Sera Prognostics (SERA) 10-Q 9 Aug 23 2023 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 30, 2023	Aug. 04, 2023
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2023
Document Transition Report	false
Entity File Number	001-40606
Entity Registrant Name	SERA PROGNOSTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-1911522
Entity Address, Address Line One	2749 East Parleys Way
Entity Address, Address Line Two	Suite 200
Entity Address, City or Town	Salt Lake City
Entity Address, State or Province	UT
Entity Address, Postal Zip Code	84109
City Area Code	801
Local Phone Number	990-0520
Title of 12(b) Security	Class A Common Stock, $0.0001 par value per share
Trading Symbol	SERA
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Central Index Key	0001534969
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Amendment Flag	false
Class A common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		29,877,246
Class B common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		1,405,259

Condensed Balance Sheets (unaud

Condensed Balance Sheets (unaudited) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 32,285	$ 29,878
Marketable securities	31,536	52,826
Accounts receivable	163	113
Other receivables	0	6,000
Prepaid expenses and other current assets	444	1,308
Total current assets	64,428	90,125
Property and equipment, net	2,411	3,059
Long-term marketable securities	28,307	21,329
Other assets	1,534	1,816
Total assets	96,680	116,329
Current liabilities:
Accounts payable	1,244	1,548
Accrued and other current liabilities	3,444	4,444
Finance lease obligation, current portion	446	464
Deferred revenue	9,049	9,082
Total current liabilities	14,183	15,538
Finance lease obligation, net of current portion	422	626
Long-term portion	938	1,222
Total liabilities	15,543	17,386
Commitments and Contingencies
Stockholders' equity:
Common stock, $0.0001 par value; 150,000,000 Class A shares authorized; 29,793,246 and 29,612,687 Class A shares issued and outstanding as of June 30, 2023 and December 31, 2022, respectively; 1,500,000 Class B shares authorized; 1,405,259 Class B shares issued and outstanding as of June 30, 2023 and December 31, 2022.	3	3
Additional paid-in capital	313,567	310,575
Accumulated other comprehensive loss	(672)	(981)
Accumulated deficit	(231,761)	(210,654)
Total stockholders' equity	81,137	98,943
Total liabilities and stockholders' equity	$ 96,680	$ 116,329

Condensed Balance Sheets (una_2

Condensed Balance Sheets (unaudited) (Parenthetical) - $ / shares	Jun. 30, 2023	Dec. 31, 2022
Class A common stock
Common stock, par value (in shares)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	29,793,246	29,612,687
Common stock, shares outstanding (in shares)	29,793,246	29,612,687
Class B common stock
Common stock, par value (in shares)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	1,500,000	1,500,000
Common stock, shares issued (in shares)	1,405,259	1,405,259
Common stock, shares outstanding (in shares)	1,405,259	1,405,259

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Statement [Abstract]
Revenue	$ 123	$ 78	$ 223	$ 116
Operating expenses:
Cost of revenue	80	56	142	76
Research and development	3,688	3,261	7,791	6,583
Selling and marketing	2,872	4,219	5,690	8,677
General and administrative	4,943	4,288	9,389	8,826
Total operating expenses	11,583	11,824	23,012	24,162
Loss from operations	(11,460)	(11,746)	(22,789)	(24,046)
Interest expense	(14)	(18)	(30)	(22)
Other income, net	932	244	1,712	340
Net loss	$ (10,542)	$ (11,520)	$ (21,107)	$ (23,728)
Net loss per share, basic (in usd per share)	$ (0.34)	$ (0.37)	$ (0.68)	$ (0.77)
Net loss per share, diluted (in usd per share)	$ (0.34)	$ (0.37)	$ (0.68)	$ (0.77)
Weighted-average shares of common stock outstanding, basic (in shares)	31,077,420	30,945,616	31,048,526	30,873,995
Weighted-average shares of common stock outstanding, diluted (In shares)	31,077,420	30,945,616	31,048,526	30,873,995
Other comprehensive (loss) gain:
Unrealized (loss) gain on available-for-sale debt securities	$ (215)	$ (162)	$ 309	$ (635)
Total other comprehensive (loss) gain	(215)	(162)	309	(635)
Comprehensive loss	$ (10,757)	$ (11,682)	$ (20,798)	$ (24,363)

Condensed Statements of Convert

Condensed Statements of Convertible Preferred Stock and Stockholders’ Equity (Deficit) (unaudited) - USD ($) $ in Thousands	Total	Common Stock (Class A and B)	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at the beginning (in shares) at Dec. 31, 2021		30,774,126
Balance at the beginning at Dec. 31, 2021	$ 138,564	$ 3	$ 305,212	$ (183)	$ (166,468)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		123,467
Issuance of common stock upon exercise of stock options	98		98
Stock-based compensation expense	1,222		1,222
Other comprehensive gain	(473)			(473)
Net loss	(12,208)				(12,208)
Balance at the ending (in shares) at Mar. 31, 2022		30,897,593
Balance at the ending at Mar. 31, 2022	127,203	$ 3	306,532	(656)	(178,676)
Balance at the beginning (in shares) at Dec. 31, 2021		30,774,126
Balance at the beginning at Dec. 31, 2021	138,564	$ 3	305,212	(183)	(166,468)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive gain	(635)
Net loss	(23,728)
Balance at the ending (in shares) at Jun. 30, 2022		30,991,986
Balance at the ending at Jun. 30, 2022	116,905	$ 3	307,916	(818)	(190,196)
Balance at the beginning (in shares) at Mar. 31, 2022		30,897,593
Balance at the beginning at Mar. 31, 2022	127,203	$ 3	306,532	(656)	(178,676)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		94,393
Issuance of common stock upon exercise of stock options	170		170
Stock-based compensation expense	1,214		1,214
Other comprehensive gain	(162)			(162)
Net loss	(11,520)				(11,520)
Balance at the ending (in shares) at Jun. 30, 2022		30,991,986
Balance at the ending at Jun. 30, 2022	116,905	$ 3	307,916	(818)	(190,196)
Balance at the beginning (in shares) at Dec. 31, 2022		31,017,946
Balance at the beginning at Dec. 31, 2022	98,943	$ 3	310,575	(981)	(210,654)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		4,094
Issuance of common stock upon exercise of stock options	4		4
Stock-based compensation expense	1,304		1,304
Other comprehensive gain	524			524
Net loss	(10,565)				(10,565)
Balance at the ending (in shares) at Mar. 31, 2023		31,022,040
Balance at the ending at Mar. 31, 2023	90,210	$ 3	311,883	(457)	(221,219)
Balance at the beginning (in shares) at Dec. 31, 2022		31,017,946
Balance at the beginning at Dec. 31, 2022	$ 98,943	$ 3	310,575	(981)	(210,654)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)	121,933
Other comprehensive gain	$ 309
Net loss	(21,107)
Balance at the ending (in shares) at Jun. 30, 2023		31,198,505
Balance at the ending at Jun. 30, 2023	81,137	$ 3	313,567	(672)	(231,761)
Balance at the beginning (in shares) at Mar. 31, 2023		31,022,040
Balance at the beginning at Mar. 31, 2023	90,210	$ 3	311,883	(457)	(221,219)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		117,839
Issuance of common stock upon exercise of stock options	178		178
Stock Issued During Period, Value, Employee Stock Purchase Plan	66		66
Stock Issued During Period, Shares, Employee Stock Purchase Plans		58,626
Stock-based compensation expense	1,440		1,440
Other comprehensive gain	(215)			(215)
Net loss	(10,542)				(10,542)
Balance at the ending (in shares) at Jun. 30, 2023		31,198,505
Balance at the ending at Jun. 30, 2023	$ 81,137	$ 3	$ 313,567	$ (672)	$ (231,761)

Condensed Statements of Conve_2

Condensed Statements of Convertible Preferred Stock and Stockholders’ Equity (Deficit) (unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Issuance of common stock upon exercise of stock options (in shares)					121,933
Issuance of common stock upon exercise of stock options	$ 178	$ 4	$ 170	$ 98
Stock-based compensation expense	1,440	1,304	1,214	1,222
Other comprehensive gain	(215)	524	(162)	(473)	$ 309	$ (635)
Net loss	(10,542)	(10,565)	(11,520)	(12,208)	(21,107)	(23,728)
Stockholders' Equity Attributable to Parent	$ 81,137	$ 90,210	$ 116,905	$ 127,203	$ 81,137	$ 116,905	$ 98,943	$ 138,564
Common Stock (Class A and B)
Issuance of common stock upon exercise of stock options (in shares)	117,839	4,094	94,393	123,467
Common stock, shares issued (in shares)	31,198,505	31,022,040	30,991,986	30,897,593	31,198,505	30,991,986	31,017,946	30,774,126
Stockholders' Equity Attributable to Parent	$ 3	$ 3	$ 3	$ 3	$ 3	$ 3	$ 3	$ 3
Additional Paid-In Capital
Issuance of common stock upon exercise of stock options	178	4	170	98
Stock-based compensation expense	1,440	1,304	1,214	1,222
Stockholders' Equity Attributable to Parent	313,567	311,883	307,916	306,532	313,567	307,916	310,575	305,212
Accumulated Other Comprehensive Loss
Other comprehensive gain	(215)	524	(162)	(473)
Stockholders' Equity Attributable to Parent	(672)	(457)	(818)	(656)	(672)	(818)	(981)	(183)
Accumulated Deficit
Net loss	(10,542)	(10,565)	(11,520)	(12,208)
Stockholders' Equity Attributable to Parent	$ (231,761)	$ (221,219)	$ (190,196)	$ (178,676)	$ (231,761)	$ (190,196)	$ (210,654)	$ (166,468)

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities
Net loss	$ (21,107)	$ (23,728)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	472	350
Operating Lease, Right-of-Use Asset, Amortization Expense	259	223
Stock-based compensation	2,744	2,436
Non-cash interest expense	0	9
Other	(414)	5
Changes in operating assets and liabilities:
Accounts receivable	(50)	(46)
Other receivables	6,000	3,116
Prepaid expenses and other assets	872	1,054
Accounts payable	(289)	(484)
Accrued and other current liabilities	(1,284)	(1,516)
Deferred revenue	(32)	(14)
Net cash used in operating activities	(12,829)	(18,595)
Cash flows from investing activities
Purchases of marketable securities	(23,068)	(21,217)
Proceeds from maturities and sales of marketable securities	38,113	34,852
Purchases of property and equipment	(86)	(226)
Proceeds from disposal of property and equipment	269	16
Net cash provided by investing activities	15,228	13,425
Cash flows from financing activities
Proceeds from exercise of stock options	182	214
Proceeds from employee stock purchase plan	66	0
Finance lease principal payments	(240)	(85)
Net cash provided by financing activities	8	129
Net increase (decrease) in cash and cash equivalents	2,407	(5,041)
Cash and cash equivalents at beginning of period	29,878	58,932
Cash and cash equivalents at end of period	32,285	53,891
Supplemental disclosure of cash flow information
Cash paid for interest	30	13
Supplemental disclosure of non-cash investing and financing information
Purchases of property and equipment in accounts payable and accruals	$ 0	$ 68

Description of Business and Fin

Description of Business and Financial Condition	6 Months Ended
	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Financial Condition	Description of Business and Financial Condition Sera Prognostics, Inc. (the “Company”) is a women’s health company utilizing its proprietary proteomics and bioinformatics platform to discover, develop, and commercialize biomarker tests with an initial focus on improving pregnancy outcomes. The Company was incorporated in the State of Delaware on January 17, 2008 and its operations are located in Salt Lake City, Utah, including a Clinical Laboratory Improvement Amendments (“CLIA”)-certified laboratory. Since its inception, the Company’s activities have consisted of performing research and development and conducting clinical studies for its pipeline products and services, acquiring product rights, raising capital, establishing facilities, and organizing commercial operations to market PreTRM. Liquidity and Capital Resources The accompanying condensed financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. The Company has incurred net losses and negative cash flows from operations since inception and had an accumulated deficit of $231.8 million as of June 30, 2023. The Company’s management expects the Company to incur significant additional operating losses and negative cash flows for the foreseeable future, principally as a result of the Company’s activities relating to the PreTRM test and the Company’s other pipeline products and services, including clinical and preclinical trials and anticipated research and development activities as well as commercialization activities. There can be no assurance that the Company will eventually achieve significant revenues or profitability to sustain operations, or if achieved, can sustain either on a continuing basis. If the Company is unable to achieve significant revenues or raise additional funds, when needed, it may not be able to continue the development or commercialization of its products and services and could be required to delay, scale back, or abandon some or all of its operations. No assurance can be given that the Company will be successful in raising the required capital on reasonable terms and at the required times, or at all. Any additional equity financing, if available to the Company, may not be available on favorable terms and may be dilutive to current stockholders, and any debt financing, if available, may involve restrictive covenants and dilutive financing instruments. The Company’s future operations are highly dependent on a combination of factors, including (i) the commercialization and market acceptance of the PreTRM test and the successful development, commercial launch, marketing, and distribution of other pipeline products and services; (ii) the success of scientific and clinical studies and other research and development programs that support current and future products and services; (iii) the development of competitive products by other biotechnology and laboratory companies; (iv) the Company’s ability to manage growth of the organization; (v) the Company’s ability to protect its intellectual property, technology, and products; and, ultimately (vi) the timely and successful completion of any additional financing. The principal sources of the Company’s working capital to date have been the proceeds from the sale and issuance of convertible preferred stock and convertible notes, bank loans, and the sale and issuance of Class A common stock in an initial public offering (“IPO”), which was completed in July 2021. As of June 30, 2023, the Company had aggregate cash, cash equivalents, and available-for-sale securities of $92.1 million. See Note 3—Cash, Cash Equivalents and Marketable Securities. The Company believes that its existing financial resources are sufficient to continue operating activities at least 12 months from the issuance date of these unaudited condensed financial statements.

Significant Accounting Policies

Significant Accounting Policies	6 Months Ended
	Jun. 30, 2023
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. As such, these unaudited condensed financial statements should be read in conjunction with the audited financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. The unaudited interim condensed financial statements have been prepared on a basis consistent with the audited annual financial statements as of and for the year ended December 31, 2022, and, in the opinion of the Company’s management, reflect all adjustments, consisting solely of normal recurring adjustments, necessary for the fair presentation of the Company’s financial results. The balance sheet as of December 31, 2022 has been derived from the audited financial statements at that date but does not include all information and footnotes required by U.S. GAAP for complete financial statements. The results of the three and six months ended June 30, 2023 are not necessarily indicative of the results to be expected for the full year ending December 31, 2023, or any other period. There have been no significant changes in the Company’s significant accounting policies during the six months ended June 30, 2023, as compared with those disclosed in its Annual Report on Form 10-K for the year ended December 31, 2022 filed with the SEC on March 22, 2023. Any reference in these notes to applicable accounting guidance is meant to refer to the authoritative U.S. GAAP included in the Accounting Standards Codification (“ASC”), and Accounting Standards Updates (“ASU”) issued by the Financial Accounting Standards Board (“FASB”). Certain prior period amounts have been reclassified to conform with the current period’s presentation. The reclassifications did not have a significant impact on the condensed financial statements. Use of Estimates The preparation of the condensed financial statements in conformity with U.S. GAAP requires the Company’s management to make estimates and assumptions that affect the amounts reported in the condensed financial statements and accompanying notes. The Company evaluates these estimates on an ongoing basis. The Company bases these estimates on historical and anticipated results, trends, and various other assumptions that the Company believes are reasonable under the circumstances, including assumptions as to future events. Actual results could differ materially from those estimates. The Company’s financial statements as of and for the three and six months ended June 30, 2023 reflect the Company’s estimates of the impact of the current macroeconomic environment, including the impact of inflation and higher interest rates. The extent to which these conditions will directly or indirectly impact the Company’s business, results of operations, and financial condition is uncertain. The Company is not aware of any specific event or circumstance that would require an update to its estimates, judgments and assumptions or a revision of the carrying value of the Company’s assets or liabilities as of the date of this filing.

Cash, Cash Equivalents and Mark

Cash, Cash Equivalents and Marketable Securities	6 Months Ended
	Jun. 30, 2023
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Marketable Securities	Cash, Cash Equivalents and Marketable Securities The Company has classified its marketable securities as available-for-sale. The Company’s cash, cash equivalents and marketable securities by major security type as of June 30, 2023 and December 31, 2022 were as follows (in thousands): June 30, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and cash equivalents: Cash $ 1,784 $ — $ — $ 1,784 Money market funds 85 — — 85 Commercial paper 30,423 — (7) 30,416 Total cash and cash equivalents 32,292 — (7) 32,285 Current marketable securities: Commercial paper 9,236 — (14) 9,222 U.S. federal agency securities 9,068 — (130) 8,938 U.S. government securities 13,561 — (185) 13,376 Total current marketable securities 31,865 — (329) 31,536 Long-term marketable securities: U.S. federal agency securities 20,338 — (254) 20,084 U.S. government securities 7,150 — (74) 7,076 Corporate debt securities 1,156 — (9) 1,147 Total long-term marketable securities 28,644 — (337) 28,307 Total cash, cash equivalents and marketable securities $ 92,801 $ — $ (673) $ 92,128 December 31, 2022 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and cash equivalents: Cash $ 913 $ — $ — $ 913 Money market funds 2,618 — — 2,618 Commercial paper 26,356 — (9) 26,347 Total cash and cash equivalents 29,887 — (9) 29,878 Current marketable securities: Commercial paper 15,219 2 (66) 15,155 Corporate debt securities 507 — (5) 502 U.S. federal agency securities 28,964 — (364) 28,600 U.S. government securities 8,702 — (133) 8,569 Total current marketable securities 53,392 2 (568) 52,826 Long-term marketable securities: U.S. federal agency securities 9,810 — (199) 9,611 U.S. government securities 10,770 — (208) 10,562 Corporate debt securities 1,156 — — 1,156 Total long-term marketable securities 21,736 — (407) 21,329 Total cash, cash equivalents and marketable securities $ 105,015 $ 2 $ (984) $ 104,033 The following tables summarize the Company’s available-for-sale debt securities and cash equivalents with unrealized losses as of June 30, 2023 and December 31, 2022, aggregated by major security type and the length of time that individual securities have been in a continuous loss position (in thousands): June 30, 2023 Less than 12 months 12 months or greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Commercial paper $ 39,638 $ (21) $ — $ — $ 39,638 $ (21) Corporate debt securities 1,147 (9) — — 1,147 (9) U.S. federal agency securities 23,851 (288) 5,171 (96) 29,022 (384) U.S. government securities 16,276 (241) 4,176 (18) 20,452 (259) Total $ 80,912 $ (559) $ 9,347 $ (114) $ 90,259 $ (673) December 31, 2022 Less than 12 months 12 months or greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Commercial paper $ 40,063 $ (75) $ — $ — $ 40,063 $ (75) Corporate debt securities 1,156 — 502 (5) 1,658 (5) U.S. federal agency securities 12,869 (228) 25,342 (335) 38,211 (563) U.S. government securities 10,562 (208) 8,569 (133) 19,131 (341) Total $ 64,650 $ (511) $ 34,413 $ (473) $ 99,063 $ (984) As of June 30, 2023 and December 31, 2022, the Company had not recorded any allowance for credit losses related to its available-for-sale securities. The Company attributes the declines in the fair value of its available-for-sale securities to normal market and interest rate fluctuations. The declines in fair value are not attributed to declines in credit quality. The Company does not intend to sell investments while they are in an unrealized loss position and does not believe that it is more likely than not that the Company will be required to sell the investments before recovery of their amortized cost basis, which may be maturity. All of the Company’s investments mature in less than two years. The Company’s marketable securities classified by contractual maturities as of June 30, 2023 were as follows (in thousands): Amortized Cost Fair Value Due within one year $ 31,865 $ 31,536 Due after one year through five years 28,644 28,307 Total $ 60,509 $ 59,843

Property and Equipment

Property and Equipment	6 Months Ended
	Jun. 30, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment The following table presents the components of property and equipment, net, as of June 30, 2023 and December 31, 2022 (in thousands): June 30, December 31, Laboratory equipment $ 5,738 $ 5,914 Computer equipment 1,214 1,230 Leasehold improvements 710 710 Software 1,141 1,141 Furniture and fixtures 320 320 Total property and equipment 9,123 9,315 Less accumulated depreciation and amortization (6,712) (6,256) Property and equipment, net $ 2,411 $ 3,059

Accrued and Other Current Liabi

Accrued and Other Current Liabilities	6 Months Ended
	Jun. 30, 2023
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued and Other Current Liabilities	Accrued and Other Current Liabilities The following table presents the components of accrued and other current liabilities as of June 30, 2023 and December 31, 2022 (in thousands): June 30, December 31, Accrued compensation $ 1,678 $ 2,290 Accrued vacation 433 430 Accrued 401(k) matching contributions 135 568 Operating lease liability, current portion 548 519 Other current liabilities 650 637 Total accrued and other current liabilities $ 3,444 $ 4,444

Other Income, net

Other Income, net	6 Months Ended
	Jun. 30, 2023
Other Income and Expenses [Abstract]
Other Income, net	Other Income, net The following table presents the components of other income, net, for the three and six months ended June 30, 2023 and 2022 (in thousands): Three Months Ended Six Months Ended 2023 2022 2023 2022 Interest income $ 337 $ 66 $ 593 $ 144 Investment income, net 595 178 1,119 196 Other income, net $ 932 $ 244 $ 1,712 $ 340

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value MeasurementsAs of June 30, 2023 and December 31, 2022, the carrying amounts of the Company’s receivables, prepaid and other current assets, accounts payable, and accrued and other current liabilities approximate their fair values, principally due to the short-term nature of the assets and liabilities. The recorded values of the finance leases approximate fair value as the interest rates approximate market interest rates. Money market funds are highly liquid investments and are actively traded. The pricing information on money market funds is readily available and can be independently validated as of the measurement date. This approach results in the classification of these securities as Level 1 of the fair value hierarchy. U.S. government agency bonds, U.S. government bonds, commercial paper, and corporate debt securities are measured at fair value using Level 2 inputs. The Company reviews trading activity and pricing for these investments as of each measurement date. The Company follows a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The three levels of the fair value hierarchy are as follows: Level 1 inputs are observable, quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company can access at the measurement date. Level 2 inputs are observable inputs other than quoted prices included in Level 1 that are observable either directly or indirectly or 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 assets or liabilities. Level 3 inputs are unobservable inputs in which there is little or no market data, which require the Company to develop its own assumptions. The following table shows the Company’s assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands) as of June 30, 2023: Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 85 $ — $ — Commercial paper — 30,416 — Marketable securities: Commercial paper — 9,222 — Corporate debt securities — 1,147 — U.S. federal agency securities — 29,022 — U.S. government securities — 20,452 — Total assets $ 85 $ 90,259 $ — The following table shows the Company’s assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands) as of December 31, 2022: Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 2,618 $ — $ — Commercial paper — 26,347 — Marketable securities: Commercial paper — 15,155 — Corporate debt securities — 1,658 — U.S. federal agency securities — 38,211 — U.S. government securities — 19,131 — Total assets $ 2,618 $ 100,502 $ —

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions In June 2019, the Company entered into a master services agreement with Carelon Research, a subsidiary of Elevance Health, Inc. (“Elevance Health”). This agreement covers a range of research projects, including Carelon Research’s role as a contract research organization for the P rematurity R isk Assessment Combined With Clinical I nterventions for Improving Neonatal outco ME s (“PRIME”) study. The Company paid fees related to this agreement of $0.8 million and $0.4 million for the three months ended June 30, 2023 and 2022, respectively, and $1.7 million and $1.1 million for the six months ended June 30, 2023 and 2022, respectively, which were recorded in research and development expenses. Fees incurred under this agreement generally increase as the Company enrolls more PRIME study patients. In November 2020, the Company entered into a Laboratory Services Agreement with Elevance Health related to the PRIME study. This agreement provides a contracted rate for certain tests performed pursuant to the study, and revenue varies depending on the number of tests performed for PRIME patients that are members of the Elevance Health network. The Company recognized revenues related to this agreement of $14 thousand and $23 thousand for the three months ended June 30, 2023 and 2022, respectively, and $34 thousand and $42 thousand for the six months ended June 30, 2023 and 2022, respectively. In February 2021, the Company entered into a commercial collaboration agreement with Elevance Health and its affiliates (the “Commercial Collaboration Agreement”). The Commercial Collaboration Agreement provides defined payment within a defined period for use of the PreTRM test within Elevance Health’s network of covered members. Pursuant to the Commercial Collaboration Agreement, Elevance Health agreed to purchase a certain minimum number of tests for each of the first three years of the term of the agreement. Additionally, Elevance Health agreed to pay a certain minimum amount per year for the first three years of the term of the Commercial Collaboration Agreement. The Company received $6.0 million during the six months ended June 30, 2023, which amount related to the minimum payments for the year ended December 31, 2022. Such minimum payments were initially recorded as deferred revenue. Deferred revenue is recognized as revenue when the Company delivers PreTRM test results to Elevance Health patients pursuant to the Commercial Collaboration Agreement. The Company also agreed to develop a sales, marketing, and customer service program, and to provide training and marketing to duly licensed physicians specializing in obstetrics and gynecology or family medicine, or licensed nurse midwives, at the reasonable request of Elevance Health. Elevance Health has been participating in the Company’s PRIME study, and at the conclusion of the PRIME study, under the Commercial Collaboration Agreement, the parties agreed to use commercially reasonable efforts to enter into Elevance Health’s standard lab provider agreement. Unless earlier terminated due to breach, the Commercial Collaboration Agreement will remain in effect until the later of (a) the third anniversary of the effective date or (b) the date on which Elevance Health has purchased a fixed number of PreTRM tests as agreed by the parties. The Commercial Collaboration Agreement with Elevance Health is considered to be within the scope of ASC Topic 808, Collaborative Arrangements (“ASC 808”), as the parties are active participants and exposed to the risks and rewards of the collaborative activity. The Company determined the PreTRM tests to be a performance obligation for which Elevance Health is a customer and a unit of account within the scope of ASC 606. The associated transaction price is based on the contractual minimum number of tests and the agreed upon defined payment amount per test. The transaction price was allocated to this single performance obligation, which will be recognized upon delivery of test results expected to

Capital Structure

Capital Structure	6 Months Ended
	Jun. 30, 2023
Stockholders' Equity Note [Abstract]
Capital Structure	Capital Structure The Company has two authorized classes of common stock, Class A and Class B. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote and shares of Class B common stock are non-voting. Each share of Class B common stock may be converted at any time to one share of Class A common stock at the option of its holder, subject to the ownership limitations provided for in the Company’s amended and restated certificate of incorporation. The following shares of Class A common stock were reserved for future issuance: June 30, December 31, Warrants to purchase Class A common stock 2,775,978 2,775,978 Options to purchase Class A common stock 8,062,442 8,428,441 Restricted stock units outstanding 240,832 — Class A common stock available for future grants under the 2021 Equity Incentive Plan 3,114,097 1,926,356 Class A common stock available for future grants under the 2021 Employee Stock Purchase Plan 836,277 598,777 Total 15,029,626 13,729,552

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation Equity Incentive Plans In November 2011, the Company established the 2011 Employee, Director and Consultant Equity Incentive Plan (the “2011 Plan”) and reserved shares of the Company’s common stock for sale and issuance under the 2011 Plan. Options granted under the 2011 Plan generally vest over a four-year period and generally expire ten years from the date of grant. Options are exercisable only to the extent vested. The 2011 Plan terminated in November 2021, and accordingly, no additional shares are available for grant under the 2011 Plan. The 2011 Plan continues to govern outstanding awards granted under the 2011 Plan. The 2021 Equity Incentive Plan (the “2021 Plan”) was established in July 2021. The 2021 Plan provides for the grant of incentive and non-statutory stock options as well as other stock rights to employees, directors, and consultants of the Company. Options generally vest over a four-year period, are exercisable only to the extent vested, and generally expire ten years from the date of grant. Restricted stock units (“RSUs”) generally vest over a four-year period. The 2021 Plan includes provisions for annual automatic increases to the number of shares of Class A common stock reserved for issuance under the 2021 Plan. In addition, any shares that otherwise would be returned to the 2011 Plan as a result of the expiration or cancellation of stock options may be added to the 2021 Plan. As of June 30, 2023, there were 3,114,097 shares of the Company’s Class A common stock that were available for future grants under the 2021 Plan. The 2021 Employee Stock Purchase Plan (the “2021 ESPP”) was established in July 2021. The 2021 ESPP includes provisions for annual automatic increases to the number of shares of Class A common stock reserved for issuance under the 2021 ESPP. As of June 30, 2023, there were 836,277 shares of the Company’s Class A common stock that were available for future grants under the 2021 ESPP. Stock Options Unless otherwise noted, references to “options” in the subsequent disclosures, refers to the combined incentive and non-statutory stock options issued as employee and non-employee stock-based compensation, and authorized under the 2011 Plan and the 2021 Plan. The following table summarizes information about these options granted and outstanding: Number of Weighted- Weighted- Aggregate Outstanding — December 31, 2022 8,428,441 $ 3.65 7.7 $ 115 Granted 991,866 3.49 Expired — — Cancelled (1,235,932) 4.06 Exercised (121,933) 1.49 Outstanding — June 30, 2023 8,062,442 $ 3.60 7.4 $ 6,701 Vested and expected to vest at June 30, 2023 7,828,850 $ 3.58 7.3 $ 6,659 Vested and exercisable at June 30, 2023 5,411,736 $ 3.09 6.7 $ 6,070 RSUs The following table summarizes information about RSUs granted and outstanding under the 2021 Plan: Number of Awards Weighted-Average Grant Date Fair Value Outstanding — December 31, 2022 — $ — Granted 347,824 3.79 Forfeited (106,992) 3.75 Vested — — Outstanding — June 30, 2023 240,832 $ 3.80 Stock-Based Compensation Expense The following table presents the impact of stock-based compensation expense in the statements of operations for the periods indicated (in thousands): Three Months Ended Six Months Ended 2023 2022 2023 2022 Research and development expense $ 382 $ 451 $ 732 $ 834 Sales and marketing expense 294 76 477 389 General and administrative expense 764 687 1,535 1,213 Total employee stock-based compensation $ 1,440 $ 1,214 $ 2,744 $ 2,436 The information about unrecognized stock-based compensation expense for outstanding unvested stock options and RSUs as of June 30, 2023 was as follows (in thousands, except years): Unrecognized Stock-Based Compensation Expense Weighted-Average Period of Recognition (in years) Stock Options $ 7,303 2.0 RSUs 670 3.7 Total unrecognized stock-based compensation expense $ 7,973

Warrants

Warrants	6 Months Ended
	Jun. 30, 2023
Warrants and Rights Note Disclosure [Abstract]
Warrants	Warrants All outstanding common stock warrants were exercisable immediately when granted. All outstanding common stock warrants are exercisable for shares of Class A common stock. The Company’s common stock warrants outstanding were as follows: Number of Warrants Outstanding as of: Exercise Price June 30, 2023 December 31, 2022 $ 5.20 3,473 3,473 9.03 1,032,404 1,032,404 10.84 1,009,795 1,009,795 12.38 8,083 8,083 20.77 722,223 722,223 2,775,978 2,775,978

Commitments and Contingences

Commitments and Contingences	6 Months Ended
	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingences	Commitments and Contingencies Leases The Company is the lessee in all of its lease arrangements. The Company did not enter into any leases with related parties during the presented periods. The Company makes assumptions and judgments when assessing contracts for lease components, determining lease classifications, and calculating right-of-use asset and lease liability values. These assumptions and judgments may include the useful lives and fair values of the leased assets, the implicit rate underlying the Company’s leases, the Company’s incremental borrowing rate or the Company’s intent to exercise or not exercise options available in lease contracts. The following table shows right-of-use assets and lease liabilities, and the associated financial statement line items as of June 30, 2023 and December 31, 2022 (in thousands): Lease-Related Assets and Liabilities Financial Statement Line Items June 30, December 31, Right-of-use assets: Operating leases Other assets $ 1,448 $ 1,707 Finance leases Property and equipment, net 1,169 1,317 Total right-of-use assets $ 2,617 $ 3,024 Lease liabilities: Operating leases Accrued and other current liabilities $ 548 $ 519 Operating lease obligation, net of current portion 938 1,222 Finance leases Finance lease obligation, current portion 446 464 Finance lease obligation, net of current portion 422 626 Total lease liabilities $ 2,354 $ 2,831 Lease costs and other information consisted of the following (in thousands, except terms and rates): Three Months Ended Six Months Ended 2023 2022 2023 2022 Lease cost Finance lease cost: Amortization of right-of-use assets $ 83 $ 67 $ 166 $ 113 Interest on lease liabilities 14 18 30 22 Operating lease cost 159 116 318 233 Total lease cost $ 256 $ 201 $ 514 $ 368 Other information Finance leases: Operating cash outflows $ 14 $ 11 $ 30 $ 13 Financing cash outflows $ 120 $ 67 $ 240 $ 85 Right-of-use assets obtained in exchange for lease liabilities $ 18 $ 295 $ 18 $ 1,253 Weighted-average remaining lease term (in years) 1.8 2.7 1.8 2.7 Weighted-average discount rate 6.5% 6.4% 6.5% 6.4% Operating leases: Operating cash outflows $ 157 $ 151 $ 314 $ 302 Right-of-use assets obtained in exchange for lease liabilities $ — $ — $ — $ 453 Weighted-average remaining lease term (in years) 2.5 0.5 2.5 0.5 Weighted-average discount rate 7.5% 4.5% 7.5% 4.5% Future minimum lease payments for the Company’s leases as of June 30, 2023 were as follows (in thousands): Operating Leases Finance Leases Total 2023 $ 314 $ 252 $ 566 2024 646 469 1,115 2025 666 198 864 2026 — 2 2 2027 and thereafter — — — Total minimum lease payments 1,626 921 2,547 Less: imputed interest (140) (53) (193) Present value of future lease payments 1,486 868 2,354 Less: current portion 548 446 994 Long-term portion $ 938 $ 422 $ 1,360 Operating Leases The Company leases a total of approximately 24,300 square feet of office and laboratory space under a single non-cancelable operating lease with a termination date of December 31, 2025 (as amended, the “Office Lease”). The Office Lease includes an early termination right which termination would occur under certain circumstances, as provided in the amended Office Lease, after July 1, 2024, if exercised. The Company is not currently reasonably certain it will exercise the termination right. The implicit rate provided in the Company’s operating lease is not readily determinable. As such, the Company uses its incremental borrowing rate to calculate the present value of its operating lease liabilities. Finance Leases The Company leases certain equipment related to its information technology infrastructure and laboratory operations. All of the Company’s current finance leases include bargain purchase options that the Company is reasonably certain to exercise. The Company has elected not to separate lease and non-lease components for its equipment leases. The rates implicit in the Company’s finance leases are determinable, and the Company uses those rates to calculate the present value of its finance lease liabilities. Indemnification The Company has agreed to indemnify its officers and directors for certain events or occurrences while the officer or director is or was serving at the Company’s request in such capacity. The maximum amount of potential future indemnification is unlimited; however, the Company purchases director and officer insurance coverage that provides for corporate reimbursements of covered obligations that limits the Company’s exposure and enables it to recover a portion of potential future amounts paid. The Company is unable to reasonably estimate the maximum amount that could be payable under these arrangements since these obligations are not capped but are conditional to the unique facts and circumstances involved. Accordingly, the Company has no liabilities recorded for these agreements as of June 30, 2023 and December 31, 2022. The Company has never incurred costs to defend lawsuits or settle claims related to these indemnification agreements. Employee Agreements The Company has signed various employment agreements with key executives pursuant to which, if their employment is terminated by the Company without cause or by the employees for good reason, or following a change of control of the Company, the employees are entitled to receive certain benefits, including severance payments, accelerated vesting of stock and stock options, and certain insurance benefits. Legal Matters The Company is not currently a party to any material litigation or other material legal proceedings. The Company may, from time to time, be involved in various legal proceedings arising from the normal course of business activities, and an unfavorable resolution of any of these matters could materially affect the Company’s future results of operations, cash flows, or financial position.

Net loss per share

Net loss per share	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Net loss per share	Net loss per share The Company calculates net loss per share of Class A and Class B common stock using the two-class method. For periods in which the Company reports a net loss, all potentially dilutive shares are anti-dilutive and are therefore excluded from the calculation of diluted net loss per share. For the three and six months ended June 30, 2023 and 2022, the Company reported net losses and as such, basic and diluted net loss per share are the same. As the liquidation and dividend rights are identical for Class A and Class B common stock, the undistributed earnings are allocated on a proportionate basis and the resulting amount per share for Class A and Class B common stock was the same for the three and six months ended June 30, 2023 and 2022. The Company excluded the following potentially dilutive securities, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share for the periods indicated because their impact would have been anti-dilutive: June 30, 2023 2022 Warrants to purchase Class A common stock 2,775,978 2,788,484 Options to purchase Class A common stock 8,062,442 8,743,143 Restricted stock units outstanding 240,832 — Total 11,079,252 11,531,627

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. As such, these unaudited condensed financial statements should be read in conjunction with the audited financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. The unaudited interim condensed financial statements have been prepared on a basis consistent with the audited annual financial statements as of and for the year ended December 31, 2022, and, in the opinion of the Company’s management, reflect all adjustments, consisting solely of normal recurring adjustments, necessary for the fair presentation of the Company’s financial results. The balance sheet as of December 31, 2022 has been derived from the audited financial statements at that date but does not include all information and footnotes required by U.S. GAAP for complete financial statements. The results of the three and six months ended June 30, 2023 are not necessarily indicative of the results to be expected for the full year ending December 31, 2023, or any other period. There have been no significant changes in the Company’s significant accounting policies during the six months ended June 30, 2023, as compared with those disclosed in its Annual Report on Form 10-K for the year ended December 31, 2022 filed with the SEC on March 22, 2023. Any reference in these notes to applicable accounting guidance is meant to refer to the authoritative U.S. GAAP included in the Accounting Standards Codification (“ASC”), and Accounting Standards Updates (“ASU”) issued by the Financial Accounting Standards Board (“FASB”).
Use of Estimates	Use of Estimates The preparation of the condensed financial statements in conformity with U.S. GAAP requires the Company’s management to make estimates and assumptions that affect the amounts reported in the condensed financial statements and accompanying notes. The Company evaluates these estimates on an ongoing basis. The Company bases these estimates on historical and anticipated results, trends, and various other assumptions that the Company believes are reasonable under the circumstances, including assumptions as to future events. Actual results could differ materially from those estimates. The Company’s financial statements as of and for the three and six months ended June 30, 2023 reflect the Company’s estimates of the impact of the current macroeconomic environment, including the impact of inflation and higher interest rates. The extent to which these conditions will directly or indirectly impact the Company’s business, results of operations, and financial condition is uncertain. The Company is not aware of any specific event or circumstance that would require an update to its estimates, judgments and assumptions or a revision of the carrying value of the Company’s assets or liabilities as of the date of this filing.

Cash, Cash Equivalents and Ma_2

Cash, Cash Equivalents and Marketable Securities (Tables)	6 Months Ended
	Jun. 30, 2023
Cash and Cash Equivalents [Abstract]
Schedule of Cash, Cash Equivalents and Marketable Securities by Major Security Type	The Company’s cash, cash equivalents and marketable securities by major security type as of June 30, 2023 and December 31, 2022 were as follows (in thousands): June 30, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and cash equivalents: Cash $ 1,784 $ — $ — $ 1,784 Money market funds 85 — — 85 Commercial paper 30,423 — (7) 30,416 Total cash and cash equivalents 32,292 — (7) 32,285 Current marketable securities: Commercial paper 9,236 — (14) 9,222 U.S. federal agency securities 9,068 — (130) 8,938 U.S. government securities 13,561 — (185) 13,376 Total current marketable securities 31,865 — (329) 31,536 Long-term marketable securities: U.S. federal agency securities 20,338 — (254) 20,084 U.S. government securities 7,150 — (74) 7,076 Corporate debt securities 1,156 — (9) 1,147 Total long-term marketable securities 28,644 — (337) 28,307 Total cash, cash equivalents and marketable securities $ 92,801 $ — $ (673) $ 92,128 December 31, 2022 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and cash equivalents: Cash $ 913 $ — $ — $ 913 Money market funds 2,618 — — 2,618 Commercial paper 26,356 — (9) 26,347 Total cash and cash equivalents 29,887 — (9) 29,878 Current marketable securities: Commercial paper 15,219 2 (66) 15,155 Corporate debt securities 507 — (5) 502 U.S. federal agency securities 28,964 — (364) 28,600 U.S. government securities 8,702 — (133) 8,569 Total current marketable securities 53,392 2 (568) 52,826 Long-term marketable securities: U.S. federal agency securities 9,810 — (199) 9,611 U.S. government securities 10,770 — (208) 10,562 Corporate debt securities 1,156 — — 1,156 Total long-term marketable securities 21,736 — (407) 21,329 Total cash, cash equivalents and marketable securities $ 105,015 $ 2 $ (984) $ 104,033
Schedule of Marketable Securities Classified by Contractual Maturities	The Company’s marketable securities classified by contractual maturities as of June 30, 2023 were as follows (in thousands): Amortized Cost Fair Value Due within one year $ 31,865 $ 31,536 Due after one year through five years 28,644 28,307 Total $ 60,509 $ 59,843
Schedule of Marketable Securities and Cash Equivalents in Unrealized Loss Positions	The following tables summarize the Company’s available-for-sale debt securities and cash equivalents with unrealized losses as of June 30, 2023 and December 31, 2022, aggregated by major security type and the length of time that individual securities have been in a continuous loss position (in thousands): June 30, 2023 Less than 12 months 12 months or greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Commercial paper $ 39,638 $ (21) $ — $ — $ 39,638 $ (21) Corporate debt securities 1,147 (9) — — 1,147 (9) U.S. federal agency securities 23,851 (288) 5,171 (96) 29,022 (384) U.S. government securities 16,276 (241) 4,176 (18) 20,452 (259) Total $ 80,912 $ (559) $ 9,347 $ (114) $ 90,259 $ (673) December 31, 2022 Less than 12 months 12 months or greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Commercial paper $ 40,063 $ (75) $ — $ — $ 40,063 $ (75) Corporate debt securities 1,156 — 502 (5) 1,658 (5) U.S. federal agency securities 12,869 (228) 25,342 (335) 38,211 (563) U.S. government securities 10,562 (208) 8,569 (133) 19,131 (341) Total $ 64,650 $ (511) $ 34,413 $ (473) $ 99,063 $ (984)

Property and Equipment (Tables)

Property and Equipment (Tables)	6 Months Ended
	Jun. 30, 2023
Property, Plant and Equipment [Abstract]
Schedule of Components of Property and Equipment, Net	The following table presents the components of property and equipment, net, as of June 30, 2023 and December 31, 2022 (in thousands): June 30, December 31, Laboratory equipment $ 5,738 $ 5,914 Computer equipment 1,214 1,230 Leasehold improvements 710 710 Software 1,141 1,141 Furniture and fixtures 320 320 Total property and equipment 9,123 9,315 Less accumulated depreciation and amortization (6,712) (6,256) Property and equipment, net $ 2,411 $ 3,059

Accrued and Other Current Lia_2

Accrued and Other Current Liabilities (Tables)	6 Months Ended
	Jun. 30, 2023
Accounts Payable and Accrued Liabilities, Current [Abstract]
Schedule of Components of Accrued and Other Current Liabilities	The following table presents the components of accrued and other current liabilities as of June 30, 2023 and December 31, 2022 (in thousands): June 30, December 31, Accrued compensation $ 1,678 $ 2,290 Accrued vacation 433 430 Accrued 401(k) matching contributions 135 568 Operating lease liability, current portion 548 519 Other current liabilities 650 637 Total accrued and other current liabilities $ 3,444 $ 4,444

Other Income, net (Tables)

Other Income, net (Tables)	6 Months Ended
	Jun. 30, 2023
Other Income and Expenses [Abstract]
Schedule of Components of Other Income, Net	The following table presents the components of other income, net, for the three and six months ended June 30, 2023 and 2022 (in thousands): Three Months Ended Six Months Ended 2023 2022 2023 2022 Interest income $ 337 $ 66 $ 593 $ 144 Investment income, net 595 178 1,119 196 Other income, net $ 932 $ 244 $ 1,712 $ 340

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of Financial Assets that are Measured at Fair Value on a Recurring basis	The following table shows the Company’s assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands) as of June 30, 2023: Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 85 $ — $ — Commercial paper — 30,416 — Marketable securities: Commercial paper — 9,222 — Corporate debt securities — 1,147 — U.S. federal agency securities — 29,022 — U.S. government securities — 20,452 — Total assets $ 85 $ 90,259 $ — The following table shows the Company’s assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands) as of December 31, 2022: Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 2,618 $ — $ — Commercial paper — 26,347 — Marketable securities: Commercial paper — 15,155 — Corporate debt securities — 1,658 — U.S. federal agency securities — 38,211 — U.S. government securities — 19,131 — Total assets $ 2,618 $ 100,502 $ —

Capital Structure (Tables)

Capital Structure (Tables)	6 Months Ended
	Jun. 30, 2023
Stockholders' Equity Note [Abstract]
Schedule of Common Stock Reserved for Future Issuance	The following shares of Class A common stock were reserved for future issuance: June 30, December 31, Warrants to purchase Class A common stock 2,775,978 2,775,978 Options to purchase Class A common stock 8,062,442 8,428,441 Restricted stock units outstanding 240,832 — Class A common stock available for future grants under the 2021 Equity Incentive Plan 3,114,097 1,926,356 Class A common stock available for future grants under the 2021 Employee Stock Purchase Plan 836,277 598,777 Total 15,029,626 13,729,552

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2023
Share-Based Payment Arrangement [Abstract]
Summary of Options Granted and Outstanding	The following table summarizes information about these options granted and outstanding: Number of Weighted- Weighted- Aggregate Outstanding — December 31, 2022 8,428,441 $ 3.65 7.7 $ 115 Granted 991,866 3.49 Expired — — Cancelled (1,235,932) 4.06 Exercised (121,933) 1.49 Outstanding — June 30, 2023 8,062,442 $ 3.60 7.4 $ 6,701 Vested and expected to vest at June 30, 2023 7,828,850 $ 3.58 7.3 $ 6,659 Vested and exercisable at June 30, 2023 5,411,736 $ 3.09 6.7 $ 6,070
Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity	The following table summarizes information about RSUs granted and outstanding under the 2021 Plan: Number of Awards Weighted-Average Grant Date Fair Value Outstanding — December 31, 2022 — $ — Granted 347,824 3.79 Forfeited (106,992) 3.75 Vested — — Outstanding — June 30, 2023 240,832 $ 3.80
Schedule of Impact of Stock-based Compensation Expense in the Statements of Operations	The following table presents the impact of stock-based compensation expense in the statements of operations for the periods indicated (in thousands): Three Months Ended Six Months Ended 2023 2022 2023 2022 Research and development expense $ 382 $ 451 $ 732 $ 834 Sales and marketing expense 294 76 477 389 General and administrative expense 764 687 1,535 1,213 Total employee stock-based compensation $ 1,440 $ 1,214 $ 2,744 $ 2,436
Share-Based Payment Arrangement, Nonvested Award, Cost	The information about unrecognized stock-based compensation expense for outstanding unvested stock options and RSUs as of June 30, 2023 was as follows (in thousands, except years): Unrecognized Stock-Based Compensation Expense Weighted-Average Period of Recognition (in years) Stock Options $ 7,303 2.0 RSUs 670 3.7 Total unrecognized stock-based compensation expense $ 7,973

Warrants (Tables)

Warrants (Tables)	6 Months Ended
	Jun. 30, 2023
Warrants and Rights Note Disclosure [Abstract]
Schedule of Warrants or Rights	The Company’s common stock warrants outstanding were as follows: Number of Warrants Outstanding as of: Exercise Price June 30, 2023 December 31, 2022 $ 5.20 3,473 3,473 9.03 1,032,404 1,032,404 10.84 1,009,795 1,009,795 12.38 8,083 8,083 20.77 722,223 722,223 2,775,978 2,775,978

Commitment and Contingencies (T

Commitment and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Schedule of Leases in Financial Statement	The following table shows right-of-use assets and lease liabilities, and the associated financial statement line items as of June 30, 2023 and December 31, 2022 (in thousands): Lease-Related Assets and Liabilities Financial Statement Line Items June 30, December 31, Right-of-use assets: Operating leases Other assets $ 1,448 $ 1,707 Finance leases Property and equipment, net 1,169 1,317 Total right-of-use assets $ 2,617 $ 3,024 Lease liabilities: Operating leases Accrued and other current liabilities $ 548 $ 519 Operating lease obligation, net of current portion 938 1,222 Finance leases Finance lease obligation, current portion 446 464 Finance lease obligation, net of current portion 422 626 Total lease liabilities $ 2,354 $ 2,831
Schedule of Lease Cost and Other Information	Lease costs and other information consisted of the following (in thousands, except terms and rates): Three Months Ended Six Months Ended 2023 2022 2023 2022 Lease cost Finance lease cost: Amortization of right-of-use assets $ 83 $ 67 $ 166 $ 113 Interest on lease liabilities 14 18 30 22 Operating lease cost 159 116 318 233 Total lease cost $ 256 $ 201 $ 514 $ 368 Other information Finance leases: Operating cash outflows $ 14 $ 11 $ 30 $ 13 Financing cash outflows $ 120 $ 67 $ 240 $ 85 Right-of-use assets obtained in exchange for lease liabilities $ 18 $ 295 $ 18 $ 1,253 Weighted-average remaining lease term (in years) 1.8 2.7 1.8 2.7 Weighted-average discount rate 6.5% 6.4% 6.5% 6.4% Operating leases: Operating cash outflows $ 157 $ 151 $ 314 $ 302 Right-of-use assets obtained in exchange for lease liabilities $ — $ — $ — $ 453 Weighted-average remaining lease term (in years) 2.5 0.5 2.5 0.5 Weighted-average discount rate 7.5% 4.5% 7.5% 4.5%
Schedule of Future Minimum Lease Payments	Future minimum lease payments for the Company’s leases as of June 30, 2023 were as follows (in thousands): Operating Leases Finance Leases Total 2023 $ 314 $ 252 $ 566 2024 646 469 1,115 2025 666 198 864 2026 — 2 2 2027 and thereafter — — — Total minimum lease payments 1,626 921 2,547 Less: imputed interest (140) (53) (193) Present value of future lease payments 1,486 868 2,354 Less: current portion 548 446 994 Long-term portion $ 938 $ 422 $ 1,360
Schedule of Future Minimum Lease Payments	Future minimum lease payments for the Company’s leases as of June 30, 2023 were as follows (in thousands): Operating Leases Finance Leases Total 2023 $ 314 $ 252 $ 566 2024 646 469 1,115 2025 666 198 864 2026 — 2 2 2027 and thereafter — — — Total minimum lease payments 1,626 921 2,547 Less: imputed interest (140) (53) (193) Present value of future lease payments 1,486 868 2,354 Less: current portion 548 446 994 Long-term portion $ 938 $ 422 $ 1,360

Net loss per share (Tables)

Net loss per share (Tables)	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Schedule of Anti-dilutive Securities Excluded from the Computation of Earnings per Share	The Company excluded the following potentially dilutive securities, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share for the periods indicated because their impact would have been anti-dilutive: June 30, 2023 2022 Warrants to purchase Class A common stock 2,775,978 2,788,484 Options to purchase Class A common stock 8,062,442 8,743,143 Restricted stock units outstanding 240,832 — Total 11,079,252 11,531,627

Description of Business and F_2

Description of Business and Financial Condition (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ (231,761)	$ (210,654)
Fair Value	$ 92,128	$ 104,033

Cash, Cash Equivalents and Ma_3

Cash, Cash Equivalents and Marketable Securities - Cash, Cash Equivalents and Marketable Securities by Major Security Type (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 60,509
Fair Value	59,843
Amortized Cost	92,801	$ 105,015
Gross Unrealized Gains	0	2
Gross Unrealized Losses	(673)	(984)
Fair Value	92,128	104,033
Cash and cash equivalents:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	32,292	29,887
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(7)	(9)
Fair Value	32,285	29,878
Cash and cash equivalents: | Cash
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,784	913
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	1,784	913
Cash and cash equivalents: | Money market funds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	85	2,618
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	85	2,618
Cash and cash equivalents: | Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	30,423	26,356
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(7)	(9)
Fair Value	30,416	26,347
Current marketable securities:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	31,865	53,392
Gross Unrealized Gains	0	2
Gross Unrealized Losses	(329)	(568)
Fair Value	31,536	52,826
Current marketable securities: | Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	9,236	15,219
Gross Unrealized Gains	0	2
Gross Unrealized Losses	(14)	(66)
Fair Value	9,222	15,155
Current marketable securities: | Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		507
Gross Unrealized Gains		0
Gross Unrealized Losses		(5)
Fair Value		502
Current marketable securities: | U.S. federal agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	9,068	28,964
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(130)	(364)
Fair Value	8,938	28,600
Current marketable securities: | U.S. government securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	13,561	8,702
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(185)	(133)
Fair Value	13,376	8,569
Long-term marketable securities:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	28,644	21,736
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(337)	(407)
Fair Value	28,307	21,329
Long-term marketable securities: | Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,156	1,156
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(9)	0
Fair Value	1,147	1,156
Long-term marketable securities: | U.S. federal agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	20,338	9,810
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(254)	(199)
Fair Value	20,084	9,611
Long-term marketable securities: | U.S. government securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,150	10,770
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(74)	(208)
Fair Value	$ 7,076	$ 10,562

Cash, Cash Equivalents and Ma_4

Cash, Cash Equivalents and Marketable Securities - Marketable Securities and Cash Equivalents in Unrealized Loss Positions (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair Value	$ 80,912	$ 64,650
Unrealized Losses	559	511
Fair Value	9,347	34,413
Unrealized Losses	114	473
Fair Value	90,259	99,063
Unrealized Losses	673	984
Commercial paper
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair Value	39,638	40,063
Unrealized Losses	21	75
Fair Value	0	0
Unrealized Losses	0	0
Fair Value	39,638	40,063
Unrealized Losses	21	75
Corporate debt securities
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair Value	1,147	1,156
Unrealized Losses	9	0
Fair Value	0	502
Unrealized Losses	0	5
Fair Value	1,147	1,658
Unrealized Losses	9	5
U.S. federal agency securities
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair Value	23,851	12,869
Unrealized Losses	288	228
Fair Value	5,171	25,342
Unrealized Losses	96	335
Fair Value	29,022	38,211
Unrealized Losses	384	563
U.S. government securities
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair Value	16,276	10,562
Unrealized Losses	241	208
Fair Value	4,176	8,569
Unrealized Losses	18	133
Fair Value	20,452	19,131
Unrealized Losses	$ 259	$ 341

Cash, Cash Equivalents and Ma_5

Cash, Cash Equivalents and Marketable Securities - Narrative (Details) - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Abstract]
Fair Value	$ 9,347,000	$ 34,413,000
Debt Securities, Available-for-Sale, Allowance for Credit Loss	$ 0	$ 0

Cash, Cash Equivalents and Ma_6

Cash, Cash Equivalents and Marketable Securities - Marketable Securities Classified by Contractual Maturities (Details) $ in Thousands	Jun. 30, 2023 USD ($)
Amortized Cost
Due within one year	$ 31,865
Due after one year through five years	28,644
Amortized Cost	60,509
Fair Value
Due within one year	31,536
Due after one year through five years	28,307
Fair Value	$ 59,843

Property and Equipment - Compon

Property and Equipment - Components of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 9,123	$ 9,315
Less accumulated depreciation and amortization	(6,712)	(6,256)
Property and equipment, net	2,411	3,059
Laboratory equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	5,738	5,914
Computer equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	1,214	1,230
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	710	710
Software
Property, Plant and Equipment [Line Items]
Total property and equipment	1,141	1,141
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 320	$ 320

Property and Equipment - Narrat

Property and Equipment - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 200	$ 200	$ 472	$ 350

Accrued and Other Current Lia_3

Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued compensation	$ 1,678	$ 2,290
Accrued vacation	433	430
Accrued 401(k) matching contributions	135	568
Operating lease liability, current portion	548	519
Other current liabilities	650	637
Total accrued and other current liabilities	$ 3,444	$ 4,444

Other Income, net (Details)

Other Income, net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Other Income and Expenses [Abstract]
Interest income	$ 337	$ 66	$ 593	$ 144
Investment income, net	595	178	1,119	196
Other income, net	$ 932	$ 244	$ 1,712	$ 340

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets that are Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Assets:
Marketable securities:	$ 59,843
Level 1 | Recurring
Assets:
Total assets	85	$ 2,618
Level 1 | Recurring | Commercial paper
Assets:
Marketable securities:	0	0
Level 1 | Recurring | Corporate debt securities
Assets:
Marketable securities:	0	0
Level 1 | Recurring | U.S. federal agency securities
Assets:
Marketable securities:	0	0
Level 1 | Recurring | U.S. government securities
Assets:
Marketable securities:	0	0
Level 1 | Recurring | Money market funds
Assets:
Cash equivalents:	85	2,618
Level 1 | Recurring | Commercial paper
Assets:
Cash equivalents:	0	0
Level 2 | Recurring
Assets:
Total assets	90,259	100,502
Level 2 | Recurring | Commercial paper
Assets:
Marketable securities:	9,222	15,155
Level 2 | Recurring | Corporate debt securities
Assets:
Marketable securities:	1,147	1,658
Level 2 | Recurring | U.S. federal agency securities
Assets:
Marketable securities:	29,022	38,211
Level 2 | Recurring | U.S. government securities
Assets:
Marketable securities:	20,452	19,131
Level 2 | Recurring | Money market funds
Assets:
Cash equivalents:	0	0
Level 2 | Recurring | Commercial paper
Assets:
Cash equivalents:	30,416	26,347
Level 3 | Recurring
Assets:
Total assets	0	0
Level 3 | Recurring | Commercial paper
Assets:
Marketable securities:	0	0
Level 3 | Recurring | Corporate debt securities
Assets:
Marketable securities:	0	0
Level 3 | Recurring | U.S. federal agency securities
Assets:
Marketable securities:	0	0
Level 3 | Recurring | U.S. government securities
Assets:
Marketable securities:	0	0
Level 3 | Recurring | Money market funds
Assets:
Cash equivalents:	0	0
Level 3 | Recurring | Commercial paper
Assets:
Cash equivalents:	$ 0	$ 0

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2021	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Related Party Transaction [Line Items]
Operating Expenses		$ 11,583	$ 11,824	$ 23,012	$ 24,162
Revenue		123	78	223	116
Master services agreement | Related Party | Healthcore Inc
Related Party Transaction [Line Items]
Operating Expenses		800	400	1,700	1,100
Laboratory Services Agreement | Related Party | Elevance Health, Inc
Related Party Transaction [Line Items]
Revenue		$ 14	$ 23	34	$ 42
Commercial Collaboration Agreement | Related Party | Elevance Health, Inc
Related Party Transaction [Line Items]
Term of agreement	3 years
Cash receipts				$ 6,000

Capital Structure - Narrative (

Capital Structure - Narrative (Details)	Jun. 30, 2023 vote common_stock_class
Class of Stock [Line Items]
Number of common stock classes authorized | common_stock_class	2
Common stock, conversion ratio	1
Class A common stock
Class of Stock [Line Items]
Number of votes per share | vote	1

Capital Structure - Common Stoc

Capital Structure - Common Stock (Details) - Class A common stock - shares	Jun. 30, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	15,029,626	13,729,552
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	240,832	0
Warrants to purchase Class A common stock
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	2,775,978	2,775,978
Options to purchase Class A common stock
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	8,062,442	8,428,441
Class A common stock available for future grants under the 2021 Equity Incentive Plan
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	3,114,097	1,926,356
Class A common stock available for future grants under the 2021 Employee Stock Purchase Plan
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	836,277	598,777

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - shares	1 Months Ended
	Jul. 31, 2021	Nov. 30, 2011	Jun. 30, 2023	Dec. 31, 2022
Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares)			15,029,626	13,729,552
2011 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
Expiration term		10 years
2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Expiration term	10 years
2021 Plan | Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares)			3,114,097
2021 ESPP | Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares)			836,277

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Options (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Number of Shares Subject to Options Outstanding
Outstanding at the beginning (in shares) | shares	8,428,441
Granted (in shares) | shares	991,866
Expired (in shares) | shares	0
Cancelled (in shares) | shares	(1,235,932)
Exercised (in shares) | shares	(121,933)
Outstanding at the end (in shares) | shares	8,062,442	8,428,441
Number of shares subject to options outstanding, vested and expected to vest at the end (in shares) | shares	7,828,850
Number of shares subject to options outstanding, vested and exercisable at the end | shares	5,411,736
Weighted- Average Exercise Price Per Share
Outstanding at the beginning (in usd per share) | $ / shares	$ 3.65
Granted (in usd per share) | $ / shares	3.49
Expired (in usd per share) | $ / shares	0
Cancelled (in usd per share) | $ / shares	4.06
Exercised (in usd per share) | $ / shares	1.49
Outstanding at the end (in usd per share) | $ / shares	3.60	$ 3.65
Weighted average exercise price per share, vested and expected to vest at the end (in usd per share) | $ / shares	3.58
Weighted average exercise price per share, vested and exercisable at the end (in usd per share) | $ / shares	$ 3.09
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual life, outstanding	7 years 4 months 24 days	7 years 8 months 12 days
Weighted average remaining contractual life, vested and expected to vest at the end	7 years 3 months 18 days
Weighted average remaining contractual life, vested and exercisable at the end	6 years 8 months 12 days
Aggregate intrinsic value, outstanding | $	$ 6,701	$ 115
Aggregate intrinsic value, vested and expected to vest at the end | $	6,659
Aggregate intrinsic value, vested and exercisable at the end | $	$ 6,070

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Units (Details) - Restricted Stock Units (RSUs)	6 Months Ended
	Jun. 30, 2023 $ / shares shares
Number of Awards
Outstanding, beginning balance (in shares) | shares	0
Granted (in shares) | shares	347,824
Forfeited (in shares) | shares	(106,992)
Vested (in shares) | shares	0
Outstanding, ending balance (in shares) | shares	240,832
Weighted-Average Grant Date Fair Value
Outstanding, beginning balance (in usd per share) | $ / shares	$ 0
Granted (in usd per share) | $ / shares	3.79
Forfeited (in usd per share) | $ / shares	3.75
Vested (in usd per share) | $ / shares	0
Outstanding, ending balance (in usd per share) | $ / shares	$ 3.80

Stock-Based Compensation - Expe

Stock-Based Compensation - Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total employee stock-based compensation	$ 1,440	$ 1,214	$ 2,744	$ 2,436
Research and development expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total employee stock-based compensation	382	451	732	834
Sales and marketing expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total employee stock-based compensation	294	76	477	389
General and administrative expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total employee stock-based compensation	$ 764	$ 687	$ 1,535	$ 1,213

Stock-Based Compensation - Unre

Stock-Based Compensation - Unrecognized Cost (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized stock-based compensation cost	$ 7,303
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 7,973
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	2 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount	$ 670
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	3 years 8 months 12 days

Warrants - Common Stock Warrant

Warrants - Common Stock Warrants Outstanding (Details) - $ / shares	Jun. 30, 2023	Dec. 31, 2022
Class of Warrant or Right [Line Items]
Number of warrants outstanding (in shares)	2,775,978	2,775,978
5.20
Class of Warrant or Right [Line Items]
Exercise price (in usd per share)	$ 5.20
Number of warrants outstanding (in shares)	3,473	3,473
9.03
Class of Warrant or Right [Line Items]
Exercise price (in usd per share)	$ 9.03
Number of warrants outstanding (in shares)	1,032,404	1,032,404
10.84
Class of Warrant or Right [Line Items]
Exercise price (in usd per share)	$ 10.84
Number of warrants outstanding (in shares)	1,009,795	1,009,795
12.38
Class of Warrant or Right [Line Items]
Exercise price (in usd per share)	$ 12.38
Number of warrants outstanding (in shares)	8,083	8,083
20.77
Class of Warrant or Right [Line Items]
Exercise price (in usd per share)	$ 20.77
Number of warrants outstanding (in shares)	722,223	722,223

Commitments and Contingences -

Commitments and Contingences - Leases in Financial Statement (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Right-of-use assets:
Operating leases	$ 1,448	$ 1,707
Finance leases	1,169	1,317
Total right-of-use assets	2,617	3,024
Lease liabilities:
Operating leases	548	519
Long-term portion	938	1,222
Finance lease obligation, current portion	446	464
Finance lease obligation, net of current portion	422	626
Total lease liabilities	$ 2,354	$ 2,831
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property and equipment, net	Property and equipment, net
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities and Other Liabilities	Accrued Liabilities and Other Liabilities

Commitments and Contingences _2

Commitments and Contingences - Lease Cost and Other Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Lease cost
Amortization of right-of-use assets	$ 83	$ 67	$ 166	$ 113
Interest on lease liabilities	14	18	30	22
Operating lease cost	159	116	318	233
Total lease cost	256	201	514	368
Finance leases:
Operating cash outflows	14	11	30	13
Financing cash outflows	120	67	240	85
Right-of-use assets obtained in exchange for lease liabilities	$ 18	$ 295	$ 18	$ 1,253
Weighted-average remaining lease term (in years)	1 year 9 months 18 days	2 years 8 months 12 days	1 year 9 months 18 days	2 years 8 months 12 days
Weighted-average discount rate	650%	640%	650%	640%
Operating leases:
Operating cash outflows	$ 157	$ 151	$ 314	$ 302
Right-of-use assets obtained in exchange for lease liabilities	$ 0	$ 0	$ 0	$ 453
Weighted-average remaining lease term (in years)	2 years 6 months	6 months	2 years 6 months	6 months
Weighted-average discount rate	750%	450%	750%	450%

Commitments and Contingences _3

Commitments and Contingences - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Operating Leases
2023	$ 314
2024	646
2025	666
Lease, Liability, to be Paid, Year Three	2
Finance Lease, Liability, to be Paid, Year Three	2
Lessee, Operating Lease, Liability, to be Paid, Year Three	0
2027 and thereafter	0
Total minimum lease payments	1,626
Less: imputed interest	(140)
Present value of future lease payments	1,486
Less: current portion	548	$ 519
Long-term portion	938	1,222
Finance Leases
2023	252
2024	469
2025	198
Total minimum lease payments	921
Less: imputed interest	(53)
Present value of future lease payments	868
Less: current portion	446	464
Long-term portion	422	626
Total
2023	566
2024	1,115
2025	864
2027 and thereafter	0
Total minimum lease payments	2,547
Less: imputed interest	(193)
Total lease liabilities	2,354	$ 2,831
Less: current portion	994
Long-term portion	1,360
2027 and thereafter	$ 0

Commitments and Contingences _4

Commitments and Contingences - Narrative (Details)	Jun. 30, 2023 USD ($) ft²	Dec. 31, 2022 USD ($)
Commitments And Contingencies [Line Items]
Indemnification liability | $	$ 0	$ 0
Office and laboratory space
Commitments And Contingencies [Line Items]
Number of square feet under lease | ft²	24,300

Net loss per share - Anti-Dilut

Net loss per share - Anti-Dilutive Securities Excluded from the Computation of Diluted Net Loss Per Share (Details) - shares	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of earnings per share (in shares)	11,079,252	11,531,627
Warrants to purchase Class A common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of earnings per share (in shares)	2,775,978	2,788,484
Options to purchase Class A common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of earnings per share (in shares)	8,062,442	8,743,143
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of earnings per share (in shares)	240,832	0