issuance costs	$	27,478

Stock Option Plan - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee options, weighted-average grant date fair value per share (in dollars per share)	$ 8.83	$ 7.55
Common stock, fair value per share (in dollars per share)	$ 11.63	$ 13.20
Intrinsic value of options exercised	$ 100	$ 1,000
Stock options, unrecognized compensation cost	$ 6,300
Stock options, cost not yet recognized, remaining weighted average vesting period	2 years
Stock-based compensation expense	$ 4,728	2,694
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual percentage increase in shares available for issuance under the Plan	1.00%
Maximum Employee payroll deduction percentage	20.00%
Shares reserved for issuance under Stock Option Plan	327,516
Stock options, cost not yet recognized, remaining weighted average vesting period	2 months 12 days
Stock-based compensation expense	$ 200	$ 100
Unrecognized compensation cost related to stock purchase	$ 100
Employee stock purchase plan \| Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase (decrease) in number of shares authorized (in shares)			161,649
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, fair value per share (in dollars per share)	$ 16.54	$ 0
Stock options, unrecognized compensation cost	$ 5,600
Stock options, cost not yet recognized, remaining weighted average vesting period	3 years 3 months 18 days
2019 Incentive Award Plan \| Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, expiration period	10 years
Stock options, vesting period	4 years
Annual percentage increase in shares available for issuance under the Plan	4.00%
Shares that remain available for future awards	1,179,571
2019 Incentive Award Plan \| Stock options \| Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase (decrease) in number of shares authorized (in shares)			646,599

Stock Option Plan

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Stock Option Plan

2019 Incentive Award Plan

In September 2019, the Company's Board of Directors adopted, and the Company's stockholders approved, the 2019 Plan. Under the 2019 Plan, which expires in September 2029, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units and other awards to individuals who are then employees, officers, non-employee directors or consultants of the Company or its subsidiaries. The options generally expire ten years after the date of grant and are exercisable to the extent vested. Vesting is established by the Board of Directors and is generally four years from the date of grant. The 2019 Plan contains an "evergreen provision" that allows annual increases in the number of shares available for issuance on the first day of each calendar year through January 1, 2029 in an amount equal to the lesser of: (i) 4% of the outstanding capital stock on each

December 31st, or (ii) such lesser amount determined by the Board of Directors. As of December 31, 2021, 1,179,571 shares remained available for future awards. Under the evergreen provision, on January 1, 2022, an additional 646,599 shares became available for issuance under the 2019 Plan.

2019 Employee Stock Purchase Plan

In September 2019, the Board of Directors adopted, and the Company's stockholders approved, the ESPP. The ESPP became effective on the day the ESPP was adopted by the Company's Board of Directors. The ESPP permits participants to purchase common stock through payroll deductions of up to 20% of their eligible compensation. The number of shares of common stock available for issuance under the ESPP will be annually increased on the first day of each calendar year during the term of the ESPP through January 1, 2029 in an amount equal to the lesser of (i) 1% of the outstanding capital stock on each December 31st, or (ii) such lesser amount determined by the Board of Directors. As of December 31, 2021, 327,516 shares of common stock remained available for issuance under the ESPP. Under the evergreen provision, on January 1, 2022, an additional 161,649 shares became available for issuances under the ESPP.

Stock Options

Stock option activity under the Company's 2019 Plan is set forth below:


	Number of Options	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding, December 31, 2020	1,975,761	$	11.81	8.71	$	6,750
Granted	229,850	$	16.79
Exercised	(11,950)	$	7.40
Forfeited	(128,665)	$	14.44
Expired	(50,666)	$	17.18
Outstanding, December 31, 2021	2,014,330	$	12.10	7.87	$	5,428
Vested and expected to vest, December 31, 2021	2,014,330	$	12.10	7.87	$	5,428
Options exercisable, December 31, 2021	1,050,036	$	10.17	7.53	$	4,262

The weighted-average grant date fair value per share of employee options granted to employees during the years ended December 31, 2021 and 2020 was $8.83 and $7.55, respectively. The intrinsic value is calculated as the difference between the fair value of the Company's common stock and the exercise price of the stock options. The fair value of the Company's common stock is $11.63 and $13.20 per share at December 31, 2021 and 2020, respectively. The intrinsic value of options exercised for the years ended December 31, 2021 and 2020 was $0.1 million and $1.0 million, respectively. As of December 31, 2021, total unrecognized compensation cost related to option awards was $6.3 million, which is expected to be recognized over a remaining weighted-average vesting period of 2.0 years.

Restricted Stock Units

Restricted stock unit activity under the Company's 2019 Plan is set forth below:


	Number of Shares	Weighted- Average Grant Date Fair Value		Aggregate Intrinsic Value
Outstanding, December 31, 2020	—	$	—	$	—
Awards granted	449,000	$	16.51
Awards released	—	$	—
Awards canceled	(33,675)	$	16.24
Outstanding, December 31, 2021	415,325	$	16.54	$	4,830

As of December 31, 2021, all of the outstanding restricted stock units are unvested. As of December 31, 2021, total unrecognized compensation cost related to restricted stock units was $5.6 million, which is expected to be recognized over a remaining weighted-average vesting period of 3.3 years.

Stock-Based Compensation Expense

Stock Options

The fair value of employee stock options was estimated using the following assumptions to determine the fair value of stock options granted:


	Years Ended December 31,
		2021	2020
Expected volatility		56%-60%	47%-53%
Risk-free interest rate		0.8%-1.1%	0.4%-1.7%
Dividend yield		—	—
Expected term (in years)		5.50-6.08	5.5-6.08

Employee Stock Purchase Plan

The following assumptions were used to calculate the stock-based compensation for each stock purchase right granted under the ESPP:


	Years Ended December 31,
		2021	2020
Expected volatility		45%-60%	58.0%-83.0%
Risk-free interest rate		0.1%	0.1%-1.1%
Dividend yield		—	—
Expected term (in years)		0.5	0.5


	Years Ended December 31,
		2021		2020
Cost of revenue		$	164	$	33
Selling, general and administrative		3,943		2,419
Research and development		621		242
Total		$	4,728	$	2,694

Common stock reserved for future issuance consists of the following at December 31, 2021:


Warrants to purchase common stock						1,214,059
Common stock option grants issued and outstanding						2,014,330
Common stock reserved for issuance upon vesting of outstanding restricted stock units						415,325
Common shares available for grant under the 2019 Plan						1,179,571
Common shares available for future issuance under ESPP						327,516
Total						5,150,801

Commitment and Contingencies - Minimum annual lease payments under non-cancelable lease arrangements (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Capital Leases
2022	$ 641
2023	566
2024	313
2025	66
2026	0
Thereafter	0
Total minimum lease payments	1,586
Less: amount representing interest	(116)
Present value of future minimum lease payments	1,470
Less: current portion	(587)	$ (308)
Long-term capital lease obligations	883
Operating Leases
2022	1,337
2023	1,445
2024	1,489
2025	1,533
2026	1,584
Thereafter	539
Total minimum lease payments	$ 7,927

Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) installment segment	Dec. 31, 2020 USD ($)	Aug. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash	$ 100,000	$ 100,000
Contract with customer, timing of performance obligation and payment	Collection of the Company's net revenues from payors is normally a function of providing complete and correct billing information to the healthcare insurers and generally occurs within 30 to 90 days of billing
Revenue recognized	$ 700,000	800,000
Revenue	48,299,000	41,975,000
Advertising Expense	$ 1,700,000	1,300,000
Dividend yield	0.00%
Number of annual vesting installments \| installment	4
Number of operating segments \| segment	1
Janssen Promotion Agreement
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Termination of agreement			$ 600,000
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment, useful life	3 years
Joint venture, quarterly promotion fee per prescription		750
Joint venture, quarterly promotion fee				$ 300,000	$ 300,000
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment, useful life	5 years
Joint venture, quarterly promotion fee per prescription		1,250
Shipping and Handling
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of revenue	$ 2,100,000	$ 1,400,000
Revenue Benchmark \| Supplier Concentration Risk \| Two Suppliers
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Concentration risk percentage	97.00%	97.00%
Revenue Benchmark \| AVISE CTD Test \| Product Concentration Risk
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Concentration risk percentage	81.00%	70.00%
Janssen (SIMPONI)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	$ 1,200,000	$ 5,100,000
Other assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash	$ 100,000

Other Financial Information - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$ 0.9	$ 0.5
Assets Held under Capital Leases
Property, Plant and Equipment [Line Items]
Gross book value of assets under capital leases	2.5	$ 1.2
Leasehold improvements
Property, Plant and Equipment [Line Items]
Gross book value of assets under capital leases	$ 1.5

Borrowings

12 Months Ended

Dec. 31, 2021

Debt Disclosure [Abstract]

Borrowings

2017 Term Loan

In September 2017, the Company executed a term loan agreement (the 2017 Term Loan) with Innovatus Life Sciences Lending Fund I, LP (Innovatus) and borrowed $20.0 million, $17.8 million of which was immediately used to repay the Company's existing loan with Capital Royalty Partners II L.P. and its affiliates. On December 7, 2018, the Company borrowed an additional $5.0 million under the 2017 Term Loan. The 2017 Term Loan was subsequently amended in November 2019 and November 2021. At December 31, 2021, no additional amounts remain available to borrow under the 2017 Term Loan.

In November 2021, the Company executed the Second Amendment to the Loan and Security Agreement (the 2017 Loan Amendment). The interest rate on all borrowings under the 2017 Loan Amendment is 8.0%, of which 2.0% is paid in-kind in the form of additional term loans (PIK Loans) until December of 2024, after which interest accrues at an annual rate of 8.0%. The Company has estimated the effective interest rate of this loan to be approximately 8.5%. Accrued interest is due and payable monthly, unless the Company elects to pay paid-in-kind interest. The outstanding principal and accrued interest on the 2017 Loan Amendment will be repaid in twenty-four equal monthly installments commencing in December 2024. Upon repayment of the final installment under the 2017 Loan Amendment, the Company is required to pay an additional fee of $1.0 million. This obligation is being accreted into interest expense over the term of Loan Amendment using the effective interest method. For each of the years ended December 31, 2021 and 2020, the Company issued PIK Loans totaling $0.5 million.

The 2017 Loan Amendment requires a prepayment premium of 3% of the aggregate outstanding principal. The prepayment premium decreases by 1% on November 1, 2022, 2023 and 2024.

The 2017 Loan Amendment is collateralized by a first priority security interest in substantially all of the Company's assets, including intellectual property. The affirmative covenants of the 2017 Loan Amendment require that the Company timely file taxes, maintain good standing and government compliance, maintain liability and other insurance, provide prompt notification of significant corporate events, and furnish audited financial statements within 150 days of fiscal year end without qualification as to the scope of the audit or as to going concern and without any other similar qualification.

The affirmative covenants require that the Company achieve a specified level of revenue, as measured quarterly on a rolling twelve-month basis, and commencing with the quarter ending December 31, 2022. The consequences of failing to achieve the performance covenant may be cured if, within sixty days of failing to achieve the performance covenant, the Company issues additional equity securities or subordinated debt with net proceeds sufficient to fund

any cash flow deficiency generated from operations, as defined. The 2017 Loan Amendment requires that the Company maintain certain levels of minimum liquidity and maintains an unrestricted cash balance of $2.0 million.

The negative covenants provide, among other things, that without the prior consent of Innovatus subject to certain exceptions, the Company may not dispose of certain assets, engage in certain business combinations or acquisitions, incur additional indebtedness or encumber any of the Company's property, pay dividends on the Company's capital stock or make prohibited investments. The Loan Amendment agreement provides that an event of default will occur if, among other triggers, (i) the Company defaults in the payment of any amount payable under the agreement when due, (ii) there occurs any circumstance(s) that could reasonably be expected to result in a material adverse effect on the Company's business, operations or condition, or on the Company's ability to perform its obligations under the agreement, (iii) the Company becomes insolvent, (iv) the Company undergoes a change in control or (v) the Company breaches any negative covenants or certain affirmative covenants in the agreement or, subject to a cure period, otherwise neglects to perform or observe any material item in the agreement.

At December 31, 2021, the Company was in compliance with all covenants of the 2017 Loan Amendment.

Upon an event of default in any of the 2017 Loan Amendment covenants, the repayment of the 2017 Loan Amendment may be accelerated, and the applicable interest rate will be increased by 4.0% until the default is cured. Although repayment of the 2017 Loan Amendment can be accelerated under certain circumstances, the Company believes acceleration of this loan is not probable as of the date of these financial statements. Accordingly, the Company has reflected the amounts of the 2017 Loan Amendment due beyond twelve months of the balance sheet date as non-current.

Future Minimum Payments on the Outstanding Borrowings

As of December 31, 2021, future minimum aggregate payments, including interest, for outstanding borrowings under the Loan Amendment are as follows (in thousands):


	Years Ending December 31,


2022	$	1,653
2023	1,686
2024	2,980
2025	16,152
2026	14,786
Total	37,257
Less:
Unamortized debt discount and issuance costs	(208)
Interest	(9,571)
Total borrowings, net of discounts and debt issuance costs	$	27,478

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-URI http://asc.fasb.org/topic&trid=2208564

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1E
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

+ Details

Summary of Significant Accounting Policies - Cash, cash equivalents and restricted cash (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Cash and cash equivalents	$ 99,442	$ 57,448
Restricted cash	100	100
Total cash, cash equivalents and restricted cash	$ 99,542	$ 57,548	$ 72,184

Stock Option Plan - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, December 31, 2020 (in shares)	1,975,761
Granted (in shares)	229,850
Exercised (in shares)	(11,950)
Forfeited (in shares)	(128,665)
Expired (in shares)	(50,666)
Outstanding, December 31, 2021 (in shares)	2,014,330	1,975,761
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding, December 31, 2020, Weighted Average Exercise Price (in dollars per share)	$ 11.81
Granted, Weighted Average Exercise Price (in dollars per share)	16.79
Exercised, Weighted Average Exercise Price (in dollars per share)	7.40
Forfeited, Weighted Average Exercise Price (in dollars per share)	14.44
Expired, Weighted Average Exercise Price (in dollars per share)	17.18
Outstanding, December 31, 2021, Weighted Average Exercise Price (in dollars per share)	$ 12.10	$ 11.81
Stock Options, Additional Disclosures [Abstract]
Outstanding, Weighted Average Remaining Contractual Term	7 years 10 months 13 days	8 years 8 months 15 days
Vested and expected to vest, Weighted Average Remaining Contractual Term	7 years 10 months 13 days
Options exercisable, Weighted Average Remaining Contractual Term	7 years 6 months 10 days
Outstanding, Aggregate Intrinsic Value	$ 5,428	$ 6,750
Vested and expected to vest, Aggregate Intrinsic Value	5,428
Options exercisable, Aggregate Intrinsic Value	$ 4,262
Vested and expected to vest, December 31, 2021 (in shares)	2,014,330
Vested and expected to vest, December 31, 2021, Weighted Average Exercise Price (in dollars per share)	$ 12.10
Options exercisable, December 31, 2021 (in Shares)	1,050,036
Options exercisable, December 31, 2021, Weighted Average Exercise Price (in dollars per share)	$ 10.17

Income Taxes - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Current:
Federal	$ 0	$ 0
State	27	27
Total current	27	27
Deferred:
Federal	137	(117)
State	11	11
Total deferred	148	(106)
Provision (benefit) for income tax	$ 175	$ (79)

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Covid-19 (Details) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
Covid-19 (Details) - USD ($) $ in Thousands	Apr. 16, 2020	Apr. 30, 2020	Dec. 31, 2021	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Coronavirus, Aid, Relief, And Economic Securities (CARES) Act, deferred tax assets, income tax expense (benefit)			$ 100	$ (100)
Proceeds from Paycheck Protection Program loan		$ 700	$ 0	$ 2,865
Paycheck Protection Program, CARES Act
Restructuring Cost and Reserve [Line Items]
Proceeds from promissory note pursuant to Paycheck Protection Program	$ 2,900

Organization	12 Months Ended
Organization	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Description of Business The Company is dedicated to transforming the care continuum for patients suffering from debilitating and chronic autoimmune diseases by enabling timely differential diagnosis and optimizing therapeutic intervention. Liquidity The Company has incurred recurring losses and negative cash flows from operating activities since inception. The Company anticipates that it will continue to incur net losses into the foreseeable future. At December 31, 2021, the Company had cash and cash equivalents of $99.4 million and had an accumulated deficit of $208.1 million. Since inception, the Company has financed its operations primarily through a combination of equity financings of common stock and private placements of preferred securities, debt financing arrangements, and revenue from sales of the Company's products. Based on the Company's current business plan, management believes that its existing capital resources will be sufficient to fund the Company's obligations for at least twelve months following the issuance of these financial statements. To execute its business plans, the Company may need additional funding to support its continuing operations and pursue its growth strategy. Until such time as the Company can achieve significant cash flows from operations, if ever, it expects to finance its operations through the sale of its stock, debt financings or other strategic transactions. Although the Company has been successful in raising capital in the past, there is no assurance that it will be successful in obtaining such additional financing on terms acceptable to the Company, if at all. The terms of any financing may adversely affect the holdings or the rights of the Company's stockholders. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate some or all of its programs, product portfolio expansion plans or commercialization efforts, which could have a material adverse effect on the Company's business, operating results and financial condition and the Company's ability to achieve its intended business objectives.

Income Taxes

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Income Taxes

The provision for income taxes consists of the following (in thousands):


	Years Ended December 31,
	2021		2020
Current:
Federal	$	—	$	—
State	27		27
Total current	27		27
Deferred:
Federal	137		(117)
State	11		11
Total deferred	148		(106)
Provision (benefit) for income tax	$	175	$	(79)

The effective tax rate of our provision for income taxes differs from the federal statutory rate as follows:


	Years Ended December 31,
	2021		2020
Federal statutory tax rate	(21.0)	%	(21.0)	%
State income taxes, net of federal tax benefits	(3.8)	%	(3.9)	%
Research and development tax credits	(1.2)	%	(0.5)	%
Stock compensation	0.9	%	1.0	%
Non-deductible expenses	1.1	%	1.1	%

Change in valuation allowance	24.6	%	22.6	%

Other	—	%	0.2	%
Effective tax rate	0.6	%	(0.5)	%

Significant components of the Company’s deferred tax assets at December 31, 2021 and 2020 are shown below. A valuation allowance has been established as realization of the Company’s deferred tax assets has not met the more likely-than-not threshold requirement. If the Company’s judgment changes and it is determined that the Company will be able to realize these deferred tax assets, the tax benefits relating to any reversal of the valuation allowance on deferred tax assets will be accounted for as a reduction to income tax expense (in thousands).


	December 31,
	2021		2020
Deferred tax assets:
Net operating loss carryforwards	$	22,365	$	17,733
Research and development tax credits	1,102		629
Accruals, reserves and other	1,055		920
Interest expense	1,953		1,306
Basis differences in fixed and intangible assets	—		117
Stock compensation	1,407		528
Total gross deferred tax assets	27,882		21,233
Less: valuation allowance	(27,158)		(20,596)
Deferred tax assets, net	724		637
Deferred tax liabilities:
Financing and acquisition-related liabilities	(335)		(336)
Indefinite lived assets	(521)		(459)
Basis differences in fixed and intangible assets	(175)		—
Deferred tax liabilities, net	(1,031)		(795)
Net deferred tax liabilities	$	(307)	$	(158)


	December 31,
	2021		2020
Valuation allowance at the beginning of the year	$	20,596	$	16,797
Decreases recorded as benefits to income tax provision	—		—
Increases recorded to income tax provision	6,562		3,799
Valuation allowance at the end of the year	$	27,158	$	20,596

At December 31, 2021 and 2020, the Company had federal NOL carryforwards of approximately $89.4 million and $70.6 million, respectively. At December 31, 2021 and 2020, the Company had state NOL carryforwards of $61.0 million and $48.9 million, respectively. Approximately $43.5 million of the federal tax loss carryforwards will begin to expire in 2022, unless previously utilized. The federal NOL carryforwards generated in after December 31, 2017 of $45.9 million will carryforward indefinitely. The Company’s state tax loss carryforwards will expire in 2032, unless previously utilized.

At December 31, 2019, the Company's deferred tax assets are primarily comprised of federal and state tax NOL carryforwards. The Company completed a formal study through the year ended December 31, 2019 and determined ownership changes within the meaning of Internal Revenue Code (IRC), Section 382 had occurred in 2003, 2008, 2012, 2017 and 2019. Based on the analysis, $61.8 million of the Company's tax attribute carryforwards through December 31, 2017 cannot be utilized under IRC Section 382. The Company's ability to utilize NOL carryforwards generated after December 31, 2017 will not expire under the Tax Cuts and Jobs Act of 2017. The Company adjusted tax attribute carry forwards and deferred tax assets accordingly. As the deferred tax assets associated with the tax attribute carry forwards were fully offset by a valuation allowance, a corresponding reduction in the Company's valuation allowance was also recorded, resulting in no income tax impact.

The Company is subject to taxation in the U.S. and in various state jurisdictions. The Company’s tax years for 2002 and forward are subject to examination by the U.S. and state tax authorities due to the carryforward of unutilized net operating losses and research and development credits.

The Company recognizes interest and/or penalties related to income tax matters in its provision for income taxes. The Company does not have any accruals for, and did not recognize any, interest or penalties in these financial statements in any period presented.

Uncertain Tax Positions

At December 31, 2021 and 2020, the Company had no unrecognized tax benefits.

The Company does not believe that the balance of unrecognized tax benefits will materially change within the next twelve months.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 21
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32857-109319

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-URI http://asc.fasb.org/extlink&oid=122134291&loc=d3e330215-122817

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 17
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32809-109319

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-URI http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32705-109319

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 270
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6424409&loc=d3e44925-109338

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-URI http://asc.fasb.org/topic&trid=2144680

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6424122&loc=d3e41874-109331

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details