0000950170-22-024531 | 10-Q | XBRL Viewer

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Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Accrued interest on investments	$ 100	$ 100
Estimated fair value of term loan	4,900	$ 5,000
Debt securities, available-for-sale, realized gain (loss)	0
Debt securities, available-for-sale, Continuous unrealized loss position, 12 months or longer	0
Debt securities, available-for-sale, realized gain (loss), excluding other-than-temporary impairment	$ 0
Cash equivalents and short term investments due term	1 year

Net Loss Per Share - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator:
Net loss	$ (11,401)	$ (11,447)	$ (35,036)	$ (33,108)
Denominator:
Weighted-average shares of common stock outstanding, basic	23,560,250	23,367,140	23,515,651	23,330,399
Weighted-average shares of common stock outstanding, diluted	23,560,250	23,367,140	23,515,651	23,330,399
Net loss per share, basic	$ (0.48)	$ (0.49)	$ (1.49)	$ (1.42)
Net loss per share, diluted	$ (0.48)	$ (0.49)	$ (1.49)	$ (1.42)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

CONDENSED BALANCE SHEETS (Parenthetical) (Unaudited) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred Stock, Par Value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	23,560,250	23,491,881
Common stock, shares outstanding	23,560,250	23,491,881

Balance Sheet Components (Tables)

9 Months Ended

Sep. 30, 2022

Balance Sheet Related Disclosures [Abstract]

Schedule of Accrued Expenses and Other Current Liabilities

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


	September 30, 2022		December 31, 2021
Accrued research and development expenses	$	6,722	$	3,837
Accrued compensation and benefits		993		1,435
Accrued general and administrative expenses		499		416
Lease liabilities, current portion		390		360
Total accrued expenses and other current liabilities	$	8,604	$	6,048

Equity Incentive Plans and Stock-Based Compensation Expense - Summary of RSU Activity (Details) - RSU	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares, Unvested, Beginning Balance \| shares	460,000
Shares, Granted \| shares	92,200
Shares, Vested \| shares	(64,347)
Shares, Forfeited \| shares	(151,288)
Shares, Unvested, Ending Balance \| shares	336,565
Weighted Average Grant Date Fair Value Per Share, Beginning Balance \| $ / shares	$ 2.48
Weighted Average Grant Date Fair Value Per Share, Granted \| $ / shares	2.58
Weighted Average Grant Date Fair Value Per Share, Vested \| $ / shares	2.49
Weighted Average Grant Date Fair Value Per Share, Forfeited \| $ / shares	2.51
Weighted Average Grant Date Fair Value Per Share, Ending Balance \| $ / shares	$ 2.49

Term Loan - Future Payments of Principal and Interest (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
2022 (remaining 3 months)	$ 82
2023	1,913
2024	1,802
2025	1,691
2026	135
Total	5,623
Total interest under term loan	(624)
Term Loan, gross	5,000
Less: unamortized debt issuance costs	(99)
Less: Term Loan, current portion	(1,216)	$ 0
Term loan, net of current portion	$ 3,685	$ 4,878

Equity Incentive Plans and Stock-Based Compensation Expense

9 Months Ended

Sep. 30, 2022

Share-Based Payment Arrangement [Abstract]

Equity Incentive Plans and Stock-Based Compensation Expense

9. Stock-Based Compensation Expense

Equity Incentive Plans

The Company adopted the 2020 Equity Incentive Plan (the 2020 Plan) in October 2020. The 2020 Plan is a successor to and continuation of the Amended and Restated 2016 Equity Incentive Plan (the 2016 Plan) and provides for the granting of stock options, stock appreciation rights, restricted stock, restricted stock units, and other stock or cash-based awards to individuals who are then employees, officers, directors or consultants. The number of shares of common stock available for issuance under the 2020 Plan will be automatically increased on the first day of each calendar year during the ten-year term of the 2020 Plan, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to 5% of the outstanding number of shares of the Company’s common stock on December 31st of the preceding calendar year or such lesser amount as determined by the Company’s Board of Directors. No further grants will be made under the 2016 Plan; however, shares subject to awards granted under the 2016 Plan will continue to be governed by the 2016 Plan.

Under the 2020 Plan and the 2016 Plan, individuals can be granted the ability to early exercise their options. There were no shares, related to the early exercise of options, subject to repurchase by the Company as of September 30, 2022. As of September 30, 2022, 2,466,502 shares remained available for issuance under the 2020 Plan and no shares remained available for issuance under the 2016 Plan.

A summary of the Company’s stock option activity and related information is as follows (in thousands, except share and per share amounts):


	Outstanding Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value (in thousands)
Balance as of December 31, 2021		2,215,942		$	4.72		6.9	$	3,959
Granted		2,678,625		$	2.95
Exercised		(992	)	$	1.39
Forfeited		(512,907	)	$	6.71
Balance as of September 30, 2022		4,380,668		$	3.40		7.8	$	118
Vested and expected to vest as of September 30, 2022		4,240,668		$	3.36		7.7	$	118
Vested and exercisable as of September 30, 2022		1,475,250		$	3.55		4.9	$	109

Stock options vested and expected to vest differs from total stock options outstanding as it excludes performance-based stock options for which the performance criteria have not been achieved and achievement is not expected as of September 30, 2022.

The aggregate intrinsic values of options outstanding and exercisable were calculated as the difference between the exercise price of the options and the estimated fair value of the Company’s common stock as of the respective balance sheet date. The total intrinsic value of options exercised was nominal for the nine months ended September 30, 2022. There were no options exercised during the three months ended September 30, 2022.

For the nine months ended September 30, 2022, the weighted-average fair value of options granted was $2.34 per share.

Restricted Stock Units (RSUs)

A summary of the Company’s RSU activity and related information is as follows:


	Number of RSUs			Weight-Average Grant Date Fair Value
Balance as of December 31, 2021		460,000		$	2.48
Granted		92,200			2.58
Vested		(64,347	)		2.49
Forfeited		(151,288	)		2.51
Balance as of September 30, 2022		336,565		$	2.49

During the nine months ended September 30, 2022, the Company granted 92,200 RSUs, including 68,775 RSUs subject to time-based vesting in installments through September 30, 2023, and 23,425 RSUs subject to performance-based vesting conditions related to the satisfaction of certain clinical development milestones.

Employee Stock Purchase Plan

The Board of Directors adopted and the Company’s stockholders approved the 2020 Employee Stock Purchase Plan (the ESPP) in October 2020. The ESPP allows eligible employees to purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15% of their eligible compensation. At the end of each purchase period, employees are able to purchase shares at 85% of the lower of the fair market value of the Company’s common stock as of the offering date or the applicable purchase date. The number of shares of common stock available for issuance under the ESPP will be automatically increased on the first day of each calendar year during the first ten-years of the term of the ESPP, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to the lesser of (i) 1% of the outstanding number of shares of the Company’s common stock on December 31st of the preceding calendar year, (ii) 441,280 shares of common stock or (iii) such lesser amount as determined by the Board of Directors.

As of September 30, 2022, 642,573 shares of common stock remained available for issuance under the ESPP.

Stock-Based Compensation Expense

The following table summarizes the components of stock-based compensation expense recognized in the Company’s condensed statements of operations and comprehensive loss during the three and nine months ended September 30, 2022 and 2021 (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Research and development	$	197	$	254	$	742	$	864
General and administrative		586		777		2,087		2,297
Total stock-based compensation expense	$	783	$	1,031	$	2,829	$	3,161

As of September 30, 2022, there was approximately $7.7 million of unrecognized stock-based compensation expense related to stock options and RSUs, which is expected to be recognized over a weighted-average vesting term of 2.6 years.

CONDENSED STATEMENTS OF CASH FLOWS (Parenthetical) (Unaudited) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Statement of Cash Flows [Abstract]
Proceeds from issuance of term loan, issuance costs	$ 10

Capital Structure

9 Months Ended

Sep. 30, 2022

Equity [Abstract]

Capital Structure

8. Capital Structure

Common Stock

As of September 30, 2022 and December 31, 2021, the Company was authorized to issue 200,000,000 shares of common stock $0.0001 par value per share. Holders of the Company’s common stock are entitled to dividends if and when declared by the Board of Directors of the Company (Board of Directors). The holder of each share of common stock is entitled to one vote. As of September 30, 2022, no dividends were declared.

Shares reserved for future issuance

Common stock reserved for future issuance, on an as converted basis, consisted of the following:


	September 30, 2022		December 31, 2021
Stock options, issued and outstanding		4,380,668		2,215,942
Restricted and performance stock units, issued and outstanding		336,565		460,000
Shares available for future issuance under 2020 Equity Incentive Plan		2,466,502		2,636,506
Employee stock purchase plan, available for future issuance		642,573		433,200
Total shares reserved		7,826,308		5,745,648

In February 2022, the SEC declared effective a registration statement on Form S-3 (Shelf Registration) covering the sale of up to $200.0 million of the Company's securities. Also, in February 2022, the Company entered into an Open Market Sales AgreementSM (Sales Agreement), with Jefferies LLC (Jefferies), pursuant to which the Company may elect to issue and sell, from time to time, shares of common stock having an aggregate offering price of up to $21.0 million under the Shelf Registration through Jefferies acting as the sales agent and/or principal. As of September 30, 2022, the Company has not issued any shares of common stock pursuant to the Sales Agreement.

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-URI https://asc.fasb.org/topic&trid=2208762

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 505
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-Section 50
-Paragraph 14
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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-Paragraph 18
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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-Topic 505
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Paragraph 16
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-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496180-112644

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
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-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 1
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126731327&loc=SL126733271-114008

+ Details

Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Cash and cash equivalents	$ 21,649	$ 42,748	$ 58,363
Total cash, cash equivalents and restricted cash	$ 21,865	$ 42,964	$ 58,579	$ 157,366

Leases - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Feb. 29, 2020	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Leases [Abstract]
Operating lease commencement date	2020-09
Operating lease termination date	2025-11
Operating lease term	63 months
Operating leases, gross commitment	$ 2.3
Operating Leases, option to renew lease term description				The lease includes an option to renew the lease term for an additional period of 60 months. The renewal option is not included in the lease term as the Company is not reasonably certain to exercise the option.
Operating leases, renew lease term	60 months
Operating leases, lease expense		$ 0.1	$ 0.1	$ 0.4	$ 0.3
Weighted-average remaining lease term for operating leases		3 years 2 months 12 days		3 years 2 months 12 days
weighted-average discount rate		7.00%		7.00%
Cash paid for amounts included in measurement of lease liabilities				$ 0.3	$ 0.3
Total operating lease liability		$ 1.4		$ 1.4

Capital Structure - Summary of Common Stock Reserved for Future Issuance (Details) - shares	Sep. 30, 2022	Dec. 31, 2021
Class Of Stock [Line Items]
Shares reserved for future issuance	7,826,308	5,745,648
Employee Stock Purchase Plan, Available for Future Issuance
Class Of Stock [Line Items]
Shares reserved for future issuance	642,573	433,200
Stock Options, Issued and Outstanding
Class Of Stock [Line Items]
Shares reserved for future issuance	4,380,668	2,215,942
Restricted and Performance Stock Units, Issued and Outstanding [Member]
Class Of Stock [Line Items]
Shares reserved for future issuance	336,565	460,000
Shares available for future issuance under 2020 Equity Incentive Plan
Class Of Stock [Line Items]
Shares reserved for future issuance	2,466,502	2,636,506

Net Loss Per Share - Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	4,945,656	2,563,125
Shares Subject to Outstanding Common Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	4,380,668	2,534,530
Shares Subject To Outstanding Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	336,565	0
Estimated Shares Issuable Under ESPP
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	228,423	28,595

Net Loss Per Share (Tables)

9 Months Ended

Sep. 30, 2022

Earnings Per Share [Abstract]

Schedule of Computation of Basic and Diluted Net Loss Per Share

The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share amounts):


	Three Months Ended September 30,						Nine Months Ended September 30,
	2022			2021			2022			2021
Numerator:
Net loss	$	(11,401	)	$	(11,447	)	$	(35,036	)	$	(33,108	)
Denominator:
Weighted-average shares of common stock outstanding		23,560,250			23,367,140			23,515,651			23,330,399
Net loss per share, basic and diluted	$	(0.48	)	$	(0.49	)	$	(1.49	)	$	(1.42	)

Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Per Share

Basic net loss per share was the same as diluted net loss per share for all periods as the inclusion of potentially dilutive securities would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations were as follows:


	September 30,
	2022		2021
Shares subject to outstanding common stock options		4,380,668		2,534,530
Shares subject to outstanding RSUs		336,565		—
Estimated shares issuable under the ESPP		228,423		28,595
Total		4,945,656		2,563,125

Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Accrued research and development expenses	$ 6,722	$ 3,837
Accrued compensation and benefits	993	1,435
Accrued general and administrative expenses	499	416
Lease liabilities, current portion	390	360
Total accrued expenses and other current liabilities	$ 8,604	$ 6,048

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2022

Fair Value Disclosures [Abstract]

Summary of Financial Assets Measured at Fair Value on Recurring Basis

The following table summarizes the Company's financial assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


		September 30, 2022
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Money market funds	Level 1	$	13,482	$	—	$	—		$	13,482
U.S treasury securities	Level 1		4,269		1		—			4,270
Total cash equivalents			17,751		1		—			17,752
Corporate bonds	Level 2		14,614		—		(152	)		14,462
U.S. treasury securities	Level 1		55,011		—		(722	)		54,289
Total short-term investments			69,625		—		(874	)		68,751
Total cash equivalents and investments		$	87,376	$	1	$	(874	)	$	86,503


		December 31, 2021
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Money market funds	Level 1	$	38,067	$	—	$	—		$	38,067
Total cash equivalents			38,067		—		—			38,067
Commercial paper	Level 2		33,973		—		—			33,973
Corporate bonds	Level 1		6,285		—		(23	)		6,262
U.S. treasury securities	Level 1		5,999		—		(13	)		5,986
Total short-term investments			46,257		—		(36	)		46,221
Corporate bonds	Level 1		8,470		—		(34	)		8,436
U.S. treasury securities	Level 1		24,137		—		(114	)		24,023
Total long-term investments			32,607		—		(148	)		32,459
Total cash equivalents and investments		$	116,931	$	—	$	(184	)	$	116,747

Leases

9 Months Ended

Sep. 30, 2022

Leases [Abstract]

Leases

. Leases

The Company leases space under a non-cancelable operating lease, which requires the Company to pay base rent, real estate taxes, insurance, general repairs, and maintenance. The Company does not have financing leases.

In February 2020, the Company entered into a non-cancelable operating lease for office space with a commencement date of September 2020 and a termination date of November 2025. The monthly payments escalate over the 63-month term with total gross commitments of $2.3 million. The lease includes an option to renew the lease term for an additional period of 60 months. The renewal option is not included in the lease term as the Company is not reasonably certain to exercise the option. Lease incentives, which relate to rent abatement, were considered in the calculation of the lease liability and right-of-use asset. Lease expense for the three and nine months ended September 30, 2022 was $0.1 million and $0.4 million, respectively. Lease expense for the three and nine months ended September 30, 2021 was $0.1 million and $0.3 million, respectively.

As of September 30, 2022, the weighted-average remaining lease term for operating leases was 3.2 years, the weighted-average discount rate was 7.0% and the total operating lease liability was $1.4 million. Cash paid for amounts included in the measurement of lease liabilities was $0.3 million for the nine months ended September 30, 2022 and 2021.

Commitments and Contingencies - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2022 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Aggregate license agreement amount	$ 23,000,000.0
Additional aggregate license agreement amount	0
Legal fees	$ 0

Equity Incentive Plans and Stock-Based Compensation Expense (Tables)

9 Months Ended

Sep. 30, 2022

Share-Based Payment Arrangement [Abstract]

Summary of Stock Option Activity

A summary of the Company’s stock option activity and related information is as follows (in thousands, except share and per share amounts):


	Outstanding Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value (in thousands)
Balance as of December 31, 2021		2,215,942		$	4.72		6.9	$	3,959
Granted		2,678,625		$	2.95
Exercised		(992	)	$	1.39
Forfeited		(512,907	)	$	6.71
Balance as of September 30, 2022		4,380,668		$	3.40		7.8	$	118
Vested and expected to vest as of September 30, 2022		4,240,668		$	3.36		7.7	$	118
Vested and exercisable as of September 30, 2022		1,475,250		$	3.55		4.9	$	109

Summary of RSU Activity

A summary of the Company’s RSU activity and related information is as follows:


	Number of RSUs			Weight-Average Grant Date Fair Value
Balance as of December 31, 2021		460,000		$	2.48
Granted		92,200			2.58
Vested		(64,347	)		2.49
Forfeited		(151,288	)		2.51
Balance as of September 30, 2022		336,565		$	2.49

Summary of Stock-Based Compensation Expense


	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Research and development	$	197	$	254	$	742	$	864
General and administrative		586		777		2,087		2,297
Total stock-based compensation expense	$	783	$	1,031	$	2,829	$	3,161

Organization and Principal Activities - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Organization And Principal Activities [Line Items]
Cash, cash equivalents, and short-term investments	$ 90,400		$ 90,400
Net loss	(11,401)	$ (11,447)	(35,036)	$ (33,108)
Cash in operations			29,900
Accumulated deficit	$ (138,169)		$ (138,169)		$ (103,133)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

Capital Structure (Tables)

9 Months Ended

Sep. 30, 2022

Equity [Abstract]

Schedule of common stock shares reserved for future issuance

Common stock reserved for future issuance, on an as converted basis, consisted of the following:


	September 30, 2022		December 31, 2021
Stock options, issued and outstanding		4,380,668		2,215,942
Restricted and performance stock units, issued and outstanding		336,565		460,000
Shares available for future issuance under 2020 Equity Incentive Plan		2,466,502		2,636,506
Employee stock purchase plan, available for future issuance		642,573		433,200
Total shares reserved		7,826,308		5,745,648

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2022
Accounting Policies [Abstract]
Interim Condensed Financial Statements	The financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) and applicable rules and regulations of the U.S. Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules and regulations, certain notes or other financial information normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The condensed balance sheet as of September 30, 2022, the condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2022 and 2021, the condensed statement of stockholders’ equity for the three and nine months ended September 30, 2022 and 2021, and the condensed statements of cash flows for the nine months ended September 30, 2022 and 2021 are unaudited. The interim condensed financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal, recurring adjustments that are necessary to present fairly the Company’s results for the interim periods presented. The condensed balance sheet as of December 31, 2021, is derived from the Company’s audited financial statements. The results of operations for the three and nine months ended September 30, 2022, are not necessarily indicative of the results to be expected for the year ending December 31, 2022, or for any other future annual or interim period. These interim condensed financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2021 filed with the SEC on March 14, 2022 (Annual Report).
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses as well as related disclosure of contingent assets and liabilities. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, accrued research and development expenses, stock-based compensation and uncertain tax positions. The Company bases its estimates on its historical experience and on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates.
Risks and Uncertainties	Risks and Uncertainties Any product candidates developed by the Company will require approvals from the U.S. Food and Drug Administration (FDA) or foreign regulatory agencies prior to commercial sales. There can be no assurance that the Company’s current and future product candidates will meet desired efficacy and safety requirements to obtain the necessary approvals. If approval is denied or delayed, it may have a material adverse impact on the Company’s business and its financial statements. The Company is subject to a number of risks similar to other late-stage biopharmaceutical companies including, but not limited to, dependency on the clinical success of the Company’s product candidate, tildacerfont, ability to obtain regulatory approval of tildacerfont, the need for substantial additional financing to achieve its goals, uncertainty of broad adoption of its approved products, if any, by physicians and consumers, significant competition, untested manufacturing capabilities, and dependence on key individuals and sole source suppliers. The Company’s business has been and could continue to be adversely affected by the evolving COVID-19 pandemic. For example, the COVID-19 pandemic has resulted in and could result in delays to the Company’s clinical trials for numerous reasons including additional delays or difficulties in enrolling patients, diversion of healthcare resources away from the conduct of clinical trials, interruption or delays in the operations of the FDA or other regulatory authorities, and delays in clinical sites receiving the supplies and materials to conduct our clinical trials. At this time, the extent to which the COVID-19 pandemic impacts the Company’s business will depend on future developments, which are highly uncertain. While vaccines have become widely available in certain countries, and businesses and economies have reopened, the status of global economic recovery remains uncertain and unpredictable and will continue to be impacted by developments in the pandemic including any subsequent waves of outbreak or new variant strains of the COVID-19 virus which may require re-closures or other preventative measures. The Company will continue to evaluate the impact that these events could have on its future operations, financial position, results of operations and cash flows. In addition to the ongoing COVID-19 pandemic, global economic and business activities continue to face widespread macroeconomic uncertainties, including labor shortages, inflation and monetary supply shifts, recession risks and potential disruptions from the Russia-Ukraine conflict. The Company continues to actively monitor the impact of these macroeconomic factors on its financial condition, liquidity, operations, and workforce. The extent of the impact of these factors on the Company’s operational and financial performance, including its ability to execute its business strategies and initiatives in the expected time frame, will depend on future developments, which are uncertain and cannot be predicted; however, any continued or renewed disruption resulting from these factors could negatively impact the Company’s business.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash, cash equivalents and investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents to the extent recorded in the balance sheet. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held.
Significant Accounting Policies	Significant Accounting Policies There have been no significant changes to the accounting policies during the nine months ended September 30, 2022, as compared to the significant accounting policies described in the Annual Report.
Restricted Cash	Restricted Cash The Company has cash in a collateral account related to a letter of credit issued on behalf of the Company for the security deposit on the non-cancelable operating lease for an office facility. The collateralized cash in connection with the letter of credit was classified as restricted cash on the balance sheets as of September 30, 2022 and December 31, 2021 based on the terms of the lease agreement, which expires in 2025 unless extended.
Emerging Growth Company Status	Emerging Growth Company Status The Company is an emerging growth company (EGC) as defined in the Jumpstart Our Business Startups Act of 2012 (JOBS Act) and may take advantage of reduced reporting requirements that are otherwise applicable to public companies. Section 107 of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards.
Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted In June 2016, the Financial Accounting Standards Board (FASB) issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13). ASU 2016-13 requires companies to measure credit losses utilizing a methodology that reflects expected credit losses and requires a consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 is effective for non-EGC’s electing to use the extended transition period for complying with new or revised accounting standards for fiscal years beginning after December 15, 2019, and for EGC’s for fiscal years beginning after December 15, 2022, with early adoption permitted. The Company expects to adopt this ASU on January 1, 2023. The Company is currently assessing the impact of adopting this standard, but based on a preliminary assessment, does not expect the adoption of this guidance to have a material impact on its financial statements.

CONDENSED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 21,649	$ 42,748
Short-term investments	68,751	46,221
Prepaid expenses and other current assets	2,786	2,926
Total current assets	93,186	91,895
Restricted cash	216	216
Operating lease right-of-use assets	1,229	1,479
Long-term investments	0	32,459
Other assets	667	437
Total assets	95,298	126,486
Current liabilities:
Accounts payable	2,181	2,823
Term loan, current portion	1,216	0
Accrued expenses and other current liabilities	8,604	6,048
Total current liabilities	12,001	8,871
Term loan, net of current portion	3,685	4,878
Operating lease liability, net of current portion	998	1,293
Other liabilities	139	73
Total liabilities	16,823	15,115
Commitments and contingencies (Note 7)
Stockholders’ equity:
Preferred stock, $0.0001 par value, 10,000,000 shares authorized and no shares issued or outstanding as of September 30, 2022 and December 31, 2021	0	0
Common stock, $0.0001 par value, 200,000,000 shares authorized as of September 30, 2022 and December 31, 2021; 23,560,250 and 23,491,881 shares issued and outstanding as of September 30, 2022 and December 31, 2021, respectively	3	3
Additional paid-in capital	217,514	214,685
Accumulated other comprehensive loss	(873)	(184)
Accumulated deficit	(138,169)	(103,133)
Total stockholders equity	78,475	111,371
Total liabilities and stockholders’ equity	$ 95,298	$ 126,486

Commitments and Contingencies

9 Months Ended

Sep. 30, 2022

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

. Commitments and Contingencies

From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of business. The Company evaluates the likelihood of an unfavorable outcome in legal or regulatory proceedings to which it is a party and records a loss contingency on an undiscounted basis when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. These judgments are subjective and based on the status of such legal proceedings, the merits of the Company’s defenses, and consultation with legal counsel. Actual outcomes of these legal proceedings may differ materially from the Company’s estimates.

License Agreement

In May 2016, the Company entered into a license agreement (the License Agreement), with Eli Lilly and Company (Lilly). Pursuant to the terms of the License Agreement, Lilly granted the Company an exclusive, worldwide, royalty bearing, sublicensable license under certain technology, patent rights, know-how and proprietary materials related to certain compounds, to research, develop, and commercialize such compounds for all pharmaceutical uses. The Company is also required to pay Lilly up to an aggregate of $23.0 million upon the achievement, during the time the License Agreement remains in effect, of certain milestones relating to the clinical development and commercial sales of products licensed under the License Agreement. Such payments are for predetermined fixed amounts, are paid only upon the first occurrence of each event and are due shortly after achieving the applicable milestone. In addition, the Company is required to pay Lilly tiered royalties on annual worldwide net sales with rates ranging from mid-single digits to sub-teens. No additional amounts were paid by the Company to Lilly during any of the periods presented, nor were due as of such dates pursuant to the License Agreement.

Legal Matters

The Company’s industry is characterized by frequent claims and litigation, including claims regarding intellectual property. As a result, the Company may be subject to various legal proceedings from time to time. The results of any future litigation cannot be predicted with certainty, and regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources and other factors. The Company was not subject to any material legal proceedings during the nine months ended September 30, 2022.

Term Loan (Tables)

9 Months Ended

Sep. 30, 2022

Debt Disclosure [Abstract]

Schedule of Future Principal Payments

As of September 30, 2022, future payments of principal and interest are as follows (in thousands):


	September 30, 2022
2022 (remaining 3 months)	$	82
2023		1,913
2024		1,802
2025		1,691
2026		135
Total	$	5,623
Less: Interest		(624	)
Term Loan, gross	$	5,000
Less: Unamortized debt issuance costs		(99	)
Less: Term Loan, current portion		(1,216	)
Term Loan, net of current portion	$	3,685

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and investments securities, Amortized Cost	$ 87,376	$ 116,931
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	(874)	(184)
Total cash equivalents and available-for-sale securities	86,503	116,747
Short Term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and investments securities, Amortized Cost	69,625	46,257
Gross Unrealized Holding Losses	(874)	(36)
Total cash equivalents and available-for-sale securities	68,751	46,221
Long Term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and investments securities, Amortized Cost		32,607
Gross Unrealized Holding Losses		(148)
Total cash equivalents and available-for-sale securities		32,459
Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	17,752	38,067
Cash equivalents and investments securities, Amortized Cost	17,751	38,067
Gross Unrealized Holding Gains	1
Level 1 \| Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	13,482	38,067
Cash equivalents and investments securities, Amortized Cost	13,482	38,067
Level 1 \| US Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	4,270
Cash equivalents and investments securities, Amortized Cost	4,269
Gross Unrealized Holding Gains	1
Level 1 \| Short-Term Investments , Corporate Bond Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and investments securities, Amortized Cost		6,285
Gross Unrealized Holding Losses		(23)
Total cash equivalents and available-for-sale securities		6,262
Level 1 \| Short-Term Investments, US Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and investments securities, Amortized Cost	55,011	5,999
Gross Unrealized Holding Losses	(722)	(13)
Total cash equivalents and available-for-sale securities	54,289	5,986
Level 1 \| Long-Term Investments, Corporate Bond Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and investments securities, Amortized Cost		8,470
Gross Unrealized Holding Losses		(34)
Total cash equivalents and available-for-sale securities		8,436
Level 1 \| Long-Term Investments, US Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and investments securities, Amortized Cost		24,137
Gross Unrealized Holding Losses		(114)
Total cash equivalents and available-for-sale securities		24,023
Level 2 \| Short-Term Investments , Corporate Bond Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and investments securities, Amortized Cost	14,614
Gross Unrealized Holding Losses	(152)
Total cash equivalents and available-for-sale securities	$ 14,462
Level 2 \| Short-Term Investments, Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and investments securities, Amortized Cost		33,973
Total cash equivalents and available-for-sale securities		$ 33,973

Equity Incentive Plans and Stock-Based Compensation Expense - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended	9 Months Ended
	Oct. 31, 2020	Sep. 30, 2022	Sep. 30, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for issuance		7,826,308	7,826,308	5,745,648
Equity incentive plan, terms			No further grants will be made under the 2016 Plan; however, shares subject to awards granted under the 2016 Plan will continue to be governed by the 2016 Plan.
Number of shares early exercised under any plan		0	0
Aggregate intrinsic value of options exercised		$ 0
Weighted-average fair value of options granted			$ 2.34
Unrecognized stock-based compensation expense		$ 7,700,000	$ 7,700,000
RSU
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Granted			92,200
Unrecognized stock-based compensation expense expected to be recognized over weighted-average vesting term			2 years 7 months 6 days
RSU \| Share Based Compensation Award Tranche Three Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Granted			68,775
RSU \| Share Based Compensation Award Tranche Four Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Granted			23,425
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity incentive plan, terms	number of shares of common stock available for issuance under the 2020 Plan will be automatically increased on the first day of each calendar year during the ten-year term of the 2020 Plan, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to 5% of the outstanding number of shares of the Company’s common stock on December 31st of the preceding calendar year or such lesser amount as determined by the Company’s Board of Directors.
Shares remained available for issuance		2,466,502	2,466,502
Term of automatically increase in common stock available for issuance	10 years
Percentage of outstanding shares subject to automatic increase in common stock	5.00%
2016 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares remained available for issuance		0	0
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity incentive plan, terms			he number of shares of common stock available for issuance under the ESPP will be automatically increased on the first day of each calendar year during the first ten-years of the term of the ESPP, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to the lesser of (i) 1% of the outstanding number of shares of the Company’s common stock on December 31st of the preceding calendar year, (ii) 441,280 shares of common stock or (iii) such lesser amount as determined by the Board of Directors.
Shares remained available for issuance	441,280	642,573	642,573
Maximum percentage of compensation that an employee is allowed to purchase shares	15.00%
Purchase price of common stock expressed as a percentage of fair market value	85.00%
Term of automatically increase in common stock available for issuance	10 years
Percentage of outstanding shares subject to automatic increase in common stock	1.00%

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2022	Nov. 04, 2022
Cover [Abstract]
Entity Registrant Name	Spruce Biosciences, Inc.
Entity Central Index Key	0001683553
Document Type	10-Q
Document Period End Date	Sep. 30, 2022
Trading Symbol	SPRB
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		23,560,250
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Small Business	true
Entity File Number	001-39594
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-2154263
Entity Address, Address Line One	2001 Junipero Serra Boulevard
Entity Address, Address Line Two	Suite 640
Entity Address, City or Town	Daly City
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94014
City Area Code	415
Local Phone Number	655-4168
Document Quarterly Report	true
Document Transition Report	false
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Security Exchange Name	NASDAQ

CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating expenses:
Research and development	$ 8,791	$ 8,607	$ 26,359	$ 24,440
General and administrative	2,766	2,793	8,814	8,491
Total operating expenses	11,557	11,400	35,173	32,931
Loss from operations	(11,557)	(11,400)	(35,173)	(32,931)
Interest expense	(110)	(88)	(291)	(257)
Interest and other income, net	266	41	428	80
Net loss	(11,401)	(11,447)	(35,036)	(33,108)
Unrealized (loss) gain on available for sale securities	(28)	13	(689)	(16)
Comprehensive loss	$ (11,429)	$ (11,434)	$ (35,725)	$ (33,124)
Net loss per share, basic	$ (0.48)	$ (0.49)	$ (1.49)	$ (1.42)
Net loss per share, diluted	$ (0.48)	$ (0.49)	$ (1.49)	$ (1.42)
Weighted-average shares of common stock outstanding, basic	23,560,250	23,367,140	23,515,651	23,330,399
Weighted-average shares of common stock outstanding, diluted	23,560,250	23,367,140	23,515,651	23,330,399

Equity Incentive Plans and Stock-Based Compensation Expense - Summary of Stock Option Activity (Details) - 2020 Equity Incentive Plan - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Beginning Balance, Outstanding Stock Options	2,215,942
Granted, Outstanding Stock Options	2,678,625
Exercised, Outstanding Stock Options	(992)
Forfeited, Outstanding Stock Options	(512,907)
Ending Balance, Outstanding Stock Options	4,380,668	2,215,942
Vested and expected to vest, Outstanding Stock Options	4,240,668
Vested and exercisable, Outstanding Stock Options	1,475,250
Weighted Average Grant Date Fair Value Per Share, Beginning Balance	$ 4.72
Granted, Weighted-Average Exercise Price	2.95
Exercised, Weighted-Average Exercise Price	1.39
Forfeited, Weighted-Average Exercise Price	6.71
Ending Balance, Weighted-Average Exercise Price	3.40	$ 4.72
Vested and expected to vest, Weighted-Average Exercise Price	3.36
Vested and exercisable, Weighted-Average Exercise Price	$ 3.55
Weighted-Average Remaining Contractual Life (Years)	7 years 9 months 18 days	6 years 10 months 24 days
Vested and expected to vest, Weighted-Average Remaining Contractual Life (Years)	7 years 8 months 12 days
Vested and exercisable, Weighted-Average Remaining Contractual Life (Years)	4 years 10 months 24 days
Aggregate Intrinsic Value	$ 118	$ 3,959
Vested and expected to vest, Aggregate Intrinsic Value	118
Vested and exercisable, Aggregate Intrinsic Value	$ 109

Fair Value Measurements

9 Months Ended

Sep. 30, 2022

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Fair Value Measurements

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. Fair value measurement establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value.

The Company determined the fair value of financial assets and liabilities using the fair value hierarchy that describes three levels of inputs that may be used to measure fair value, as follows:

Level 1 — Quoted prices in active markets for identical assets and liabilities;

Level 2 — Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, 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; and

Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company classifies money market funds, corporate bonds and U.S. treasury securities as Level 1 investments as the Company uses quoted prices in active markets for identical assets to determine the fair value. The Company classifies commercial paper as Level 2 investments as the Company uses quoted prices for similar assets sourced from certain third-party pricing services. The third-party pricing services generally utilize industry standard valuation models for which all significant inputs are observable, either directly or indirectly, to estimate the price or fair value of the securities. The primary input generally includes reported trades of or quotes on the same or similar securities. The Company does not make additional judgments or assumptions made to the pricing data sourced from the third-party pricing services.

The carrying value of cash and cash equivalents, prepaid expenses, accounts payable, and accrued expenses, are generally considered to be representative of their respective fair values because of the short-term nature of those instruments.

The following table summarizes the Company's financial assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


		September 30, 2022
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Money market funds	Level 1	$	13,482	$	—	$	—		$	13,482
U.S treasury securities	Level 1		4,269		1		—			4,270
Total cash equivalents			17,751		1		—			17,752
Corporate bonds	Level 2		14,614		—		(152	)		14,462
U.S. treasury securities	Level 1		55,011		—		(722	)		54,289
Total short-term investments			69,625		—		(874	)		68,751
Total cash equivalents and investments		$	87,376	$	1	$	(874	)	$	86,503


		December 31, 2021
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Money market funds	Level 1	$	38,067	$	—	$	—		$	38,067
Total cash equivalents			38,067		—		—			38,067
Commercial paper	Level 2		33,973		—		—			33,973
Corporate bonds	Level 1		6,285		—		(23	)		6,262
U.S. treasury securities	Level 1		5,999		—		(13	)		5,986
Total short-term investments			46,257		—		(36	)		46,221
Corporate bonds	Level 1		8,470		—		(34	)		8,436
U.S. treasury securities	Level 1		24,137		—		(114	)		24,023
Total long-term investments			32,607		—		(148	)		32,459
Total cash equivalents and investments		$	116,931	$	—	$	(184	)	$	116,747

As of September 30, 2022 and December 31, 2021, $0.1 million of accrued interest on investments was recorded to other assets on the condensed balance sheets.

There have been no realized gains or losses on available for sale securities for the periods presented. No available for sale securities held as of September 30, 2022 have been in a continuous unrealized loss position for more than 12 months and unrealized gains and losses are included in accumulated other comprehensive loss within stockholders' equity on the condensed balance sheets. As of September 30, 2022, unrealized losses on available for sale securities are not attributed to credit risk and are considered temporary. The Company believes that it is more-likely-than-not that investments in an unrealized loss position will be held until maturity or the cost basis of the investment will be recovered. The Company believes it has no other-than-temporary impairments on its securities as it does not intend to sell these securities and does not believe it is more likely than not that it will be required to sell these securities before the recovery of their amortized cost basis. To date, the Company has not recorded any impairment charges on securities related to other-than-temporary declines in fair value. The Company’s short-term investments are securities with contractual maturities of less than one year. As of September 30, 2022, the weighted-average remaining contractual maturities of investments was approximately six months.

The estimated fair value of the term loan was $4.9 million and $5.0 million as of September 30, 2022, and December 31, 2021, respectively, and was based on market observable interest rates, a Level 2 input.

- Definition

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

+ References + Details

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2022

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation

The financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) and applicable rules and regulations of the U.S. Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules and regulations, certain notes or other financial information normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The condensed balance sheet as of September 30, 2022, the condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2022 and 2021, the condensed statement of stockholders’ equity for the three and nine months ended September 30, 2022 and 2021, and the condensed statements of cash flows for the nine months ended September 30, 2022 and 2021 are unaudited. The interim condensed financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal, recurring adjustments that are necessary to present fairly the Company’s results for the interim periods presented. The condensed balance sheet as of December 31, 2021, is derived from the Company’s audited financial statements. The results of operations for the three and nine months ended September 30, 2022, are not necessarily indicative of the results to be expected for the year ending December 31, 2022, or for any other future annual or interim period.

These interim condensed financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2021 filed with the SEC on March 14, 2022 (Annual Report).

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses as well as related disclosure of contingent assets and liabilities. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, accrued research and

development expenses, stock-based compensation and uncertain tax positions. The Company bases its estimates on its historical experience and on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates.

Risks and Uncertainties

Any product candidates developed by the Company will require approvals from the U.S. Food and Drug Administration (FDA) or foreign regulatory agencies prior to commercial sales. There can be no assurance that the Company’s current and future product candidates will meet desired efficacy and safety requirements to obtain the necessary approvals. If approval is denied or delayed, it may have a material adverse impact on the Company’s business and its financial statements.

The Company is subject to a number of risks similar to other late-stage biopharmaceutical companies including, but not limited to, dependency on the clinical success of the Company’s product candidate, tildacerfont, ability to obtain regulatory approval of tildacerfont, the need for substantial additional financing to achieve its goals, uncertainty of broad adoption of its approved products, if any, by physicians and consumers, significant competition, untested manufacturing capabilities, and dependence on key individuals and sole source suppliers.

The Company’s business has been and could continue to be adversely affected by the evolving COVID-19 pandemic. For example, the COVID-19 pandemic has resulted in and could result in delays to the Company’s clinical trials for numerous reasons including additional delays or difficulties in enrolling patients, diversion of healthcare resources away from the conduct of clinical trials, interruption or delays in the operations of the FDA or other regulatory authorities, and delays in clinical sites receiving the supplies and materials to conduct our clinical trials. At this time, the extent to which the COVID-19 pandemic impacts the Company’s business will depend on future developments, which are highly uncertain. While vaccines have become widely available in certain countries, and businesses and economies have reopened, the status of global economic recovery remains uncertain and unpredictable and will continue to be impacted by developments in the pandemic including any subsequent waves of outbreak or new variant strains of the COVID-19 virus which may require re-closures or other preventative measures. The Company will continue to evaluate the impact that these events could have on its future operations, financial position, results of operations and cash flows.

In addition to the ongoing COVID-19 pandemic, global economic and business activities continue to face widespread macroeconomic uncertainties, including labor shortages, inflation and monetary supply shifts, recession risks and potential disruptions from the Russia-Ukraine conflict. The Company continues to actively monitor the impact of these macroeconomic factors on its financial condition, liquidity, operations, and workforce. The extent of the impact of these factors on the Company’s operational and financial performance, including its ability to execute its business strategies and initiatives in the expected time frame, will depend on future developments, which are uncertain and cannot be predicted; however, any continued or renewed disruption resulting from these factors could negatively impact the Company’s business.

Concentration of Credit Risk

Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash, cash equivalents and investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents to the extent recorded in the balance sheet. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held.

Significant Accounting Policies

There have been no significant changes to the accounting policies during the nine months ended September 30, 2022, as compared to the significant accounting policies described in the Annual Report.

Restricted Cash

The Company has cash in a collateral account related to a letter of credit issued on behalf of the Company for the security deposit on the non-cancelable operating lease for an office facility. The collateralized cash in connection with the letter of credit was classified as restricted cash on the balance sheets as of September 30, 2022 and December 31, 2021 based on the terms of the lease agreement, which expires in 2025 unless extended.

Emerging Growth Company Status

The Company is an emerging growth company (EGC) as defined in the Jumpstart Our Business Startups Act of 2012 (JOBS Act) and may take advantage of reduced reporting requirements that are otherwise applicable to public companies. Section 107 of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards.

Recent Accounting Pronouncements Not Yet Adopted

In June 2016, the Financial Accounting Standards Board (FASB) issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13). ASU 2016-13 requires companies to measure credit losses utilizing a methodology that reflects expected credit losses and requires a consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 is effective for non-EGC’s electing to use the extended transition period for complying with new or revised accounting standards for fiscal years beginning after December 15, 2019, and for EGC’s for fiscal years beginning after December 15, 2022, with early adoption permitted. The Company expects to adopt this ASU on January 1, 2023. The Company is currently assessing the impact of adopting this standard, but based on a preliminary assessment, does not expect the adoption of this guidance to have a material impact on its financial statements.

Net Loss Per Share

9 Months Ended

Sep. 30, 2022

Earnings Per Share [Abstract]

Net Loss Per Share

11. Net Loss Per Share

The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share amounts):


	Three Months Ended September 30,						Nine Months Ended September 30,
	2022			2021			2022			2021
Numerator:
Net loss	$	(11,401	)	$	(11,447	)	$	(35,036	)	$	(33,108	)
Denominator:
Weighted-average shares of common stock outstanding		23,560,250			23,367,140			23,515,651			23,330,399
Net loss per share, basic and diluted	$	(0.48	)	$	(0.49	)	$	(1.49	)	$	(1.42	)


	September 30,
	2022		2021
Shares subject to outstanding common stock options		4,380,668		2,534,530
Shares subject to outstanding RSUs		336,565		—
Estimated shares issuable under the ESPP		228,423		28,595
Total		4,945,656		2,563,125

Equity Incentive Plans and Stock-Based Compensation Expense - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 783	$ 1,031	$ 2,829	$ 3,161
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	197	254	742	864
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 586	$ 777	$ 2,087	$ 2,297

Term Loan

9 Months Ended

Sep. 30, 2022

Debt Disclosure [Abstract]

Term Loan

6. Term Loan

In September 2019, the Company entered into a Loan and Security Agreement, as subsequently amended (the Loan Agreement) with Silicon Valley Bank (SVB) providing for a term loan (the Term Loan) for an aggregate principal amount of $4.5 million.

In September 2019 and in connection with the Loan Agreement, the Company issued a warrant to purchase up to an aggregate of 49,609 shares of common stock at $1.44 per share. The Company determined the initial fair value of the warrant to be $0.1 million using the Black-Scholes option-pricing model. The fair value of the warrant was recorded to equity and as a debt discount, which was being amortized to interest expense using the effective interest method over the term of the Term Loan. In November 2020, the warrant was net-exercised for 46,358 shares of common stock.

In March 2021, the Company entered into a First Amendment to Loan and Security Agreement (the First Amendment), which increased the aggregate principal amount of the Term Loan to $30.0 million, of which $20.0 million was immediately available under the first tranche (First Tranche) and $10.0 million is available under the second tranche through December 31, 2022 (Second Tranche), subject to the completion of certain clinical or financial milestones. Pursuant to the First Amendment, the Term Loan will mature on January 1, 2026.

In May 2022, the Company entered into a Second Amendment to Loan and Security Agreement (the Second Amendment), which amended the milestones for the Second Tranche, added a liquidity covenant for the Second Tranche and amended the interest and prepayment terms.

The Loan Agreement provides for monthly cash interest-only payments following the funding date of each respective tranche and continuing thereafter through December 31, 2022, to the extent that the Company does not borrow any part of the Second Tranche, or June 30, 2023 if the Company has borrowed some or all of the Second Tranche. The Term Loan is subject to a floating per annum interest rate equal to the greater of (a) 0.50% above the Prime Rate (as defined in the Loan Agreement) or (b) 3.75%. Following the interest-only period, the outstanding Term Loan balance will be payable in (i) 37 consecutive monthly payments (or 31 if the Company borrows under the Second Tranche) after the end of the interest-only period and continuing on the same day of each month thereafter, in amounts that would fully amortize such Term Loan balance, as of the first business day of the first month following the amended interest-only period, over the repayment period, plus (ii) monthly payments of accrued but unpaid interest.

The final payment is due on the maturity date and includes all outstanding principal plus accrued unpaid interest and an end of term payment totaling (x) 6.0% of the original funded principal amount of the First Tranche, and (y) 4.0% of the original funded principal amount under the Second Tranche if the Company does borrow under the Second Tranche (the Supplemental Final Payment). The Company may prepay amounts outstanding under the Term Loan at any time provided certain notification conditions are met, in which case, all outstanding principal plus accrued and unpaid interest, the Supplemental Final Payment, a prepayment fee of 1% or 2% of the principal amount of the First and Second Tranches, and any bank expenses become due and payable.

The Company is subject to customary affirmative and restrictive covenants under the Loan Agreement. The Company’s obligations under the Loan Agreement are secured by a first priority security interest in substantially all of its current and future assets, other than intellectual property. The Company also agreed not to encumber its intellectual property assets, except as permitted by the Loan Agreement. Further, in the event that the Second Tranche becomes available and the Company obtains an advance thereunder, the Company will be required to comply with a liquidity covenant of at least $50.0 million at all times. If the Company does not comply with the foregoing liquidity covenant, a springing cash pledge will occur, pursuant to which the Company must maintain a cash secured blocked account with SVB with a cash balance in an amount equal to the outstanding SVB obligations at such time (excluding Bank Services (as defined in the Loan Agreement)). The foregoing cash collateral requirement will terminate upon a certain additional equity raise, which must occur on or before September 30, 2024.

The Loan Agreement also contains customary indemnification obligations and customary events of default, including, among other things, the Company’s failure to fulfill certain obligations under the Loan Agreement and the occurrence of a material adverse change in its business, operations, or condition (financial or otherwise), a material impairment of the prospect of repayment of any portion of the loan, or a material impairment in the perfection or priority of lender’s lien in the collateral or in the value of such collateral. In the event of default by the Company under the Loan Agreement, the lender would be entitled to exercise their remedies thereunder, including the right to accelerate the debt, upon which the Company may be required to repay all amounts then outstanding under the Loan Agreement. As of September 30, 2022, management believes that the Company was in compliance with all financial covenants under the Loan Agreement and there had been no material adverse change.

As of September 30, 2022, the carrying value of the Term Loan was $4.9 million, consisting of the outstanding principal under the First Tranche of $5.0 million, less unamortized debt discount and issuance costs of $0.1 million which are being amortized using

the effective interest method over the life of the Term Loan. As of September 30, 2022, future payments of principal and interest are as follows (in thousands):


	September 30, 2022
2022 (remaining 3 months)	$	82
2023		1,913
2024		1,802
2025		1,691
2026		135
Total	$	5,623
Less: Interest		(624	)
Term Loan, gross	$	5,000
Less: Unamortized debt issuance costs		(99	)
Less: Term Loan, current portion		(1,216	)
Term Loan, net of current portion	$	3,685

- Definition

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

+ References

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+ Details

Organization and Principal Activities

9 Months Ended

Sep. 30, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization and Principal Activities

1. Organization and Principal Activities

Description of Business

Spruce Biosciences, Inc. (the Company) is a late-stage biopharmaceutical company focused on developing and commercializing novel therapies for rare endocrine disorders with significant unmet medical need. The Company is initially developing its wholly-owned product candidate, tildacerfont, as the potential first non-steroidal therapy for patients suffering from classic congenital adrenal hyperplasia (CAH). The Company is also developing tildacerfont for females suffering from polycystic ovary syndrome (PCOS) with adrenal dysfunction. The Company is located in Daly City, California and was incorporated in the state of Delaware in April 2016.

Liquidity and Capital Resources

As of September 30, 2022, the Company had cash, cash equivalents, and short-term investments of $90.4 million, which management believes is sufficient to fund its planned operations and debt obligations for a period of at least twelve months following the issuance of the accompanying condensed financial statements.

The Company has incurred significant losses and negative cash flows from operations. During the nine months ended September 30, 2022, the Company incurred a net loss of $35.0 million and used $29.9 million of cash in operations. As of September 30, 2022, the Company had an accumulated deficit of $138.2 million and does not expect positive cash flows from operations in the foreseeable future. The Company has funded its operations primarily through the issuance and sale of equity securities and debt.

The Company anticipates that it will need to raise substantial additional financing in the future to fund its operations. In order to meet these additional cash requirements, the Company may seek to sell additional equity or issue debt, convertible debt or other securities that may result in dilution to its stockholders. If the Company raises additional funds through the issuance of debt or convertible debt securities, these securities could have rights senior to those of its shares of common stock and could contain covenants that restrict its operations. There can be no assurance that the Company will be able to obtain additional equity or debt financing on terms acceptable to it, if at all. Additional debt financing, if available, would result in increased fixed payment obligations and may involve agreements that include covenants limiting or restricting the Company’s ability to take specific actions such as incurring debt, making capital expenditures or declaring dividends. The Company’s failure to obtain sufficient funds on acceptable terms when needed could have a material adverse effect on its business, results of operations, and financial condition.

CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities
Net loss	$ (35,036)	$ (33,108)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,829	3,161
Depreciation and amortization	50	48
Amortization of discount on investments	109	60
Non-cash lease expense	250	233
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	140	1,738
Other assets	78	131
Accounts payable and accrued expenses	1,864	1,753
Other liabilities	(229)	(94)
Net cash used in operating activities	(29,945)	(26,078)
Cash flows from investing activities
Purchases of property and equipment	(8)	(87)
Purchase of investments	(33,869)	(73,098)
Proceeds from maturities of investments	43,000	0
Net cash provided by (used in) investing activities	9,123	(73,185)
Cash flows from financing activities
Payment of deferred offering costs	(277)	0
Proceeds from exercise of stock options	2	160
Proceeds from issuance of common stock related to employee stock purchase plan	38	96
Tax withholding payments on restricted stock units	(40)	0
Proceeds from issuance of term loan, net of issuance costs of $10		4,990
Repayment of term loan		(4,770)
Net cash (used in) provided by financing activities	(277)	476
Net increase (decrease) in cash, cash equivalents and restricted cash	(21,099)	(98,787)
Cash, cash equivalents, and restricted cash at beginning of period	42,964	157,366
Cash, cash equivalents, and restricted cash at end of period	21,865	58,579
Reconciliation of cash, cash equivalents, and restricted cash
Cash and cash equivalents	21,649	58,363
Restricted cash	216	216
Total cash, cash equivalents and restricted cash	21,865	58,579
Supplemental cash flow data:
Cash paid for interest	180	$ 152
Supplemental disclosure of non-cash investing and financing activities:
Deferred offering costs included in accrued expenses	$ 50

Balance Sheet Components

9 Months Ended

Sep. 30, 2022

Text Block [Abstract]

Balance Sheet Components

4. Balance Sheet Components

Accrued Expenses and Other Current Liabilities

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


	September 30, 2022		December 31, 2021
Accrued research and development expenses	$	6,722	$	3,837
Accrued compensation and benefits		993		1,435
Accrued general and administrative expenses		499		416
Lease liabilities, current portion		390		360
Total accrued expenses and other current liabilities	$	8,604	$	6,048

Accrued research and development expenses were primarily related to clinical trials and manufacturing of clinical drug supply.

Income Taxes

9 Months Ended

Sep. 30, 2022

Income Tax Disclosure [Abstract]

Income Taxes

10. Income Taxes

The Company accounts for income taxes under ASC Topic 740, Income Taxes. Under this standard, deferred tax assets and liabilities are recognized for future tax benefits or consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled.

A valuation allowance is provided for significant deferred tax assets when it is more likely than not that such assets will not be realized through future operations. No provision for income taxes has been recorded due to losses incurred to date. Future tax benefits which may arise as a result of these losses have not been recognized in these financial statements, as their realization is determined not likely to occur and accordingly, the Company has recorded a full valuation allowance for deferred tax assets.

- Definition

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

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Term Loan - Additional Information (Details)	1 Months Ended		9 Months Ended
Term Loan - Additional Information (Details)	Nov. 30, 2020 shares	Sep. 30, 2019 USD ($) $ / shares shares	Sep. 30, 2022 USD ($) Installment
Debt Instrument [Line Items]
Aggregate principal amount			$ 5,623,000
Silicon Valley Bank
Debt Instrument [Line Items]
Debt liquidity covenant			If the Company does not comply with the foregoing liquidity covenant, a springing cash pledge will occur, pursuant to which the Company must maintain a cash secured blocked account with SVB with a cash balance in an amount equal to the outstanding SVB obligations at such time (excluding Bank Services (as defined in the Loan Agreement)). The foregoing cash collateral requirement will terminate upon a certain additional equity raise, which must occur on or before September 30, 2024.
Liquidity covenant amount			Further, in the event that the Second Tranche becomes available and the Company obtains an advance thereunder, the Company will be required to comply with a liquidity covenant of at least $50.0 million at all times.
Term Loan \| Silicon Valley Bank
Debt Instrument [Line Items]
Aggregate principal amount		$ 4,500,000
Amount of total debt available			$ 30,000,000.0
Debt instrument, maturity date			Jan. 01, 2026
Number of Monthly Installments \| Installment			37
End of term payment, percentage			4.00%
Debt issuance costs			$ 4,900
Unamortized debt discount and issuance costs			$ 100,000
Term Loan \| Silicon Valley Bank \| Warrant
Debt Instrument [Line Items]
Number of shares issuable upon the exercise of warrant \| shares		49,609
Warrants exercise price \| $ / shares		$ 1.44
Estimated fair value of the warrant		$ 100,000
Term Loan \| Silicon Valley Bank \| Maximum
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage			2.00%
Term Loan \| Silicon Valley Bank \| Minimum
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage			1.00%
Term Loan \| Common Stock \| Silicon Valley Bank \| Warrant
Debt Instrument [Line Items]
Net exercised of common stock \| shares	46,358
First Tranche Term Loan \| Silicon Valley Bank
Debt Instrument [Line Items]
Amount of debt available under the first tranche			$ 20,000,000.0
End of term payment, percentage			6.00%
Debt issuance costs			$ 5,000.0
Second Tranche Term Loan \| Silicon Valley Bank
Debt Instrument [Line Items]
Amount of debt available under the second tranche			$ 10,000,000.0
Debt instrument, maturity date			Dec. 31, 2022
Number of Monthly Installments \| Installment			31
Second Tranche Term Loan \| Silicon Valley Bank \| Prime Rate
Debt Instrument [Line Items]
Floating interest scenario two			3.75%
Second Tranche Term Loan \| Silicon Valley Bank \| Prime Rate \| Maximum
Debt Instrument [Line Items]
Floating interest scenario one			0.50%

CONDENSED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at Dec. 31, 2020	$ 149,427	$ 2	$ 210,266	$ 0	$ (60,841)
Balance, Shares at Dec. 31, 2020		23,260,399
Exercise of stock options	160	$ 1	159
Exercise of stock options, Shares		109,361
Issuance of common stock related to employee stock purchase plan	96		96
Issuance of common stock related to employee stock purchase plan, Shares		10,127
Stock-based compensation	3,161		3,161
Unrealized (loss) gain on available for sale securities	(16)			(16)
Net loss	(33,108)				(33,108)
Balance at Sep. 30, 2021	119,720	$ 3	213,682	(16)	(93,949)
Balance, Shares at Sep. 30, 2021		23,379,887
Balance at Jun. 30, 2021	130,106	$ 3	212,634	(29)	(82,502)
Balance, Shares at Jun. 30, 2021		23,370,070
Exercise of stock options	17	$ 0	17
Exercise of stock options, Shares		9,817
Stock-based compensation	1,031		1,031
Unrealized (loss) gain on available for sale securities	13			13
Net loss	(11,447)				(11,447)
Balance at Sep. 30, 2021	119,720	$ 3	213,682	(16)	(93,949)
Balance, Shares at Sep. 30, 2021		23,379,887
Balance at Dec. 31, 2021	$ 111,371	$ 3	214,685	(184)	(103,133)
Balance, Shares at Dec. 31, 2021	23,491,881	23,491,881
Exercise of stock options	$ 2		2
Exercise of stock options, Shares		992
Issuance of common stock related to employee stock purchase plan	38		38
Issuance of common stock related to employee stock purchase plan, Shares		25,545
Issuance of common stock related to vesting of restricted stock units, net of tax withholdings	(40)		(40)
Issuance of common stock related to vesting of restricted stock units, net of tax withholdings, shares		41,832
Stock-based compensation	2,829		2,829
Unrealized (loss) gain on available for sale securities	(689)			(689)
Net loss	(35,036)				(35,036)
Balance at Sep. 30, 2022	$ 78,475	$ 3	217,514	(873)	(138,169)
Balance, Shares at Sep. 30, 2022	23,560,250	23,560,250
Balance at Jun. 30, 2022	$ 89,121	$ 3	216,731	(845)	(126,768)
Balance, Shares at Jun. 30, 2022		23,560,250
Stock-based compensation	783		783
Unrealized (loss) gain on available for sale securities	(28)			(28)
Net loss	(11,401)				(11,401)
Balance at Sep. 30, 2022	$ 78,475	$ 3	$ 217,514	$ (873)	$ (138,169)
Balance, Shares at Sep. 30, 2022	23,560,250	23,560,250

Capital Structure - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2022	Feb. 28, 2022	Dec. 31, 2021
Class Of Stock [Line Items]
Common stock shares authorized	200,000,000		200,000,000
Common stock par value per share	$ 0.0001		$ 0.0001
Common stockholders voting rights	one vote
Common stock dividends declared	$ 0
Common stock, shares issued	23,560,250		23,491,881
Shelf Registration And Sales Agreement
Class Of Stock [Line Items]
Maximum amount of sale covered in shelf registration statement		$ 200,000,000.0
Shelf Registration And Sales Agreement \| Jefferies LLC
Class Of Stock [Line Items]
Maximum amount of offering issuance and sale covered in sales agreement		$ 21,000,000.0