Sera Prognostics (SERA) 10-Q 6 Nov 24 2024 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2024	Nov. 01, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
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	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false
Class A common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		32,804,741
Class B common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		967,759

Condensed Balance Sheets (unaud

Condensed Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 2,684	$ 3,880
Marketable securities	47,068	45,199
Accounts receivable	79	160
Other receivables	0	11,310
Prepaid expenses and other current assets	1,276	795
Total current assets	51,107	61,344
Property and equipment, net	1,428	1,999
Long-term marketable securities	24,591	30,841
Other assets	1,875	1,257
Total assets	79,001	95,441
Current liabilities:
Accounts payable	1,378	1,046
Accrued and other current liabilities	2,273	2,722
Finance lease obligation, current portion	305	440
Deferred revenue	20,226	20,235
Total current liabilities	24,182	24,443
Finance lease obligation, net of current portion	3	196
Operating lease obligation, net of current portion	165	644
Total liabilities	24,350	25,283
Commitments and contingencies (Note 13)
Stockholders' equity:
Common stock, $0.0001 par value; 150,000,000 Class A shares authorized; 32,774,950 and 30,736,513 Class A shares issued and outstanding as of September 30, 2024 and December 31, 2023, respectively; 1,500,000 Class B shares authorized; 1,405,259 Class B shares issued as of September 30, 2024 and December 31, 2023; 967,759 Class B shares outstanding as of September 30, 2024 and December 31, 2023.	3	3
Additional paid-in capital	325,571	317,066
Accumulated other comprehensive income (loss)	292	(15)
Accumulated deficit	(271,215)	(246,896)
Total stockholders' equity	54,651	70,158
Total liabilities and stockholders' equity	$ 79,001	$ 95,441

Condensed Balance Sheets (una_2

Condensed Balance Sheets (unaudited) (Parenthetical) - $ / shares	Sep. 30, 2024	Dec. 31, 2023
Class A common stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	32,774,950	30,736,513
Common stock, shares outstanding	32,774,950	30,736,513
Class B common stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	1,500,000	1,500,000
Common stock, shares issued	1,405,259	1,405,259
Common stock, shares outstanding	967,759	967,759

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Revenue	$ 29	$ 42	$ 53	$ 265
Operating expenses:
Cost of revenue	13	44	50	186
Research and development	3,502	3,539	11,591	11,330
Selling and marketing	1,181	1,355	3,507	7,045
General and administrative	4,195	3,288	12,117	12,677
Total operating expenses	8,891	8,226	27,265	31,238
Loss from operations	(8,862)	(8,184)	(27,212)	(30,973)
Interest expense	(5)	(14)	(22)	(44)
Other income, net	948	988	2,915	2,700
Net loss	$ (7,919)	$ (7,210)	$ (24,319)	$ (28,317)
Net loss per share, basic	$ (0.24)	$ (0.23)	$ (0.74)	$ (0.91)
Net loss per share, diluted	$ (0.24)	$ (0.23)	$ (0.74)	$ (0.91)
Weighted-average shares outstanding, basic, basic	33,522,726	31,286,148	32,894,191	31,128,604
Weighted-average shares outstanding, basic, diluted	33,522,726	31,286,148	32,894,191	31,128,604
Other comprehensive income:
Unrealized gain on available-for-sale debt securities, net of tax	$ 503	$ 58	$ 307	$ 367
Total other comprehensive income	503	58	307	367
Comprehensive loss	$ (7,416)	$ (7,152)	$ (24,012)	$ (27,950)

Condensed Statements of Stockho

Condensed Statements of Stockholders' Equity (unaudited) - USD ($) $ in Thousands	Total	Common Stock (Class A and B)	Additional Paid-In Capital	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit
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)
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 income (loss)	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)
Other comprehensive income (loss)	367
Net loss	(28,317)
Balance at the ending (in shares) at Sep. 30, 2023		31,336,512
Balance at the ending at Sep. 30, 2023	75,411	$ 3	314,993	(614)	(238,971)
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)
Issuance of common stock upon exercise of stock options (in shares)		117,839
Issuance of common stock upon exercise of stock options	178		178
Issuance of common stock under employee stock purchase plan (in shares)		58,626
Issuance of common stock under employee stock purchase plan	66		66
Stock-based compensation expense	1,440		1,440
Other comprehensive income (loss)	(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)
Issuance of common stock upon exercise of stock options (in shares)		138,007
Issuance of common stock upon exercise of stock options	244		244
Stock-based compensation expense	1,182		1,182
Other comprehensive income (loss)	58			58
Net loss	(7,210)				(7,210)
Balance at the ending (in shares) at Sep. 30, 2023		31,336,512
Balance at the ending at Sep. 30, 2023	75,411	$ 3	314,993	(614)	(238,971)
Balance at the beginning (in shares) at Dec. 31, 2023		31,704,272
Balance at the beginning at Dec. 31, 2023	70,158	$ 3	317,066	(15)	(246,896)
Issuance of common stock upon exercise of stock options (in shares)		425,749
Issuance of common stock upon exercise of stock options	1,162		1,162
Issuance of restricted stock units (in shares)		431,152
Common stock warrant exercises (in shares)		6,168
Stock-based compensation expense	1,693		1,693
Other comprehensive income (loss)	(166)			(166)
Net loss	(8,097)				(8,097)
Balance at the ending (in shares) at Mar. 31, 2024		32,567,341
Balance at the ending at Mar. 31, 2024	64,750	$ 3	319,921	(181)	(254,993)
Balance at the beginning (in shares) at Dec. 31, 2023		31,704,272
Balance at the beginning at Dec. 31, 2023	$ 70,158	$ 3	317,066	(15)	(246,896)
Issuance of common stock upon exercise of stock options (in shares)	953,357
Common stock warrant exercises (in shares)	7,971
Other comprehensive income (loss)	$ 307
Net loss	(24,319)
Balance at the ending (in shares) at Sep. 30, 2024		33,742,709
Balance at the ending at Sep. 30, 2024	54,651	$ 3	325,571	292	(271,215)
Balance at the beginning (in shares) at Mar. 31, 2024		32,567,341
Balance at the beginning at Mar. 31, 2024	64,750	$ 3	319,921	(181)	(254,993)
Issuance of common stock upon exercise of stock options (in shares)		464,305
Issuance of common stock upon exercise of stock options	1,258		1,258
Issuance of restricted stock units (in shares)		287,729
Issuance of common stock under employee stock purchase plan (in shares)		32,669
Issuance of common stock under employee stock purchase plan	55		55
Common stock warrant exercises (in shares)		1,803
Stock-based compensation expense	2,023		2,023
Other comprehensive income (loss)	(30)			(30)
Net loss	(8,303)				(8,303)
Balance at the ending (in shares) at Jun. 30, 2024		33,353,847
Balance at the ending at Jun. 30, 2024	59,753	$ 3	323,257	(211)	(263,296)
Issuance of common stock upon exercise of stock options (in shares)		63,303
Issuance of common stock upon exercise of stock options	228		228
Issuance of restricted stock units (in shares)		271,732
Other issuance of common stock (in shares)		53,827
Other issuance of common stock	406		406
Stock-based compensation expense	1,680		1,680
Other comprehensive income (loss)	503			503
Net loss	(7,919)				(7,919)
Balance at the ending (in shares) at Sep. 30, 2024		33,742,709
Balance at the ending at Sep. 30, 2024	$ 54,651	$ 3	$ 325,571	$ 292	$ (271,215)

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities
Net loss	$ (24,319)	$ (28,317)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	622	688
Stock-based compensation	5,396	3,926
Non-cash lease expense	421	391
Non-cash investment income, net	(726)	(731)
Other	16	(7)
Changes in operating assets and liabilities:
Accounts receivable	81	(42)
Other receivables	11,310	6,000
Prepaid expenses and other assets	(272)	(44)
Accounts payable	73	(262)
Accrued and other current liabilities	(522)	(1,983)
Deferred revenue	(9)	(42)
Net cash used in operating activities	(7,929)	(20,423)
Cash flows from investing activities
Purchases of marketable securities	(30,336)	(49,248)
Proceeds from maturities and sales of marketable securities	35,734	49,113
Purchases of property and equipment	(48)	(112)
Proceeds from disposal of property and equipment	0	311
Purchases of intangible assets	(992)	0
Net cash provided by investing activities	4,358	64
Cash flows from financing activities
Proceeds from exercise of stock options	2,648	426
Proceeds from employee stock purchase plan	55	66
Finance lease principal payments	(328)	(356)
Net cash provided by financing activities	2,375	136
Net decrease in cash and cash equivalents	(1,196)	(20,223)
Cash and cash equivalents at beginning of period	3,880	29,878
Cash and cash equivalents at end of period	2,684	9,655
Supplemental disclosure of cash flow information
Cash paid for interest	22	44
Supplemental disclosure of non-cash investing and financing information
Issuance of stock to settle accrued and other current liabilities	406	0
Purchases of property and equipment in accounts payable and accrued and other current liabilities	$ 3	$ 0

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (7,919)	$ (8,303)	$ (8,097)	$ (7,210)	$ (10,542)	$ (10,565)	$ (24,319)	$ (28,317)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Rule 10b5-1 Arrangement Modified	false
Non-Rule 10b5-1 Arrangement Modified	false

Description of Business and Fin

Description of Business and Financial Condition	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Financial Condition	1. Description of Business and Financial Condition Sera Prognostics, Inc. (the “Company”) is a women’s health company utilizing its proprietary proteomics and bioinformatics platform, and significant data resources, to improve maternal and neonatal health by discovering, developing, and commercializing blood-based biomarker tests and predictive analytic products and services. 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 its testing and analytics products, primarily the PreTRM test. 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 $ 271.2 million as of September 30, 2024. 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. In August 2024, the Company filed a universal shelf registration on Form S-3 with the U.S. Securities and Exchange Commission (the “SEC”), which was declared effective on August 13, 2024 (the “2024 Form S-3”), pursuant to which the Company registered for sale up to $ 100.0 million of any combination of Class A common stock, preferred stock, debt securities, warrants, rights and/or units from time to time and at prices and on terms that the Company may determine. In August 2024, the Company entered into a sales agreement with TD Securities (USA) LLC (“TD Cowen”) with respect to an at-the-market offering program under which the Company may offer and sell, from time to time at the Company’s sole discretion, shares of Class A common stock having an aggregate offering price of up to $ 50.0 million (the “2024 Sales Agreement”). As of September 30, 2024 , the Company has no t sold any shares of Class A common stock under the 2024 Sales Agreement. 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, products and services; 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 September 30, 2024, the Company had aggregate cash, cash equivalents, and available-for-sale securities of $ 74.3 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	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Significant Accounting Policies	2 . 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 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, 2023. 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, 2023, 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, 2023 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 nine months ended September 30, 2024 are not necessarily indicative of the results to be expected for the full year ending December 31, 2024, or any other period. There have been no significant changes in the Company’s significant accounting policies during the nine months ended September 30, 2024, as compared with those disclosed in its Annual Report on Form 10-K for the year ended December 31, 2023 filed with the SEC on March 20, 2024. 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 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 nine months ended September 30, 2024 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. Recently Issued Accounting Pronouncements Not Yet Adopted In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures , which is intended to improve the transparency of income tax disclosures by requiring consistent categories and greater disaggregation of information in the effective tax rate reconciliation and income taxes paid by jurisdiction. The ASU is effective for public business entities’ annual periods beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the impact of adopting this guidance on its financial statements. In November 2023, the FASB issued ASU No. 2023-07, Improvements to Reportable Segments Disclosures. While ASU 2023-07 requires incremental disclosures, it does not change how an entity identifies its operating segments, aggregates those operating segments, or applies the quantitative thresholds to determine reportable segments. This ASU is effective for all public business entities for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Entities must adopt the changes to the segment reporting guidance on a retrospective basis. The Company is currently evaluating the impact of adopting this guidance on its financial statements. Early adoption is permitted; however, the Company is not early adopting the standard.

Cash, Cash Equivalents and Mark

Cash, Cash Equivalents and Marketable Securities	9 Months Ended
	Sep. 30, 2024
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Marketable Securities	3 . 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 September 30, 2024 and December 31, 2023 were as follows (in thousands): September 30, 2024 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and cash equivalents: Cash $ 1,225 $ — $ — $ 1,225 Money market funds 1,459 — — 1,459 Total cash and cash equivalents 2,684 — — 2,684 Current marketable securities: Commercial paper 1,982 — ( 1 ) 1,981 Corporate debt securities 21,201 127 ( 1 ) 21,327 U.S. federal agency securities 17,366 14 ( 7 ) 17,373 U.S. government securities 6,384 4 ( 1 ) 6,387 Total current marketable securities 46,933 145 ( 10 ) 47,068 Long-term marketable securities: Corporate debt securities 18,544 158 — 18,702 Municipal debt securities 3,034 8 — 3,042 U.S. federal agency securities 2,856 — ( 9 ) 2,847 Total long-term marketable securities 24,434 166 ( 9 ) 24,591 Total cash, cash equivalents and marketable securities $ 74,051 $ 311 $ ( 19 ) $ 74,343 December 31, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and cash equivalents: Cash $ 2,608 $ — $ — $ 2,608 Money market funds 1,272 — — 1,272 Total cash and cash equivalents 3,880 — — 3,880 Current marketable securities: Commercial paper 11,769 6 ( 2 ) 11,773 Corporate debt securities 1,155 — ( 2 ) 1,153 U.S. federal agency securities 19,644 — ( 102 ) 19,542 U.S. government securities 12,812 — ( 81 ) 12,731 Total current marketable securities 45,380 6 ( 187 ) 45,199 Long-term marketable securities: U.S. federal agency securities 9,406 27 ( 17 ) 9,416 U.S. government securities 4,388 3 ( 5 ) 4,386 Corporate debt securities 16,880 159 — 17,039 Total long-term marketable securities 30,674 189 ( 22 ) 30,841 Total cash, cash equivalents and marketable securities $ 79,934 $ 195 $ ( 209 ) $ 79,920 The following tables summarize the Company’s available-for-sale debt securities and cash equivalents with unrealized losses as of September 30, 2024 and December 31, 2023, aggregated by major security type and the length of time that individual securities have been in a continuous loss position (in thousands): September 30, 2024 Less than 12 months 12 months or greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Commercial paper $ 1,982 $ ( 1 ) $ — $ — $ 1,982 $ ( 1 ) Corporate debt securities — — 1,168 ( 1 ) 1,168 ( 1 ) U.S. federal agency securities 3,851 ( 10 ) 11,471 ( 6 ) 15,322 ( 16 ) U.S. government securities — — 1,896 ( 1 ) 1,896 ( 1 ) Total $ 5,833 $ ( 11 ) $ 14,535 $ ( 8 ) $ 20,368 $ ( 19 ) December 31, 2023 Less than 12 months 12 months or greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Commercial paper $ 5,453 $ ( 2 ) $ — $ — $ 5,453 $ ( 2 ) Corporate debt securities 1,153 ( 2 ) — — 1,153 ( 2 ) U.S. federal agency securities 15,308 ( 52 ) 8,751 ( 67 ) 24,059 ( 119 ) U.S. government securities 4,769 ( 13 ) 10,895 ( 73 ) 15,664 ( 86 ) Total $ 26,683 $ ( 69 ) $ 19,646 $ ( 140 ) $ 46,329 $ ( 209 ) As of September 30, 2024 and December 31, 2023 , the Company had no t 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 three years. During the nine months ended September 30, 2024 , the Company received approximately $ 5.0 million in proceeds from the sale of available-for-sale securities prior to maturity. There was an immaterial amount of gross realized losses on the sales. The Company sold the securities in order to reinvest the funds at improved rates. The Company’s marketable securities classified by contractual maturities as of September 30, 2024 were as follows (in thousands): Amortized Cost Fair Value Due within one year $ 46,933 $ 47,068 Due after one year through five years 24,434 24,591 Total $ 71,367 $ 71,659

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
Property and Equipment	4 . Property and Equipment The following table presents the components of property and equipment, net, as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Laboratory equipment $ 5,742 $ 5,734 Computer equipment 1,095 1,054 Leasehold improvements 772 772 Software 1,141 1,141 Furniture and fixtures 320 320 Total property and equipment 9,070 9,021 Less accumulated depreciation and amortization ( 7,642 ) ( 7,022 ) Property and equipment, net $ 1,428 $ 1,999 Depreciation and amortization expense was $ 0.2 million for each of the three months ended September 30, 2024 and 2023. Depreciation and amortization expense was $ 0.6 million and $ 0.7 million for the nine months ended September 30, 2024 and 2023 , respectively.

Other Assets

Other Assets	9 Months Ended
	Sep. 30, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets	5 . Other Assets The following table presents the components of other assets as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Operating right-of-use asset $ 759 $ 1,180 Intangible assets 992 — Other assets 124 77 Total other assets $ 1,875 $ 1,257 During the nine months ended September 30, 2024 , the Company acquired domain names resulting in capitalized intangible assets of approximately $ 0.7 million. The Company determined that the domain names have an indefinite useful life and are therefore not subject to amortization. The Company assesses its intangible assets for impairment annually, or more frequently if circumstances dictate. During the nine months ended September 30, 2024 , the Company capitalized approximately $ 0.3 million of costs associated with development of a software intangible asset. The Company will begin to amortize the software intangible asset when it is available for general release to customers.

Accrued and Other Current Liabi

Accrued and Other Current Liabilities	9 Months Ended
	Sep. 30, 2024
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued and Other Current Liabilities	6 . Accrued and Other Current Liabilities The following table presents the components of accrued and other current liabilities as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Accrued compensation $ 773 $ 779 Accrued vacation 486 365 Accrued 401(k) matching contributions — 74 Operating lease liability, current portion 627 578 Other current liabilities 387 926 Total accrued and other current liabilities $ 2,273 $ 2,722

Other Income, Net

Other Income, Net	9 Months Ended
	Sep. 30, 2024
Other Income and Expenses [Abstract]
Other Income, Net	7 . Other Income, Net The following table presents the components of other income, net, for the three and nine months ended September 30, 2024 and 2023 (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Interest income $ 733 $ 474 $ 2,074 $ 1,067 Investment income, net 215 514 841 1,633 Other income, net $ 948 $ 988 $ 2,915 $ 2,700

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	8 . Fair Value Measurements As of September 30, 2024 and December 31, 2023, 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, corporate debt securities, and municipal 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 September 30, 2024: Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 1,459 $ — $ — Marketable securities: Commercial paper — 1,981 — Corporate debt securities — 40,029 — Municipal debt securities — 3,042 — U.S. federal agency securities — 20,220 — U.S. government securities — 6,387 — Total assets $ 1,459 $ 71,659 $ — 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, 2023: Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 1,272 $ — $ — Marketable securities: Commercial paper — 11,773 — Corporate debt securities — 18,192 — U.S. federal agency securities — 28,958 — U.S. government securities — 17,117 — Total assets $ 1,272 $ 76,040 $ —

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2024
Related Party Transactions [Abstract]
Related Party Transactions	9 . 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 $ 0.9 million and $ 0.8 million for the three months ended September 30, 2024 and 2023, respectively, and $ 2.3 million and $ 2.5 million for the nine months ended September 30, 2024 and 2023, respectively, which were recorded in research and development expenses in the Company’s condensed statements of operations and comprehensive loss. 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. In December 2023, enrollment in the PRIME study was stopped due to efficacy, and as such, there was an immaterial amount of revenue recognized related to this agreement for the three and nine months ended September 30, 2024. The Company recognized revenue related to this agreement of $ 14 thousand and $ 48 thousand for the three and nine months ended September 30, 2023, 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 $ 11.2 million during the nine months ended September 30, 2024, which amount related to the minimum payments for the year ended December 31, 2023. 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 occur over the term of the agreement. All other items promised to Elevance Health are immaterial in the context of the Commercial Collaboration Agreement. There were no material revenues related to the Commercial Collaboration Agreement for the three and nine months ended September 30, 2024 and 2023 .

Capital Structure

Capital Structure	9 Months Ended
	Sep. 30, 2024
Stockholders' Equity Note [Abstract]
Capital Structure	10 . 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. In August 2024, the Company entered into the 2024 Sales Agreement for “at-the-market offerings” with TD Cowen, which allows the Company to issue and sell shares of Class A common stock pursuant to a shelf registration statement for total gross sales proceeds of up to $ 50.0 million from time to time through TD Cowen, acting as its agent. As of September 30, 2024 , the Company has no t sold any shares of Class A common stock under the 2024 Sales Agreement. The following shares of Class A common stock were reserved for future issuance: September 30, 2024 December 31, 2023 Warrants to purchase Class A common stock 2,646,247 2,775,978 Options to purchase Class A common stock 6,276,770 7,251,663 Restricted stock units outstanding 1,889,219 2,692,459 Class A common stock available for future grants under the 2021 Equity Incentive Plan 2,065,714 1,002,091 Class A common stock available for future grants under the 2021 Employee Stock Purchase Plan 1,076,364 801,668 Total 13,954,314 14,523,859

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	11 . 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 either a two-year or 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 September 30, 2024, there were 2,065,714 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 September 30, 2024, there were 1,076,364 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 Shares Subject to Options Outstanding Weighted-Average Exercise Price Per Share Weighted-Average Remaining Contractual Life (In Years) Aggregate Intrinsic Value (In Thousands) Outstanding – December 31, 2023 7,251,663 $ 3.66 6.9 $ 20,014 Granted 84,392 8.43 Expired — — Cancelled ( 105,928 ) 3.98 Exercised ( 953,357 ) 2.78 Outstanding – September 30, 2024 6,276,770 $ 3.85 6.5 $ 26,240 Vested and expected to vest at September 30, 2024 6,218,363 $ 3.84 6.5 $ 26,035 Vested and exercisable at September 30, 2024 5,319,830 $ 3.63 6.3 $ 23,357 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, 2023 2,692,459 $ 2.01 Granted 230,290 8.62 Forfeited ( 42,917 ) 2.05 Vested ( 990,613 ) 2.55 Outstanding – September 30, 2024 1,889,219 $ 2.54 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 Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Research and development expense $ 552 $ 397 $ 1,996 $ 1,129 Sales and marketing expense 106 106 283 583 General and administrative expense 1,022 679 3,117 2,214 Total employee stock-based compensation $ 1,680 $ 1,182 $ 5,396 $ 3,926 The information about unrecognized stock-based compensation expense for outstanding unvested stock options and RSUs as of September 30, 2024 was as follows (in thousands, except years): Unrecognized Stock-Based Compensation Expense Weighted-Average Period of Recognition (in years) Stock Options $ 2,770 1.1 RSUs 3,614 1.9 Total unrecognized stock-based compensation expense $ 6,384

Warrants

Warrants	9 Months Ended
	Sep. 30, 2024
Warrants and Rights Note Disclosure [Abstract]
Warrants	12 . 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 September 30, 2024 December 31, 2023 $ 5.20 — 3,473 9.03 969,275 1,032,404 10.84 946,666 1,009,795 12.38 8,083 8,083 20.77 722,223 722,223 2,646,247 2,775,978 During the nine months ended September 30, 2024 , 126,258 common stock warrants were net exercised, resulting in the issuance of 7,971 shares of Class A common stock. Additionally, 3,473 common stock warrants expired unexercised during the nine months ended September 30, 2024 .

Commitments and Contingences

Commitments and Contingences	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingences	13 . 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 September 30, 2024 and December 31, 2023 (in thousands): Lease-Related Assets and Liabilities Financial Statement Line Items September 30, 2024 December 31, 2023 Right-of-use assets: Operating leases Other assets $ 759 $ 1,180 Finance leases Property and equipment, net 777 1,008 Total right-of-use assets $ 1,536 $ 2,188 Lease liabilities: Operating leases Accrued and other current liabilities $ 627 $ 578 Operating lease obligation, net of current portion 165 644 Finance leases Finance lease obligation, current portion 305 440 Finance lease obligation, net of current portion 3 196 Total lease liabilities $ 1,100 $ 1,858 Lease costs and other information consisted of the following (in thousands, except terms and rates): Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Lease cost Finance lease cost: Amortization of right-of-use assets $ 78 $ 78 $ 235 $ 244 Interest on lease liabilities 6 14 22 44 Operating lease cost 159 159 477 477 Total lease cost $ 243 $ 251 $ 734 $ 765 Other information Finance leases: Operating cash outflows $ 6 $ 14 $ 22 $ 44 Financing cash outflows $ 111 $ 117 $ 328 $ 356 Right-of-use assets obtained in exchange for lease liabilities $ — $ — $ — $ 18 Weighted-average remaining lease term (in years) 0.6 1.6 0.6 1.6 Weighted-average discount rate 6.6 % 6.5 % 6.6 % 6.5 % Operating leases: Operating cash outflows $ 162 $ 157 $ 485 $ 471 Right-of-use assets obtained in exchange for lease liabilities $ — $ — $ — $ — Weighted-average remaining lease term (in years) 1.3 2.3 1.3 2.3 Weighted-average discount rate 7.5 % 7.5 % 7.5 % 7.5 % Future minimum lease payments for the Company’s leases as of September 30, 2024 were as follows (in thousands): Operating Leases Finance Leases Total 2024 $ 161 $ 116 $ 277 2025 666 197 863 2026 — 2 2 2027 and thereafter — — — Total minimum lease payments 827 315 1,142 Less: imputed interest ( 35 ) ( 7 ) ( 42 ) Present value of future lease payments 792 308 1,100 Less: current portion ( 627 ) ( 305 ) ( 932 ) Long-term portion $ 165 $ 3 $ 168 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 September 30, 2024 and December 31, 2023. 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	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Net loss per share	14 . 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 nine months ended September 30, 2024 and 2023, 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 nine months ended September 30, 2024 and 2023. 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: September 30, 2024 2023 Warrants to purchase Class A common stock 2,646,247 2,775,978 Options to purchase Class A common stock 6,276,770 7,740,767 Restricted stock units outstanding 1,889,219 238,896 Total 10,812,236 10,755,641

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
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 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, 2023. 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, 2023, 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, 2023 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 nine months ended September 30, 2024 are not necessarily indicative of the results to be expected for the full year ending December 31, 2024, or any other period. There have been no significant changes in the Company’s significant accounting policies during the nine months ended September 30, 2024, as compared with those disclosed in its Annual Report on Form 10-K for the year ended December 31, 2023 filed with the SEC on March 20, 2024. 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 nine months ended September 30, 2024 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.
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently Issued Accounting Pronouncements Not Yet Adopted In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures , which is intended to improve the transparency of income tax disclosures by requiring consistent categories and greater disaggregation of information in the effective tax rate reconciliation and income taxes paid by jurisdiction. The ASU is effective for public business entities’ annual periods beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the impact of adopting this guidance on its financial statements. In November 2023, the FASB issued ASU No. 2023-07, Improvements to Reportable Segments Disclosures. While ASU 2023-07 requires incremental disclosures, it does not change how an entity identifies its operating segments, aggregates those operating segments, or applies the quantitative thresholds to determine reportable segments. This ASU is effective for all public business entities for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Entities must adopt the changes to the segment reporting guidance on a retrospective basis. The Company is currently evaluating the impact of adopting this guidance on its financial statements. Early adoption is permitted; however, the Company is not early adopting the standard.

Cash, Cash Equivalents and Ma_2

Cash, Cash Equivalents and Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2024
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 September 30, 2024 and December 31, 2023 were as follows (in thousands): September 30, 2024 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and cash equivalents: Cash $ 1,225 $ — $ — $ 1,225 Money market funds 1,459 — — 1,459 Total cash and cash equivalents 2,684 — — 2,684 Current marketable securities: Commercial paper 1,982 — ( 1 ) 1,981 Corporate debt securities 21,201 127 ( 1 ) 21,327 U.S. federal agency securities 17,366 14 ( 7 ) 17,373 U.S. government securities 6,384 4 ( 1 ) 6,387 Total current marketable securities 46,933 145 ( 10 ) 47,068 Long-term marketable securities: Corporate debt securities 18,544 158 — 18,702 Municipal debt securities 3,034 8 — 3,042 U.S. federal agency securities 2,856 — ( 9 ) 2,847 Total long-term marketable securities 24,434 166 ( 9 ) 24,591 Total cash, cash equivalents and marketable securities $ 74,051 $ 311 $ ( 19 ) $ 74,343 December 31, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and cash equivalents: Cash $ 2,608 $ — $ — $ 2,608 Money market funds 1,272 — — 1,272 Total cash and cash equivalents 3,880 — — 3,880 Current marketable securities: Commercial paper 11,769 6 ( 2 ) 11,773 Corporate debt securities 1,155 — ( 2 ) 1,153 U.S. federal agency securities 19,644 — ( 102 ) 19,542 U.S. government securities 12,812 — ( 81 ) 12,731 Total current marketable securities 45,380 6 ( 187 ) 45,199 Long-term marketable securities: U.S. federal agency securities 9,406 27 ( 17 ) 9,416 U.S. government securities 4,388 3 ( 5 ) 4,386 Corporate debt securities 16,880 159 — 17,039 Total long-term marketable securities 30,674 189 ( 22 ) 30,841 Total cash, cash equivalents and marketable securities $ 79,934 $ 195 $ ( 209 ) $ 79,920
Schedule of Available-for-sale Debt 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 September 30, 2024 and December 31, 2023, aggregated by major security type and the length of time that individual securities have been in a continuous loss position (in thousands): September 30, 2024 Less than 12 months 12 months or greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Commercial paper $ 1,982 $ ( 1 ) $ — $ — $ 1,982 $ ( 1 ) Corporate debt securities — — 1,168 ( 1 ) 1,168 ( 1 ) U.S. federal agency securities 3,851 ( 10 ) 11,471 ( 6 ) 15,322 ( 16 ) U.S. government securities — — 1,896 ( 1 ) 1,896 ( 1 ) Total $ 5,833 $ ( 11 ) $ 14,535 $ ( 8 ) $ 20,368 $ ( 19 ) December 31, 2023 Less than 12 months 12 months or greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Commercial paper $ 5,453 $ ( 2 ) $ — $ — $ 5,453 $ ( 2 ) Corporate debt securities 1,153 ( 2 ) — — 1,153 ( 2 ) U.S. federal agency securities 15,308 ( 52 ) 8,751 ( 67 ) 24,059 ( 119 ) U.S. government securities 4,769 ( 13 ) 10,895 ( 73 ) 15,664 ( 86 ) Total $ 26,683 $ ( 69 ) $ 19,646 $ ( 140 ) $ 46,329 $ ( 209 )
Schedule of Marketable Securities Classified by Contractual Maturities	The Company’s marketable securities classified by contractual maturities as of September 30, 2024 were as follows (in thousands): Amortized Cost Fair Value Due within one year $ 46,933 $ 47,068 Due after one year through five years 24,434 24,591 Total $ 71,367 $ 71,659

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2024
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 September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Laboratory equipment $ 5,742 $ 5,734 Computer equipment 1,095 1,054 Leasehold improvements 772 772 Software 1,141 1,141 Furniture and fixtures 320 320 Total property and equipment 9,070 9,021 Less accumulated depreciation and amortization ( 7,642 ) ( 7,022 ) Property and equipment, net $ 1,428 $ 1,999

Other Assets (Tables)

Other Assets (Tables)	9 Months Ended
	Sep. 30, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Components of Other Assets	The following table presents the components of other assets as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Operating right-of-use asset $ 759 $ 1,180 Intangible assets 992 — Other assets 124 77 Total other assets $ 1,875 $ 1,257

Accrued and Other Current Lia_2

Accrued and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2024
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 September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Accrued compensation $ 773 $ 779 Accrued vacation 486 365 Accrued 401(k) matching contributions — 74 Operating lease liability, current portion 627 578 Other current liabilities 387 926 Total accrued and other current liabilities $ 2,273 $ 2,722

Other Income, Net (Tables)

Other Income, Net (Tables)	9 Months Ended
	Sep. 30, 2024
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 nine months ended September 30, 2024 and 2023 (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Interest income $ 733 $ 474 $ 2,074 $ 1,067 Investment income, net 215 514 841 1,633 Other income, net $ 948 $ 988 $ 2,915 $ 2,700

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2024
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 September 30, 2024: Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 1,459 $ — $ — Marketable securities: Commercial paper — 1,981 — Corporate debt securities — 40,029 — Municipal debt securities — 3,042 — U.S. federal agency securities — 20,220 — U.S. government securities — 6,387 — Total assets $ 1,459 $ 71,659 $ — 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, 2023: Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 1,272 $ — $ — Marketable securities: Commercial paper — 11,773 — Corporate debt securities — 18,192 — U.S. federal agency securities — 28,958 — U.S. government securities — 17,117 — Total assets $ 1,272 $ 76,040 $ —

Capital Structure (Tables)

Capital Structure (Tables)	9 Months Ended
	Sep. 30, 2024
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: September 30, 2024 December 31, 2023 Warrants to purchase Class A common stock 2,646,247 2,775,978 Options to purchase Class A common stock 6,276,770 7,251,663 Restricted stock units outstanding 1,889,219 2,692,459 Class A common stock available for future grants under the 2021 Equity Incentive Plan 2,065,714 1,002,091 Class A common stock available for future grants under the 2021 Employee Stock Purchase Plan 1,076,364 801,668 Total 13,954,314 14,523,859

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Summary of Options Granted and Outstanding	The following table summarizes information about these options granted and outstanding: Number of Shares Subject to Options Outstanding Weighted-Average Exercise Price Per Share Weighted-Average Remaining Contractual Life (In Years) Aggregate Intrinsic Value (In Thousands) Outstanding – December 31, 2023 7,251,663 $ 3.66 6.9 $ 20,014 Granted 84,392 8.43 Expired — — Cancelled ( 105,928 ) 3.98 Exercised ( 953,357 ) 2.78 Outstanding – September 30, 2024 6,276,770 $ 3.85 6.5 $ 26,240 Vested and expected to vest at September 30, 2024 6,218,363 $ 3.84 6.5 $ 26,035 Vested and exercisable at September 30, 2024 5,319,830 $ 3.63 6.3 $ 23,357
Summary of Information about RSUs Granted and Outstanding	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, 2023 2,692,459 $ 2.01 Granted 230,290 8.62 Forfeited ( 42,917 ) 2.05 Vested ( 990,613 ) 2.55 Outstanding – September 30, 2024 1,889,219 $ 2.54
Schedule of Impact of Stock-based Compensation Expense in 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 Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Research and development expense $ 552 $ 397 $ 1,996 $ 1,129 Sales and marketing expense 106 106 283 583 General and administrative expense 1,022 679 3,117 2,214 Total employee stock-based compensation $ 1,680 $ 1,182 $ 5,396 $ 3,926
Summary of Unrecognized Stock-based Compensation Expense for Outstanding Unvested Stock Options and RSUs	The information about unrecognized stock-based compensation expense for outstanding unvested stock options and RSUs as of September 30, 2024 was as follows (in thousands, except years): Unrecognized Stock-Based Compensation Expense Weighted-Average Period of Recognition (in years) Stock Options $ 2,770 1.1 RSUs 3,614 1.9 Total unrecognized stock-based compensation expense $ 6,384

Warrants (Tables)

Warrants (Tables)	9 Months Ended
	Sep. 30, 2024
Warrants and Rights Note Disclosure [Abstract]
Schedule of Common Stock Warrants Outstanding	The Company’s common stock warrants outstanding were as follows: Number of Warrants Outstanding as of: Exercise Price September 30, 2024 December 31, 2023 $ 5.20 — 3,473 9.03 969,275 1,032,404 10.84 946,666 1,009,795 12.38 8,083 8,083 20.77 722,223 722,223 2,646,247 2,775,978

Commitment and Contingencies (T

Commitment and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2024
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 September 30, 2024 and December 31, 2023 (in thousands): Lease-Related Assets and Liabilities Financial Statement Line Items September 30, 2024 December 31, 2023 Right-of-use assets: Operating leases Other assets $ 759 $ 1,180 Finance leases Property and equipment, net 777 1,008 Total right-of-use assets $ 1,536 $ 2,188 Lease liabilities: Operating leases Accrued and other current liabilities $ 627 $ 578 Operating lease obligation, net of current portion 165 644 Finance leases Finance lease obligation, current portion 305 440 Finance lease obligation, net of current portion 3 196 Total lease liabilities $ 1,100 $ 1,858
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 Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Lease cost Finance lease cost: Amortization of right-of-use assets $ 78 $ 78 $ 235 $ 244 Interest on lease liabilities 6 14 22 44 Operating lease cost 159 159 477 477 Total lease cost $ 243 $ 251 $ 734 $ 765 Other information Finance leases: Operating cash outflows $ 6 $ 14 $ 22 $ 44 Financing cash outflows $ 111 $ 117 $ 328 $ 356 Right-of-use assets obtained in exchange for lease liabilities $ — $ — $ — $ 18 Weighted-average remaining lease term (in years) 0.6 1.6 0.6 1.6 Weighted-average discount rate 6.6 % 6.5 % 6.6 % 6.5 % Operating leases: Operating cash outflows $ 162 $ 157 $ 485 $ 471 Right-of-use assets obtained in exchange for lease liabilities $ — $ — $ — $ — Weighted-average remaining lease term (in years) 1.3 2.3 1.3 2.3 Weighted-average discount rate 7.5 % 7.5 % 7.5 % 7.5 %
Schedule of Future Minimum Lease Payments	Future minimum lease payments for the Company’s leases as of September 30, 2024 were as follows (in thousands): Operating Leases Finance Leases Total 2024 $ 161 $ 116 $ 277 2025 666 197 863 2026 — 2 2 2027 and thereafter — — — Total minimum lease payments 827 315 1,142 Less: imputed interest ( 35 ) ( 7 ) ( 42 ) Present value of future lease payments 792 308 1,100 Less: current portion ( 627 ) ( 305 ) ( 932 ) Long-term portion $ 165 $ 3 $ 168

Net loss per share (Tables)

Net loss per share (Tables)	9 Months Ended
	Sep. 30, 2024
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: September 30, 2024 2023 Warrants to purchase Class A common stock 2,646,247 2,775,978 Options to purchase Class A common stock 6,276,770 7,740,767 Restricted stock units outstanding 1,889,219 238,896 Total 10,812,236 10,755,641

Description of Business and F_2

Description of Business and Financial Condition - Additional Information (Details) - USD ($)	1 Months Ended
	Aug. 31, 2024	Sep. 30, 2024	Dec. 31, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Accumulated deficit		$ (271,215,000)	$ (246,896,000)
Total cash, cash equivalents and marketable securities, Fair Value		$ 74,343,000	$ 79,920,000
Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Amount from sale of combination of securities under shelf registration	$ 100,000,000
Class A common stock
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock, shares issued		32,774,950	30,736,513
2024 Sales Agreement | TD Cowen | At-the-Market Offering | Class A common stock
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock, shares issued		0
2024 Sales Agreement | TD Cowen | At-the-Market Offering | Class A common stock | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Aggregate offering price from sale of common stock	$ 50,000,000

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	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Amortized Cost	$ 71,367
Marketable securities, Fair Value	71,659
Total cash, cash equivalents and marketable securities, Amortized Cost	74,051	$ 79,934
Total cash, cash equivalents and marketable securities, Gross Unrealized Gains	311	195
Total cash, cash equivalents and marketable securities, Gross Unrealized Losses	(19)	(209)
Total cash, cash equivalents and marketable securities, Fair Value	74,343	79,920
Cash and cash equivalents:
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents, Amortized Cost	2,684	3,880
Cash and cash equivalents, Gross Unrealized Gains	0	0
Cash and cash equivalents, Gross Unrealized Losses	0	0
Cash and cash equivalents, Fair Value	2,684	3,880
Cash and cash equivalents: | Cash
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents, Amortized Cost	1,225	2,608
Cash and cash equivalents, Gross Unrealized Gains	0	0
Cash and cash equivalents, Gross Unrealized Losses	0	0
Cash and cash equivalents, Fair Value	1,225	2,608
Cash and cash equivalents: | Money market funds
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents, Amortized Cost	1,459	1,272
Cash and cash equivalents, Gross Unrealized Gains	0	0
Cash and cash equivalents, Gross Unrealized Losses	0	0
Cash and cash equivalents, Fair Value	1,459	1,272
Current marketable securities:
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Amortized Cost	46,933	45,380
Marketable securities, Gross Unrealized Gains	145	6
Marketable securities, Gross Unrealized Losses	(10)	(187)
Marketable securities, Fair Value	47,068	45,199
Current marketable securities: | Commercial paper
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Amortized Cost	1,982	11,769
Marketable securities, Gross Unrealized Gains	0	6
Marketable securities, Gross Unrealized Losses	(1)	(2)
Marketable securities, Fair Value	1,981	11,773
Current marketable securities: | Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Amortized Cost	21,201	1,155
Marketable securities, Gross Unrealized Gains	127	0
Marketable securities, Gross Unrealized Losses	(1)	(2)
Marketable securities, Fair Value	21,327	1,153
Current marketable securities: | U.S. federal agency securities
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Amortized Cost	17,366	19,644
Marketable securities, Gross Unrealized Gains	14	0
Marketable securities, Gross Unrealized Losses	(7)	(102)
Marketable securities, Fair Value	17,373	19,542
Current marketable securities: | U.S. government securities
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Amortized Cost	6,384	12,812
Marketable securities, Gross Unrealized Gains	4	0
Marketable securities, Gross Unrealized Losses	(1)	(81)
Marketable securities, Fair Value	6,387	12,731
Long-term marketable securities:
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Amortized Cost	24,434	30,674
Marketable securities, Gross Unrealized Gains	166	189
Marketable securities, Gross Unrealized Losses	(9)	(22)
Marketable securities, Fair Value	24,591	30,841
Long-term marketable securities: | Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Amortized Cost	18,544	16,880
Marketable securities, Gross Unrealized Gains	158	159
Marketable securities, Gross Unrealized Losses	0	0
Marketable securities, Fair Value	18,702	17,039
Long-term marketable securities: | Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Amortized Cost	3,034
Marketable securities, Gross Unrealized Gains	8
Marketable securities, Gross Unrealized Losses	0
Marketable securities, Fair Value	3,042
Long-term marketable securities: | U.S. federal agency securities
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Amortized Cost	2,856	9,406
Marketable securities, Gross Unrealized Gains	0	27
Marketable securities, Gross Unrealized Losses	(9)	(17)
Marketable securities, Fair Value	$ 2,847	9,416
Long-term marketable securities: | U.S. government securities
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Amortized Cost		4,388
Marketable securities, Gross Unrealized Gains		3
Marketable securities, Gross Unrealized Losses		(5)
Marketable securities, Fair Value		$ 4,386

Cash, Cash Equivalents and Ma_4

Cash, Cash Equivalents and Marketable Securities - Available-for-sale Debt Securities and Cash Equivalents in Unrealized Loss Positions (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Fair Value	$ 5,833	$ 26,683
Less than 12 months, Unrealized Losses	(11)	(69)
12 months or greater, Fair Value	14,535	19,646
12 months or greater, Unrealized Losses	(8)	(140)
Total, Fair Value	20,368	46,329
Total, Unrealized Losses	(19)	(209)
Commercial paper
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Fair Value	1,982	5,453
Less than 12 months, Unrealized Losses	(1)	(2)
12 months or greater, Fair Value	0	0
12 months or greater, Unrealized Losses	0	0
Total, Fair Value	1,982	5,453
Total, Unrealized Losses	(1)	(2)
Corporate debt securities
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Fair Value	0	1,153
Less than 12 months, Unrealized Losses	0	(2)
12 months or greater, Fair Value	1,168	0
12 months or greater, Unrealized Losses	(1)	0
Total, Fair Value	1,168	1,153
Total, Unrealized Losses	(1)	(2)
U.S. federal agency securities
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Fair Value	3,851	15,308
Less than 12 months, Unrealized Losses	(10)	(52)
12 months or greater, Fair Value	11,471	8,751
12 months or greater, Unrealized Losses	(6)	(67)
Total, Fair Value	15,322	24,059
Total, Unrealized Losses	(16)	(119)
U.S. government securities
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 months, Fair Value	0	4,769
Less than 12 months, Unrealized Losses	0	(13)
12 months or greater, Fair Value	1,896	10,895
12 months or greater, Unrealized Losses	(1)	(73)
Total, Fair Value	1,896	15,664
Total, Unrealized Losses	$ (1)	$ (86)

Cash, Cash Equivalents and Ma_5

Cash, Cash Equivalents and Marketable Securities - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Cash and Cash Equivalents [Abstract]
Debt Securities, Available-for-Sale, Allowance for Credit Loss	$ 0	$ 0
Proceeds from the sale of available-for-sale securities prior to maturity	$ 5,000,000

Cash, Cash Equivalents and Ma_6

Cash, Cash Equivalents and Marketable Securities - Marketable Securities Classified by Contractual Maturities (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Amortized Cost
Due within one year	$ 46,933
Due after one year through five years	24,434
Marketable securities, Amortized Cost	71,367
Fair Value
Due within one year	47,068
Due after one year through five years	24,591
Fair Value	$ 71,659

Property and Equipment - Compon

Property and Equipment - Components of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 9,070	$ 9,021
Less accumulated depreciation and amortization	(7,642)	(7,022)
Property and equipment, net	1,428	1,999
Laboratory equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	5,742	5,734
Computer equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	1,095	1,054
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	772	772
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 - Additi

Property and Equipment - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 200	$ 200	$ 622	$ 688

Other Assets - Schedule of Comp

Other Assets - Schedule of Components of Other Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Operating right-of-use asset	$ 759	$ 1,180
Intangible assets	992	0
Other assets	124	77
Total other assets	$ 1,875	$ 1,257

Other Assets - Additional Infor

Other Assets - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Capitalized intangible assets acquired	$ 992	$ 0
Indefinite-Lived Intangible Assets (Excluding Goodwill)	700
Capitalized costs asociated with development of software intagible asset	$ 300

Accrued and Other Current Lia_3

Accrued and Other Current Liabilities - Schedule of Components of Accrued and Other Current Liabilities (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued compensation	$ 773,000	$ 779,000
Accrued vacation	486,000	365,000
Accrued 401(k) matching contributions	0	74,000
Operating lease liability, current portion	627,000	578,000
Other current liabilities	387,000	926,000
Total accrued and other current liabilities	$ 2,273,000	$ 2,722,000

Other Income, Net - Schedule of

Other Income, Net - Schedule of Components of Other Income, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Other Income and Expenses [Abstract]
Interest income	$ 733	$ 474	$ 2,074	$ 1,067
Investment income, net	215	514	841	1,633
Other income, net	$ 948	$ 988	$ 2,915	$ 2,700

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets that are Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Assets:
Marketable securities:	$ 71,659
Level 1 | Recurring
Assets:
Total assets	1,459	$ 1,272
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 | Municipal Bonds
Assets:
Marketable securities:	0
Level 1 | Recurring | Money market funds
Assets:
Cash equivalents:	1,459	1,272
Level 2 | Recurring
Assets:
Total assets	71,659	76,040
Level 2 | Recurring | Commercial paper
Assets:
Marketable securities:	1,981	11,773
Level 2 | Recurring | Corporate debt securities
Assets:
Marketable securities:	40,029	18,192
Level 2 | Recurring | U.S. federal agency securities
Assets:
Marketable securities:	20,220	28,958
Level 2 | Recurring | U.S. government securities
Assets:
Marketable securities:	6,387	17,117
Level 2 | Recurring | Municipal Bonds
Assets:
Marketable securities:	3,042
Level 2 | Recurring | Money market funds
Assets:
Cash equivalents:	0	0
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 | Municipal Bonds
Assets:
Marketable securities:	0
Level 3 | Recurring | Money market funds
Assets:
Cash equivalents:	$ 0	$ 0

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Feb. 28, 2021	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Related Party Transaction [Line Items]
Operating Expenses		$ 8,891	$ 8,226	$ 27,265	$ 31,238
Revenue		29	42	53	265
Master services agreement | Healthcore Inc | Investor
Related Party Transaction [Line Items]
Operating Expenses		$ 900	800	2,300	2,500
Laboratory Services Agreement | Elevance Health, Inc | Investor
Related Party Transaction [Line Items]
Revenue			$ 14		$ 48
Commercial Collaboration Agreement | Elevance Health, Inc | Investor
Related Party Transaction [Line Items]
Term of agreement	3 years
Cash receipts				$ 11,200

Capital Structure - Additional

Capital Structure - Additional Information (Details)	1 Months Ended
	Aug. 31, 2024 USD ($)	Sep. 30, 2024 Vote CommonStockClass shares	Dec. 31, 2023 shares
Class of Stock [Line Items]
Number of common stock classes authorized | CommonStockClass		2
Common stock, conversion ratio		1
Class A common stock
Class of Stock [Line Items]
Number of votes per share | Vote		1
Common stock, shares issued		32,774,950	30,736,513
Class A common stock | 2024 Sales Agreement | TD Cowen | At-the-Market Offering
Class of Stock [Line Items]
Common stock, shares issued		0
Class A common stock | 2024 Sales Agreement | TD Cowen | At-the-Market Offering | Maximum
Class of Stock [Line Items]
Gross sales proceeds from issuance of common stock | $	$ 50,000,000
Class B common stock
Class of Stock [Line Items]
Common stock, shares issued		1,405,259	1,405,259

Capital Structure - Schedule of

Capital Structure - Schedule of Common Stock Reserved for Future Issuance (Details) - Class A common stock - shares	Sep. 30, 2024	Dec. 31, 2023
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	13,954,314	14,523,859
Warrants to purchase Class A common stock
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	2,646,247	2,775,978
Options to purchase Class A common stock
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	6,276,770	7,251,663
Restricted stock units outstanding
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	1,889,219	2,692,459
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)	2,065,714	1,002,091
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)	1,076,364	801,668

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - shares	1 Months Ended
	Nov. 30, 2021	Jul. 31, 2021	Sep. 30, 2024	Dec. 31, 2023
Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares)			13,954,314	14,523,859
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 | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
2021 Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		2 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)			2,065,714
2021 ESPP | Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares)			1,076,364

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Options Granted and Outstanding (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares
Number of Shares Subject to Options Outstanding
Outstanding at the beginning (in shares) | shares	7,251,663
Granted (in shares) | shares	84,392
Expired (in shares) | shares	0
Cancelled (in shares) | shares	(105,928)
Exercised (in shares) | shares	(953,357)
Outstanding at the end (in shares) | shares	6,276,770	7,251,663
Number of shares subject to options outstanding, vested and expected to vest at the end (in shares) | shares	6,218,363
Number of shares subject to options outstanding, vested and exercisable at the end | shares	5,319,830
Weighted- Average Exercise Price Per Share
Outstanding at the beginning (in usd per share) | $ / shares	$ 3.66
Granted (in usd per share) | $ / shares	8.43
Expired (in usd per share) | $ / shares	0
Cancelled (in usd per share) | $ / shares	3.98
Exercised (in usd per share) | $ / shares	2.78
Outstanding at the end (in usd per share) | $ / shares	3.85	$ 3.66
Weighted average exercise price per share, vested and expected to vest at the end (in usd per share) | $ / shares	3.84
Weighted average exercise price per share, vested and exercisable at the end (in usd per share) | $ / shares	$ 3.63
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual life, outstanding	6 years 6 months	6 years 10 months 24 days
Weighted average remaining contractual life, vested and expected to vest at the end	6 years 6 months
Weighted average remaining contractual life, vested and exercisable at the end	6 years 3 months 18 days
Aggregate intrinsic value, outstanding | $	$ 26,240	$ 20,014
Aggregate intrinsic value, vested and expected to vest at the end | $	26,035
Aggregate intrinsic value, vested and exercisable at the end | $	$ 23,357

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Information about RSUs Granted and Outstanding (Details) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2024 $ / shares shares
Number of Awards
Outstanding, beginning balance (in shares) | shares	2,692,459
Granted (in shares) | shares	230,290
Forfeited (in shares) | shares	(42,917)
Vested (in shares) | shares	(990,613)
Outstanding, ending balance (in shares) | shares	1,889,219
Weighted-Average Grant Date Fair Value
Outstanding, beginning balance (in usd per share) | $ / shares	$ 2.01
Granted (in usd per share) | $ / shares	8.62
Forfeited (in usd per share) | $ / shares	2.05
Vested (in usd per share) | $ / shares	2.55
Outstanding, ending balance (in usd per share) | $ / shares	$ 2.54

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Impact of Stock-based Compensation Expense in Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total employee stock-based compensation	$ 1,680	$ 1,182	$ 5,396	$ 3,926
Research and development expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total employee stock-based compensation	552	397	1,996	1,129
Sales and marketing expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total employee stock-based compensation	106	106	283	583
General and administrative expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total employee stock-based compensation	$ 1,022	$ 679	$ 3,117	$ 2,214

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Unrecognized Stock-based Compensation Expense for Outstanding Unvested Stock Options and RSUs (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized stock-based compensation cost	$ 2,770
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 6,384
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 1 month 6 days
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	$ 3,614
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 10 months 24 days

Warrants - Schedule of Common S

Warrants - Schedule of Common Stock Warrants Outstanding (Details) - $ / shares	Sep. 30, 2024	Dec. 31, 2023
Class of Warrant or Right [Line Items]
Number of warrants outstanding (in shares)	2,646,247	2,775,978
5.20
Class of Warrant or Right [Line Items]
Exercise price (in usd per share)	$ 5.2
Number of warrants outstanding (in shares)	0	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)	969,275	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)	946,666	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

Warrants - Additional Informati

Warrants - Additional Information (Details)	9 Months Ended
	Sep. 30, 2024 shares
Class of Warrant or Right [Line Items]
Class of warrant or right, exercised	(126,258)
Common stock warrants exercised (in shares)	7,971
Common stock warrants expired (in shares)	3,473

Commitments and Contingences -

Commitments and Contingences - Schedule of Leases in Financial Statement (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Right-of-use assets:
Operating leases	$ 759	$ 1,180
Finance leases	777	1,008
Total right-of-use assets	1,536	2,188
Lease liabilities:
Operating leases	627	578
Long-term portion	165	644
Finance lease obligation, current portion	305	440
Finance lease obligation, net of current portion	3	196
Total lease liabilities	$ 1,100	$ 1,858
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 - Schedule of Lease Cost and Other Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Lease cost
Amortization of right-of-use assets	$ 78	$ 78	$ 235	$ 244
Interest on lease liabilities	6	14	22	44
Operating lease cost	159	159	477	477
Total lease cost	243	251	734	765
Finance leases:
Operating cash outflows	6	14	22	44
Financing cash outflows	111	117	328	356
Right-of-use assets obtained in exchange for lease liabilities	$ 0	$ 0	$ 0	$ 18
Weighted-average remaining lease term (in years)	7 months 6 days	1 year 7 months 6 days	7 months 6 days	1 year 7 months 6 days
Weighted-average discount rate	6.60%	6.50%	6.60%	6.50%
Operating leases:
Operating cash outflows	$ 162	$ 157	$ 485	$ 471
Right-of-use assets obtained in exchange for lease liabilities	$ 0	$ 0	$ 0	$ 0
Weighted-average remaining lease term (in years)	1 year 3 months 18 days	2 years 3 months 18 days	1 year 3 months 18 days	2 years 3 months 18 days
Weighted-average discount rate	7.50%	7.50%	7.50%	7.50%

Commitments and Contingences _3

Commitments and Contingences - Schedule of Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Operating Leases
2024	$ 161
2025	666
2026	0
Total minimum lease payments	827
Less: imputed interest	(35)
Present value of future lease payments	792
Less: current portion	(627)	$ (578)
Long-term portion	165	644
Finance Leases
2024	116
2025	197
2026	2
Total minimum lease payments	315
Less: imputed interest	(7)
Present value of future lease payments	308
Less: current portion	(305)	(440)
Long-term portion	3	196
Total
2024	277
2025	863
2026	2
Total minimum lease payments	1,142
Less: imputed interest	(42)
Total lease liabilities	1,100	$ 1,858
Less: current portion	(932)
Long-term portion	168
2028	0
2028	0
2028	$ 0

Commitments and Contingences _4

Commitments and Contingences - Additional Information (Details)	Sep. 30, 2024 USD ($) ft²	Dec. 31, 2023 USD ($)
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	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of earnings per share (in shares)	10,812,236	10,755,641
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)	2,646,247	2,775,978
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)	6,276,770	7,740,767
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)	1,889,219	238,896