0000950170-23-062923 | 10-Q | XBRL Viewer

Adjustments to reconcile net loss to net cash used in operating activities:

$ (15,289)

$ (10,865)

$ (13,708)

$ (18,915)

$ (38,362)

$ (45,758)

Depreciation and amortization

951

1,771

Amortization of debt issuance costs

705

989

Debt extinguishment loss upon paydown of principal

491

Debt extinguishment gain upon conversion to equity

(199)

Net accretion and amortization of premium and discounts on marketable securities

(1,199)

155

Gain on disposal of property and equipment

(247)

Impairment of long-lived assets

6,686

7,120

Non-cash rent expense

(811)

(1,891)

5,602

Changes in operating assets and liabilities:

Prepaid expenses and other current assets

(1,858)

(1,355)

Other long-term assets

Accounts payable

(642)

459

Accrued compensation

(793)

(1,067)

Accrued liabilities and other current liabilities

(335)

(632)

Other long-term liabilities

(23)

Net cash used in operating activities

(29,513)

(40,663)

Investing activities

Purchase of marketable securities

(28,609)

(86,567)

Maturities of marketable securities

74,000

62,000

Purchase of property and equipment

(11)

(59)

Sale of property and equipment

272

Net cash provided by (used in) investing activities

45,381

(24,354)

Payment of debt principal

(20,000)

Payment of debt issuance costs

(1,563)

Proceeds from issuance of common stock under 2018 ESPP

125

Net cash provided by (used in) financing activities

(20,728)

54,688

Net increase (decrease) in cash, cash equivalents and restricted cash

(4,860)

(10,329)

Cash, cash equivalents and restricted cash at beginning of the period

$ 13,632

$ 34,351

13,632

34,351

Cash, cash equivalents and restricted cash at end of the period

8,772

24,022

8,772

24,022

$ 13,632

Supplemental Disclosures of Cash Flow Information:

Cash paid for interest

1,969

1,577

Supplemental Disclosures of Non-Cash Investing and Financing Activities

Issuance of common stock in payment of debt

3,179

Cash and cash equivalents

7,876

22,576

7,876

22,576

12,736

^[1]

Restricted cash

896

1,446

896

1,446

Total cash, cash equivalents and restricted cash

$ 8,772

$ 24,022

8,772

24,022

$ 13,632

ATM Offering Program

Proceeds from issuance of common stock, net of issuance costs

744

12,003

Follow-on Offering

Proceeds from issuance of common stock, net of issuance costs

41,650

Lincoln Park Capital Fund Equity Purchase Agreement

Proceeds from issuance of common stock, net of issuance costs

$ 0

$ 910

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Equity Financing

9 Months Ended

Sep. 30, 2023

Equity [Abstract]

Equity Financing

10. Equity Financing

On October 19, 2022, the Company effected a reverse stock split of its outstanding share of common stock at a ratio of 1-for-10 pursuant to a Certificate of Amendment to the Company's Certificate of Incorporation filed with the Secretary of State of the State of Delaware. The reverse stock split was reflected on the Nasdaq Global Select Market beginning with the opening of trading on October 20, 2022. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.

The Company has 10,000,000 shares of convertible preferred stock authorized for issuance, par value of $0.0001 per share. As of September 30, 2023 and December 31, 2022, no shares of preferred stock were issued and outstanding.

The Company has 300,000,000 shares of common stock authorized for issuance, par value of $0.0001 per share. Holders of the Company’s common stock are entitled to one vote per share. As of September 30, 2023 and December 31, 2022, there were 14,614,890 and 14,215,302 shares, respectively, of common stock issued and outstanding.

Follow-On Offering

In August 2022, the Company closed an underwritten offering (the “Follow-On Offering”) in which the Company issued and sold an aggregate of 6,428,571 of the Company’s common stock together with warrants (the "Existing Warrants”) to purchase up to 6,428,572 of the Company’s common stock at an offering price of at an aggregate offering price of $7.00 per unit. The Existing Warrants have an exercise price of $8.50 per share underlying the Existing Warrant. These Existing Warrants were recorded as a component of stockholders’ equity within additional paid-in capital. The gross proceeds to the Company were $45.0 million before deducting underwriting discounts and commissions and other offering expenses. The net proceeds of the Follow-On Offering were approximately $41.7 million.

The Existing Warrants are exercisable at any time after their original issuance and on or prior to the five-year anniversary of the original issuance date. A holder of Existing Warrants may not exercise the warrant if the holder, together with its affiliates, would beneficially own more than 4.99% of the number of shares of common stock outstanding immediately after giving effect to such exercise. No warrants have been exercised as of September 30, 2023.

At-the-Market Offering

In March 2022, the Company filed a Registration Statement on Form S-3 (the “March 2022 Shelf Registration Statement”), covering the offering of up to $125.0 million of common stock, preferred stock, debt securities, warrants, and units, which was declared effective by the SEC in May 2022. In March 2022, the Company also entered into a sales agreement (the “March 2022 Sales Agreement”) with Cowen and Company, LLC ("Cowen") as sales agent to sell shares of the Company’s common stock, from time to time, with aggregate gross sales proceeds of up to $50.0 million pursuant to the March 2022 Shelf Registration Statement as an “at-the-market” offering under the Securities Act (the "March 2022 ATM Offering Program"). Cowen is entitled to up to 3.0% of the gross proceeds of any shares of common stock sold under the March 2022 Sales Agreement. For so long as its public float is less than $75.0 million, it may not sell more than the equivalent of one-third of its public float during any 12 consecutive months pursuant to the "baby shelf" rules. During the nine-month period ended September 30, 2023, there were 274,781 shares of the Company's common stock sold pursuant to the March 2022 Sales Agreement and the Company received total net proceeds of approximately $1.0 million, after deducting commissions and other offering expenses which was insignificant. On August 17, 2022, the Company entered into Amendment No. 1 (the “Amendment”) to the March 2022 Sales Agreement, which Amendment decreased the amount of the Company’s common stock that can be sold by the Company through Cowen under the March 2022 Sales Agreement, from an aggregate offering of up to $50.0 million to an aggregate offering of up to $25.0 million. Following the Amendment, $14.6 million of shares of common stock remained available for sale under the March 2022 Sales Agreement, as amended, as of September 30, 2023. On March 17, 2023, the Company entered into Amendment No. 2 (the "Second Amendment"), accompanied by a

prospectus supplement, to the March 2022 Sales Agreement. The Second Amendment added the limitations imposed on the Program by General Instruction I.B.6 of Form S-3 (“Instruction I.B.6”) to the Sales Agreement. Pursuant to Instruction I.B.6, in no event will the Company sell ATM Shares through the Program with a value exceeding more than one-third of the Company’s “public float” (the market value of the Company’s outstanding common stock held by non-affiliates) in any twelve-month period so long as the Company’s public float remains below $75.0 million.

In October 2022, the Company filed a Registration Statement on Form S-3 (the “October 2022 Shelf Registration Statement”), covering the offering of up to $250.0 million of common stock, preferred stock, debt securities, warrants, and units. In October 2022, the Company also entered into a sales agreement (the “October 2022 Sales Agreement”) with Cowen as sales agent to sell shares of the Company’s common stock, from time to time, with aggregate gross sales proceeds of up to $50.0 million pursuant to the October 2022 Shelf Registration Statement as an “at-the-market” offering under the Securities Act. Cowen is entitled to up to 3.0% of the gross proceeds of any shares of common stock sold under the October 2022 Sales Agreement. During the nine months ended September 30, 2023, there were no shares of the Company's common stock sold pursuant to the October 2022 Sales Agreement.

Equity Purchase Agreement

In September 2021, the Company entered into an equity purchase agreement (the “Purchase Agreement” or “Equity Purchase Agreement”) and a registration rights agreement with Lincoln Park Capital Fund, LLC (“Lincoln Park” or “Investor”) which provides for the sale to Lincoln Park up to $30,000,000 of shares (the “Purchase Shares”) of its common stock over the thirty-six (36) month term of the Purchase Agreement. In connection with the Purchase Agreement, Lincoln Park purchased 102,040 Purchase Shares at a purchase price of $2.94 per share, for a total gross purchase price of $3.0 million (the “Initial Purchase”), and the Company issued 25,244 shares of common stock to Lincoln Park as a commitment fee in connection with entering into the Purchase Agreement. The Company recognized $0.8 million of other expense relating to the commitment fee share issuance. From the date of the agreement through December 31, 2022, the Company had initiated the purchase of an additional 380,000 shares of the Company’s common stock amounting to $6.2 million in gross proceeds. The Company has initiated no purchases through the Purchase Agreement for the three- and nine-month period ended September 30, 2023.

Under the Purchase Agreement, the Company has sole discretion, subject to certain conditions, on any business day selected by the Company to require Lincoln Park to purchase up to 10,000 shares of common stock (the “Regular Purchase Amount”) at the Purchase Price (as defined below) per purchase notice (each such purchase, a “Regular Purchase”). The Regular Purchase Amount may be increased as follows: up to 15,000 shares if the closing price is not below $35.00, up to 20,000 shares if the closing price is not below $50.00, and up to 25,000 shares if the closing price is not below $70.00. Lincoln Park’s committed obligation under each Regular Purchase is capped at $2,000,000, unless the parties agree otherwise. The purchase price for Regular Purchases (the “Purchase Price”) shall be equal to the lesser of: (i) the lowest sale price of the common shares during the Purchase Date, or (ii) the average of the three (3) lowest closing sale prices of the common shares during the ten (10) business days prior to the Purchase Date.

In addition to Regular Purchases and subject to certain conditions and limitations, the Company in its sole discretion may require Lincoln Park on each Purchase Date to purchase on the following business day up to the lesser of (i) three (3) times the number of shares purchased pursuant to such Regular Purchase or (ii) 30% of the trading volume on the Accelerated Purchase Date (the “Accelerated Purchase”) (unless the Parties agree otherwise) at a purchase price equal to the lesser of 97% of (i) the closing sale price on the Accelerated Purchase Date, or (ii) the Accelerated Purchase Date’s volume weighted average price (the “Accelerated Purchase Price”). The Company has the sole right to set a minimum price threshold for each Accelerated Purchase in the notice provided with respect to such Accelerated Purchase and under certain circumstances and in accordance with the Purchase Agreement the Company may direct multiple Accelerated Purchases in a day.

The aggregate number of shares that the Company can sell to Lincoln Park under the Purchase Agreement may not exceed 1,106,580 shares of the common stock (which is equal to approximately 19.99% of the shares of the common stock outstanding immediately prior to the execution of the Purchase Agreement) (the “Exchange Cap”), unless (i) shareholder approval is obtained to issue Purchase Shares above the Exchange Cap, in which the Exchange Cap will no longer apply, or (ii) the average price of all applicable sales of common stock to Lincoln Park under the Purchase Agreement equals or exceeds $29.40 per share; provided that at no time may Lincoln Park (together with its affiliates) beneficially own more than 9.99% of the Company’s issued and outstanding common stock.

The Purchase Agreement contains customary representations, warranties, covenants, closing conditions, indemnification and termination provisions. The Purchase Agreement may be terminated by the Company at any time,

at its sole discretion, without any cost or penalty, by giving one business day notice to Lincoln Park. Further, Lincoln Park has covenanted not to engage in any direct or indirect short selling or hedging of the Common Shares. There are no limitations on the use of proceeds, financial or business covenants, restrictions on future financings (other than restrictions on the Company’s ability to enter into a similar type of agreement or Equity Line of Credit during the Term, excluding an At-The-Market transaction with a registered broker-dealer), rights of first refusal, participation rights, penalties or liquidated damages in the Purchase Agreement. Issuances under the Purchase Agreement were to be made pursuant to the Company's Registration Statement on Form S-3 filed in July 2019, which has since expired. The Company would need to file a new prospectus supplement covering issuances under the Purchase Agreement in order to continue using the facility.

The entire disclosure for equity.

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Fair Value Measurements - Summary of Financial Assets and Liabilities Subject to Fair Value Measurements on Recurring Basis and Level of Inputs Used in Measurements (Details) - USD ($)
$ in Thousands

Sep. 30, 2023

Dec. 31, 2022

Assets:

$ 4,912

$ 5,083

Total assets subject to fair value measurements

38,063

82,059

^[1]

42,975

87,142

Level 1

Assets:

Total assets subject to fair value measurements

4,912

5,083

4,912

5,083

Level 2

Assets:

Total assets subject to fair value measurements

38,063

82,059

38,063

82,059

Money market funds

Assets:

Money market funds | Level 1

4,912

5,083

Assets:

4,912

5,083

U.S. Treasuries

Assets:

U.S. Treasuries | Level 2

7,736

30,758

Assets:

U.S. government debt securities

7,736

30,758

Assets:

U.S. government debt securities | Level 2

30,327

51,301

Assets:

Investments, Debt and Equity Securities [Abstract]

$ 30,327

$ 51,301

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Marketable Securities

9 Months Ended

Sep. 30, 2023

Marketable Securities

4. Marketable Securities

Marketable securities, which are classified as available-for-sale, consisted of the following as of September 30, 2023, (in thousands):


	Amortized Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market funds	$	4,912	$	—	$	—		$	4,912
Total cash equivalents		4,912		—		—			4,912
Short-term marketable securities:
U.S. treasuries		7,759		—		(23	)		7,736
U.S. government debt securities		30,359		1		(33	)		30,327
Total short-term marketable securities		38,118		1		(56	)		38,063
Total	$	43,030	$	1	$	(56	)	$	42,975

Marketable securities, which are classified as available-for-sale, consisted of the following as of December 31, 2022 (in thousands):


	Amortized Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market funds	$	5,083	$	—	$	—		$	5,083
Total cash equivalents		5,083		—		—			5,083
Short-term marketable securities:
U.S. treasuries		30,820		1		(63	)		30,758
U.S. government debt securities		51,491		6		(196	)		51,301
Total short-term marketable securities		82,311		7		(259	)		82,059
Total	$	87,394	$	7	$	(259	)	$	87,142

At September 30, 2023, the remaining contractual maturities of available-for-sale securities were less than one year. There have been no significant realized gains or losses on available-for-sale securities for the periods presented. As of September 30, 2023, the Company did not hold any individual securities in an unrealized loss position for 12 months or greater. The Company has the ability and intent to hold all marketable securities that have been in a continuous loss position until maturity or recovery. No significant facts or circumstances have arisen to indicate that there has been any significant deterioration in the creditworthiness of the issuers of the securities held by the Company. The Company considered the current and expected future economic and market conditions and determined that the estimate of credit losses was not significantly impacted. Thus, there has been no change in estimate of expected credit loss during the three and nine months ended September 30, 2023 and no allowance for credit loss was recorded at September 30, 2023. The Company will continue to assess the current and expected future economic and market conditions as further development arises.

See Note 3, “Fair Value Measurements,” for further information regarding the fair value of the Company’s financial instruments.

Condensed Statements of Stockholders' Equity (Unaudited) - USD ($)
$ in Thousands

Total

Hercules Capital

ATM Equity Offering Program

Follow On Offering

Equity Purchase Agreement

Lincoln Park Capital Fund LLC

Common Stock

Hercules Capital

Common Stock

ATM Equity Offering Program

Common Stock

Follow On Offering

Common Stock

Equity Purchase Agreement

Lincoln Park Capital Fund LLC

Additional Paid-In Capital

Hercules Capital

Additional Paid-In Capital

ATM Equity Offering Program

Additional Paid-In Capital

Follow On Offering

Additional Paid-In Capital

Equity Purchase Agreement

Lincoln Park Capital Fund LLC

Accumulated Other Comprehensive (Loss)

Accumulated Deficit

Beginning balance at Dec. 31, 2021

$ 59,569

$ 1

$ 459,636

$ (44)

$ (400,024)

Beginning balance, (in shares) at Dec. 31, 2021

^[1]

6,299,158

$ 3,179

$ 3,420

$ 910

$ 3,179

$ 3,420

$ 910

^[1]

262,761

232,500

90,000

^[1]

30,358

Unrealized gain (loss) on marketable debt securities

2,660

(132)

Ending balance at Mar. 31, 2022

(18,915)

50,691

$ 1

469,805

(176)

(418,939)

Ending balance, (in shares) at Mar. 31, 2022

^[1]

6,914,777

Beginning balance at Dec. 31, 2021

59,569

$ 1

459,636

(44)

(400,024)

Beginning balance, (in shares) at Dec. 31, 2021

^[1]

6,299,158

Ending balance at Sep. 30, 2022

(45,758)

78,565

$ 1

524,623

(275)

(445,784)

Ending balance, (in shares) at Sep. 30, 2022

^[1]

14,036,215

Beginning balance at Mar. 31, 2022

50,691

$ 1

469,805

(176)

(418,939)

Beginning balance, (in shares) at Mar. 31, 2022

^[1]

6,914,777

Issuance of common stock under 2018 ESPP

125

Issuance of common stock under 2018 ESPP (in Shares)

^[1]

18,202

^[1]

25,481

Unrealized gain (loss) on marketable debt securities

2,250

(11)

Ending balance at Jun. 30, 2022

(13,137)

39,931

$ 1

472,193

(187)

(432,076)

Ending balance, (in shares) at Jun. 30, 2022

^[1]

6,958,460

8,570

$ 41,650

8,570

$ 41,650

^[1]

633,464

6,428,571

^[1]

15,720

Unrealized gain (loss) on marketable debt securities

2,210

(88)

Ending balance at Sep. 30, 2022

(13,708)

78,565

$ 1

524,623

(275)

(445,784)

Ending balance, (in shares) at Sep. 30, 2022

^[1]

14,036,215

Beginning balance at Dec. 31, 2022

$ 66,848

^[2]

$ 1

527,049

(251)

(459,951)

Beginning balance, (in shares) at Dec. 31, 2022

14,215,302

274

106,781

37,131

Unrealized gain (loss) on marketable debt securities

$ 2,270

2,270

101

Ending balance at Mar. 31, 2023

(10,865)

58,628

$ 1

529,593

(150)

(470,816)

Ending balance, (in shares) at Mar. 31, 2023

14,359,214

Beginning balance at Dec. 31, 2022

$ 66,848

^[2]

$ 1

527,049

(251)

(459,951)

Beginning balance, (in shares) at Dec. 31, 2022

14,215,302

Ending balance at Sep. 30, 2023

$ (38,362)

$ 36,206

$ 1

534,570

(55)

(498,310)

Ending balance, (in shares) at Sep. 30, 2023

14,614,890

Beginning balance at Mar. 31, 2023

$ 58,628

$ 1

529,593

(150)

(470,816)

Beginning balance, (in shares) at Mar. 31, 2023

14,359,214

518

Issuance of common stock under 2018 ESPP

168,000

Issuance of common stock under 2018 ESPP (in Shares)

41,497

26,766

Unrealized gain (loss) on marketable debt securities

2,361

Ending balance at Jun. 30, 2023

(12,205)

49,407

$ 1

532,563

(136)

(483,021)

Ending balance, (in shares) at Jun. 30, 2023

14,595,477

$ (48)

19,413

Unrealized gain (loss) on marketable debt securities

2,055

Ending balance at Sep. 30, 2023

(15,289)

$ 36,206

$ 1

$ 534,570

$ (55)

$ (498,310)

Ending balance, (in shares) at Sep. 30, 2023

14,614,890

[1]

The Company effected a reverse stock split of its outstanding shares of common stock on October 19, 2022 where every ten shares of its common stock issued and outstanding was converted into one share of common stock. Any fractional post-split shares as a result of the reverse split were rounded down to the nearest whole post-split share. Shareholders of the Company previously authorized the Board of Directors to approve a reverse stock split at the annual meeting on October 18, 2022. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.

[2]

The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2023

Fair Value Disclosures [Abstract]

Summary of Financial Assets and Liabilities Subject to Fair Value Measurements on Recurring Basis and Level of Inputs Used in Measurements

The Company’s financial assets and liabilities subject to fair value measurements and the level of inputs used in such measurements were as follows (in thousands):


	September 30, 2023
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Money market funds	$	4,912	$	4,912	$	—	$	—
Total cash equivalents		4,912		4,912		—		—
Short-term marketable securities:
U.S. treasuries		7,736		—		7,736		—
U.S. government debt securities		30,327		—		30,327		—
Total short-term marketable securities		38,063		—		38,063		—
Total assets subject to fair value measurements	$	42,975	$	4,912	$	38,063	$	—


	December 31, 2022
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Money market funds	$	5,083	$	5,083	$	—	$	—
Total cash equivalents		5,083		5,083		—		—
Short-term marketable securities:
U.S. treasuries		30,758		—		30,758		—
U.S. government debt securities		51,301		—		51,301		—
Total short-term marketable securities		82,059		—		82,059		—
Total assets subject to fair value measurements	$	87,142	$	5,083	$	82,059	$	—

Stock-Based Compensation - Summary of Restricted Stock Units, Performance Stock Units and Restricted Stock Awards Activity (Details) - RSU, RSA and PSU	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Unvested at December 31, 2022 \| shares	146,333
Shares, Vested \| shares	(83,310)
Shares, Canceled \| shares	(3,658)
Shares, Unvested at June 30, 2023 \| shares	59,365
Weighted-Average Grant Date Fair Value, Unvested at December 31, 2022 \| $ / shares	$ 27.66
Weighted-Average Grant Date Fair Value, Vested \| $ / shares	30.07
Weighted-Average Grant Date Fair Value, Canceled \| $ / shares	4.76
Weighted-Average Grant Date Fair Value, Unvested at June 30, 2023 \| $ / shares	$ 25.65

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization

9 Months Ended

Sep. 30, 2023

Organization

1. Organization

Description of Business

Unity Biotechnology, Inc. (the “Company”) is a biotechnology company engaged in the research and development of therapeutics to slow, halt, or reverse diseases of aging. The Company devotes substantially all of its time and efforts to performing research and development and raising capital. The Company’s headquarters are located in South San Francisco, California. The Company was incorporated in the State of Delaware in 2009.

Liquidity

The accompanying unaudited condensed financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. The Company has incurred operating losses and has an accumulated deficit as a result of ongoing efforts to develop drug product candidates, including conducting preclinical and clinical trials and providing general and administrative support for these operations. The Company had an accumulated deficit of $498.3 million and $460.0 million as of September 30, 2023 and December 31, 2022, respectively. The Company had net losses of $15.3 million and $13.7 million for the three months ended September 30, 2023 and 2022, respectively, net losses of $38.4 million and $45.8 million for the nine months ended September 30, 2023 and 2022, respectively, and net cash used in operating activities of $29.5 million and $40.7 million for the nine months ended September 30, 2023 and 2022, respectively. To date, none of the Company’s drug product candidates have been approved for sale, and therefore, the Company has not generated any product revenue and does not expect positive cash flows from operations in the foreseeable future. The Company has financed its operations primarily through private placements of preferred stock and promissory notes, public equity issuances and more recently, from its ATM Offering Programs (as defined in Note 10), an Equity Purchase Agreement (as defined in Note 10), and the sale of common stock and warrants under a Follow-On Offering (as defined in Note 10) and will continue to be dependent upon equity and/or debt financing until the Company is able to generate positive cash flows from its operations.

The Company had cash, cash equivalents, and marketable securities of $45.9 million as of September 30, 2023. The Company anticipates operating losses and negative operating cash flows to continue for the foreseeable future. During the nine months ended September 30, 2023, management effectuated a reduction in expenditures including a 29% reduction in force and reduced clinical program spend related to its Tie2 bispecific program. The future viability of the Company is dependent on its ability to raise additional capital to finance its operations. Although the Company has been successful in raising capital in the past, there is no assurance that it will be successful in obtaining such additional financing. If sufficient funds on acceptable terms are not available when needed, the Company could be further required to significantly reduce its operating expenses and delay, reduce the scope of, or eliminate one or more of its development programs. Failure to manage discretionary spending or raise additional financing, as needed, may adversely impact the Company’s ability to achieve its intended business objectives. The Company expects that its cash, cash equivalents, and marketable securities will be sufficient to fund its operations for a period of at least one year from the date the accompanying unaudited condensed financial statements are filed with the Securities and Exchange Commission.

License Revenue and Agreements - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2019	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2021	Dec. 31, 2022
Research And Development Arrangement Contract To Perform For Others [Line Items]
Revenue recognized					$ 236,000
Common stock, shares issued		14,614,890		14,614,890			14,215,302
Ascentage Pharma
Research And Development Arrangement Contract To Perform For Others [Line Items]
Compound library and option agreement execution month and year				2016-02
Compound library and option agreement expiration month and year				2022-02
Ascentage Pharma \| Licensed Products
Research And Development Arrangement Contract To Perform For Others [Line Items]
Royalties due from sales				$ 0
License Agreement \| Jocasta Neuroscience Inc
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront cash payments received						$ 5,000,000
Revenue recognized		$ 0	$ 0	0	200,000
Deferred revenue		0		0			$ 0
Other Licensing Agreements with Research Institutions
Research And Development Arrangement Contract To Perform For Others [Line Items]
Contingent consideration, milestone or royalty payments		0	$ 0	0	$ 0
Other Licensing Agreements with Research Institutions \| UCSF
Research And Development Arrangement Contract To Perform For Others [Line Items]
Common shares expected to be issued	3,400
Contingent consideration, milestone or royalty payments		$ 0		$ 0
Maximum milestone payments for each product licensed under agreement	$ 13,600,000
Commercial Agreements \| Ascentage Pharma
Research And Development Arrangement Contract To Perform For Others [Line Items]
Equity payments percentage				80.00%
Common stock, shares issued		0		0
Commercial Agreements \| Ascentage Pharma \| Maximum
Research And Development Arrangement Contract To Perform For Others [Line Items]
Contingent consideration additional common stock issued for one licensed product				93,333
Contingent consideration additional common stock issued for two or more licensed product				133,333
Milestone payments				$ 70,300,000
Commercial Agreements \| Ascentage Pharma \| Initial License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
License agreement termination month and year				2020-07
License agreement execution month and year				2016-02
Commercial Agreements \| Ascentage Pharma \| Second License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
License agreement execution month and year				2019-01
Commercial Agreements \| Affiliate of Clinical-Stage Biopharmaceutical Company
Research And Development Arrangement Contract To Perform For Others [Line Items]
Equity payments percentage				20.00%

Commitments and Contingencies - Summary of Supplemental Information Related to Leases (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Operating cash flows from operating leases	$ 3,599	$ 5,109
Operating leases, Weighted-average remaining lease term (years)	6 years 3 months 18 days	7 years 3 months 18 days
Operating leases, Weighted-average discount rate (percentage)	6.00%	6.00%

Term Loan Facility

9 Months Ended

Sep. 30, 2023

Debt Disclosure [Abstract]

Term Loan Facility

9. Term Loan Facility

On August 3, 2020, the Company entered into a Loan and Security Agreement (as amended, restated, supplemented or otherwise modified, the "Hercules Loan Agreement") with Hercules Capital, Inc. (“Hercules”), as administrative agent and collateral agent for the lenders, and certain banks and other financial institutions or entities from time to time parties thereto, for an aggregate principal amount of up to $80.0 million secured term loan facility (the "Hercules Facility") subject to certain terms and conditions. The first tranche of $25.0 million was advanced to the Company on the date the Loan Agreement was executed. The maturity date under the Hercules Loan Agreement was August 1, 2024.

On September 6, 2023, the Company and Hercules entered into a payoff letter for a voluntary prepayment with respect to the Hercules Loan Agreement (the “Payoff Letter”). Pursuant to the Payoff Letter, the Company paid a total of $15.0 million to Hercules, representing the outstanding principal, accrued and unpaid interest, fees, costs and expenses due to Hercules under the Hercules Facility and the Hercules Loan Agreement and related loan documents, in repayment of the Company’s outstanding obligations under the Hercules Facility and the Hercules Loan Agreement and related loan documents, and thereby terminated the Hercules Loan Agreement and the Hercules Facility and related loan documents. Under the terms of the Hercules Loan Agreement, no early termination penalty was payable as a result of such prepayment and termination as of such date. The Company recorded a loss on extinguishment of debt of $0.5 million under "Other Income (Expense), net" in the unaudited condensed financial statements for the three and nine months ended September 30, 2023 related to the write-off of the remaining balance of unamortized debt discount.

Pursuant to the Payoff Letter, the lenders’ commitments to extend further credit to the Company terminated; Hercules released and terminated all liens or security interests granted to secure the obligations under the Hercules Loan Agreement and the Company was unconditionally released from its respective guaranties and obligations under the

Hercules Facility and the Hercules Loan Agreement and related loan documents without further action (other than with respect to customary provisions and agreements that are expressly specified to survive the termination). Hercules returned to the Company, for the benefit of the Company, all of the collateral that it had in its possession.

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Share-Based Payment Arrangement [Abstract]

Defined Contribution Plan - Additional Information (Details) - Defined Contribution Plan - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2019	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Defined Contribution Plan Disclosure [Line Items]
Percent of employer matching contribution of employees' salary	4.00%
Defined Contribution Plan, Sponsor Location [Extensible Enumeration]	us-gaap:DomesticPlanMember
Matching contributions		$ 0.1	$ 0.1	$ 0.2	$ 0.4

Stock-Based Compensation - Summary of Stock Option Activity (Details)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Number of Shares
Balances at December 31, 2022 \| shares	1,609,938
Granted \| shares	421,600
Canceled \| shares	(28,155)
Balances at June 30, 2023 \| shares	2,003,383
Weighted-Average Exercise Price
Balances at December 31, 2022 \| $ / shares	$ 27.51
Granted \| $ / shares	2.85
Canceled \| $ / shares	18.14
Balances at June 30, 2023 \| $ / shares	$ 13.88

Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2023

Summary of Stock Option Activity

A summary of the Company’s stock option activity under the 2013 Equity Incentive Plan, 2018 Incentive Award Plan (the "2018 Plan"), and 2020 Employment Inducement Incentive Plan for the nine months ended September 30, 2023 is as follows:


	Number of Shares			Weighted- Average Exercise Price
Balances at December 31, 2022		1,609,938		$	27.51
Granted		421,600		$	2.85
Canceled		(28,155	)	$	18.14
Balances at September 30, 2023		2,003,383		$	13.88

Summary of Restricted Stock Units, Performance Stock Units and Restricted Stock Awards Activity

A summary of the Company’s restricted stock units (“RSUs”), performance stock units (“PSUs”), and restricted stock awards (“RSAs”) activity for the nine months ended September 30, 2023 is as follows:


	Number of Shares			Weighted- Average Grant Date Fair Value
Unvested at December 31, 2022		146,333		$	27.66
Granted		—		$	—
Vested		(83,310	)	$	30.07
Canceled		(3,658	)	$	4.76
Unvested at September 30, 2023		59,365		$	25.65

Summary of Stock-based Compensation Expense

The following table sets forth the total stock-based compensation expense for all options granted to employees and nonemployees, including shares sold through the issuance of non-recourse promissory notes which are considered to be options for accounting purposes, and costs associated with the Company’s 2018 Employee Stock Purchase Plan (“2018 ESPP”) included in the Company’s condensed statements of operations and comprehensive loss (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Research and development	$	674	$	799	$	2,239	$	2,723
General and administrative		1,381		1,411		4,447		4,397
Total	$	2,055	$	2,210	$	6,686	$	7,120

Condensed Statements of Operations and Comprehensive Loss (Parenthetical) (Unaudited)	Oct. 19, 2022
Statement of Comprehensive Income [Abstract]
Reverse stock split ratio	0.1

Stock-Based Compensation - Additional Information (Details) $ / shares in Units, $ in Millions	May 11, 2023 USD ($) Employee $ / shares shares	May 04, 2023 $ / shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Restructuring implementation date		May 04, 2023
2018 Incentive Award Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Exercise price \| $ / shares	$ 2.77	$ 6
Number of employees who met the eligibility terms \| Employee	26
Number of shares of common stock under option grants that met the eligibility criteria	444,273
Additional stock-based compensation from vested options \| $	$ 0.2
Number of vested options	251,821
Number of unvested options	192,452
Anticipated additional amount expensed \| $	$ 0.1

Condensed Balance Sheets (Unaudited) - USD ($)
$ in Thousands

Sep. 30, 2023

Dec. 31, 2022

Current assets:

Cash and cash equivalents

$ 7,876

$ 12,736

^[1]

Prepaid expenses and other current assets

38,063

82,059

^[1]

3,599

1,740

^[1]

Total current assets

49,538

96,535

^[1]

Property and equipment, net

5,314

7,825

^[1]

Operating lease right-of-use assets

13,522

19,042

^[1]

Long-term restricted cash

896

^[1]

Other long-term assets

^[1]

Total assets

69,270

124,350

^[1]

Current liabilities:

Accounts payable

1,149

1,790

^[1]

Accrued compensation

2,226

3,020

^[1]

Accrued and other current liabilities

5,258

5,334

^[1]

Current portion of long-term debt

9,476

^[1]

Total current liabilities

8,633

19,620

^[1]

Operating lease liability, net of current portion

24,431

26,991

^[1]

Long-term debt, net of current portion

10,891

^[1]

Total liabilities

33,064

57,502

^[1]

Commitments and contingencies (Note 8)

Stockholders’ equity:

Convertible preferred stock, $0.0001 par value; 10,000,000 shares authorized; no shares issued and outstanding

^[1]

Common stock, $0.0001 par value; 300,000,000 shares authorized as of September 30, 2023 and December 31, 2022; 14,614,890 and 14,215,302 shares issued and outstanding as of September 30, 2023 and December 31, 2022, respectively

^[2]

^[1]

Additional paid-in capital

534,570

527,049

^[1]

Accumulated other comprehensive loss

(55)

(251)

^[1]

Accumulated deficit

(498,310)

(459,951)

^[1]

Total stockholders’ equity

36,206

66,848

^[1]

Total liabilities and stockholders’ equity

$ 69,270

$ 124,350

^[1]

[1]

The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

[2]

Marketable Securities - Additional Information (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Marketable Securities [Line Items]
Realized gains or losses on available-for-sale debt securities	$ 0	$ 0
Maximum
Marketable Securities [Line Items]
Available-for sale securities, remaining contractual maturity	1 year

Subsequent Events - Additional Information (Details) - Subsequent Event $ / shares in Units, $ in Thousands	Nov. 09, 2023 USD ($) $ / shares shares
Placement Agent Warrants \| Placement Agent
Subsequent Event [Line Items]
Warrants issued to purchase common stock \| shares	128,580
Exercise price for warrant	$ 2.5563
Inducement Letter \| Existing Warrants \| Holders
Subsequent Event [Line Items]
Warrants issued to purchase common stock \| shares	2,143,000
Exercise price for warrant	$ 8.5
Reduced exercise price of warrant	$ 2.045
Expected aggregate gross proceeds from exercise of warrants \| $	$ 4,380
Inducement Letter \| New Warrants \| Holders
Subsequent Event [Line Items]
Warrants issued to purchase common stock \| shares	2,143,000
Exercise price for warrant	$ 1.92
Inducement Letter \| New Warrants \| Holders \| Maximum
Subsequent Event [Line Items]
Warrants exercisable term	5 years

Stock-Based Compensation - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,055	$ 2,210	$ 6,686	$ 7,120
Research And Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	674	799	2,239	2,723
General And Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,381	$ 1,411	$ 4,447	$ 4,397

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2023

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation

These condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for interim reporting.

Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted. Accordingly, the unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 filed with the SEC.

The Company effected a reverse stock split on October 19, 2022 of its outstanding shares of common stock at a ratio of 1-for-10 pursuant to a Certificate of Amendment to the Company's Certificate of Incorporation filed with the Secretary of State of the State of Delaware. The reverse stock split was reflected on the Nasdaq Global Select Market beginning with the opening of trading on October 20, 2022. The reverse stock split did not change the par value of the Company's common stock or the authorized number of shares of the Company's common stock. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.

Unaudited Condensed Financial Statements

The accompanying financial information for the three and nine months ended September 30, 2023 and 2022 are unaudited. The unaudited condensed financial statements have been prepared on the same basis as the annual audited financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s financial position as of September 30, 2023 and its results of operations for the three and nine months ended September 30, 2023 and 2022 and cash flows for the nine months ended September 30, 2023 and 2022. The results for interim periods are not necessarily indicative of the results expected for the full fiscal year or any other periods.

Use of Estimates

The condensed financial statements have been prepared in accordance with GAAP, which requires management to make estimates and assumptions that affect the amounts and disclosures reported in the condensed financial statements and accompanying notes. The Company bases its estimates on historical experience and market-specific or other relevant assumptions that it believes are reasonable under the circumstances. The amounts of assets and liabilities reported in the Company’s condensed balance sheets and the amount of expenses and income reported for each of the periods presented are affected by estimates and assumptions, which are used for, but are not limited to, determining the fair value of assets and liabilities, the fair value of right-of-use assets and lease liabilities, and stock-based compensation. Actual results could differ from such estimates or assumptions.

Impairment of Long-Lived Assets

The Company evaluates long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be fully recoverable. If indicators of impairment exist and the undiscounted future cash flows that the assets are expected to generate are less than the carrying value of the assets, the Company reduces the carrying amount of the assets through an impairment charge, to their estimated fair value based on a discounted cash flow approach or, when available and appropriate, to comparable market values.

Segments

The Company has one operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a consolidated basis for the purposes of allocating resources.

Recently Adopted Accounting Pronouncements

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments, as clarified in subsequent amendments. ASU 2016-13 changes the impairment model for certain financial instruments. The new model is a forward-looking expected loss model and will apply to financial assets subject to credit losses and measured at amortized cost and certain off-balance sheet credit exposures. This includes loans, held-to-maturity debt securities, loan commitments, financial guarantees and net investments in leases, as well as trade receivables. For available-for-sale debt securities with unrealized losses, credit losses will be measured in a manner similar to today, except that the losses will be recognized as allowances rather than reductions in the amortized cost of the securities. In October 2019, the FASB voted to delay the effective date of this standard. Topic 326 will be effective for the Company for fiscal years beginning after December 15, 2022. Early adoption is permitted. We adopted ASU 2016-13 on January 1, 2023 and the adoption did not have a material impact on the Company’s condensed financial statements and related disclosures.

In November 2021, the FASB issued ASU 2021-10, Government Assistance, or Topic 832, which requires enhanced disclosures of transactions with governments that are accounted for by applying a grant or contribution model. The

new pronouncement requires entities to provide information about the nature of the transaction, terms and conditions associated with the transaction and financial statement line items affected by the transaction. The Company adopted the standard for the annual period beginning January 1, 2023. The employee retention credit received under the CARES Act qualifies as a government assistance program under Topic 832 and resulted in enhanced required disclosures, as described in Note 7, "Government Assistance Program".

Net Loss per Common Share - Schedule of Reconciliation of Numerators and Denominators Used In Computing Net Loss From Continuing Operations Per Share (Details) - USD ($)
$ / shares in Units, $ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2023

Jun. 30, 2023

Mar. 31, 2023

Sep. 30, 2022

Jun. 30, 2022

Mar. 31, 2022

Sep. 30, 2023

Sep. 30, 2022

Numerator:

Weighted-average number of shares outstanding—basic

$ (15,289)

$ (12,205)

$ (10,865)

$ (13,708)

$ (13,137)

$ (18,915)

$ (38,362)

$ (45,758)

Denominator:

^[1]

14,598,218

10,072,077

14,446,672

7,928,729

Weighted-average number of shares outstanding—diluted

^[1]

14,598,218

10,072,077

14,446,672

7,928,729

Net loss per share, basic

$ (1.05)

$ (1.36)

$ (2.66)

$ (5.77)

Net loss per share, diluted

$ (1.05)

$ (1.36)

$ (2.66)

$ (5.77)

[1]

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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Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Prepaid Expenses and Other Current Assets

9 Months Ended

Sep. 30, 2023

Prepaid Expenses and Other Current Assets

5. Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following:


	September 30, 2023		December 31, 2022
Prepaid research and development expenses	$	328	$	378
Prepaid insurance expenses		931		710
Tax credit receivable		1,493		—
Interest receivable		218		235
Other prepaid expenses and current assets		629		417
Total prepaid expenses & other current assets	$	3,599	$	1,740

Organization - Additional Information (Details) - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2023

Jun. 30, 2023

Mar. 31, 2023

Sep. 30, 2022

Jun. 30, 2022

Mar. 31, 2022

Sep. 30, 2023

Sep. 30, 2022

Dec. 31, 2022

^[1]

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Accumulated deficit

$ (498,310)

$ (459,951)

Cash, cash equivalents and marketable securities

(15,289)

$ (12,205)

$ (10,865)

$ (13,708)

$ (13,137)

$ (18,915)

(38,362)

$ (45,758)

Cash used in operations

(29,513)

(40,663)

Product revenue

$ 0

$ 45,900

Percentage of reduction in force

29.00%

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

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

Amount of accumulated undistributed earnings (deficit).

+ References + Details

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

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Restructuring and Related Activities [Abstract]

Term Loan Facility - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023	Sep. 06, 2023	Aug. 03, 2020
Debt Instrument [Line Items]
Loss on extinguishment of debt	$ (0.5)	$ (0.5)
Term Loan \| Payoff Letter Loan Agreement \| Hercules Capital
Debt Instrument [Line Items]
Debt payoff amount			$ 15.0
Secured Term Loan Facility \| Loan Agreement \| Hercules Capital
Debt Instrument [Line Items]
Principal amount of first tranche				$ 25.0
Long-term debt, maturity date				Aug. 01, 2024
Secured Term Loan Facility \| Loan Agreement \| Hercules Capital \| Maximum
Debt Instrument [Line Items]
Debt instrument aggregate principal amount				$ 80.0

Corporate Restructuring

9 Months Ended

Sep. 30, 2023

Corporate Restructuring

11. Corporate Restructuring

In May 2023, the Company implemented a reduction in its workforce to align operations with the changes in its corporate strategy to focus on resource optimization to enable the initiation and advancement of key data readouts. The reduction decreased its headcount by nine employees, or approximately 29% of the Company’s workforce, effective as of May 31, 2023 with three employees who departed as of June 30, 2023. The Company recognized the employee benefits and severance charge of approximately $0.6 million in operating expenses in the second quarter of 2023. Restructuring charges primarily consisted of employee termination benefits, which included $0.5 million of severance costs, $0.1 million of employee-related benefits, and a negligible amount of payroll taxes. Charges and other costs related to the restructuring, and non-cash share-based compensation credits related to the forfeiture of stock options were negligible and are included in operating expenses in the condensed statements of operations and comprehensive loss. Of the total charge, $0.4 million was recorded to research and development expenses and $0.2 million was recorded to general and administrative expenses during the nine months ended September 30, 2023.

Summary of Significant Accounting Policies - Additional Information (Details)		9 Months Ended
	Oct. 19, 2022	Sep. 30, 2023 Segment
Reverse stock split ratio	0.1
Number of operating segment		1
ASU 2016-13
Change in accounting principle, accounting standards update, adopted [true false]		true
Accounting standards, adoption date		Jan. 01, 2023
Change in accounting principle, accounting standards update, immaterial effect [true false]		true
ASU 2021-10
Change in accounting principle, accounting standards update, adopted [true false]		true
Accounting standards, adoption date		Jan. 01, 2023

Indicates (true false) whether accounting standards update was adopted.

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Date accounting standards update was adopted, in YYYY-MM-DD format.

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Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2023

Summary of Components of Lease Expense

The following table summarizes the components of lease expense, which are included in operating expenses in the Company’s condensed statements of operations and comprehensive loss (in thousands):


	Three Months Ended September 30,						Nine Months Ended September 30,
	2023			2022			2023			2022
Operating lease cost	$	930		$	1,088		$	2,790		$	3,239
Variable lease cost		203			407			546			1,114
Sublease income		(976	)		(1,391	)		(2,904	)		(3,405	)
Total lease cost	$	157		$	104		$	432		$	948

Summary of Supplemental Information Related to Leases

The following table summarizes supplemental information related to leases (in thousands):


	Nine Months Ended September 30,
	2023			2022
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$	3,599		$	5,109
Weighted-average remaining lease term (years)
Operating leases		6.3			7.3
Weighted-average discount rate (percentage)
Operating leases		6.0	%		6.0	%

Summary of Maturities of Lease Liabilities

The following table summarizes the maturities of lease liabilities as of September 30, 2023 (in thousands):


	Amount
2023 (remaining 3 months)	$	1,211
2024		4,964
2025		5,123
2026		5,287
2027		5,457
Thereafter		11,435
Total future minimum lease payments		33,477
Less: Amount representing interest		(5,684	)
Present value of future minimum lease payments		27,793
Less: Current portion of operating lease liability		(3,362	)
Noncurrent portion of operating lease liability	$	24,431

Marketable Securities - Summary of Marketable Securities Classified as Available-for-Sale (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	$ 43,030	$ 87,394
Unrealized Gains	1	7
Unrealized Losses	(56)	(259)
Fair Value	42,975	87,142
Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	4,912	5,083
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	4,912	5,083
Cash Equivalents \| Money market funds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	4,912	5,083
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	4,912	5,083
Short Term Marketable Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	38,118	82,311
Unrealized Gains	1	7
Unrealized Losses	(56)	(259)
Fair Value	38,063	82,059
Short Term Marketable Securities \| U.S. government debt securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	30,359	51,491
Unrealized Gains	1	6
Unrealized Losses	(33)	(196)
Fair Value	30,327	51,301
Short Term Marketable Securities \| U S Treasuries
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	7,759	30,820
Unrealized Gains	0	1
Unrealized Losses	(23)	(63)
Fair Value	$ 7,736	$ 30,758

Condensed Balance Sheets (Parenthetical) (Unaudited)	Sep. 30, 2023 $ / shares shares	Dec. 31, 2022 $ / shares shares
Statement of Financial Position [Abstract]
Convertible preferred stock, par value \| $ / shares	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	10,000,000	10,000,000
Convertible preferred stock, shares issued	0	0
Convertible preferred stock, shares outstanding	0	0
Common stock, par value \| $ / shares	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	14,614,890	14,215,302
Common stock, shares outstanding	14,614,890	14,215,302

Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2023

Investments, Debt and Equity Securities [Abstract]

Summary of Marketable Securities Classified as Available-for-Sale

Marketable securities, which are classified as available-for-sale, consisted of the following as of September 30, 2023, (in thousands):


	Amortized Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market funds	$	4,912	$	—	$	—		$	4,912
Total cash equivalents		4,912		—		—			4,912
Short-term marketable securities:
U.S. treasuries		7,759		—		(23	)		7,736
U.S. government debt securities		30,359		1		(33	)		30,327
Total short-term marketable securities		38,118		1		(56	)		38,063
Total	$	43,030	$	1	$	(56	)	$	42,975

Marketable securities, which are classified as available-for-sale, consisted of the following as of December 31, 2022 (in thousands):


	Amortized Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market funds	$	5,083	$	—	$	—		$	5,083
Total cash equivalents		5,083		—		—			5,083
Short-term marketable securities:
U.S. treasuries		30,820		1		(63	)		30,758
U.S. government debt securities		51,491		6		(196	)		51,301
Total short-term marketable securities		82,311		7		(259	)		82,059
Total	$	87,394	$	7	$	(259	)	$	87,142

Tabular disclosure of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

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-SubTopic 10
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-Section 50
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-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
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-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($)
$ in Thousands

Sep. 30, 2023

Dec. 31, 2022

Prepaid research and development expenses

$ 328

$ 378

Prepaid insurance expenses

931

710

Tax credit receivable

1,493

Interest receivable

218

235

Other prepaid expenses and current assets

629

417

Total prepaid expenses & other current assets

$ 3,599

$ 1,740

^[1]

[1]	The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Defined Contribution Plan

9 Months Ended

Sep. 30, 2023

Retirement Benefits [Abstract]

Defined Contribution Plan

14. Defined Contribution Plan

The Company sponsors a 401(k) Plan that stipulates that eligible employees can elect to contribute to the 401(k) Plan, subject to certain limitations, on a pretax basis. In January 2019, the Company began to match 4% of employees’ salary. During the three months ended September 30, 2023 and 2022, the Company recorded matching contributions of $0.1 million and $0.1 million, respectively, and $0.2 million and $0.4 million for the nine months ended September 30, 2023 and 2022, respectively.

The entire disclosure for retirement benefits.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (l)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//715/tableOfContent

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (o)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (p)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480126/715-20-S99-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 60
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480266/715-60-50-3

Equity Financing - Additional Information (Details)

1 Months Ended

3 Months Ended

9 Months Ended

16 Months Ended

Oct. 19, 2022

Aug. 31, 2022

USD ($)

$ / shares

Aug. 17, 2022

USD ($)

Oct. 31, 2022

USD ($)

Mar. 31, 2022

USD ($)

Sep. 30, 2021

USD ($)

$ / shares

Sep. 30, 2020

$ / shares

Sep. 30, 2023

USD ($)

$ / shares

Sep. 30, 2022

USD ($)

Mar. 31, 2022

USD ($)

Sep. 30, 2023

USD ($)

$ / shares

Dec. 31, 2022

USD ($)

$ / shares

Jun. 30, 2023

Mar. 31, 2023

Jun. 30, 2022

^[1]

Dec. 31, 2021

^[1]

Reverse stock split ratio

0.1

Number of stock, authorized for issuance

10,000,000

Number of stock, par value per share | $ / shares

$ 0.0001

Number of stock, shares issued

Number of stock, shares outstanding

Common stock, shares authorized

300,000,000

Common stock, par value per share | $ / shares

$ 0.0001

Common stock, shares issued

14,614,890

14,215,302

Common stock, shares outstanding

14,614,890

14,215,302

$ 250,000,000

$ 125,000,000

Common Stock

Common stock, shares outstanding

6,914,777

^[1]

14,614,890

14,036,215

^[1]

6,914,777

^[1]

14,614,890

14,215,302

14,595,477

14,359,214

6,958,460

6,299,158

March 2022 ATM Offering Program | Common Stock | Cowen | March 2022 Sales Agreement

Percentage of gross sales proceeds of common stock payable as compensation

3.00%

Maximum public float | $

$ 75,000,000

Proceeds from sale of common stock | $

274,781

$ 1,000,000

March 2022 ATM Offering Program | Common Stock | Cowen | March 2022 Sales Agreement | Maximum

March 2022 ATM Offering Program Amendment | March 2022 Sales Agreement

$ 50,000,000

50,000,000

Common stock amount remained available for sale | $

$ 14,600,000

March 2022 ATM Offering Program Amendment | Common Stock | Cowen | March 2022 Sales Agreement | Maximum

October 2022 At The Market Equity Offering Program | Cowen | October 2022 Sales Agreement

$ 25,000,000

Percentage of gross sales proceeds of common stock payable as compensation

3.00%

October 2022 At The Market Equity Offering Program | Cowen | October 2022 Sales Agreement | Maximum

Equity Purchase Agreement | Lincoln Park Capital Fund LLC

$ 50,000,000

Issuance of common stock, value | $

102,040

380,000

$ 910,000

Purchase agreement term

36 months

Share purchase price | $ / shares

$ 2.94

Total gross purchase price of share | $

$ 3,000,000

Regular purchase capped amount | $

$ 2,000,000

Percentage of trading volume

30.00%

Percentage of purchase price

97.00%

Percentage of shares issued to common shares outstanding immediately prior to the execution of the purchase agreement.

19.99%

Purchase agreement price per share | $ / shares

$ 29.4

Maximum percentage ownership of issued and outstanding shares

9.99%

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Purchase Agreement 35.00 Closing Price

Regular purchase amount closing price per share | $ / shares

$ 35

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Purchase Agreement 50.00 Closing Price

Regular purchase amount closing price per share | $ / shares

$ 50

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Purchase Agreement 70.00 Closing Price

Regular purchase amount closing price per share | $ / shares

$ 70

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Maximum

Issuance of common stock, value | $

1,106,580

$ 30,000,000

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Maximum | Purchase Agreement 35.00 Closing Price

Regular purchase amount shares

15,000

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Maximum | Purchase Agreement 50.00 Closing Price

Regular purchase amount shares

20,000

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Maximum | Purchase Agreement 70.00 Closing Price

Regular purchase amount shares

25,000

Equity Purchase Agreement | Common Stock | Lincoln Park Capital Fund LLC

Proceeds from sale of common stock | $

25,244

90,000

^[1]

$ 6,200,000

Other expense related to transaction with Lincoln Park Capital Fund | $

$ 800,000

Equity Purchase Agreement | Common Stock | Lincoln Park Capital Fund LLC | Regular Purchase Amount per Business Day | Maximum

10,000

Follow On Offering

Proceeds from sale of common stock | $

Gross proceeds | $

$ 45,000,000

$ 41,700,000

Number of warrants exercised

Issuance of common stock, value | $

$ 41,650,000

Follow On Offering | Maximum

Warrants exercisable term

5 years

Warrant exercise percentage of ordinary shares outstanding beneficially owned

4.99%

Follow On Offering | Common Stock

Share purchase price | $ / shares

6,428,571

^[1]

$ 7

Follow On Offering | Existing Warrants

Exercise price for warrant | $ / shares

$ 8.5

Warrants issued to purchase ordinary shares

6,428,572

[1]

Prepaid Expenses and Other Current Assets (Tables)

9 Months Ended

Sep. 30, 2023

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Schedule of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following:


	September 30, 2023		December 31, 2022
Prepaid research and development expenses	$	328	$	378
Prepaid insurance expenses		931		710
Tax credit receivable		1,493		—
Interest receivable		218		235
Other prepaid expenses and current assets		629		417
Total prepaid expenses & other current assets	$	3,599	$	1,740

Commitments and Contingencies

9 Months Ended

Sep. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

8. Commitments and Contingencies

Leases

In February 2019, the Company entered into a lease agreement for new office and laboratory space in South San Francisco, California. The term of the lease agreement commenced in May 2019. The lease has an initial term from occupancy of approximately ten years ending on December 31, 2029 with an option to extend the term for an additional eight years at then-market rental rates. The total base rent payment escalates annually based on a fixed percentage beginning from the 13th month of the lease agreement. The Company will also be responsible for the operating expenses and real estate taxes allocated to the building and common areas. Pursuant to the lease agreement, the landlord provided the Company with a tenant improvement allowance of $10.7 million, which was included in deferred rent and leasehold improvements on the balance sheet at December 31, 2019. In connection with the execution of the lease agreement, the Company delivered a letter of credit of approximately $0.9 million to the landlord.

The Company’s operating leases include various covenants, indemnities, defaults, termination rights, security deposits and other provisions customary for lease transactions of this nature.

The following table summarizes the components of lease expense, which are included in operating expenses in the Company’s condensed statements of operations and comprehensive loss (in thousands):


	Three Months Ended September 30,						Nine Months Ended September 30,
	2023			2022			2023			2022
Operating lease cost	$	930		$	1,088		$	2,790		$	3,239
Variable lease cost		203			407			546			1,114
Sublease income		(976	)		(1,391	)		(2,904	)		(3,405	)
Total lease cost	$	157		$	104		$	432		$	948

Variable lease payments include amounts relating to common area maintenance, real estate taxes and insurance and are recognized in the condensed statements of operations and comprehensive loss as incurred.

The following table summarizes supplemental information related to leases (in thousands):


	Nine Months Ended September 30,
	2023			2022
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$	3,599		$	5,109
Weighted-average remaining lease term (years)
Operating leases		6.3			7.3
Weighted-average discount rate (percentage)
Operating leases		6.0	%		6.0	%

The following table summarizes the maturities of lease liabilities as of September 30, 2023 (in thousands):


	Amount
2023 (remaining 3 months)	$	1,211
2024		4,964
2025		5,123
2026		5,287
2027		5,457
Thereafter		11,435
Total future minimum lease payments		33,477
Less: Amount representing interest		(5,684	)
Present value of future minimum lease payments		27,793
Less: Current portion of operating lease liability		(3,362	)
Noncurrent portion of operating lease liability	$	24,431

In June 2021, the Company entered into an agreement to sublease a portion of the first floor of the South San Francisco, California facility, consisting of approximately 23,000 square feet, to Freenome Holdings, Inc., through June 30, 2024. The base sublease rent rate is $6.25 per rental square foot per month and will increase annually by 3.5% through expiration of the agreement. Additionally, the subtenant is required to pay approximately 37% of operating expenses and property management fees that the Company is required to pay under the lease for the South San Francisco, California facility. The Company incurred initial direct costs of $0.2 million in sublease commissions related to entering into the agreements to sublease the South San Francisco, California facility. To account for the commissions, the Company capitalized the total commissions amount and will amortize the balance over the term of the sublease. Sublease income was $0.6 million and $1.0 million for the three months ended September 30, 2023 and 2022, respectively, and $1.7 million and $2.1 million for the nine months ended September 30, 2023 and 2022, respectively, which was offset against total rent expense.

In May 2022, the Company entered into an agreement to sublease a portion of the second floor of the South San Francisco, California facility, consisting of approximately 15,000 square feet, to Initial Therapeutics, Inc. ("Initial Therapeutics"). The original sublease term commenced on July 1, 2022 and continued through June 30, 2024 and further extended through June 30, 2026 upon execution of an amendment as defined below. The base sublease rent rate is $7.80 per rental square foot per month and will increase by 3.5% annually through the expiration of the agreement. Additionally, the subtenant is required to pay approximately 24% of operating expenses and property management fees that the Company is required to pay under the lease for the South San Francisco, California facility. The Company incurred initial direct costs of $0.1 million in sublease commissions related to entering into the agreements to sublease the South San Francisco, California facility. To account for the commissions, the Company capitalized the total commissions amount and will amortize the balance over the term of the sublease. Sublease income was $0.4 million and $0.4 million for the three months ended September 30, 2023 and 2022, respectively, and $1.2 million and $0.4 million for the nine months ended September 30, 2023 and 2022, respectively, which was offset against total rent expense.

On September 15, 2023, the Company entered into an amendment with Initial Therapeutics to sublease the remainder of the second floor of the South San Francisco, California facility, consisting of an additional 17,000 square feet. The sublease term will commence on October 1, 2023 and extends the existing sublease agreement that commenced on July 1, 2022 through June 30, 2026. The additional space will be subleased at a monthly rent rate of $1.00 per square foot starting a month after Initial Therapeutics first takes possession of the additional space through June 30, 2024. Starting July 1, 2024, the rent rate for the entirety of Initial Therapeutics' subleased space will be $6.02 per rental square foot per month and will increase 3.5% on December 1, 2024 and 2025. Additionally, Initial Therapeutics will be required to pay approximately 51% of operating expenses and property management fees that the Company is required to pay under the lease for the South San Francisco, California facility. The Company incurred initial direct costs of $0.3 million in sublease commissions.

On September 15, 2023, the Company entered into a sub-sublease agreement with GT Biopharma, Inc. to sublease a portion of its first floor at 8000 Marina Boulevard, Brisbane, California, consisting of 4,500 square feet. The sub-sublease term will commence on October 6, 2023 through June 30, 2024. The space will be subleased at a rent rate of $2.00 per rent square feet.

Impairment of Operating Lease Right-of-Use Asset and Other Long-Lived Assets

The Company is subleasing its South San Francisco facility through June 30, 2026, the Company determined an impairment indicator was present. The Company determined all of its long-lived assets represent entity wide asset group for the purpose of the long-lived asset impairment assessment. The Company concluded that the carrying value of the entity wide asset group was not recoverable as it exceeded the future net undiscounted cash flows that are expected to be generated from the use and eventual disposition of the assets within the asset group. To allocate and recognize the impairment loss, the Company determined the fair value of the Company using the adjusted net asset method under the cost approach. The implied allocated impairment loss to any individual asset within the long-lived asset group shall not reduce the carrying amount of that asset below its fair value. To determine the fair value of the individual assets within the asset group, the Company utilized the discounted cash flow method using the income approach. Based on this analysis, during the three and nine months ended September 30, 2023, the Company recognized a non-cash impairment charge of $5.6 million, including $4.0 million for the right-of-use assets and $1.6 million for the leasehold improvements. This represents a Level 3 nonrecurring fair value measurement. Calculating the fair value of the assets involves significant estimates and assumptions. These estimates and assumptions include, among others, projected future cash flows, risk-adjusted discount rates and market conditions. Changes in the factors and assumptions used could materially affect the amount of impairment loss recognized in the period the asset was considered impaired.

Indemnifications

The Company indemnifies each of its officers and directors for certain events or occurrences, subject to certain limits, while the officer or director is or was serving at the Company’s request in such capacity, as permitted under Delaware law and in accordance with the Company’s amended and restated certificate of incorporation and bylaws. The term of the indemnification period lasts as long as an officer or director may be subject to any proceeding arising out of acts or omissions of such officer or director in such capacity.

The maximum amount of potential future indemnification is unlimited; however, the Company currently holds director and officer liability insurance. This insurance allows the transfer of risk associated with the Company’s exposure and may enable the Company to recover a portion of any future amounts paid. The Company believes that the fair value of these potential indemnification obligations is minimal. Accordingly, the Company has not recognized any liabilities relating to these obligations for any period presented.

Net Loss per Common Share

9 Months Ended

Sep. 30, 2023

Earnings Per Share [Abstract]

Net Loss per Common Share

13. Net Loss per Common Share

Basic net loss per share is calculated by dividing net loss by the weighted-average number of shares outstanding for the period. Diluted net loss per share is calculated by dividing net loss by the weighted-average number of shares of common stock and potential dilutive common stock equivalents outstanding during the period if the effect is dilutive.

The calculation of diluted earnings (loss) per share also requires that, to the extent contingencies are satisfied during the period and the presumed issuance of additional shares as contingent consideration is dilutive to earnings (loss) per share for the period, adjustments to net income or net loss used in the calculation are required to remove the change in fair value of the contingent consideration liability for the period. Likewise, adjustments to the denominator are

required to reflect the related dilutive shares. In all periods presented, the Company’s outstanding stock options, RSUs (including PSUs), early exercised common stock subject to future vesting, restricted stock accounted for as options, shares subject to the 2018 ESPP and presumed issuance of additional shares as contingent consideration were excluded from the calculation of diluted net loss per share because their effects were antidilutive.

A reconciliation of the numerators and denominators used in computing net loss from continuing operations per share is as follows (in thousands, except share and per share amounts):


	Three Months Ended September 30,						Nine Months Ended September 30,
	2023			2022			2023			2022
Numerator:
Net loss	$	(15,289	)	$	(13,708	)	$	(38,362	)	$	(45,758	)
Denominator:
Weighted-average number of shares outstanding—basic and diluted		14,598,218			10,072,077			14,446,672			7,928,729
Net loss per share—basic and diluted	$	(1.05	)	$	(1.36	)	$	(2.66	)	$	(5.77	)

Since the Company was in a net loss position for all periods presented, basic net loss per common share is the same as diluted net loss per common share as the inclusion of all potential common shares outstanding would have been anti-dilutive.

Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows:


	Nine Months Ended September 30,
	2023		2022
Options to purchase common stock		2,003,383		913,023
Outstanding warrants to purchase common stock		6,428,572		6,428,572
Early exercised common stock subject to future vesting		3,336		3,336
RSUs		59,365		151,801
Shares subject to 2018 ESPP		30,462		9,255
Total		8,525,118		7,505,987

Up to 3,390 shares may be contingently issued, if certain performance conditions are met under the Company’s in-licensing agreements.

Corporate Restructuring - Additional Information (Details) $ in Millions			3 Months Ended	9 Months Ended
	Jun. 30, 2023 Employee	May 31, 2023 Employee	Jun. 30, 2023 USD ($)	Sep. 30, 2023 USD ($)
Restructuring Cost And Reserve [Line Items]
Restructuring implementation date		May 31, 2023
Expected number of employees departing \| Employee	3	9
Percentage of employees eliminated		29.00%
Operating Expenses
Restructuring Cost And Reserve [Line Items]
Severance charge in operating expenses			$ 0.6
Employee Termination Benefits
Restructuring Cost And Reserve [Line Items]
Severance charge in operating expenses				$ 0.5
Employee Termination Benefits \| Research And Development Expense
Restructuring Cost And Reserve [Line Items]
Severance charge in operating expenses				0.4
Employee Termination Benefits \| Employee-Related Benefits
Restructuring Cost And Reserve [Line Items]
Severance charge in operating expenses				0.1
Employee Termination Benefits \| General And Administrative Expense
Restructuring Cost And Reserve [Line Items]
Severance charge in operating expenses				$ 0.2

Fair Value Measurements

9 Months Ended

Sep. 30, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Fair Value Measurements

The Company determines the fair value of financial and non-financial assets and liabilities based on the assumptions that market participants would use in pricing the asset or liability in an orderly transaction between market participants at the measurement date. The identification of market participant assumptions provides a basis for determining what inputs are to be used for pricing each asset or liability. A fair value hierarchy has been established which gives precedence to fair value measurements calculated using observable inputs over those using unobservable inputs. This hierarchy prioritized the inputs into three broad levels as follows:

•

Level 1: Quoted prices in active markets for identical instruments

•

Level 2: Other significant observable inputs (including quoted prices in active markets for similar instruments)

•

Level 3: Significant unobservable inputs (including assumptions in determining the fair value of certain investments)

The carrying amounts of financial instruments such as cash and cash equivalents, restricted cash, prepaid expenses and other current assets, accounts payable, accrued compensation, accrued and other current liabilities approximate the related fair values due to the short maturities of these instruments. As the long-term debt is subject to variable interest rates that are based on market rates which are regularly reset, considering Level 2 inputs, the Company believes the carrying value of the long-term debt approximates its fair value.

The Company’s financial assets and liabilities subject to fair value measurements and the level of inputs used in such measurements were as follows (in thousands):


	September 30, 2023
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Money market funds	$	4,912	$	4,912	$	—	$	—
Total cash equivalents		4,912		4,912		—		—
Short-term marketable securities:
U.S. treasuries		7,736		—		7,736		—
U.S. government debt securities		30,327		—		30,327		—
Total short-term marketable securities		38,063		—		38,063		—
Total assets subject to fair value measurements	$	42,975	$	4,912	$	38,063	$	—


	December 31, 2022
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Money market funds	$	5,083	$	5,083	$	—	$	—
Total cash equivalents		5,083		5,083		—		—
Short-term marketable securities:
U.S. treasuries		30,758		—		30,758		—
U.S. government debt securities		51,301		—		51,301		—
Total short-term marketable securities		82,059		—		82,059		—
Total assets subject to fair value measurements	$	87,142	$	5,083	$	82,059	$	—

The Company's available-for-sale investments rely on the pricing services that utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads; benchmark securities; prepayment/default projections based on historical data; and other observable inputs. See Note 4, “Marketable Securities,” for further information regarding the carrying value of the Company's financial instruments.

Schedule of Reconciliation of Numerators and Denominators Used In Computing Net Loss From Continuing Operations Per Share

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

Commitments and Contingencies - Additional Information (Details) $ in Thousands		1 Months Ended		3 Months Ended		9 Months Ended
	Sep. 15, 2023 USD ($) ft² $ / ft²	May 31, 2022 USD ($) ft² $ / ft²	Jun. 30, 2021 USD ($) ft² $ / ft²	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Feb. 28, 2019 USD ($)
Commitments And Contingencies [Line Items]
Impairment loss				$ 5,600		$ 5,600
Impairment of operating lease right-of-use asset				4,000		4,000
Impairment of leasehold improvements				1,600		1,600
Sublease income				$ 976	$ 1,391	$ 2,904	$ 3,405
South San Francisco, California
Commitments And Contingencies [Line Items]
Lessee, operating lease, description						In February 2019, the Company entered into a lease agreement for new office and laboratory space in South San Francisco, California. The term of the lease agreement commenced in May 2019. The lease has an initial term from occupancy of approximately ten years ending on December 31, 2029 with an option to extend the term for an additional eight years at then-market rental rates
Operating lease, initial lease term				10 years		10 years
Operating lease, renewal term				8 years		8 years
Tenant improvement allowance								$ 10,700
Letter of credit, delivered in connection of lease agreement				$ 900		$ 900
Lease commencement date						2019-05
Operating lease, option to extend description						option to extend the term for an additional eight years
Operating lease, existence of option to extend						true
Lease expiration date						Dec. 31, 2029
South San Francisco, California \| Office and Laboratory Space, Second Floor
Commitments And Contingencies [Line Items]
Space subleased (in square feet) \| ft²	17,000	15,000
Sublease start date	Oct. 01, 2023	Jul. 01, 2022
Sublease expiration date	Jun. 30, 2026	Jun. 30, 2026
Sublease rent per square foot \| $ / ft²	1	7.8
Annual percentage increase in sublease base rent	3.50%	3.50%
Increase in sublease rent per square foot \| $ / ft²	6.02
Percentage of operating expenses and property management fees to be paid by subtenant	51.00%	24.00%
Incurred initial direct costs of sublease	$ 300	$ 100
Sublease income				400	400	$ 1,200	400
South San Francisco, California \| Office And Laboratory Space First Floor
Commitments And Contingencies [Line Items]
Space subleased (in square feet) \| ft²			23,000
Sublease expiration date			Jun. 30, 2024
Sublease rent per square foot \| $ / ft²			6.25
Annual percentage increase in sublease base rent			3.50%
Percentage of operating expenses and property management fees to be paid by subtenant			37.00%
Incurred initial direct costs of sublease			$ 200
Sublease income				$ 600	$ 1,000	$ 1,700	$ 2,100
Brisbane, California \| Office And Laboratory Space First Floor
Commitments And Contingencies [Line Items]
Space subleased (in square feet) \| ft²	4,500
Sublease expiration date	Jun. 30, 2024
Sublease rent per square foot \| $ / ft²	2

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2023	Nov. 08, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Amendment Flag	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Trading Symbol	UBX
Entity Registrant Name	Unity Biotechnology, Inc.
Entity Central Index Key	0001463361
Current Fiscal Year End Date	--12-31
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding		14,620,671
Entity Shell Company	false
Entity File Number	001-38470
Entity Tax Identification Number	26-4726035
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	285 East Grand Ave.
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	650
Local Phone Number	416-1192
Title of 12(b) Security	Common Stock, par value $0.0001
Security Exchange Name	NASDAQ

Net Loss per Common Share (Tables)

9 Months Ended

Sep. 30, 2023

Earnings Per Share [Abstract]

A reconciliation of the numerators and denominators used in computing net loss from continuing operations per share is as follows (in thousands, except share and per share amounts):


	Three Months Ended September 30,						Nine Months Ended September 30,
	2023			2022			2023			2022
Numerator:
Net loss	$	(15,289	)	$	(13,708	)	$	(38,362	)	$	(45,758	)
Denominator:
Weighted-average number of shares outstanding—basic and diluted		14,598,218			10,072,077			14,446,672			7,928,729
Net loss per share—basic and diluted	$	(1.05	)	$	(1.36	)	$	(2.66	)	$	(5.77	)

Summary of Potentially Dilutive Securities Excluded from Computation of Diluted Per Share

Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows:


	Nine Months Ended September 30,
	2023		2022
Options to purchase common stock		2,003,383		913,023
Outstanding warrants to purchase common stock		6,428,572		6,428,572
Early exercised common stock subject to future vesting		3,336		3,336
RSUs		59,365		151,801
Shares subject to 2018 ESPP		30,462		9,255
Total		8,525,118		7,505,987

Commitments and Contingencies - Summary of Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Lease, Cost [Abstract]
Operating lease cost	$ 930	$ 1,088	$ 2,790	$ 3,239
Variable lease cost	203	407	546	1,114
Sublease income	(976)	(1,391)	(2,904)	(3,405)
Total lease cost	$ 157	$ 104	$ 432	$ 948

Stock-Based Compensation

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

12. Stock-Based Compensation

Stock Options and Restricted Stock Units Activity


	Number of Shares			Weighted- Average Exercise Price
Balances at December 31, 2022		1,609,938		$	27.51
Granted		421,600		$	2.85
Canceled		(28,155	)	$	18.14
Balances at September 30, 2023		2,003,383		$	13.88


	Number of Shares			Weighted- Average Grant Date Fair Value
Unvested at December 31, 2022		146,333		$	27.66
Granted		—		$	—
Vested		(83,310	)	$	30.07
Canceled		(3,658	)	$	4.76
Unvested at September 30, 2023		59,365		$	25.65

For stock options granted to employees with service-based vesting, the fair value of stock options granted to employees was estimated on the date of grant using the Black-Scholes option pricing model and utilizing assumptions that were determined as follows:

Expected Term—The expected term represents the period that the options granted are expected to be outstanding and is determined using the simplified method (based on the mid-point between the vesting date and the end of the contractual term) as the Company has concluded that its stock option exercise history does not provide a reasonable basis upon which to estimate expected term.

Expected Volatility—Due to limited historical data, the Company estimates stock price volatility based on a combined weighted-average of the Company’s historical average volatility and that of a selected peer group of comparable publicly traded companies within the biotechnology and pharmaceutical industry that were deemed to be representative of future stock price trends over the expected life of the award.

Risk-Free Interest Rate—The Company based the risk-free interest rate over the expected term of the options based on the constant maturity rate of U.S. Treasury securities with similar maturities as of the date of the grant.

Expected Dividends—The Company has never paid any dividends and does not plan to pay dividends in the foreseeable future. Therefore, the expected dividend yield is zero.

Stock Based Compensation Expense


	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Research and development	$	674	$	799	$	2,239	$	2,723
General and administrative		1,381		1,411		4,447		4,397
Total	$	2,055	$	2,210	$	6,686	$	7,120

Repricing

On May 4, 2023, and in accordance with the terms of the Company’s 2018 Plan, the Company’s Board of Directors approved a stock option repricing (the “Repricing”) for employees and certain service providers that were not affected by the reduction in its workforce, as well as affected employees and certain service providers entering into or subject to a continuing consulting agreement, as of May 11, 2023. Pursuant to the terms of the Repricing, the exercise price of each outstanding option to purchase shares of the Company's common stock granted under its 2018 Plan that had an original exercise price above $6.00, was reduced to an exercise price of $2.77, the closing price for the Company's common stock on May 11, 2023, the effective date of the Repricing.

On the effective date of the Repricing, 26 employees and certain service providers held 444,273 shares of the Company's common stock under option grants that met the eligibility criteria. Eligible outstanding options continue to remain outstanding in accordance with their current terms and conditions. On the effective date of the Repricing, the Company recognized $0.2 million of additional stock-based compensation from 251,821 shares of its common stock under vested options. The Company anticipates an additional $0.1 million will be expensed over the period from the effective date of the Repricing through 2025 relating to 192,452 shares of the Company's common stock under unvested options.

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation These condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for interim reporting. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted. Accordingly, the unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 filed with the SEC. The Company effected a reverse stock split on October 19, 2022 of its outstanding shares of common stock at a ratio of 1-for-10 pursuant to a Certificate of Amendment to the Company's Certificate of Incorporation filed with the Secretary of State of the State of Delaware. The reverse stock split was reflected on the Nasdaq Global Select Market beginning with the opening of trading on October 20, 2022. The reverse stock split did not change the par value of the Company's common stock or the authorized number of shares of the Company's common stock. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.
Unaudited Condensed Financial Statements	Unaudited Condensed Financial Statements The accompanying financial information for the three and nine months ended September 30, 2023 and 2022 are unaudited. The unaudited condensed financial statements have been prepared on the same basis as the annual audited financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s financial position as of September 30, 2023 and its results of operations for the three and nine months ended September 30, 2023 and 2022 and cash flows for the nine months ended September 30, 2023 and 2022. The results for interim periods are not necessarily indicative of the results expected for the full fiscal year or any other periods.
Use of Estimates	Use of Estimates The condensed financial statements have been prepared in accordance with GAAP, which requires management to make estimates and assumptions that affect the amounts and disclosures reported in the condensed financial statements and accompanying notes. The Company bases its estimates on historical experience and market-specific or other relevant assumptions that it believes are reasonable under the circumstances. The amounts of assets and liabilities reported in the Company’s condensed balance sheets and the amount of expenses and income reported for each of the periods presented are affected by estimates and assumptions, which are used for, but are not limited to, determining the fair value of assets and liabilities, the fair value of right-of-use assets and lease liabilities, and stock-based compensation. Actual results could differ from such estimates or assumptions.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be fully recoverable. If indicators of impairment exist and the undiscounted future cash flows that the assets are expected to generate are less than the carrying value of the assets, the Company reduces the carrying amount of the assets through an impairment charge, to their estimated fair value based on a discounted cash flow approach or, when available and appropriate, to comparable market values.
Segments	Segments The Company has one operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a consolidated basis for the purposes of allocating resources.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments, as clarified in subsequent amendments. ASU 2016-13 changes the impairment model for certain financial instruments. The new model is a forward-looking expected loss model and will apply to financial assets subject to credit losses and measured at amortized cost and certain off-balance sheet credit exposures. This includes loans, held-to-maturity debt securities, loan commitments, financial guarantees and net investments in leases, as well as trade receivables. For available-for-sale debt securities with unrealized losses, credit losses will be measured in a manner similar to today, except that the losses will be recognized as allowances rather than reductions in the amortized cost of the securities. In October 2019, the FASB voted to delay the effective date of this standard. Topic 326 will be effective for the Company for fiscal years beginning after December 15, 2022. Early adoption is permitted. We adopted ASU 2016-13 on January 1, 2023 and the adoption did not have a material impact on the Company’s condensed financial statements and related disclosures. In November 2021, the FASB issued ASU 2021-10, Government Assistance, or Topic 832, which requires enhanced disclosures of transactions with governments that are accounted for by applying a grant or contribution model. The new pronouncement requires entities to provide information about the nature of the transaction, terms and conditions associated with the transaction and financial statement line items affected by the transaction. The Company adopted the standard for the annual period beginning January 1, 2023. The employee retention credit received under the CARES Act qualifies as a government assistance program under Topic 832 and resulted in enhanced required disclosures, as described in Note 7, "Government Assistance Program".
Fair Value Measurements	The Company determines the fair value of financial and non-financial assets and liabilities based on the assumptions that market participants would use in pricing the asset or liability in an orderly transaction between market participants at the measurement date. The identification of market participant assumptions provides a basis for determining what inputs are to be used for pricing each asset or liability. A fair value hierarchy has been established which gives precedence to fair value measurements calculated using observable inputs over those using unobservable inputs. This hierarchy prioritized the inputs into three broad levels as follows: • Level 1: Quoted prices in active markets for identical instruments • Level 2: Other significant observable inputs (including quoted prices in active markets for similar instruments) • Level 3: Significant unobservable inputs (including assumptions in determining the fair value of certain investments) The Company's available-for-sale investments rely on the pricing services that utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads; benchmark securities; prepayment/default projections based on historical data; and other observable inputs.