CytomX Therapeutics, Inc. 10-Q

Item 4 Controls and Procedures 30 PART II – OTHER INFORMATION Item 1. Legal Proceedings 31 Item 1A. Risk Factors 31 Item 2. Unregistered Sales of Equity Securities and Use of Proceeds 72 Item 3. Defaults Upon Senior Securities 72 Item 4. Mine Safety Disclosures 73 Item 5. Other Information 73 Item 6. Exhibits 74 Signatures 75 2 Forward-Looking Statements This Quarterly Report on Form 10-Q contains certain forward-looking statements that involve risks and uncertainties. These forward-looking statements reflect our current views with respect to, among other things, future events and our financial performance. These statements are often, but not always, made through the use of words or phrases such as “may,” “might,” “should,” “could,” “predict,” “potential,” “believe,” “expect,” “continue,” “will,” “anticipate,” “seek,” “estimate,” “intend,” “plan,” “project,” “would,” “annualized” and “outlook,” or the negative version of those words or other comparable words or phrases of a future or forward-looking nature. These forward-looking statements are not historical facts, and are based on current expectations, estimates and projections about our industry, management’s beliefs and certain assumptions made by management, many of which, by their nature, are inherently uncertain and beyond our control. Accordingly, we caution you that any such forward-looking statements are not guarantees of future performance and are subject to risks, assumptions, estimates and uncertainties that are difficult to predict. Although we believe that the expectations reflected in these forward-looking statements are reasonable as of the date made, actual results may prove to be materially different from the results expressed or implied by the forward-looking statements. A number of important factors could cause our actual results to differ materially from those indicated in these forward-looking statements, including those factors identified in “Risk Factors” or “Management’s Discussion and Analysis of Financial Condition and Results of Operations” or the following: • our expectations regarding the potential benefits, activity, effectiveness and safety of our product candidates and therapeutics developed utilizing our PROBODY ® conditionally activated platform technology; • the initiation, timing, progress and results of our ongoing clinical trials, research and development programs, preclinical studies, and Investigational New Drug Application (“IND”), Clinical Trial Application, New Drug Application (“NDA”), Biologics License Application (“BLA”), and other regulatory submissions; • the timing of the completion of our ongoing clinical trials and the timing and availability of clinical data from such clinical trials; • our ability to identify and develop additional product candidates; • our dependence on collaborators for developing, obtaining regulatory approval for and commercializing product candidates in the collaboration; • our or a collaborator’s ability to obtain and maintain regulatory approval of any of our product candidates; • our receipt and timing of any milestone payments or royalties under any research collaboration and license agreements or arrangements; • our expectations and beliefs regarding the evolution of the market and competitive landscape for cancer therapies and development of the oncology industry; • the rate and degree of market acceptance of any approved product candidates; • the commercialization of any approved product candidates; • our ability to establish and maintain collaborations and retain commercial rights for our product candidates in such collaborations; • the implementation of our business model and strategic plans for our business, technologies and product candidates; • our estimates of our expenses, ongoing losses, future revenue and capital requirements; • our ability to obtain additional funds for our operations; • our or any collaborator’s ability to obtain and maintain intellectual property protection for our technologies and product candidates and our ability to operate our business without infringing the intellectual property rights of others; • our reliance on third parties to conduct our preclinical studies or any future clinical trials; • our reliance on third-party supply and manufacturing partners to supply the materials and components for, and manufacture, our research and development, preclinical and clinical trial product supplies, including third parties in Europe and China; • our ability to attract and retain qualified key management and technical personnel; • our ability to secure and maintain licenses of intellectual property to protect our technologies and product candidates; • our financial performance; 3 • developments relating to our competitors, our industry, international conflict or uncertainties; and • the extent to which any future pandemic and related governmental regulations and restrictions may impact our business, including our research, clinical trials (which include ongoing site initiation and patient enrollment), manufacturing and financial condition. Any forward-looking statements in this Quarterly Report on Form 10-Q reflect our current views with respect to future events or to our future financial performance and involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by these forward-looking statements. Factors that may cause actual results to differ materially from current expectations include, among other things, those listed under Part II, Item 1A. Risk Factors and discussed elsewhere in this Quarterly Report on Form 10-Q. Given these uncertainties, you should not place undue reliance on these forward-looking statements. Except as required by law, we assume no obligation to update or revise these forward-looking statements for any reason, even if new information becomes available in the future. This Quarterly Report on Form 10-Q also contains estimates, projections and other information concerning our industry, our business and the markets for certain drugs and therapeutic biologics, including data regarding the estimated size of those markets, their projected growth rates and the incidence of certain medical conditions. Information that is based on estimates, forecasts, projections or similar methodologies is inherently subject to uncertainties and actual events or circumstances may differ materially from events and circumstances reflected in this information. Unless otherwise expressly stated, we obtained these industry, business, market and other data from reports, research surveys, studies and similar data prepared by third parties, industry, medical and general publications, government data and similar sources. In some cases, we do not expressly refer to the sources from which these data are derived. Except where the context otherwise requires, in this Quarterly Report on Form 10-Q, “we,” “us,” “our” and the “Company” refer to CytomX Therapeutics, Inc. Trademarks This Quarterly Report on Form 10-Q includes trademarks, service marks and trade names owned by us or other companies. All trademarks, service marks and trade names included in this Quarterly Report on Form 10-Q are the property of their respective owners. 4 PART I – FINANCIAL INFORMATION Item 1. Condensed Financi al Statements (Unaudited) CYTOMX THERAPEUTICS, INC. CONDENSED BAL ANCE SHEETS (in thousands) March 31, December 31, 2026 2025 (unaudited) (1) Assets Current assets: Cash and cash equivalents $ 28,828 $ 12,667 Short-term investments 317,879 124,385 Accounts receivable 646 2,013 Prepaid expenses and other current assets 5,743 4,856 Total current assets 353,096 143,921 Property and equipment, net 1,090 1,304 Intangible assets, net 401 438 Goodwill 949 949 Restricted cash 1,527 1,527 Operating lease right-of-use asset 2,264 3,396 Other assets 31 31 Total assets $ 359,358 $ 151,566 Liabilities and Stockholders' Equity Current liabilities: Accounts payable $ 1,368 $ 1,301 Accrued liabilities 11,923 14,197 Operating lease liabilities - short-term 2,856 4,240 Deferred revenue, current portion 17,876 26,877 Total current liabilities 34,023 46,615 Deferred revenue, net of current portion 979 1,590 Other long term liabilities 4,412 4,353 Total liabilities 39,414 52,558 Commitments and contingencies Stockholders' equity: Convertible preferred stock — — Common stock 2 2 Additional paid-in capital 1,050,037 810,844 Accumulated other comprehensive income 102 111 Accumulated deficit ( 730,197 ) ( 711,949 ) Total stockholders' equity 319,944 99,008 Total liabilities and stockholders' equity $ 359,358 $ 151,566 __________________ (1) The condensed balance sheet as of December 31, 2025 was derived from the audited financial statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2025. See accompanying notes to condensed financial statements. 5 CYTOMX THERAPEUTICS, INC. CONDENSED STATEMENTS OF OPERA TIONS AND COMPREHENSIVE INCOME (LOSS) (in thousands, except share and per share data) (Unaudited) Three Months Ended March 31, 2026 2025 Revenues $ 10,258 $ 50,917 Operating expenses: Research and development 19,238 18,868 General and administrative 10,692 9,428 Total operating expenses 29,930 28,296 Income (loss) from operations ( 19,672 ) 22,621 Interest income 1,490 955 Other (expense) income, net ( 7 ) 11 Income (loss) before income taxes ( 18,189 ) 23,587 Provision for income taxes 59 62 Net income (loss) attributable to common stockholders ( 18,248 ) 23,525 Other comprehensive income (loss): Unrealized loss on investments, net of tax ( 9 ) ( 28 ) Total comprehensive income (loss) $ ( 18,257 ) $ 23,497 Net income (loss) per share: Basic $ ( 0.10 ) $ 0.27 Diluted $ ( 0.10 ) $ 0.27 Shares used to compute net income (loss) per share Basic 177,273,000 87,121,502 Diluted 177,273,000 87,150,666 See accompanying notes to condensed financial statements. 6 CYTOMX THERAPEUTICS, INC. CONDENSED STATEMENTS OF STOC KHOLDERS’ EQUITY (DEFICIT) (in thousands, except share data) (Unaudited) Accumulated Additional Other Total Common Stock Paid-in Comprehensive Accumulated Stockholders' Shares Amount Capital Income Deficit Equity Balance at December 31, 2025 170,186,365 $ 2 $ 810,844 $ 111 $ ( 711,949 ) $ 99,008 Exercise of stock options and release of RSUs 1,516,946 — 281 — — 281 Issuance of common stock in follow on offering, net of issuance cost 45,990,567 — 228,351 — — 228,351 Issuance of pre-funded warrants in follow on offering, net of issuance cost — — 5,855 — — 5,855 Stock-based compensation — — 4,706 — — 4,706 Other comprehensive loss — — — ( 9 ) — ( 9 ) Net income — — — — ( 18,248 ) ( 18,248 ) Balance at March 31, 2026 217,693,878 $ 2 $ 1,050,037 $ 102 $ ( 730,197 ) $ 319,944 Accumulated Additional Other Total Common Stock Paid-in Comprehensive Accumulated Stockholders' Shares Amount Capital Income Deficit Equity (Deficit) Balance at December 31, 2024 80,099,889 $ 1 $ 691,095 $ 27 $ ( 691,579 ) $ ( 456 ) Exercise of stock options and release of RSUs 521,404 — — — — — Stock-based compensation — — 2,008 — — 2,008 Other comprehensive loss — — — ( 28 ) — ( 28 ) Net income — — — — 23,525 23,525 Balance at March 31, 2025 80,621,293 $ 1 $ 693,103 $ ( 1 ) $ ( 668,054 ) $ 25,049 See accompanying notes to condensed financial statements. 7 CYTOMX THERAPEUTICS, INC. CONDENSED STATEMEN TS OF CASH FLOWS (in thousands) (Unaudited) Three Months Ended March 31, 2026 2025 Cash flows from operating activities: Net income (loss) $ ( 18,248 ) $ 23,525 Adjustments to reconcile net income to net cash used in operating activities: Amortization of intangible assets 37 36 Depreciation and amortization 214 349 Accretion of discounts on short-term investments ( 726 ) ( 454 ) Stock-based compensation expense 4,706 2,008 Non-cash lease expense 1,132 1,081 Changes in operating assets and liabilities Accounts receivable 1,367 1,147 Prepaid expenses and other assets ( 887 ) ( 1,202 ) Accounts payable 67 ( 804 ) Accrued liabilities and other long-term liabilities ( 3,599 ) ( 2,106 ) Deferred revenue ( 9,612 ) ( 44,623 ) Net cash used in operating activities ( 25,549 ) ( 21,043 ) Cash flows from investing activities: Purchases of property and equipment — ( 119 ) Purchases of short-term investments ( 242,777 ) ( 19,785 ) Maturities of short-term investments 50,000 50,500 Net cash (used in) provided by investing activities ( 192,777 ) 30,596 Cash flows from financing activities: Proceeds from issuance of common stock, net issuance cost 228,351 — Proceeds from issuance of pre-funded warrants, net issuance cost 5,855 — Proceeds from exercise of stock options 281 — Net cash provided by financing activities 234,487 — Net increase in cash, cash equivalents and restricted cash 16,161 9,553 Cash, cash equivalents and restricted cash, beginning of period 14,194 39,079 Cash, cash equivalents and restricted cash, end of period $ 30,355 $ 48,632 Supplemental disclosures of noncash financing activities: Common stock issuance costs included in accrued liabilities $ 780 $ — See accompanying notes to condensed financial statements. 8 CytomX Therapeutics, Inc. Notes to Condensed Financial Statements (Unaudited) 1. Descriptio n of the Business CytomX Therapeutics, Inc. (the “Company”) is a clinical-stage, oncology-focused biopharmaceutical company developing potent biologics designed to remain masked and inactive in healthy tissue and to be unmasked and preferentially activated in the tumor microenvironment. 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 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 masked drug candidates in the tumor microenvironment across multiple therapeutic modalities. The Company is located in South San Francisco, California and was incorporated in the state of Delaware in September 2010. 2. Basis of Presentation and Summary of Significant Accounting Policies 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 this interim period 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, 2025 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. Significant Accounting Policie s There have been no material changes to our significant accounting policies this interim period as compared to the significant accounting policies disclosed in “Note 2. Basis of Presentation and Summary of Significant Accounting Policies” of the “Notes to Financial Statements” included in Part II, Item 8 of our 2025 Annual Report on Form 10-K for the year ended December 31, 2025 filed with the SEC. Recently Adopted Accounting Pronouncement In July 2025, the Financial Accounting Standards Board (“FASB”) issued ASU 2025-05, Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets , which provides a practical expedient for estimating expected credit losses on current accounts receivable and current contract assets arising from transactions accounted for under ASC 606. The Company adopted ASU 2025-05 during the interim period ended March 31, 2026 on a prospective basis and elected to apply the practical expedient to its current accounts receivable. Under this expedient, the Company assumes that current economic conditions as of the balance sheet date remain unchanged for the remaining contractual life of these receivables. The adoption of ASU 2025-05 did not have a material impact on the Company's financial statements. Recently Issued Accounting Standards Not Yet Adopted In November 2024, the FASB issued Accounting Standards Update (“ASU”) 2024-03, Disaggregation of Income Statement Expenses (“ASU 2024-03”), which enhances transparency in income statement disclosures. ASU 2024-03 requires entities to disclose detailed information about specific components of income statement expenses, such as employee compensation, depreciation, and amortization, as well as other significant expense categories. The objective is to provide financial statement users with greater insight into the nature and variability of 9 CytomX Therapeutics, Inc. Notes to Condensed Financial Statements (Unaudited) expenses, improving their ability to analyze financial performance and make informed decisions. ASU 2024-03 is effective for the annual reporting periods beginning after December 15, 2026 and for interim periods within annual reporting periods beginning after December 15, 2027 with early adoption permitted. The Company expects to adopt this ASU during the year ended December 31, 2027 on a prospective basis and is currently evaluating the impact on its financial statements. 3. Net Income (Loss) Per Share Basic net income (loss) per share is calculated by dividing the net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. Diluted net income (loss) per share is calculated by using the weighted-average number of shares of common stock outstanding, plus potential dilutive common stock during the period. Diluted net loss per share is the same as basic net loss per share in the period when the effect of the potentially dilutive securities is anti-dilutive. The pre-funded warrants have been included in both the basic and diluted EPS calculation. The following table presents the calculation of basic and diluted net income per share: Three Months Ended March 31, 2026 2025 (in thousands, except share and per share data) Numerator: Net income (loss) attributable common stockholders $ ( 18,248 ) $ 23,525 Denominator: Basic Weighted-average common shares outstanding 177,102,665 80,198,376 Weighted-average pre-funded warrants 170,335 6,923,126 Weighted-average common shares outstanding used to calculate basic net income per share 177,273,000 87,121,502 Diluted Weighted-average common shares outstanding used to calculate basic net income per share 177,273,000 87,121,502 Effect of potentially dilutive securities: Stock options, ESPP & RSUs — 29,164 Weighted-average common shares outstanding used to calculate diluted net income per share 177,273,000 87,150,666 Net income (loss) per share Basic $ ( 0.10 ) $ 0.27 Diluted $ ( 0.10 ) $ 0.27 The following weighted-average outstanding shares of potentially dilutive securities are excluded from the computation of diluted net income (loss) per share for the periods presented, because including them would have been anti-dilutive: Three Months Ended March 31, 2026 2025 Options and ESPP to purchase common stock 18,209,834 16,024,352 Common stock warrants 5,769,231 11,538,462 RSUs 3,359,464 2,761,967 Total 27,338,529 30,324,781 10 CytomX Therapeutics, Inc. Notes to Condensed Financial Statements (Unaudited) 4. Fair Value Measurements and Investments 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 are comprised of Level I and Level II assets, consisting primarily of highly liquid money market funds which are included in cash equivalents and restricted cash, and U.S. Treasury securities which are included in short-term investments. The Company's U.S. Treasury securities are classified as Level II marketable securities and are valued using third-party pricing sources, which can include observable market prices, interest rates and yield curves observable at commonly quoted intervals for similar assets as observable inputs for pricing. 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, 2026 Valuation Hierarchy Amortized Cost Gross Unrealized Gains Aggregate Fair Value (in thousands) Assets Money market funds Level I $ 28,934 $ — $ 28,934 Restricted cash (money market funds) Level I 1,527 — 1,527 U.S. Treasury securities Level II 317,777 102 317,879 Total $ 348,238 $ 102 $ 348,340 December 31, 2025 Valuation Hierarchy Amortized Cost Gross Unrealized Gains Aggregate Fair Value (in thousands) Assets Money market funds Level I $ 12,775 $ — $ 12,775 Restricted cash (money market funds) Level I 1,527 — 1,527 U.S. Treasury securities Level II 124,274 111 124,385 Total $ 138,576 $ 111 $ 138,687 As of March 31, 2026 and December 31, 2025, interest receivable of $ 1.5 million and $ 0.5 mill ion, respectively, primarily related to short- term investments are included in prepaid expenses and other current assets. As of March 31, 2026, the remaining contractual terms of the U.S. Treasury securities are less than a year. Based on the scheduled maturities of our marketable securities, the Company determined that it was more likely than not that it will hold these marketable securities to maturity for a recovery of our cost basis. 11 CytomX Therapeutics, Inc. Notes to Condensed Financial Statements (Unaudited) 5. Accrued Liabilities Accrued liabilities consisted of the following: March 31, December 31, 2026 2025 (in thousands) Research and clinical expenses $ 5,055 $ 4,345 Payroll and related expenses 3,904 8,209 Legal and professional expenses 1,831 1,478 Restructuring expenses — 23 Other accrued expenses 1,133 142 Total $ 11,923 $ 14,197 6. Collaboration and License Agreements The following table summarizes the revenue by collaboration partner: Three Months Ended March 31, 2026 2025 (in thousands) Amgen $ — $ 9,486 Astellas 8,993 9,446 Bristol Myers Squibb — 30,364 Regeneron 1,265 1,614 Moderna — 7 Total revenue $ 10,258 $ 50,917 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 . Under the terms of the Amgen Agreement, as amended, the Company and Amgen were co-developing a conditionally activated T-cell engager (“TCE”) targeting epidermal growth factor receptor (the “EGFR Products”). The Company was responsible for early-stage development of EGFR Products and Amgen was to be responsible for late-stage development and commercialization of EGFR Products. Amgen had the right to select a total of up to three targets, including the two additional targets. The Company and Amgen collaborated in the research and development of conditionally activated T-cell engaging bispecifics therapies directed against such targets. Amgen had selected one such target (the “Amgen Other Product”). Except with respect to preclinical activities to be conducted by CytomX, Amgen would have been responsible, at its expense, for the development, manufacture, and commercialization of all Amgen Products. In January 2022, the IND for the EGFR Products (“CX-904”) was allowed to proceed by the U.S. Food and Drug Administration (“FDA”) and the program progressed into Phase 1 dose escalation. In March 2025, CytomX and Amgen jointly decided to not continue CX-904 development and Amgen terminated its license to the EGFR Products. As a result, all of the remaining deferred revenue of the EGFR Products was recognized in the first quarter of 2025 due to Amgen terminating its license to the EGFR Products effective May 2025. In April 2025, the Amgen Other Product was also terminated with 60 days written notice pursuant to the Amgen Agreement. The Amgen research collaboration remains in effect with the current scope being the preclinical TCE that CytomX selected from Amgen’s preclinical pipeline further discussed below. At the initiation of the collaboration, CytomX had the option to select from programs specified in the Amgen Agreement, an existing preclinical stage TCE product from the Amgen preclinical pipeline. In March 2018, CytomX selected the program and this program, CX-908, a PROBODY T cell engager targeting CDH3 and CD3, is currently in preclinical development. CytomX is responsible, at its expense, for converting this program to a conditionally activated TCE 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. 12 CytomX Therapeutics, Inc. Notes to Condensed Financial Statements (Unaudited) As of June 30, 2025, the Company had completed its performance obligations related to the EGFR Products and the Amgen Other Products and recognized all deferred revenue. 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 had the option to 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, also provided the option for the Company to co-commercialize such product in the United States. The Company had not considered the Cost Share Option as a performance obligation at the inception of the agreement as participation is at the Company’s discretion. Pursuant to the Astellas Agreement, the consideration from Astellas was comprised of an upfront fee of $ 80.0 million and total potential contingent payments for development, regulatory and sales milestones of up to an aggregate of approximately $ 1.2 billion. The Company was also entitled to tiered royalties from high-single digit to mid-teen percentage royalties from potential future sales. Astellas was responsible for all preclinical research costs incurred by either party as set forth in the preclinical research plan and the Company was entitled to receive research and development service fees based on a prescribed full-time employee ("FTE") rate. In January 2023, the Company achieved a clinical candidate milestone for the first collaboration target nomination under the Astellas Agreement which triggered a $ 5.0 million milestone payment to the Company which was fully recognized in the first quarter of 2023 as the Company had completed its related performance obligation. In March 2024, the Company achieved the good laboratory practices ("GLPs") toxicology milestone for this candidate 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 2024 as the Company had completed its related performance obligation of this first collaboration target. Also, in March 2024, the Company achieved a clinical candidate milestone for a second collaboration target nomination under the Astellas Agreement which triggered an additional $ 5.0 million milestone payment to the Company. The $ 5.0 million milestone payment for this second nomination was fully recognized in the first quarter of 2024 as the Company had completed its related performance obligation. In the first quarter of 2025, Astellas initiated GLP toxicology studies for the second collaboration target, triggering a $ 5.0 million milestone payment to CytomX. The $ 5.0 million milestone payment was fully recognized in the first quarter of 2025 as the Company had completed its related performance obligation of this second collaboration target. In the first quarter of 2026, Astellas chose not to advance the remaining preclinical programs and terminated the Astellas Agreement effective May 12, 2026, which is expected to result in the completion of the Company's performance obligation and recognition of the remaining deferred revenue by the second quarter of 2026. As a result, a cumulative adjustment of $ 7.1 million of revenue was recognized in the first quarter of 2026, which lowered the loss per share by $ 0.04 for the three months ended March 31, 2026. As of March 31, 2026 and December 31, 2025, deferred revenue relating to the Astellas Agreement was $ 47.0 thousand and $ 8.6 million, respectively. The amount due from Astellas under the Astellas Agreement wa s $ 0.4 million as of March 31, 2026 and $ 0.9 million as of December 31, 2025. 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, including the target CTLA-4. 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 13 CytomX Therapeutics, Inc. Notes to Condensed Financial Statements (Unaudited) $ 25.0 million for additional targets and contingent payments for development, regulatory and sales milestones as well as royalty payments from potential future sales. On March 17, 2017, the Company and Bristol Myers Squibb amended the BMS Agreement and 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 PR OBODY therapeutics for up to eight additional targets. The effective date of Amendment 1 was April 25, 2017. 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. In February 2021, the Company and Bristol Myers Squibb amended the BMS Agreement and entered into Amendment Number 2 to amend the Collaboration and License Agreement (“Amendment 2”), as previously 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 in 2022, all remaining targets were selected. The Company continues 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 was projected to end in April 2025. Pursuant to Amendment 2, the Company was eligible to receive contingent payments for development, regulatory and sales milestones as well as royalty payments from potential future sales. In March 2024, following a Bristol Myers Squibb corporate portfolio prioritization process, Bristol Myers Squibb notified CytomX that it did not intend to continue the development of BMS-986288 beyond the current Phase 2 study and terminated its collaboration license to the CTLA-4 target under the collaboration. BMS-986288 was Bristol Myers Squibb’s leading next generation PROBODY CTLA-4 program that it had previously prioritized over BMS-986249, which was a PROBODY version of ipilimumab. In June 2024, Bristol Myers Squibb prioritized its pre-clinical research activities under the collaboration and revised the research scope by one collaboration target. The Company determined that it had no further obligations related to the target that was deprioritized and accounted for the reduction of the target as a modification and the related remaining unrecognized transaction price was reallocated to the remaining performance obligations. T he Company had received in aggregate $ 297.0 million in upfront and milestone payments under the agreement. T he Company's research efforts on all the ongoing programs were completed in April 2025 upon which the $ 11.6 million of remaining deferred revenue was fully recognized with Bristol Myers Squibb responsible for further advancement. In May 2026, Bristol Myers Squibb decided to not advance the remaining preclinical programs resulting in a termination of the collaboration. 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), manufacturing, 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 approximatel y $ 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. Due to Moderna's budget considerations, the Company's remaining activities for its performance obligation are currently paused pending future alignment with Moderna. As of March 31, 2026 and December 31, 2025, deferred revenue relating to the Moderna Agreement was $ 9.3 million and $ 9.3 million, respectively. There was no amount due from Moderna under the Moderna Agreement as of March 31, 2026 and December 31, 2025. 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”). 14 CytomX Therapeutics, Inc. Notes to Condensed Financial Statements (Unaudited) 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, manufacturing 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, 2026 and December 31, 2025, deferred revenue relating to the Regeneron Agreement was $ 9.5 million a nd $ 10.5 million, respectively. The amount due from Regeneron under the Regeneron Agreement was $ 0.2 million and $ 0.8 million as of March 31, 2026 and December 31, 2025, respectively. Contract Liabilities The following table presents changes in the Company’s total contract liabilities during the three months ended March 31, 2026 and 2025: Deferred Revenue (in thousands) December 31, 2025 $ 28,467 Additions 646 Revenue recognized ( 10,258 ) March 31, 2026 $ 18,855 December 31, 2024 $ 94,063 Additions 1,355 Revenue recognized ( 45,978 ) March 31, 2025 $ 49,440 The Company expects that the $ 18.9 million of deferred revenue related to the following contracts as of March 31, 2026 will be recognized as revenue based on actual FTE effort and estimated 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 $ 9.3 million of deferred revenue related to the Moderna Agreement, together with research and development service fees, are expected to be recognized primarily in 2026 and 2027, pending alignment with Moderna's budget considerations. • The $ 9.5 million of deferred revenue related to the Regeneron Agreement, together with research and development service fees, are expected to be recognized until 2026 . 7. License Agreement UCSB Agreement In August 2010, the Company entered into an exclusive, worldwide license agreement with University of California, Santa Barbara (“UCSB”), relating to the use of certain patents and technology, and to patent rights the Company co-owns with UCSB that cover certain conditionally activatable antibodies (the “UCSB Agreement”). Pursuant to the UCSB Agreement, the Company has annual minimum royalty obligations of $ 0.2 million under the terms of certain exclusive licensed patent rights. In April 2019, the Company entered into Amendment No.3 to the UCSB Agreement to adjust and clarify certain sublicense terms (“Amendment No.3”). Under the terms of Amendment No.3, the Company agreed to make an additional annual license maintenance fee of $ 0.8 million through January 2031 . In the event that the Company terminates the agreement due to material concern of the safety or efficacy of the related technology, 50 % of all remaining maintenance fees 15 CytomX Therapeutics, Inc. Notes to Condensed Financial Statements (Unaudited) will become due immediately. Otherwise, all remaining maintenance fees will become due immediately upon early termination of the agreement unless there is a material breach by UCSB. In 2023, the Company incurred $ 0.2 million of sublicense fees triggered by achieving the clinical candidate milestone under the Astellas Agreement. In 2024, the Company incurred $ 0.6 million of sublicense fees triggered by achieving the GLP toxicology studies milestone for the first clinical candidate which was nominated by Astellas in 2023, as well as by achieving the clinical candidate nomination milestone for a second collaboration target under the Astellas Agreement. In the first quarter of 2025, the Company incurred $ 0.2 million of sublicense fees triggered by achieving the GLP toxicology studies milestone for the second clinical candidate which was nominated by Astellas in March 2024. For the three months ended March 31, 2026 and 2025, the Company incurred sublicense expenses of $ 0.9 million and $ 1.1 million, respectively, under the provisions of the UCSB Agreement. ImmunoGen (acquired by AbbVie in 2024) In December 2019, the Company entered into a License Agreement (the “ImmunoGen 2019 License”) with ImmunoGen, Inc. to obtain an exclusive license with respect to epithelial cell adhesion molecule (“EPCAM”). Under the ImmunoGen 2019 License, ImmunoGen agreed to transfer its know-how, patents, intellectual property rights, and technology transfer materials and information related to its EpCAM program. The license gives the Company the sole ability to develop, manufacture, use and commercialize any licensed product that incorporates, is comprised of, or otherwise derived from PROBODY technology that targets EpCAM in any human therapeutic field on a worldwide basis. In exchange, the Company made an upfront license payment of $ 7.5 million, and will pay up to $ 35.0 million in certain clinical development milestones and up to $ 320.0 million in regulatory approval and commercial milestone payments, if achieved. ImmunoGen is also entitled to royalties on product sales ranging from the mid-to-high single digits percentages. In April 2024, the Company made a $ 5.0 million payment of the $ 35.0 million in potential clinical development milestone payments to AbbVie (formerly ImmunoGen) with respect to achieving the milestone of dosing the first patient for Varseta-M under the ImmunoGen 2019 License Agreement. The remaining $ 30.0 million of potential development milestone payments under the License Agreement are expected to be triggered by the start of the first Phase 2 study and first Phase 3 study for an EpCAM program (e.g. Varseta-M) in the amounts of $ 10.0 million and $ 20.0 million, respectively. Varseta-M, which is currently in Phase 1 development, is covered under the ImmunoGen License Agreement. 8. Common Stock On March 19, 2026, the Company completed an underwritten offering of 45,990,567 shares of common stock at an offering price of $ 5.30 per share and pre-funded warrants to purchase 1,179,245 shares of common stock (the “Pre-Funded Warrants”) at a price of $ 5.29999 per share. The Pre-Funded Warrants have an exercise price of $ 0.00001 per share, subject to adjustments, and are exercisable from the date of issuance until fully exercised, subject to an ownership limitation. The aggregate net proceeds received by the Company from the offering were approximately $ 234.2 million, after deducting underwriting discounts and commissions of $ 15.0 million and offering expenses of $ 0.8 million. In addition, the Company granted the underwriters the option for 30 days to purchase up to an additional 7,075,471 shares of common stock at the public offering price of $ 5.30 per share. Such option expired unexercised in April 2026. In May 2025, the Company completed an underwritten public offering of 76,923,076 shares of common stock at a price of $ 1.30 per share. The aggregate net proceeds received by the Company from the offering were approximately $ 93.4 million, after deducting underwriting discounts and commissions of $ 6.0 million and offering expenses of $ 0.6 million. Longitude Venture Partners V, L.P. (“LVPV”) acquired approximately 11.5 million shares of common stock through the underwritten public offering. Longitude Capital Partners V, LLC (“LCPV”) is a general partner of LVPV. A member of the Company’s board of directors serves as a managing director of LCPV, and therefore, LCPV is considered a related party of the Company. The Company had no other significant related party transactions with LCPV. In June 2023, the Company entered into an agreement with BVF Partners L.P. (“BVF”) for a private placement and received an aggregate net proceeds of approximately $ 29.7 million in July 2023, after deducting issuance costs of approximately $ 0.3 million. In the private placement, the Company issued pre-funded warrants to BVF to purchase up to 14,423,077 shares of common stock (the “BVF Pre-Funded Warrants”), accompanying Tranche 1 warrants to purchase up to 5,769,231 shares of common stock and accompanying Tranche 2 warrants to purchase up to 5,769,231 shares of common stock, at a combined price of $ 2.08 per share. The initial exercise price of the Tranche 1 and Tranche 2 warrants was $ 4.16 per share and $ 6.24 per share, respectively. The public offering in May 2025 described above triggered an adjustment provision in the Tranche 1 and Tranche 2 warrants, pursuant to which the exercise prices were reduced to $ 2.73 and $ 3.77 per share, respectively. The Tranche 1 warrants expired without being exercised in July 2025 and the Tranche 2 warrants will expire in July 2026 . BVF 16 CytomX Therapeutics, Inc. Notes to Condensed Financial Statements (Unaudited) exercised the BVF Pre-Funded Warrants for 7.5 million shares of common stock in May 2024 and for the remaining 6.9 million shares in May 2025, in each case at an exercise price of $ 0.00001 per share. The following table summarizes the Company's outstanding warrants as of March 31, 2026: Pre-funded Warrants Tranche 2 Warrants Number of warrants Weighted- Average Exercise Price Per Share Number of warrants Weighted- Average Exercise Price Per Share Balance at December 31, 2025 — 5,769,231 $ 3.77 Issuance in public offering 1,179,245 $ 0.00001 — Balance at March 31, 2026 1,179,245 $ 0.00001 5,769,231 $ 3.77 9. Stock-Based Compensation Stock Options Activities for the Company’s stock option plans for the three months ended March 31, 2026 were as follows: Options Outstanding Number of Options Weighted- Average Exercise Price Per Share Balance at December 31, 2025 16,708,942 $ 5.12 Options granted 2,611,949 6.09 Options exercised ( 174,003 ) 1.62 Options forfeited/expired ( 270,500 ) 14.46 Balance at March 31, 2026 18,876,388 $ 5.15 The Company recorded $ 3.8 million and $ 1.3 million of stock-based compensation expense related to the stock option plans for the three months ended March 31, 2026 and 2025, respectively. Time-based RSUs ("TRSU") Activities for the Company’s TRSUs for the three months ended March 31, 2026 were as follows: Number of Shares Weighted Average Grant Date Fair Value Per Share Balance at December 31, 2025 2,911,194 $ 1.25 RSUs awarded 1,089,212 6.09 RSUs vested ( 1,342,943 ) 1.41 RSUs forfeited — — Balance at March 31, 2026 2,657,463 $ 3.15 The Company recorded $ 0.9 million and $ 0.2 million of stock-based compensation expense related to the TRSUs for the three months ended March 31, 2026 and 2025, respectively. Performance-based RSUs ("PSUs") 17 CytomX Therapeutics, Inc. Notes to Condensed Financial Statements (Unaudited) 2024 PSU In January 2024, the Company granted 810,000 PSUs to executive employees with an aggregate grant date fair value of approximately $ 1.3 million. Vesting for 50% of the PSUs granted would occur upon attaining specified milestones by December 2025 (“2024-Tranche-1 PSUs”), and the remaining 50% will vest upon attaining specified milestones by December 2026 (“2024-Tranche-2 PSUs”). The 2024-Tranche-1 PSUs were canceled as the related performance condition was not met by December 2025 . As of March 31, 2026, the Company determined that it is not probable that the performance conditions will be satisfied for 2024-Tranche-2 PSUs and hence no compensation cost was recorded for these awards through March 31, 2026. 2025 PSU In September 2025 and February 2026, the Company granted a total of 463,350 PSUs to executive employees with an aggregate grant date fair value of approximately $ 1.5 million. Vesting for one-third of the PSUs granted will occur upon attaining a specified milestone (“2025-Tranche-1 PSUs”), vesting for one-third of the PSUs granted will occur upon attaining a specified milestone (“2025-Tranche-2 PSUs”) on June 30, 2027 or later, and the remaining one-third will vest upon attaining a specified milestone on June 30, 2028 or later (“2025-Tranche-3 PSUs”). As of March 31, 2026, the Company determined that it is not probable that the performance conditions will be satisfied for any of these tranches and hence no compensation cost was recorded for these awards through March 31, 2026. A ctivities for the Company’s PSUs for the three months ended March 31, 2026, were as follows: Number of Shares Weighted Average Grant Date Fair Value Per Share Balance at December 31, 2025 705,850 $ 2.39 PSUs awarded 50,000 6.09 Balance at March 31, 2026 755,850 $ 2.63 Stock-based Compensation Total stock-based compensation recorded was as follows: Three Months Ended March 31, 2026 2025 (in thousands) Research and development $ 892 $ 563 General and administrative 3,814 1,445 Total stock-based compensation expense $ 4,706 $ 2,008 During the three months ended March 31, 2026, in connection with the extension of consulting arrangements for two former executives, the Company extended the vesting period of unvested options and awards and the exercisable period of vested options, as permitted under the Company's equity incentive plans. As a result, the Company recognized the full amount of the incremental stock-based compensation expense of approximately $ 2.5 million in the first quarter of 2026. 10. Income Taxes The Company maintains a full valuation allowance against its net deferred tax assets through March 31, 2026 . The Company files income taxes in the U.S. federal jurisdiction, the state of California and various other U.S. states. The state of California contested the Company’s tax position on revenue apportionment for upfront and milestone payments resulting from the Company’s collaboration and licensing agreements for the years 2017 and 2018. In September 2023, the Company received Notice of Proposed Assessment (“NOPA”) from the Franchise Tax Board. The Company recorded an uncertain tax position of $ 4.4 millio n in long term liabilities for the proposed tax assessment, penalties and interest through March 31, 2026. Additional utilization of carryforward attributes and indirect federal tax effects of the assessment would result in a reduction in deferred tax assets of $ 5.0 million. The Company filed a protest to contest the proposed assessment in November 2023. 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. 18 CytomX Therapeutics, Inc. Notes to Condensed Financial Statements (Unaudited) 11. Segment Disclosures The Company operates as a single operating segment. The Chief Executive Officer is identified as the Chief Operating Decision Maker (“CODM”). The CODM primarily reviews the Company’s financial information on an aggregate basis. The CODM utilizes the aggregated financial information to make strategic decisions, assess performance, and allocate resources across the Company. The aggregate information includes the revenue by collaboration partner, research and development expense by program, as well as net income (loss) that is reported on the Statements of Operations and Comprehensive Income (Loss). Net income (loss) is used to monitor budget versus actual results in assessing performance of the segment and in establishing management's compensation. The measure of segment assets is reported on the Balance Sheets as total assets. All of the Company’s long-lived assets are located in the United States. In addition to the revenue by collaborative partners disclosed in Note 6, the CODM reviews the following significant expenses in making decisions about the allocation of resources and assessing performance (in thousands): Three Months Ended March 31, 2026 2025 (in thousands) Total revenue $ 10,258 $ 50,917 External costs incurred by product candidate (target): Varseta-M (EpCAM) 7,814 4,270 CX-801 (IFNα2b) 344 488 CX-904 (EGFRxCD3) 241 1,111 Other wholly owned and partnered programs 143 397 General research and development expenses 2,883 2,530 Total external costs 11,425 8,796 Internal costs 7,813 10,072 Research and development expenses 19,238 18,868 General and administrative expenses 10,692 9,428 Total operating expenses 29,930 28,296 Income (loss) from operations ( 19,672 ) 22,621 Interest income 1,490 955 Other income (expense), net ( 7 ) 11 Income (loss) before income taxes ( 18,189 ) 23,587 Provision for income taxes 59 62 Net income (loss) $ ( 18,248 ) $ 23,525 19 CytomX Therapeutics, Inc. Notes to Condensed Financial Statements (Unaudited) 12. Restructuring On January 6, 2025, the Company announced a restructuring plan to streamline its organization and prioritize Varseta-M (EpCAM PROBODY ADC), CX-801 and its activities to support its research collaborations. This plan resulted in a reduction of approximately 40 % of its workforce and was substantially completed in the first quarter of 2025. The Company incurred total restructuring charges of $ 2.8 million during 2025, primarily related to one-time severance payments and other employee-related costs. This includes $ 1.7 million of research and development expenses and $ 1.1 million of general and administrative expenses that were recorded during 202 5. The restructuring was completed as of March 31, 2026. 20 Item 2. Management’s Discuss ion and Analysis of Financial Condition and Results of Operations You should read the following management’s discussion and analysis of our financial condition and results of operations in conjunction with our unaudited condensed financial statements and notes thereto included in Part I, Item 1 of this Quarterly Report on Form 10-Q and with our audited financial statements and notes thereto for the year ended December 31, 2025, included in our Annual Report on Form 10-K as filed with the U.S. Securities and Exchange Commission (“SEC”) on March 16, 2026. This discussion and other parts of this report contain forward-looking statements that involve risks and uncertainties, such as statements of our plans, objectives, expectations and intentions. Our actual results could differ materially from those discussed in these forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those discussed in the section of this report titled “Risk Factors.” Except as may be required by law, we assume no obligation to update these forward-looking statements or the reasons that results could differ from these forward-looking statements. Overview We are a clinical-stage, oncology-focused biopharmaceutical company dedicated to developing innovative therapies to address major unmet need in oncology. We have led the field of conditionally activated, masked biologics through the development of our PROBODY technology platform. This versatile, multi-modality platform is built on a strong foundation of tumor biology expertise, including deep knowledge of tumor-associated enzymes known as proteases. Our masking strategy is designed to reduce binding of biologic therapeutics to their targets until the mask is removed by proteases in the tumor microenvironment, providing more selective targeting of the tumor and optimizing the predicted therapeutic index of our clinical candidates. Our experience and leadership with the PROBODY platform for over 15 years has led to a highly focused strategy for the application of our technology in product development that has resulted in a current pipeline of novel clinical-stage and pre-clinical stage programs. In identifying and designing potential PROBODY therapeutics, we evaluate the following: • Target: Drug targets that have been validated previously as having clinical anti-tumor activity, but have been limited in their utility due to expression and toxicity in healthy tissues. • Indication: The significance of the clinical unmet need that may be addressed if the target could be targeted systemically and unlocked through masking. • Effector Mechanism: The PROBODY platform is highly versatile and is being applied to a wide range of modalities including antibody-drug conjugates (“ADCs”), T-cell engagers (“TCEs”), and cytokines. In PROBODY therapeutic design, the goal is to align the selected indication with the most validated drug modality (e.g. ADC, TCE) and cancer cell killing mechanism (e.g. cytotoxic payload) to maximize the potential for clinical activity. Our two current clinical programs, varsetatug masetecan (“Varseta-M”) and CX-801 are in Phase 1 clinical development and are examples of our focused program development strategy. We aim to continue to advance our clinical pipeline towards later stage development and ultimately build a commercial enterprise to maximize our impact on the treatment of cancer. Varsetatug Masetecan (Varseta-M) Our most advanced clinical-stage program is Varseta-M, an investigational, conditionally activated antibody-drug conjugate (“ADC”) targeting epithelial cell adhesion molecule (“EpCAM”). Varseta-M is initially focused on the lead indication of colorectal cancer (“CRC”). Varseta-M is designed to bring the promise of ADCs, which have made a meaningful clinical difference in other solid tumors such as lung and breast cancer, to CRC by leveraging EpCAM as a potentially ideal CRC antigen to target this disease. Varseta-M is a high affinity EpCAM antibody that is designed to preferentially bind EpCAM in the tumor microenvironment and minimize toxicities in healthy tissues, which have limited prior attempts in the field to target EpCAM systemically. Varseta-M is armed with a topoisomerase-1 inhibitor payload. Topoisomerase-1 inhibitors are known to have clinical activity in CRC, including irinotecan chemotherapy which is a standard component of the approved standard of care in CRC. EpCAM is a high potential oncology target based on its documented high expression in many solid tumors, including CRC where it was first discovered due to its very high and uniform expression. Historically, previous efforts across the drug development landscape to target this antigen systemically have been limited by dose-limiting toxicities. For example, high affinity EpCAM antibodies were limited by pancreatitis and liver toxicities and discontinued. However, EpCAM has been validated as a cancer target, including by the drug KORJUNY ® , which is approved for the treatment of malignant ascites in Europe. KORJUNY ® , however, must be given directly into the peritoneum due to systemic toxicity, but its approval provides evidence that local delivery of an EpCAM therapeutic to the tumor can be effective. The Varseta-M payload is a topoisomerase-1 inhibitor licensed from AbbVie (formerly ImmunoGen), tailored to have anti-tumor activity against EpCAM-expressing cancer types. The payload-antibody linker is specifically designed to drive bystander killing of neighboring tumor cells, contributing to robust anti-tumor activity. Overall, the design of Varseta-M seeks to establish, for the first time, a clinically meaningful therapeutic window for the systemic treatment of patients with EpCAM-expressing cancers. 21 Varseta-M is designed to potentially address a broad range of EpCAM-expressing tumors, but is initially focused in CRC which is one of the largest unmet needs in oncology with over 1.9 million cases diagnosed annually around the world. It is also a disease that is expected to grow and estimated that there will be over 3 million cases globally by 2040. CRC is the second leading cause of cancer death worldwide and has a 5 year survival rate in the metastatic setting of only 13%. CRC is also the leading cause of cancer death in the U.S. for patients under the age of 50 and has been growing in incidence in younger patients over the last 3 decades. Varseta-M clinical development is initially being focused on late-line metastatic CRC where there is significant unmet need and treatment options are highly inadequate. In third line or later metastatic CRC, patients have typically progressed through multiple chemotherapy-based regimens. Later stage treatment is limited to therapies that provide single digit percentage response rates, median progression free survival of 2 to 5.6 months and overall survival outcomes ranging from approximately 6 to 11 months. It is estimated that there are more than 35,000 patients in the U.S. with 3 rd line or later metastatic CRC, with the number expected to grow over the next decade. While Varseta-M is initially being developed in late-line metastatic CRC, the program was developed with the vision to help a broad population of metastatic CRC patients, including those in the first- and second-line settings. Given Varseta-M’s mechanism of action, our longer-term development vision is to make Varseta-M a core component of the CRC treatment landscape in earlier lines of therapy, consistent with the development strategy that has been employed for other solid tumor ADCs. We plan to pursue combination strategies to progress this vision to move Varseta-M to earlier lines of therapy and initiated a Phase 1 combination study with bevacizumab in the first quarter of 2026. Additionally, given the broad solid tumor expression profile of EpCAM, Varseta-M has the potential to be an innovative new treatment option in a wide range of solid tumors. High expression of EpCAM has been documented in other tumors such as gastric, gastroesophageal, pancreatic, ovarian, endometrial, non-small cell lung and triple negative breast cancers. We plan to potentially initiate development in indications outside of CRC in the second half of 2026, with the ultimate vision to develop Varseta-M as a pan-tumor therapy. Varsetatug Masetecan Development The investigational new drug application (“IND”) for Varseta-M was allowed to proceed by the FDA in January 2024, and a Phase 1 clinical trial in patients with EpCAM-expressing solid tumors, with an initial focus on metastatic CRC, commenced in April 2024. No pre-screening of CRC patients by EpCAM expression has been conducted due to the anticipated high and uniform EpCAM expression in CRC. As of May 2025, the Phase 1 study had reached the seventh dose escalation level and had enrolled only mCRC patients. In May 2025, we announced positive interim Phase 1 data as of an April 7, 2025 data cutoff in advanced metastatic CRC. The data encompassed results from 25 CRC patients treated with Varseta-M at 5 dose levels ranging from 2.4 mg/kg to 10 mg/kg, administered every three weeks (“Q3W”). The 2.4 mg/kg and 4.8 mg/kg doses were single patient dose escalation cohorts not anticipated to be therapeutically active. At the 7.2 mg/kg, 8.6 mg/kg, and 10 mg/kg doses, 23 patients were treated, 18 of whom were efficacy evaluable, having had at least one post-baseline tumor assessment as of the data cutoff. Patients enrolled in the study at the time of data cutoff had previously received a median of 4 prior lines of therapy and all patients had previously been treated with irinotecan. 64% of patients had liver metastases, 64% had KRAS mutations, and 96% were microsatellite stable. Patients were not preselected based on EpCAM expression levels. As of the data cutoff, 18 patients were efficacy-evaluable at doses of 7.2 mg/kg, 8.6 mg/kg, and 10 mg/kg Q3W. Five of eighteen (28%) patients demonstrated confirmed partial responses per RECIST v1.1. Three of seven (43%) efficacy evaluable patients at the dose of 10 mg/kg Q3W demonstrated confirmed partial responses per RECIST v1.1. Seventeen of eighteen patients (94%) had disease control, defined as having an objective response or stable disease. Preliminary median progression free survival (“PFS”) was 5.8 months as of the data cutoff with 10 of 18 patients remaining on study treatment. As of the data cutoff, 25 patients were evaluable for safety. Varseta-M was generally well-tolerated as of the data cutoff with manageable adverse events, with no dose limiting toxicities. Most treatment related adverse events (“TRAEs”) were Grade 1 or Grade 2 in severity. The most common reported TRAEs were diarrhea (18 patients, 5 Grade 3), nausea (11 patients, 1 Grade 3), vomiting (8 patients, No Grade 3), fatigue (8 patients, 1 Grade 3), anemia (5 patients, 3 Grade 3), hypokalemia (3 patients, 1 Grade 3), neutrophil count decrease (2 patients, 2 Grade 3) and neutropenia (2 patients, 1 Grade 3). TRAEs included serious adverse events (“SAEs”) in 5 patients (1 Grade 2, 4 Grade 3). The SAEs included Grade 3 Diarrhea (1 patient), Grade 3 Anemia (1 patient), Grade 3 colitis (1 patient), Grade 3 Diarrhea and Acute kidney injury (1 patient) and Grade 2 Asthenia (1 patient). No Grade 4 or 5 TRAEs were observed as of the April 7, 2025 data cutoff. No events of interstitial lung disease or febrile neutropenia were reported as of the data cutoff. On August 13, 2025, we announced that a single Grade 5 treatment-related acute kidney injury occurred in a patient with a complex medical history, including having a solitary kidney. The Grade 5 event was believed to be secondary to nausea, vomiting and diarrhea. We reported the event to the FDA in accordance with regulatory requirements. The CTMX-2051-101 Safety Review Committee reviewed the event and supported continued study execution. Based on the positive interim Phase 1 dose escalation data in May 2025, dose expansions were initiated at the dose levels of 7.2 mg/kg, 8.6 mg/kg, and 10 mg/kg, administered Q3W and are currently ongoing. 22 Varsetatug Masetecan March 2026 Interim Data Update from Phase 1 Dose Expansions In March 2026, we announced positive interim results from the ongoing Phase 1 dose expansions as of a January 16, 2026 data cutoff date. As of the data cutoff, a total of 93 patients with late-line metastatic CRC had been enrolled in the study. 60 patients were enrolled across the Phase 1 expansion dose range of 7.2 mg/kg, 8.6 mg/kg, and 10 mg/kg of which 56 were efficacy evaluable as of the data cutoff. Starting in October 2025, the expansion doses of 8.6 mg/kg and 10 mg/kg were prioritized for dose optimization utilizing optimized adverse event management guidelines and adjusted ideal body weight (AIBW) dosing. 20 patients had been enrolled in expanded dose optimization as of the January 16 th data cutoff towards an enrollment goal of 40 patients. Patients enrolled in the study had previously received a median of 3 prior lines of therapy in the metastatic setting and 96% of patients had previously been treated with irinotecan. 76% of patients had liver metastases and 71% had KRAS mutations. Patients were not preselected based on EpCAM expression levels. All patients with evaluable tumor biopsies had high EpCAM levels as measured by immunohistochemistry. 1 As of the data cutoff, 56 patients were efficacy-evaluable at the expansion doses of 7.2 mg/kg, 8.6 mg/kg, and 10 mg/kg Q3W. Median duration of follow-up across the efficacy-evaluable patient population was approximately 8 months. Efficacy data across the Phase 1 Expansion doses are summarized below in Table 1. Table 1. Varseta-M Efficacy Summary by Phase 1 Expansion Dose 7.2 mg/kg 8.6 mg/kg 10 mg/kg Confirmed Overall Response Rate (cORR) 6% (1/17) 20% (4/20) 32% (6/19) Median Progression Free Survival (PFS) 5.5 mo. (95% CI: 2.5, NE) 6.8 mo. (95% CI: 2.8, NE) 7.1 mo. (95% CI: 3.9, NE) Disease Control Rate (DCR) 88% (15/17) 90% (18/20) 84% (16/19) At the 8.6 mg/kg dose, the confirmed response rate was 20% with an estimated median PFS of 6.8 months and at the 10 mg/kg dose, the confirmed response rate was 32% with an estimated median PFS of 7.1 months. The disease control rate was 88% (49/56) across the expansion doses of 7.2 – 10 mg/kg. The doses of 8.6 mg/kg and 10 mg/kg have been prioritized for further evaluation with the goal of selecting a dose or doses for a registrational study. Dose optimization at 8.6 mg/kg and 10 mg/kg utilizing AIBW dosing and updated prophylaxis for adverse event management is ongoing. At the doses of 11 mg/kg Q3W and 12 mg/kg Q3W, which were not expanded for further evaluation, the overall response rate was 30% (3/10). As of the data cutoff, 93 patients were evaluable for safety including 80 patients across the expansion dose range of 7.2 mg/kg to 10 mg/kg. Varseta-M’s safety profile was generally consistent with data presented in Phase 1 dose escalation. Most TRAEs were Grade 1 or Grade 2 in severity. No interstitial lung disease, febrile neutropenia or pancreatitis were observed. The most common TRAE was diarrhea which was generally manageable and reversible. In Phase 1 dose expansions starting in Q2 2025, prophylactic strategies for diarrhea management were investigated. In dose optimization starting in Q4 2025, an updated prophylaxis regimen of anti-motility medication (loperamide or diphenoxylate/atropine) plus budesonide was implemented. 2 In the 20 patients receiving the updated prophylactic regimen at the Varseta-M expansion doses of 8.6 mg/kg and 10 mg/kg, Grade 3 diarrhea was 10%. 3 , 4 Overall, as of the January 16, 2026 data cutoff, in the 80 patients treated at expansion and optimization doses ranging between 7.2 mg/kg to 10 mg/kg, the most common TRAEs were diarrhea (68 pts, 19 Gr 3), nausea (44 pts, 4 Gr 3), vomiting (29 pts, 3 Gr 3), fatigue (32 pts, 2 Gr 3), hypokalemia (21 pts, 13 Gr 3+), and anemia (13 pts, 6 Gr 3). Serious treatment related adverse events (SAEs) in > 1 patient included diarrhea (4), vomiting (3), hypokalemia (3), dehydration (3), acute kidney injury (2), and colitis (2). As previously reported on August 13, 2025, there was one treatment-related grade 5 acute kidney injury (AKI) in a patient treated at the 7.2 mg/kg dose. The patient had a complex medical history including having a solitary kidney, and the AKI was determined to be secondary to Grade 3 nausea and Grade 2 diarrhea. No other Grade 5 TRAEs have been reported as of the January 16 th 2026 data cutoff. 1 96% of patients with an evaluable biopsy had an H score by immunohistochemistry above 250 and all patients had H scores above 200. 2 Budesonide is a corticosteroid locally absorbed in the gastrointestinal (GI) tract. 3 8.6 mg/kg and 10 mg/kg dosed utilizing adjusted ideal body weight (AIBW). 4 Based on March 2, 2026 data snapshot . 23 At the 11 mg/kg and 12 mg/kg doses, there were no dose limiting toxicities in dose escalation. The most common TRAEs across the patients in the 11 mg/kg dose (n=8) and 12 mg/kg dose (n=3) were diarrhea (9 pts, 6 GR 3), nausea, (8 pts, 0 Gr 3), and vomiting (8 pts, 1 Gr 3). Patients treated at the 11 and 12 mg/kg doses did not receive the optimized prophylactic regimen or adjusted ideal body weight dosing. Varsetatug Masetecan Development Status As of April 2026, enrollment into Varseta-M Dose Optimization cohorts is complete, having reached the goal of 40 total patients across the 8.6 mg/kg Q3W and 10 mg/kg Q3W doses. Additional Phase 1 Varseta-M data, including data from ongoing dose optimization, is anticipated to be presented at a medical meeting in the second half of 2026. This update is expected to support monotherapy dose selection and a potential registrational trial design in late line CRC. FDA interactions are also planned in 2026 with the goal of aligning on potential first registrational study for Varseta-M monotherapy in advanced CRC to start in the first half of 2027. A Phase 1 Varseta-M combination study with bevacizumab in CRC has commenced with an initial focus on determining combination dose(s) for later phase development, including in earlier lines of therapy. Varseta-M doses to be assessed in combination with bevacizumab will include Q2W and Q4W schedules to align with the approved bevacizumab CRC dose of 5 mg/kg Q2W. Initial clinical data are anticipated by the first half of 2027. Phase 1/2 combination study including Varseta-M administered with bevacizumab, 5-fluorouracil, and leucovorin is planned to start in the second half of 2026. Initiation of initial Phase 1 expansion cohort(s) in non-CRC indications is planned for the second half of 2026. CX-801 In addition to Varseta-M, our pipeline includes CX-801, an investigational, masked version of interferon alpha-2b (“IFNα2b”), currently in a Phase 1 clinical trial. CX-801 leverages a similarly focused application of the PROBODY technology platform in that it leverages a well validated and high potential mechanism that has been limited by systemic toxicity. Interferon-alpha was one of the first immunotherapies approved, but has fallen out of broad use because of poor tolerability. Like EpCAM, IFNα2b has also been validated as a localized therapy, including the approved therapy ADSTILADRIN ® for bladder cancer, which is a gene therapy encoding the protein IFNα2b that is administered directly into the bladder as a single agent, providing evidence that localized IFNα2b can be a powerful and effective therapy. IFNα2b is also an attractive cytokine in that it is a potent and multi-faceted modulator of the immune system that also has direct anti-tumor cell killing effects, providing a potentially superior approach to activating anti-tumor immune responses compared with other cytokines such as IL-2, IL-12 or IL-15. We have applied our significant masking and protein engineering expertise to the design of CX-801, which is a dually-masked, conditionally activated version of IFNα2b that is designed to be inactive in the periphery. The dual masks on CX-801 include a peptide mask on the cytokine domain designed to limit binding in normal tissues as well as a steric Fc mask designed to further mitigate systemic activity as well as extend CX-801’s half-life. For CX-801, we have also employed a focused initial development strategy in Phase 1, centered on the treatment of late-line melanoma where patient options are limited once they have typically progressed through earlier line checkpoint-based therapies. With CX-801, our initial focus is to treat patients with CX-801 in the late-line setting to potentially re-activate the immune system and improve patient outcomes in combination with PD-1 inhibition. Our ultimate vision for CX-801 is to potentially become a cornerstone of combination immunotherapy for a wide range of tumor types, including cancers beyond melanoma. CX-801 Development The IND for CX-801 was allowed to proceed by the FDA in January 2024, and in the third quarter of 2024 the first patient was dosed in the CX-801 Phase 1 dose escalation study in solid tumors. The Phase 1 dose escalation study is focused on patients with advanced melanoma. In Phase 1 dose escalation, the study will evaluate safety, translational biomarkers and signs of clinical activity for CX-801 monotherapy and in combination with KEYTRUDA ® . In the second quarter of 2024, we announced a clinical collaboration with Merck to supply KEYTRUDA for evaluation of its combination with CX-801 in the Phase 1 study. The Phase 1 study is currently in the fourth monotherapy dose escalation cohort. In May 2025, Phase 1 dose escalation enrollment of CX-801 in combination with KEYTRUDA ® (pembrolizumab) in advanced melanoma was initiated and is currently enrolling at the third dose level. Phase 1 CX-801 monotherapy translational data in melanoma patients was presented at the Society of Immunotherapy of Cancer (“SITC”) 2025 Annual Meeting in November 2025, providing evidence that the CX-801 mechanism of action was working as designed. As of the November 8, 2025 SITC presentation, CX-801 had been generally well tolerated and the translational data presented suggest consistently increased expression of interferon-stimulated genes in paired tumor biopsies. Upregulation of immune checkpoint genes, including PD-1 and PD-L1, and activation of immune cell populations, was also observed, providing a rationale for evaluating the combination of CX-801 and pembrolizumab. Pharmacokinetics (“PK”) analysis also demonstrated dose-proportional exposure of CX-801, which remained predominantly in its intact (masked) form in circulation. Phase 1 clinical data from the CX-801 and KEYTRUDA ® combination dose escalation portion of the study are expected by the end of 2026. 24 Preclinical PROBODY Program and Platform In addition to our clinical program focus on PROBODY ADCs such as Varseta-M and PROBODY cytokines such as CX-801, we view the field of masked biologics as having broad potential applicability across a range of therapeutic modalities, reflecting the versatility of our platform technology. A key focus of our current work with collaboration partners is T-cell engaging bispecific therapies (“TCEs”) where we have significant ongoing efforts with Regeneron and maintain significant research expertise. For example, at SITC 2025, we presented preclinical data for CX-908, a dually-masked PROBODY TCE targeting CDH3 and CD3. CX-908 potently induced tumor regressions in established breast and lung cancer xenograft tumor models and demonstrated a 100-fold improvement in tolerability, including significantly reduced cytokine release vs. an unmasked CDH3xCD3 molecule. We view masking as a key strategy to widen a therapeutic window for TCEs and view strategic partnering in this area as an important way to extend the reach of the PROBODY platform. We do not have any products approved for sale, and we continue to incur significant research and development as well as general and administrative expenses related to our operations. As of March 31, 2026 and December 31, 2025, we had an accumulated deficit of $730.2 million and $711.9 million, respectively. Global health authorities, including the FDA, regulate many aspects of a product candidate’s life cycle, including research and development and preclinical and clinical testing. We will need to commit significant time, resources, and funding to develop our wholly-owned and partnered product candidates in clinical trials. We are unable to provide the nature, timing, and estimated costs of the efforts necessary to complete the development of our product candidates because, among other reasons, of regulatory uncertainty, manufacturing limitations, and the pace of enrollment of our clinical trials, which is a function of many factors, including the availability and proximity of patients with the relevant condition. We currently have no manufacturing capabilities and do not intend to establish any such capabilities in the near term. As such, we are dependent on third parties to supply our product candidates according to our specifications, in sufficient quantities, on time, in compliance with appropriate regulatory standards and at competitive prices. Critical Accounting Policies and Estimates The preparation of our Condensed Financial Statements requires us to make estimates and judgments that affect the reported amounts in the financial statements and related disclosures. On an ongoing basis, management evaluates its significant accounting policies and estimates. We base our estimates on historical experience and on various market-specific and other relevant assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ significantly from these estimates. Estimates are assessed each period and updated to reflect current information. A summary of our critical accounting policies and estimates is presented in Part II, Item 7 of our Annual Report on Form 10-K for the year ended December 31, 2025. Except as noted in the revenue discussion below, there have been no material changes to our critical accounting policies and estimates for the three months ended March 31, 2026. Components of Results of Operations Revenue Our revenue to date has been primarily derived from non-refundable license payments, milestone payments and reimbursements for research and development expenses under our research, collaboration, and license agreements. We recognize revenue from upfront payments over the term of our estimated period of performance under the agreement using an input method for the entire performance obligation. In applying the input method of revenue recognition, we use 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 addition to receiving upfront payments, we are entitled to variable payments related to research and development services provided and may be entitled to milestone and other contingent payments upon achieving predefined objectives. Revenue from variable payments related to research and development or milestones and other contingent payments, when it is probable that there will not be a significant revenue reversal, is also recognized over the performance period based on a similar method. For the foreseeable future, we do not expect to generate any revenue from the sale of products unless and until such time as our product candidates have advanced through clinical development and obtained regulatory approval. We expect that any revenue we generate in the foreseeable future will fluctuate from year to year as a result of the timing and amount of milestones and other payments from our collaboration agreements with Astellas, Regeneron, Bristol Myers Squibb, Moderna and any other collaboration partners, and as a result of the fluctuations in the research and development expenses we incur in the performance of assigned activities under these agreements. Research and Development Expenses Our research and development expenses consist primarily of costs incurred to conduct research, such as the discovery and development of our product candidates, clinical development, including activities with third parties, and contract development and manufacturing organizations 25 (“CMO”), and the manufacture of drug products used in clinical trials, as well as the development of product candidates pursuant to our research, collaboration and license agreements. Research and development expenses include personnel costs, including stock-based compensation expense, contractor services, laboratory materials and supplies, depreciation and maintenance of research equipment, and an allocation of related facilities costs. We expense research and development costs as incurred. We expect our research and development expenses could vary substantially in the future as we prioritize our pipeline opportunities, advance our product candidates through clinical trials, initiate additional clinical trials, and pursue regulatory approval of our product candidates. The process of conducting the necessary clinical research to obtain regulatory approval is costly and time-consuming. The actual probability of success for our product candidates may be affected by a variety of factors including: the safety and efficacy of our product candidates, early clinical data, investment in our clinical program, the ability of collaborators to successfully develop our licensed product candidates, competition, manufacturing capability and commercial viability. We may never succeed in achieving regulatory approval for any of our product candidates. As a result of the uncertainties discussed above, we are unable to determine the duration and completion costs of our research and development projects or when and to what extent we will generate revenue from the commercialization and sale of our product candidates. General and Administrative Expenses General and administrative expenses include personnel costs, expenses for outside professional services and other allocated expenses. Personnel costs consist of salaries, bonuses, benefits and stock-based compensation. Outside professional services consist of accounting and audit services, legal and other consulting fees. Allocated expenses primarily consist of rent expense related to our office and information technology related costs. Interest Income Interest income primarily consists of interest income from our cash equivalents and investments, and accretion of discounts or amortization of premiums on our investments. Other Income (Expense), Net Other income (expense), net consists primarily of gains and losses resulting from changes to currency exchange rates. Income Taxes Income taxes are recorded in accordance with ASC 740, Accounting for Income Taxes, or ASC 740, which provides for deferred taxes using an asset and liability approach. We recognize deferred tax assets and liabilities for the expected future tax consequences of events that have been included in our financial statements or tax returns. We determine our deferred tax assets and liabilities based on differences between the financial reporting and tax bases of assets and liabilities, which are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. We also account for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, we recognize the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. 26 Results of Operations Revenue The following table summarizes our revenue by collaboration partner during the respective periods: Three Months Ended March 31, 2026 2025 Change (in thousands) Amgen $ — $ 9,486 $ (9,486 ) Astellas 8,993 9,446 (453 ) Bristol Myers Squibb — 30,364 (30,364 ) Regeneron 1,265 1,614 (349 ) Moderna — 7 (7 ) Total revenue $ 10,258 $ 50,917 $ (40,659 ) The decrease in revenue of $40.7 million for the three months ended March 31, 2026, compared to the corresponding period of 2025 was primarily due to: • A decrease in revenue under the BMS Agreement driven by the completion of our performance obligations in the second quarter of 2025; • The recognition of all remaining deferred revenue under the Amgen Agreement resulting from Amgen terminating its license to the EGFR Products effective May 2025; • A decrease in revenue under the Astellas Agreement primarily driven by a $5.0 million preclinical milestone payment and higher research activities in the first quarter of 2025 compared to the corresponding period of 2026, partially offset by a $7.1 million accelerated recognition of its deferred revenue due to Astellas' notice of termination of the Astellas Agreement in the first quarter of 2026. The completion of our performance obligation under the Astellas Agreement is expected by the second quarter of 2026; • The continued primary focus on the lead preclinical program in 2026 under the Regeneron Agreement; and • The continued pause of the programs under the Moderna Agreement, driven by Moderna's budget considerations. The remaining research and development activities are pending Moderna's budget considerations. Operating Costs and Expenses Research and Development Expenses The following table summarizes our research and development expenses by program incurred during the respective periods presented: Three Months Ended March 31, 2026 2025 Change (in thousands) External costs incurred by product candidate (target): Varseta-M (EpCAM) $ 7,814 $ 4,270 $ 3,544 CX-801 (IFNα2b) 344 488 (144 ) CX-904 (EGFRxCD3) 241 1,111 (870 ) Other wholly owned and partnered programs 143 397 (254 ) General research and development expenses 2,883 2,530 353 Total external costs 11,425 8,796 2,629 Internal costs 7,813 10,072 (2,259 ) Total research and development expenses $ 19,238 $ 18,868 $ 370 Research and development expenses increased by $0.4 million for the three months ended March 31, 2026, compared to the corresponding period of 2025 primarily due to a $3.5 million increase in external costs for Varseta-M manufacturing and clinical activities, partially offset by a $2.3 million decrease in internal costs reflecting the absence of $1.7 million of restructuring expenses incurred in the first quarter of 27 2025. We expect program development expenses in future quarters to be primarily focused on Varseta-M with expected continued growth in Varseta-M development spend. General and Administrative Expenses Three Months Ended March 31, 2026 2025 Change (in thousands) General and administrative $ 10,692 $ 9,428 $ 1,264 General and administrative expenses increased by $1.3 million for the three months ended March 31, 2026, compared to the corresponding period of 2025, primarily driven by increased consulting expenses and stock based compensation expenses in the first quarter of 2026, partially offset by $1.1 million of restructuring expenses incurred in the first quarter of 2025. Interest Income and Other Income (Expense), Net Three Months Ended March 31, 2026 2025 Change (in thousands) Interest income $ 1,490 $ 955 $ 535 Other income (expense), net (7 ) 11 (18 ) Total interest income and other expense $ 1,483 $ 966 $ 517 Interest income increased by $0.5 million during the three months ended March 31, 2026 compared to the corresponding period of 2025. The increase was primarily driven by the increase in cash and cash equivalents and short-term investments position in the first quarter of 2026 as a result of the underwritten public offering in March 2026. Liquidity and Capital Resources Sources of Liquidity As of March 31, 2026, we had cash, cash equivalents and short-term investments of $346.7 million and an accumulated deficit of $730.2 million, compared to cash, cash equivalents and short-term investments of $137.1 million and an accumulated deficit of $711.9 million as of December 31, 2025. To date, we have financed our operations primarily through sales of our common stock in conjunction with the IPO, subsequent stock offerings and through our at-the-market offering, sales of our convertible preferred securities prior to our IPO, payments received under our collaboration agreements and proceeds from private placements of our common stock, warrants and pre-funded warrants. In May 2025, we completed an underwritten public offering of 76,923,076 shares of common stock at a price of $1.30 per share and received net proceeds of approximately $93.4 million, after deducting underwriting discounts and commissions of $6.0 million and offering expenses of $0.6 million. In March 2026, we completed an underwritten public offering of 45,990,567 shares of common stock at an offering price of $5.30 per share and pre-funded warrants to purchase 1,179,245 shares of common stock (the “Pre-Funded Warrants”) at a price of $5.29999 per Pre-Funded Warrant and received the aggregate net proceeds of approximately $234.2 million, after deducting underwriting discounts and commissions of $15.0 million and offering expenses of $0.8 million. We also have an at-the-market offering program (“ATM Program”) pursuant to a sales agreement with Jefferies, LLC (as amended on March 4, 2022 and August 9, 2024, the “Sales Agreement”). In 2025, we sold 4,872,861 shares at a weighted average price of $3.44 per share under our ATM offering for net proceeds of approximately $16.3 million after deducting sales commissions and related issuance costs. As of March 31, 2026, we had an aggregate of $39.4 million remaining for issuance under our ATM Program. Based upon our current operating plan and liquidity requirements, we expect our existing capital resources will be sufficient to fund operations into at least the second half of 2028. However, if the anticipated operating results are not achieved in future periods, our planned expenditures may need to be reduced in order to extend the time period over which the then-available resources would be able to fund the operations. The amounts and timing of our actual expenditures depend on numerous factors, including the progress of our preclinical and clinical development efforts, the results of any clinical trials and other studies, our operating costs and expenditures and other factors described under the caption “Risk Factors” in this Quarterly Report on Form 10-Q. The cost and timing of developing our product candidates is highly uncertain and subject to substantial risks and changes. As such, we may alter our expenditures as a result of contingencies such as the failure of one or all of our product candidates currently in clinical development, the acceleration of one or all of our product candidates in 28 clinical development, the initiating of clinical trials for additional product candidates, the identification of more promising product candidates in our research efforts or unexpected operating costs and expenditures. We will need to raise additional capital to fund our operations in the future. There can be no assurance, however, that such efforts will be successful; or if they are successful, that the terms and conditions of such financing will be favorable to us. Summary Statement of Cash Flows The following table summarizes our cash flows for the periods indicated: Three Months Ended March 31, 2026 2025 (in thousands) Net cash used in operating activities $ (25,549 ) $ (21,043 ) Net cash (used in) provided by investing activities (192,777 ) 30,596 Net cash provided by financing activities 234,487 — Net increase in cash, cash equivalents and restricted cash $ 16,161 $ 9,553 Cash Flows from Operating Activities Net cash used in operating activities of $25.5 million and $21.0 million for the three months ended March 31, 2026 and 2025, respectively, was largely due to ongoing research and development activities and general and administrative expenses to support those activities. Net loss for the three months ended March 31, 2026 and net income for the three months ended March 31, 2025 included, among other items, non-cash charges of stock-based compensation, non-cash lease expense, depreciation and amortization, partially offset by net accretion of discounts on short-term investments. Cash Flows from Investing Activities During the three months ended March 31, 2026, net cash used in investing activities was $192.8 million, primarily due to increased purchases of short-term investments following the funds received from our equity via the underwritten public offering in March 2026. These purchases were partially offset by proceeds from the maturities of marketable securities. During the three months ended March 31, 2025, net cash provided by investing activities was $30.6 million, primarily due to proceeds from the maturities of short-term investments, partially offset by purchases of short-term investments. Cash Flows from Financing Activities During the three months ended March 31, 2026, net cash provided by financing activities of $234.5 million was primarily due to net proceeds from equity issuance via the underwritten public offering in March 2026. During the three months ended March 31, 2025, there was no cash used in or provided by financing activities. Contractual Obligations During the three months ended March 31, 2026, there were no material changes in contractual obligations from the amounts disclosed in our Annual Report on Form 10-K for the year ended December 31, 2025. 29 Item 3. Quantitative and Qualitat ive Disclosures About Market Risk We are exposed to market risks in the ordinary course of our business. These risks primarily relate to interest rate fluctuations. We had cash, cash equivalents and short-term investments of $346.7 million and $137.1 million as of March 31, 2026 and December 31, 2025, respectively, which consist of bank deposits, money market funds and U.S. Treasury securities. Such interest-bearing instruments carry a degree of interest rate risk; however, historical fluctuations of interest income have not been significant for us. We do not enter into investments for trading or speculative purposes and have not used any derivative financial instruments to manage our interest rate exposure. We have not historically been exposed to material risks due to changes in interest rates. Based on our investment positions as of March 31, 2026, a hypothetical 100 basis point change in interest rates would not have a material effect on the fair value of the portfolio. We are also exposed to foreign currency exchange risk related to foreign currency-based expenses. To date, foreign currency transaction gains and losses have not been material to our financial statements. We do not currently hedge our foreign currency exposure. Item 4. Controls and Proc edures Evaluation of Disclosure Controls and Procedures The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) refers to controls and other procedures of an issuer that are designed to ensure that information required to be disclosed by the issuer in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by an issuer in the reports that it files or submits under the Exchange Act is accumulated and communicated to the issuer’s management, including its Principal Executive Officer and Principal Financial Officer, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure. In designing and evaluating the disclosure controls and procedures, our management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives and our management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures. Our disclosure controls and procedures are designed to provide reasonable assurance of achieving their control objectives. Our management, with the participation of our Principal Executive Officer and Principal Financial Officer, has evaluated the effectiveness of our disclosure controls and procedures as of March 31, 2026, the end of the period covered by this Quarterly Report on Form 10-Q. Based on their evaluation, the Principal Executive Officer and Principal Financial Officer concluded that our disclosure controls and procedures were effective at the reasonable assurance level as of March 31, 2026. Changes in Internal Control Over Financial Reporting There was no change in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) that occurred during our fiscal quarter ended March 31, 2026 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting. 30 PART II – OTHER INFORMATION