0000950170-23-019654 | 10-Q | XBRL Viewer

Restricted cash - non-current assets

$ 56,357

$ 193,650

^[1]

$ 163,488

$ 205,530

917

^[1]

917

Total

$ 57,274

$ 194,567

$ 164,405

$ 206,447

[1]	The condensed balance sheet as of December 31, 2022 was derived from the audited financial statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2022.

Restructuring - Summary of Accrued Restructuring Cost (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 1,676
Cash payment	(1,425)
Change in estimates	(168)
Ending Balance	83
Severance and Benefits Costs
Restructuring Cost and Reserve [Line Items]
Beginning Balance	1,512
Cash payment	(1,375)
Change in estimates	(54)
Ending Balance	83
Contract Termination Cost
Restructuring Cost and Reserve [Line Items]
Beginning Balance	164
Cash payment	(50)
Change in estimates	(114)
Ending Balance	0
Stock Based Compensation
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0
Change in estimates	0
Ending Balance	$ 0

Collaboration and License Agreements - Schedule of Revenue by Collaboration Partners (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue	$ 23,499	$ 9,040
AbbVie
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue	3,988	1,751
Amgen
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue	1,776	2,237
Astellas
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue	8,705	4,766
Bristol Myers Squibb
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue	7,725	$ 286
Regeneron
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue	581
Moderna
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue	$ 724

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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

Stock-Based Compensation - Total Stock-based Compensation Recognized (Details) - Stock Compensation Plan - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 2,409	$ 3,370
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	961	1,605
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 1,448	$ 1,765

Collaboration and License Agreements - Contract Liabilities - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 283,917	$ 301,326	$ 276,734	$ 284,760
AbbVie Ireland Unlimited Company \| CD71 Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	4,000
Amgen Inc \| EGFR Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 16,400
Deferred Revenue Recognition Maturity Year	2026
Amgen Inc \| Amgen Other Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 400
Deferred Revenue Recognition Maturity Year	2023
Astellas Pharma Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 41,800
Deferred Revenue Recognition Maturity Year	2026
Bristol Myers Squibb Company
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 161,500
Deferred Revenue Recognition Maturity Year	2025
ModernaTX, Inc
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 34,300
Deferred Revenue Recognition Maturity Year	2028
Regeneron Pharmaceuticals, Inc
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 29,500
Deferred Revenue Recognition Maturity Year	2026

Net Loss Per Share (Tables)

3 Months Ended

Mar. 31, 2023

Earnings Per Share [Abstract]

The following weighted-average outstanding shares of potentially dilutive securities are excluded from the computation of diluted net loss per share for the periods presented, because including them would have been anti-dilutive:


	Three Months Ended
	March 31,
	2023		2022
Options and ESPP to purchase common stock		13,986,524		13,755,440
RSUs		1,539,053		789,974
Total		15,525,577		14,545,414

CONDENSED BALANCE SHEETS - USD ($)
$ in Thousands

Mar. 31, 2023

Dec. 31, 2022

Current assets:

Prepaid expenses and other current assets

$ 56,357

$ 193,650

^[1]

Short-term investments

148,145

^[1]

Accounts receivable

1,090

35,986

^[1]

6,685

7,466

^[1]

Total current assets

212,277

237,102

^[1]

Property and equipment, net

4,573

5,072

^[1]

Intangible assets, net

839

875

^[1]

Goodwill

949

^[1]

Restricted cash

917

^[1]

Operating lease right-of-use asset

15,048

15,949

^[1]

Other assets

^[1]

Total assets

234,630

260,891

^[1]

Current liabilities:

Accounts payable

2,203

2,809

^[1]

Accrued liabilities

22,275

28,532

^[1]

Deferred revenue, current portion

126,784

121,267

^[1]

Total current liabilities

151,262

152,608

^[1]

Deferred revenue, net of current portion

157,133

180,059

^[1]

Operating lease liabilities - long term

12,872

13,975

^[1]

Total liabilities

321,267

346,642

^[1]

Commitments and contingencies (Note 8)

Stockholders' equity (deficit):

Convertible preferred stock

Common stock

^[1]

Additional paid-in capital

639,526

637,117

^[1]

Accumulated other comprehensive income

^[1]

Accumulated deficit

(726,190)

(722,879)

^[1]

Total stockholders' deficit

(86,637)

(85,751)

^[1]

Total liabilities and stockholders' equity (deficit)

$ 234,630

$ 260,891

^[1]

[1]	The condensed balance sheet as of December 31, 2022 was derived from the audited financial statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2022.

Fair Value Measurements and Investments - Schedule of Investments Subject to Fair Value Measurements on a Recurring Basis (Details) - USD ($)
$ in Thousands

Mar. 31, 2023

Dec. 31, 2022

Mar. 31, 2022

Dec. 31, 2021

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Gross Unrealized Holding Gains

$ 56,357

$ 193,650

^[1]

$ 163,488

$ 205,530

Aggregate Fair Value

205,856

95,574

Amortized Cost

205,830

95,564

Level I | Money market funds

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Level I | Restricted cash (money market funds)

56,794

64,706

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Restricted cash

917

Level I | U.S. Treasury securities

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Investments, Amortized Cost

148,119

29,941

Investments, Gross Unrealized Gains

Investments, Aggregate Fair Value

$ 148,145

$ 29,951

[1]	The condensed balance sheet as of December 31, 2022 was derived from the audited financial statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2022.

Description of the Business

3 Months Ended

Mar. 31, 2023

Disclosure Text Block [Abstract]

Description of the Business

1. Description of the Business

CytomX Therapeutics, Inc. (the “Company”) is a clinical-stage, oncology-focused biopharmaceutical company dedicated to destroying cancer differently. The Company aims to build a commercial enterprise to maximize its impact on the treatment of cancer. The Company is advancing potential first-in-class and best-in-class antibody-based therapeutics created using its Probody® therapeutic technology platform that could meaningfully improve outcomes for cancer patients. Its proprietary and unique Probody technology platform is designed to enable “conditional activation” of antibody-based drugs in the tumor microenvironment while minimizing drug activity in healthy tissues and in circulation. The Company is located in South San Francisco, California and was incorporated in the state of Delaware in September 2010.

Accrued Liabilities

3 Months Ended

Mar. 31, 2023

Accrued Liabilities, Current [Abstract]

Accrued Liabilities

5. Accrued Liabilities

Accrued liabilities consisted of the following:


	March 31,		December 31,
	2023		2022
	(in thousands)
Research and clinical expenses	$	12,500	$	13,089
Payroll and related expenses		4,372		8,060
Legal and professional expenses		757		1,413
Operating lease liabilities - short term		4,204		4,082
Restructuring expenses		83		1,627
Other accrued expenses		359		261
Total	$	22,275	$	28,532

Stock-Based Compensation - Schedule of Activities Under Company's Stock Option Plans (Details)	3 Months Ended
	Mar. 31, 2023 $ / shares shares
Number of Options
Balance,beginning of the period \| shares	13,289,838
Options granted \| shares	1,151,023
Options exercised \| shares	0
Option forfeited/expired \| shares	(307,176)
Balance, end of the period \| shares	14,133,685
Options Outstanding, Weighted-Average Exercise Price Per Share
Balances, beginning of the period \| $ / shares	$ 7.67
Options granted \| $ / shares	2.59
Options exercised \| $ / shares	0
Option forfeited/expired \| $ / shares	5.89
Balances, end of the period \| $ / shares	$ 7.30

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2023	Apr. 30, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Trading Symbol	CTMX
Entity Registrant Name	CytomX Therapeutics, Inc.
Entity Central Index Key	0001501989
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Securities Act File Number	001-37587
Entity Tax Identification Number	27-3521219
Entity Address, Address Line One	151 Oyster Point Blvd.
Entity Address, Address Line Two	Suite 400
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	515-3185
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, $0.00001 par value per share
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		66,338,938

Leases - Schedule Of Subleasing (Details) $ in Thousands	Mar. 31, 2023 USD ($)
Leases [Abstract]
Remainder of 2023	$ 974
2024	1,333
2025	1,379
2026	1,067
Total sublease income payments	$ 4,753

Leases

3 Months Ended

Mar. 31, 2023

Leases [Abstract]

Leases

11. Leases

Sublease

The Company has a lease of office and laboratory space located in South San Francisco, California for the Company’s corporate headquarters (the “2016 Lease”). The 2016 Lease has an initial term of ten years through 2026 and the Company has an option to extend the initial term for an additional five years at the then fair rental value as determined pursuant to the 2016 Lease.

In March 2023, the Company entered into a sublease agreement for a portion of its existing office and laboratory space. The sublease is classified as an operating lease whereby sublease income is recognized on a straight-line basis over the sublease term that expires on September 30, 2026. For the three months ended March 31, 2023, sublease income was immaterial.


	March 31, 2023
	(in thousands)
Future sublease income payments
Remainder of 2023	$	974
2024		1,333
2025		1,379
2026		1,067
Total sublease income payments	$	4,753

Basis of Presentation and Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2023

Accounting Policies [Abstract]

Basis of Presentation

The accompanying interim condensed financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) regarding interim financial reporting.

Unaudited Interim Financial Information

The accompanying interim condensed financial statements and related disclosures are unaudited, have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the results of operations for the periods presented.

The condensed results of operations for the three months ended March 31, 2023 are not necessarily indicative of the results to be expected for the full year or for any other future year or interim period. The accompanying 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.

Use of Estimates

The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent liabilities at the date of the financial statements and reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.

Cash, Cash Equivalents and Restricted Cash

The Company considers all highly liquid investments purchased with original maturities of three months or less at the date of purchase to be cash equivalents. Restricted cash represents a standby letter of credit issued pursuant to an office lease.

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets that sum to the total of the amounts shown in the statements of cash flows:


	March 31, 2023		December 31, 2022		March 31, 2022		December 31, 2021
	(in thousands)
Cash and cash equivalents	$	56,357	$	193,650	$	163,488	$	205,530
Restricted cash - non-current assets		917		917		917		917
Total	$	57,274	$	194,567	$	164,405	$	206,447

Revenue Recognition

The Company’s revenues are primarily derived through its license, research, development and commercialization agreements. The terms of these types of agreements may include (i) licenses for the Company’s technology or programs, (ii) research and development services, and (iii) services or obligations in connection with participation in research or steering committees. Payments to the Company under these arrangements typically include one or more of the following: nonrefundable upfront and license fees, research funding, milestone and other contingent payments to the Company for the achievement of defined collaboration objectives and certain preclinical, clinical, regulatory and sales-based events, as well as royalties on sales of any commercialized products.

The Company assesses whether the promises in its arrangements with customers are distinct performance obligations that should be accounted for separately. Judgment is required to determine whether the license to the Company’s intellectual property is distinct from the research and development services or participation on steering committees.

The Company’s collaboration and license agreements may include contingent payments related to specified research, development and regulatory milestones. Such milestone payments are typically payable under the collaborations when the collaboration partner claims or selects a target, or initiates or advances a covered product candidate in preclinical or clinical development, upon submission for marketing approval of a covered product with regulatory authorities, or upon receipt of actual marketing approvals of a covered product or for additional indications. Milestone payments that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. At each reporting date, the Company re-evaluates whether the milestones are considered probable of being achieved and estimates the amount to be included in the transaction price by using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price in such period of determination.

The Company’s collaboration and license agreements may also include contingent payments related to sales-based milestones. Sales-based milestones are typically payable when annual sales of a covered product reach specified levels. Sales-based milestones are recognized at the later of when the associated performance obligation has been satisfied or when the sales occur. Unlike other contingency payments, such as regulatory milestones, sales-based milestones are not included in the transaction price based on estimates at the inception of the contract; instead, they are included when the sales or usage occur.

Due to the early stage of the Company’s licensed technology, the license of such technology is typically combined with research and development services and steering committee participation as one performance obligation. Under the collaboration and license agreements, each collaboration target or program is generally considered to be a separate combined performance obligation. The transaction price in each arrangement is allocated to the identified performance obligations based on the relative standalone selling price (“SSP”) of each distinct performance obligation, which requires judgment. In instances where SSP is not directly observable, such as when a license or service is not sold separately, SSP is determined using information that may include market conditions and other observable inputs. Variable consideration is allocated to certain performance obligations if it is triggered by the Company’s efforts to satisfy or a specific outcome from satisfying these performance obligations. In the event that the Company receives non-cash consideration such as consideration in the form of a research license and research support services from the counterparty, the transaction price of a non-monetary exchange that has commercial substance is estimated based on the fair value of the non-cash consideration received, which may be determined through a valuation analysis. The Company recognizes revenue from upfront payments over the estimated period of performance under the agreement using an input method for the performance obligation. In applying the input method of revenue recognition, the Company uses actual full-time equivalent (FTE) hours incurred relative to estimated total FTE hours expected to be incurred for each combined performance obligation over the estimated research service period of each collaboration target.

In certain cases, the Company’s performance creates an asset that does not have an alternative use to the customer and the Company has an enforceable right to payment at all times for performance completed to date. In these cases, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition.

Any consideration payable to the Company’s customers is treated as a reduction to the transaction price and revenue, unless the payment to the customer is in exchange for distinct good and services.

Contract Balances

Customer payments are recorded as deferred revenue upon receipt or when due and may require deferral of revenue recognition to a future period until the Company satisfies its performance obligations under these arrangements. Amounts payable to the Company are recorded as accounts receivable when the Company’s right to consideration is unconditional.

Leases

The Company determines if an arrangement is or contains a lease at inception. Operating leases are recorded as operating lease right-of-use (“ROU”) assets and operating lease liabilities in the Company’s balance sheet. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating lease

ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The Company uses an implicit rate when readily available, or its incremental borrowing rate based on the information available at lease commencement date in determining the present value of lease payments. The operating lease ROU assets also include any lease prepayments made and reduced by lease incentives. The Company’s lease terms may include options to extend the lease when it is reasonably certain that such option will be exercised. Lease expenses are recognized on a straight-line basis over the lease term. The Company elected the short-term lease recognition exemption. The Company’s operating lease arrangement includes lease and non-lease components which are generally accounted for separately. The Company recognizes sublease income on a straight-line basis over the sublease term and records sublease income on a net basis against rent expense.

Disclosure of accounting policy for revenue from contract with customer.

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Share-Based Payment Arrangement [Abstract]

CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Revenues	$ 23,499	$ 9,040
Type of Revenue [Extensible List]	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember
Operating expenses:
Research and development	$ 21,175	$ 30,559
General and administrative	7,977	10,543
Total operating expenses	29,152	41,102
Loss from operations	(5,653)	(32,062)
Interest income	2,327	68
Other income, net	15	13
Net loss	(3,311)	(31,981)
Other comprehensive income (loss):
Unrealized gain (loss) on short-term investments, net of tax	16	(677)
Comprehensive loss	$ (3,295)	$ (32,658)
Net loss per share, Basic	$ (0.05)	$ (0.49)
Net loss per share, Diluted	$ (0.05)	$ (0.49)
Shares used in computing net loss per share, Basic	66,248,992	65,393,691
Shares used in computing net loss per share, Diluted	66,248,992	65,393,691

Stock-Based Compensation

3 Months Ended

Mar. 31, 2023

Stock-Based Compensation

7. Stock-Based Compensation

Stock Options

Activities for the Company’s stock option plans for the three months ended March 31, 2023 were as follows:


	Options Outstanding
	Number of Options			Weighted- Average Exercise Price Per Share
Balance at December 31, 2022		13,289,838		$	7.67
Options granted		1,151,023			2.59
Options exercised		-			-
Option forfeited/expired		(307,176	)		5.89
Balance at March 31, 2023		14,133,685		$	7.30

The Company recorded $1.9 million and $2.9 million of stock-based compensation expense related to the stock option plans for the three months end March 31, 2023 and 2022, respectively.

Time-based RSUs ("TRSU")

Activities for the Company’s TRSUs for the three months ended March 31, 2023 were as follows:


	Number of Shares			Weighted Average Grant Date Fair Value Per Share

Balance at December 31, 2022		1,212,884		$	2.81
RSU's awarded		597,767			2.50
RSU's vested		(110,892	)		3.86
RSU's cancelled		(6,941	)		3.58
Balance at March 31, 2023		1,692,818		$	2.63

The Company recorded $0.4 million and $0.3 million of stock-based compensation expense related to the TRSUs for the three months end March 31, 2023 and 2022, respectively.

Performance-based RSUs ("PSUs")

In October 2021, the Company granted 435,000 PSUs to executive employees with an aggregated grant date fair value of $2.3 million. Vesting for 50% of the PSUs granted will occur within one year of the grant date upon achievement of certain specific milestones ("2021-Tranche 1") and the remaining 50% will vest within two years of the grant date upon achievement of additional company objectives ("2021-Tranche 2").

In July 2022, the Company determined that the performance condition for 2021-Tranche 1 was met and recorded $1.0 million of stock-based compensation expense for the year ended December 31, 2022. As the achievement of the milestones for Tranche 2 was not considered probable, no compensation cost was recorded for 2021-Tranche 2 of these awards through March 31, 2023.

In August 2022, the Company granted 250,000 PSUs to executive employees with an aggregated grant date fair value of approximately $0.4 million. Vesting for 50% of the PSUs granted will occur upon attaining certain specific milestones by December 2023 (“2022-Tranche 1”), and the remaining 50% will vest upon attaining certain specific milestones by December 2024 (“2022-Tranche 2”). As of December 31, 2022, and March 31, 2023, the Company determined that it is probable that the performance conditions for 2022-Tranche 1 will be satisfied and hence recorded $55,000 and $29,000 compensation cost, respectively, for those awards for the year ended December 31, 2022 and for the three months ended March 31, 2023. As of December 31, 2022 and March 31, 2023, the Company determined that it is not probable that the performance conditions for 2022-Tranche 2 will be satisfied and hence recorded no compensation cost for those awards through March 31, 2023.

In February 2023, the Company granted 710,000 PSUs to executive employees with an aggregated grant date fair value of approximately $1.8 million. Vesting for 50% of the PSUs granted will occur upon attaining certain specific milestones by December 2024 (“2023-Tranche 1”), and the remaining 50% will vest upon attaining certain specific milestones by December 2025 (“2023-Tranche 2”). The Company determined that it is not probable that the performance conditions will be satisfied for each of these tranches and hence no compensation cost was recorded for these awards through March 31, 2023.

Activities for the Company’s PSUs for the three months ended March 31, 2023 were as follows:


	Number of Shares			Weighted Average Grant Date Fair Value Per Share

Balance at December 31, 2022		383,750		$	2.96
PSU's awarded		710,000			2.59
PSU's vested		—			-
PSU's cancelled		(13,750	)		1.59
Balance at March 31, 2023		1,080,000		$	2.73

Stock-based Compensation

Total stock-based compensation recorded was as follows:


	Three Months Ended
	March 31,
	2023		2022
	(in thousands)
Stock-based compensation expense:
Research and development	$	961	$	1,605
General and administrative		1,448		1,765
Total stock-based compensation expense	$	2,409	$	3,370

Restructuring

3 Months Ended

Mar. 31, 2023

Restructuring and Related Activities [Abstract]

Restructuring

10. Restructuring

On July 13, 2022, the Company announced a restructuring plan to prioritize its resources on its emerging pre-clinical and early clinical pipeline as well as its existing collaboration partnerships. The restructuring plan resulted in a reduction to its workforce of approximately 40%. Restructuring costs of $2.4 million and $5.1 million were recorded in general and administrative expense and research and development expense, respectively, in the third and fourth quarters of 2022. The restructuring was substantially complete as of December 31, 2022.

The following is a summary of accrued restructuring costs as of March 31, 2023 (in thousands):



	Severance and Benefits Costs			Contract Termination Cost			Stock Based Compensation		Total
Balance at December 31, 2022	$	1,512		$	164		$	-	$	1,676
Cash payment		(1,375	)		(50	)				(1,425	)
Change in estimates		(54	)		(114	)		-		(168	)
Balance at March 31, 2023	$	83		$	-		$	-	$	83

Restructuring - Additional Information (Details) - USD ($) $ in Millions		9 Months Ended	12 Months Ended
	Jul. 13, 2022	Sep. 30, 2022	Dec. 31, 2022
Restructuring Cost and Reserve [Line Items]
Percentage of company's workforce reduction	40.00%
General and Administrative Expense
Restructuring Cost and Reserve [Line Items]
RestructuringCosts		$ 2.4
Research and Development Expense
Restructuring Cost and Reserve [Line Items]
RestructuringCosts			$ 5.1

Collaboration and License Agreements - Summary of Contract Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenue from Contract with Customer [Abstract]
Beginning Balance	$ 301,326	$ 284,760
Additions	869	1,058
Revenue recognized	(18,278)	(9,084)
Ending Balance	$ 283,917	$ 276,734

Basis of Presentation and Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2023

Accounting Policies [Abstract]

Basis of Presentation and Summary of Significant Accounting Policies

2. Basis of Presentation and Summary of Significant Accounting Policies

Basis of Presentation

Unaudited Interim Financial Information

Use of Estimates

Cash, Cash Equivalents and Restricted Cash


	March 31, 2023		December 31, 2022		March 31, 2022		December 31, 2021
	(in thousands)
Cash and cash equivalents	$	56,357	$	193,650	$	163,488	$	205,530
Restricted cash - non-current assets		917		917		917		917
Total	$	57,274	$	194,567	$	164,405	$	206,447

Revenue Recognition

Contract Balances

Leases

Stock-Based Compensation - Schedule of Activities for Company's PSUs (Details) - Performance based RSU - $ / shares	1 Months Ended			3 Months Ended
	Feb. 28, 2023	Aug. 31, 2022	Oct. 31, 2021	Mar. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Balance at December 31, 2022				383,750
Units Awarded	710,000	250,000	435,000	710,000
Units vested				0
units cancelled				(13,750)
Balance at March 31, 2023				1,080,000
Weighted Average Grant Date Fair Value, Beginning Balance				$ 2.96
Units Awarded				2.59
Units vested				0
Units cancelled				1.59
Weighted Average Grant Date Fair Value, Ending Balance				$ 2.73

Income Taxes

3 Months Ended

Mar. 31, 2023

Income Tax Disclosure [Abstract]

Income Taxes

9. Income Taxes

The Company maintains a full valuation allowance against its net deferred tax assets due to the Company’s history of losses as of March 31, 2023 and December 31, 2022.

The Company files income taxes in the U.S. federal jurisdiction, the state of California and various other U.S. states. The Company is currently under examination by the state of California for the years 2017 and 2018. The examination contests the Company’s tax position on revenue apportionment for upfront and milestone payments resulting from the Company’s collaboration and licensing agreements. As of the date of this filing, the state of California has not proposed adjustments to the tax returns. Due to the ongoing nature of the examination and discussions with the state of California, the Company is unable to estimate a date by which this matter will be resolved or reasonably estimate the potential impact should the tax position be revised. Based on the Company's current expectations and understanding of the reasonably possible outcomes, the Company does not anticipate that the resolution of this matter would result in a material impact on its financial position or results of operations.

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Beginning balance at Dec. 31, 2021

Net Loss Per Share - Summary of Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	15,525,577	14,545,414
RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,539,053	789,974
Options and ESPP to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	13,986,524	13,755,440

Stock-Based Compensation - Schedule of Company's TRSU Activities (Details) - Time based RSU	3 Months Ended
	Mar. 31, 2023 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Balance at December 31, 2022 \| shares	1,212,884
Units Awarded \| shares	597,767
Units vested \| shares	(110,892)
units cancelled \| shares	(6,941)
Balance at March 31, 2023 \| shares	1,692,818
Weighted Average Grant Date Fair Value, Beginning Balance \| $ / shares	$ 2.81
Units Awarded \| $ / shares	2.50
Units vested \| $ / shares	3.86
Units cancelled \| $ / shares	3.58
Weighted Average Grant Date Fair Value, Ending Balance \| $ / shares	$ 2.63

CONDENSED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($)
$ in Thousands

Total

Common Stock

Additional Paid-in Capital

Accumulated Other Comprehensive Income (Loss)

Accumulated Deficit

$ (459)

$ 1

$ 623,344

$ (242)

$ (623,562)

Beginning balance, shares at Dec. 31, 2021

65,392,758

Exercise of stock options

Exercise of stock options, shares

5,597

Stock-based compensation

3,370

Other comprehensive income (loss)

(677)

Net loss

(31,981)

Ending balance at Mar. 31, 2022

(29,740)

$ 1

626,721

(919)

(655,543)

Ending balance, shares at Mar. 31, 2022

65,398,355

Beginning balance at Dec. 31, 2022

$ (85,751)

^[1]

$ 1

637,117

(722,879)

Beginning balance, shares at Dec. 31, 2022

66,228,046

Release of RSUs, shares

110,892

Exercise of stock options, shares

Stock-based compensation

$ 2,409

2,409

Other comprehensive income (loss)

Net loss

(3,311)

Ending balance at Mar. 31, 2023

$ (86,637)

$ 1

$ 639,526

$ 26

$ (726,190)

Ending balance, shares at Mar. 31, 2023

66,338,938

[1]	The condensed balance sheet as of December 31, 2022 was derived from the audited financial statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2022.

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

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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Restructuring and Related Activities [Abstract]

Restructuring (Tables)

3 Months Ended

Mar. 31, 2023

Summary of Accrued Restructuring Costs

The following is a summary of accrued restructuring costs as of March 31, 2023 (in thousands):



	Severance and Benefits Costs			Contract Termination Cost			Stock Based Compensation		Total
Balance at December 31, 2022	$	1,512		$	164		$	-	$	1,676
Cash payment		(1,375	)		(50	)				(1,425	)
Change in estimates		(54	)		(114	)		-		(168	)
Balance at March 31, 2023	$	83		$	-		$	-	$	83

Collaboration and License Agreements

3 Months Ended

Mar. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Collaboration and License Agreements

6. Collaboration and License Agreements

The following table summarizes the revenue by collaboration partner:


	Three Months Ended March 31,
	2023		2022
	(in thousands)
AbbVie	$	3,988	$	1,751
Amgen		1,776		2,237
Astellas		8,705		4,766
Bristol Myers Squibb		7,725		286
Regeneron		581		-
Moderna		724		-
Total revenue	$	23,499	$	9,040

AbbVie Ireland Unlimited Company

In April 2016, the Company and AbbVie entered into two agreements, a CD71 Co-Development and Licensing Agreement (the “CD71 Agreement”) and a Discovery Collaboration and Licensing Agreement (as amended and restated in June 2019, the “Discovery Agreement” and together with the CD71 Agreement the “AbbVie Agreements”). Under the terms of the CD71 Agreement, the Company and AbbVie were co-developing a conditionally activated antibody-drug conjugate (“ADC”) against CD71, with the Company being responsible for preclinical and early clinical development. AbbVie was to be responsible for later development and commercialization, with global late-stage development costs shared between the two companies. As of December 31, 2022, the Company has received in aggregate $100.0 million in upfront and milestone payments under the CD71 Agreement. In March 2023, the Company announced that it will evaluate the potential next steps for CX-2029 following the decision from AbbVie, to not advance CX-2029 into additional clinical studies. As a result of AbbVie’s decision, the 2016 CD71 License and Collaboration Agreement has been terminated and the Company has an exclusive option to re-acquire

full rights to CX-2029. The Company has completed the performance obligation under the CD71 Agreement as of March 31, 2023 and recognized the related remaining deferred revenue of $4.0 million in the first quarter of 2023.

In December 2022, the research on the two discovery targets under the Discovery Agreement has concluded with no plans to advance the discovery targets into clinical studies or to pursue new programs. The Company completed the performance obligation for the second target earlier than the original research term that was projected to end in 2024 and recorded a cumulative change in estimate of $4.4 million in the fourth quarter of 2022. In March 2023, AbbVie gave notice that the Discovery Agreement would be terminated in 60 days and all target rights will revert back to CytomX.

Amgen, Inc.

On September 29, 2017, the Company and Amgen, Inc. (“Amgen”) entered into a Collaboration and License Agreement (the “Amgen Agreement”). Pursuant to the Amgen Agreement, the Company received an upfront payment of $40.0 million in October 2017. Concurrent with the Amgen Agreement, the Company and Amgen entered into a Share Purchase Agreement pursuant to which Amgen purchased 1,156,069 shares of the Company’s common stock at a price of $17.30 per share for total proceeds of $20.0 million.

In October 2021, CytomX and Amgen executed an amendment to the Amgen Agreement primarily to (1) extend the target selection date for Amgen to select its additional targets for research and development, and (2) reduce the total number of milestone events and increase the total amount of milestone payments for EGFR Products.

Under the terms of the Amgen Agreement, as amended, the Company and Amgen will co-develop a conditionally activated T-cell engaging bispecific therapeutic targeting epidermal growth factor receptor (the “EGFR Products”). The Company is responsible for early-stage development of EGFR Products and Amgen will be responsible for late-stage development and commercialization of EGFR Products. Following early-stage development, the Company will have the right to elect to participate financially in the global co-development of EGFR Products with Amgen, during which the Company would bear certain of the worldwide development costs for EGFR Products and Amgen would bear the rest of such costs (the “EGFR Co-Development Option”). If the Company exercises its EGFR Co-Development Option, the Company will share in somewhat less than 50% of the profit and losses from sales of such EGFR Products in the U.S., subject to certain caps, offsets, and deferrals. If the Company chooses not to exercise its EGFR Co-Development Option, the Company will not bear any costs of later stage development. The Company is also eligible to receive up to $460.0 million in development, regulatory, and commercial milestone payments for EGFR Products, and royalties in the low-double-digit to mid-teen percentage of worldwide commercial sales, provided that if the Company exercises its EGFR Co-Development option, it shall receive a profit and loss split of sales in the United States and royalties in the low-double-digit to mid-teen percentage of commercial sales outside of the United States. In January 2022, the IND for the EGFR product (CX-904) was allowed to proceed by the U.S. Food and Drug Administration (“FDA”).

Amgen also has the right to select a total of up to three targets, including the two additional targets discussed below. The Company and Amgen collaborate in the research and development of conditionally activated T-cell engaging bispecifics products directed against such targets. Amgen has selected one such target (the “Amgen Other Product”). If Amgen exercises its option within a specified period of time, it can select two such additional targets (the “Amgen Option Products” and, together with the Amgen Other Product, the “Amgen Products”). Except with respect to preclinical activities to be conducted by CytomX, Amgen will be responsible, at its expense, for the development, manufacture, and commercialization of all Amgen Products. If Amgen exercises all of its options and advances all three of the Amgen Products, CytomX was initially eligible to receive up to $950.0 million in upfront, development, regulatory, and commercial milestones and tiered high single-digit to low-teen percentage royalties. The Company concluded that, at the inception of the agreement, Amgen’s option to select the two additional targets is not a material right and does not represent a performance obligation of the agreement.

At the initiation of the collaboration, CytomX had the option to select, from programs specified in the Amgen Agreement, an existing preclinical stage T-cell engaging bispecific product from the Amgen preclinical pipeline. In March 2018, CytomX selected the program. CytomX is responsible, at its expense, for converting this program to a conditionally activated T-cell engaging bispecific product, and thereafter, will be responsible for development, manufacturing, and commercialization of the product (“CytomX Product”). Amgen is eligible to receive up to $203.0 million in development, regulatory, and commercial milestone payments for the CytomX Product, and tiered mid-single digit to low double-digit percentage royalties.

As of March 31, 2023 and December 31, 2022, deferred revenue related to the EGFR Products performance obligation was $16.4 million and $18.0 million, respectively. As of March 31, 2023 and December 31, 2022, deferred revenue related to the Amgen Other Products performance obligation was $0.4 million and $0.6 million, respectively.

Astellas Pharma Inc.

The Company and Astellas Pharma, Inc. (“Astellas”) entered into a Collaboration and License Agreement (the “Astellas Agreement”) on March 23, 2020, the effective date, to collaborate on preclinical research activities to discover and develop certain antibody compounds for the treatment of cancer using the Company’s Probody therapeutic technology.

Under the terms of the Astellas Agreement, the Company granted Astellas an exclusive, worldwide right to develop and commercialize Probody therapeutics for up to four collaboration targets including one initial target and three additional targets (“Additional Targets”). In addition, Astellas had the right to expand the number of Additional Targets from three up to five (the “Expansion Option”) before the third anniversary of the effective date. Furthermore, for a specified number of targets, at a pre-specified time prior to the initiation of the first pivotal study of a product against such target, the Company may elect to participate in certain development costs and share in the profits generated in the United States with respect to such product (“Cost Share Option”). The Cost Share Option, if exercised, will also provide the option for the Company to co-commercialize such product in the United States. The Company does not consider the Cost Share Option as a performance obligation at the inception of the agreement as the participation is at the Company’s discretion.

Pursuant to the Astellas Agreement, the consideration from Astellas is comprised of an upfront fee of $80.0 million and contingent payments for development, regulatory and sales milestones of up to an aggregate of approximately $1.6 billion. The Company is also entitled to tiered royalties from high-single digit to mid-teen percentage royalties from potential future sales. Astellas is responsible for all preclinical research costs incurred by either party as set forth in the preclinical research plan and the Company will receive research and development service fees based on a prescribed full time employee ("FTE") rate.

In January 2023, the Company announced that it achieved a clinical candidate milestone under the Astellas Agreement which triggered a $5.0 million milestone payment to the Company. The $5.0 million milestone payment was fully recognized in the first quarter of 2023 as the Company had completed its performance obligation related to the collaboration target.

As of March 31, 2023 and December 31, 2022, deferred revenue relating to the Astellas Agreement was $41.8 million and $44.5 million, respectively. The amount due from Astellas under the Astellas Agreement was $1.0 million and $1.0 million as of March 31, 2023 and 2022, respectively.

Bristol Myers Squibb Company

On May 23, 2014, the Company and Bristol Myers Squibb Company (“Bristol Myers Squibb”) entered into a Collaboration and License Agreement (the “BMS Agreement”) to discover and develop compounds for use in human therapeutics aimed at multiple immuno-oncology targets using the Company’s Probody therapeutic technology. The effective date of the BMS Agreement was July 7, 2014.

Under the terms of the BMS Agreement, the Company granted Bristol Myers Squibb exclusive worldwide rights to develop and commercialize Probody therapeutics for up to four oncology targets. Bristol Myers Squibb had additional rights to substitute up to two collaboration targets within three years of the effective date of the BMS Agreement. These rights expired in May 2017. Each collaboration target had a two-year research term and the two additional targets had to be nominated by Bristol Myers Squibb within five years of the effective date of the BMS Agreement. The research term for each collaboration target could be extended in one year increments up to three times.

Pursuant to the BMS Agreement, the financial consideration from Bristol Myers Squibb was comprised of an upfront payment of $50.0 million and estimated research and development service fees, and the Company was initially entitled to receive contingent payments of up to $25.0 million for additional targets and contingent payments for development, regulatory and sales milestones. In addition, the Company was entitled to royalty payments in the mid-single digits to low double-digit percentages from potential future sales.

On March 17, 2017, the Company and Bristol Myers Squibb entered into Amendment Number 1 to Extend Collaboration and License Agreement (“Amendment 1”). Amendment 1 granted Bristol Myers Squibb exclusive worldwide rights to develop and commercialize Probody therapeutics for up to eight additional targets. The effective date of Amendment 1 was April 25, 2017 (“Amendment Effective Date”). Under the terms of Amendment 1, the Company continued to have obligations to Bristol Myers Squibb to discover and conduct preclinical development of Probody therapeutics against any targets they chose to select during the research period under the terms of Amendment 1.

Pursuant to Amendment 1, the financial consideration from Bristol Myers Squibb was comprised of an upfront payment of $200.0 million, estimated research and development service fees, and contingent payments for development, regulatory and sales milestones for the eight

targets. The Company was also entitled to tiered mid-single to low double-digit percentage royalties from potential future sales. Amendment 1 did not change the term of Bristol Myers Squibb’s royalty obligation under the BMS Agreement. Bristol Myers Squibb’s royalty obligation continues on a licensed-product by licensed-product basis until the later of (i) the expiration of the last claim of the licensed patents covering the licensed products in the country, (ii) the twelfth anniversary of the first commercial sale of a licensed product in a country, or (iii) the expiration of any applicable regulatory, pediatric, orphan drug or data exclusivity with respect to such product.

The initial transaction price for the BMS Agreement and Amendment 1, collectively, was $304.7 million consisting of the upfront fees of $250.0 million, target selection fees for the third and fourth targets of $25.0 million, estimated research and development service fees of $17.7 million and milestone payments received up to January 1, 2018, of $12.0 million. The Company determined that the remaining potential milestone payments were probable of significant revenue reversal as their achievement was highly dependent on factors outside the Company’s control. Therefore, these payments were fully constrained and were not included in the transaction price upon the adoption of ASC 606 on January 1, 2018. The initial transaction price for the combined obligation for each collaboration target is recognized using an input measure.

In February 2021, the Company and Bristol Myers Squibb entered into Amendment Number 2 to amend the Collaboration and License Agreement (“Amendment 2”), as amended by Amendment 1. Subsequent to Amendment 2, in addition to Bristol Myers Squibb’s ongoing development of the CTLA-4 program, Bristol Myers Squibb also had the exclusive worldwide rights to develop and commercialize Probody therapeutics for up to five oncology targets. Under the terms of Amendment 2, the period for target selection was extended and the Company will continue to collaborate with Bristol Myers Squibb to discover and conduct preclinical development of Probody therapeutics against targets selected by Bristol Myers Squibb over the estimated research period, which is projected to end in April 2025. Pursuant to Amendment 2, the Company was eligible to receive contingent payments for development, regulatory and sales milestones. It is also entitled to tiered mid-single to low double-digit percentage of royalties from potential future sales. The Company accounted for Amendment 2 as a modification and reallocated the remaining unrecognized transaction price to the remaining performance obligations.

In October 2022, the Company and Bristol Myers Squibb entered into Amendment Number 3 to amend the Collaboration and License Agreement (“Amendment 3”), as amended by Amendment 1 and Amendment 2, to clarify the rights and restrictions of certain new proprietary antibodies that the parties exchanged. There were no substantive changes to each party's performance obligations. As of December 31, 2022, the Company is eligible for up to approximately $2.1 billion in contingent payments for development, regulatory and sales milestones based on the ongoing collaboration projects, including the CTLA-4 program, with BMS.

The Company reevaluated the remaining potential milestone payments and determined that significant revenue reversal was probable as the achievement of such milestones was highly dependent on factors outside the Company’s control. As a result, these payments continued to be fully constrained and were not included in the transaction price as of March 31, 2023.

As of March 31, 2023 and December 31, 2022, deferred revenue relating to the BMS Agreement was $161.5 million and $169.2 million, respectively.

ModernaTX, Inc.

The Company and ModernaTX, Inc. (“Moderna”) entered into a Collaboration and License Agreement (the “Moderna Agreement”) on December 30, 2022, the effective date, to collaborate on discovery and preclinical research and development activities to create investigational messenger RNA (mRNA) based conditionally activated therapies using the Company’s Probody therapeutic technology. Moderna is solely responsible for the development (preclinical and clinical), manufacture, and commercialization of any products under the Moderna Agreement.

Under the terms of the Moderna Agreement, the Company granted Moderna an exclusive, worldwide right to develop and commercialize Probody therapeutics for the collaboration programs. In exchange, the Company received an upfront payment of $35.0 million in January 2023, including $5.0 million of prepaid research and development service fees. The Company will continue to receive research and development service fees according to the preclinical research work plans based on a prescribed FTE rate and is eligible to receive up to approximately $1.2 billion in future development, regulatory, and commercial milestone payments. The Company is also eligible to receive tiered royalties from high-single digit to low-teen percentage rates of annual global net sales of any products that are commercialized under the Moderna Agreement. The Moderna Agreement also provides Moderna with an option to participate in a future equity financing by CytomX at market price, subject to certain terms, conditions and regulatory requirements.

As of March 31, 2023 and December 31, 2022, deferred revenue relating to the Moderna Agreement was $34.3 million and $35.0 million, respectively.

Regeneron Pharmaceuticals, Inc.

The Company and Regeneron Pharmaceuticals Inc. (“Regeneron”) entered into a Collaboration and License Agreement (the “Regeneron Agreement”) on November 16, 2022, to collaborate on creation of conditionally-activated investigational bispecific cancer therapies utilizing the Company’s Probody® therapeutic platform and Regeneron’s Veloci-Bi® bispecific antibody development platform. The Company and Regeneron will collaborate on preclinical research and discovery activities for initially agreed upon collaboration programs (“Collaboration Program”) with an option to expand additional Collaboration Programs (“Additional Collaboration Program Option”).

Under the Collaboration and License Agreement, the Company granted Regeneron an exclusive, worldwide, royalty-bearing license under certain Company intellectual property to develop, manufacture, commercialize and otherwise exploit licensed products (“Licensed Products”) for all human and non-human diagnostic, prophylactic and therapeutic uses in oncology. Regeneron is responsible for funding the cost of preclinical research and discovery activities of both parties for all Licensed Products and for funding the cost of development, manufacture and commercialization of all Licensed Products worldwide.

Pursuant to the Regeneron Agreement, the consideration from Regeneron is comprised of an upfront fee of $30.0 million, contingent payments for development and regulatory milestones and commercial milestone payments of up to an aggregate of approximately $0.8 billion. If Regeneron exercises its Additional Collaboration Program Option, the Company would be eligible to receive additional upfront and milestone payments aggregating up to approximately $1.2 billion. The Company is also entitled to tiered royalties from high-single digit to low-teen percentage royalties from potential future sales. In addition, the Company will receive research and development service fees based on a prescribed FTE rate.

As of March 31, 2023 and December 31, 2022, deferred revenue relating to the Regeneron Agreement was $29.5 million and $30.0 million, respectively.

Contract Liabilities

The following table presents changes in the Company’s total contract liabilities during the three months ended March 31, 2022 and 2023:


	Balance at 12/31/2022		Additions		Revenue Recognized			Balance at 3/31/2023
	(in thousands)
Contract liabilities:
Deferred revenue	$	301,326	$	869	$	(18,278	)	$	283,917


	Balance at 12/31/2021		Additions		Revenue Recognized			Balance at 3/31/2022
	(in thousands)
Contract liabilities:
Deferred revenue	$	284,760	$	1,058	$	(9,084	)	$	276,734

The Company expects that the $283.9 million of deferred revenue related to the following contracts as of March 31, 2023 will be recognized as revenue based on actual FTE effort and program progress as set forth below. However, the timing of revenue recognition could differ from the estimates depending on facts and circumstances impacting the various contracts, including progress of research and development, resources assigned to the contracts by the Company or its collaboration partners or other factors outside of the Company’s control.

•

The $16.4 million of deferred revenue related to the Amgen EGFR Products is expected to be recognized until 2026.

•

The $0.4 million of deferred revenue related to the Amgen Other Products is expected to be recognized until 2023.

•

The $41.8 million of deferred revenue related to the Astellas Agreement, together with research and development service fees, is expected to be recognized until 2026.

•

The $161.5 million of deferred revenue related to the BMS Agreement is expected to be recognized until 2025.

•

The $34.3 million of deferred revenue related to the Moderna Agreement, together with research and development service fees, is expected to be recognized until 2028.

•

The $29.5 million of deferred revenue related to the Regeneron Agreement, together with research and development service fees, is expected to be recognized until 2026.

Fair Value Measurements and Investments (Tables)

3 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Schedule of Investments Subject to Fair Value Measurements on a Recurring Basis

The following tables set forth the fair value of the Company’s investments subject to fair value measurements on a recurring basis and the level of inputs used in such measurements:


		March 31, 2023
	Valuation Hierarchy	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Aggregate Fair Value
		(in thousands)
Assets
Money market funds	Level I	$	56,794	$	—	$	—	$	56,794
Restricted cash (money market funds)	Level I		917		—		—		917
U.S. Treasury securities	Level I		148,119		26		—		148,145
Total		$	205,830	$	26	$	—	$	205,856


		December 31, 2022
	Valuation Hierarchy	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Aggregate Fair Value
		(in thousands)
Assets
Money market funds	Level I	$	64,706	$	—	$	—	$	64,706
Restricted cash (money market funds)	Level I		917		—		—		917
U.S. Treasury securities	Level I		29,941		10		—		29,951
Total		$	95,564	$	10	$	—	$	95,574

Commitments and Contingencies

3 Months Ended

Mar. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

8. Commitments and Contingencies

Legal Proceedings

On March 4, 2020, Vytacera Bio, LLC filed a patent infringement lawsuit against the Company in the U.S. District Court for the District of Delaware. The lawsuit alleges that the Company's use, offers to sell, and/or sales of the Probody® technology platform for basic research applications constitutes infringement. The complaint seeks unspecified monetary damages. In September 2022, the Company filed a motion to dismiss the case and the Court granted the parties’ stipulation to stay all pending case deadlines until that motion is finally resolved. The Company believes that the lawsuit is without merit and intends to vigorously defend itself. The Company does not believe a loss is probable and has not recorded any amount as a contingent liability for claims associated with this lawsuit as of March 31, 2023.

Collaboration and License Agreements - Astellas Pharma Inc - Additional Information (Details) $ in Thousands		1 Months Ended	3 Months Ended
	Mar. 23, 2020 USD ($) Target	Jan. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			$ 283,917	$ 301,326	$ 276,734	$ 284,760
Astellas Pharma Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			41,800
Collaboration and License Agreement \| Astellas Pharma Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of targets selected \| Target	1
Number of additional collaboration target \| Target	3
Upfront payment received	$ 80,000
Milestone payments received		$ 5,000	5,000
Deferred revenue			41,800	44,500
Amount due from customer			$ 1,000	$ 1,000
Collaboration and License Agreement \| Astellas Pharma Inc. \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of targets \| Target	4
Right to expand the number of additional collaboration target \| Target	5
Contingent milestone payments receivable	$ 1,600,000
Collaboration and License Agreement \| Astellas Pharma Inc. \| Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Right to expand the number of additional collaboration target \| Target	3

Net Loss Per Share

3 Months Ended

Mar. 31, 2023

Earnings Per Share [Abstract]

Net Loss Per Share

3. Net Loss Per Share

Basic net loss per share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding for the period. Diluted net loss per share is calculated using the weighted-average number of common shares outstanding, plus potential dilutive common stock during the period. Diluted net loss per share is the same as basic net loss per share since the effect of the potentially dilutive securities is anti-dilutive.


	Three Months Ended
	March 31,
	2023		2022
Options and ESPP to purchase common stock		13,986,524		13,755,440
RSUs		1,539,053		789,974
Total		15,525,577		14,545,414

Collaboration and License Agreements - Amgen, Inc - Additional Information (Details) $ / shares in Units, $ in Thousands		1 Months Ended
	Sep. 29, 2017 USD ($) Target	Oct. 31, 2017 USD ($) $ / shares shares	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			$ 283,917	$ 301,326	$ 276,734	$ 284,760
Amgen Inc \| EGFR Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			16,400
Amgen Inc \| Amgen Other Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			400
Collaboration and License Agreement \| Amgen Inc
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment received		$ 40,000
Common stock, shares issuable under agreement \| shares		1,156,069
Common stock, shares issuable under agreement, price per share \| $ / shares		$ 17.30
Common stock, value of shares issued in connection with agreement		$ 20,000
Number of targets selected \| Target	1
Number of additional collaboration target \| Target	2
Collaboration and License Agreement \| Amgen Inc \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent payments payable	$ 203,000
Collaboration and License Agreement \| Amgen Inc \| EGFR Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			16,400	18,000
Collaboration and License Agreement \| Amgen Inc \| EGFR Products \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent milestone payments receivable	$ 460,000
Percentage share of profit and losses	50.00%
Collaboration and License Agreement \| Amgen Inc \| Amgen Products \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent milestone payments receivable	$ 950,000
Number of targets \| Target	3
Collaboration and License Agreement \| Amgen Inc \| Amgen Other Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			$ 400	$ 600

Accrued Liabilities (Tables)

3 Months Ended

Mar. 31, 2023

Accrued Liabilities, Current [Abstract]

Schedule of Accrued Liabilities

Accrued liabilities consisted of the following:


	March 31,		December 31,
	2023		2022
	(in thousands)
Research and clinical expenses	$	12,500	$	13,089
Payroll and related expenses		4,372		8,060
Legal and professional expenses		757		1,413
Operating lease liabilities - short term		4,204		4,082
Restructuring expenses		83		1,627
Other accrued expenses		359		261
Total	$	22,275	$	28,532

Fair Value Measurements and Investments

3 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements and Investments

4. Fair Value Measurements and Investments

In accordance with Accounting Standards Codification (“ASC”) 820-10, Fair Value Measurements and Disclosures, the Company determines the fair value of financial and non-financial assets and liabilities using the fair value hierarchy, which establishes three levels of inputs that may be used to measure fair value, as follows:

•

Level I: Inputs which include quoted prices in active markets for identical assets and liabilities.

•

Level II: Inputs other than Level I that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

•

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

The carrying amounts of the Company’s financial instruments, including restricted cash, accounts receivable, accounts payable and accrued liabilities approximate fair value due to their relatively short maturities. The Company’s financial instruments consist of Level I assets which consist primarily of highly liquid money market funds, some of which are included in restricted cash and U.S. Treasury securities that are included in cash equivalents or short-term investments.

The following tables set forth the fair value of the Company’s investments subject to fair value measurements on a recurring basis and the level of inputs used in such measurements:


		March 31, 2023
	Valuation Hierarchy	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Aggregate Fair Value
		(in thousands)
Assets
Money market funds	Level I	$	56,794	$	—	$	—	$	56,794
Restricted cash (money market funds)	Level I		917		—		—		917
U.S. Treasury securities	Level I		148,119		26		—		148,145
Total		$	205,830	$	26	$	—	$	205,856


		December 31, 2022
	Valuation Hierarchy	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Aggregate Fair Value
		(in thousands)
Assets
Money market funds	Level I	$	64,706	$	—	$	—	$	64,706
Restricted cash (money market funds)	Level I		917		—		—		917
U.S. Treasury securities	Level I		29,941		10		—		29,951
Total		$	95,564	$	10	$	—	$	95,574

As of March 31, 2023, the remaining contractual terms of those investments are less than a year.