CytomX Therapeutics, Inc.

1. Description 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 Policies

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 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:

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

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:

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

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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.

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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:

As of March 31, 2026 and December 31, 2025, interest receivable of$1.5 million and $0.5 million, 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.

5. Accrued Liabilities

Accrued liabilities consisted of the following:

6. Collaboration and License Agreements

The following table summarizes the revenue by collaboration partner:

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 tothree targets, including thetwo 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 selectedone 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 programand 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.

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 tofour collaboration targets includingone initial target andthree additional targets (“Additional Targets”). In addition, Astellas had the right to expand the number of Additional Targets from three up tofive (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 adjustmentof $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 was $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 tofour oncology targets. Bristol Myers Squibb had additional rights to substitute up totwo collaboration targets within three years of the effective date of the BMS Agreement. These rights expired in May 2017. Each collaboration target had atwo-year research term and thetwo 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 inone year increments up tothree times.

Pursuant to the BMS Agreement, the financial consideration from Bristol Myers Squibb was comprised of an upfront payment of $50.0 millionand estimated research and development service fees, and the Company was initially entitled to receive contingent payments of up to

$25.0 million for additional targets and contingent payments for development, regulatory and sales milestones 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 PROBODY therapeutics for up toeight 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 theeight 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. The Company had received in aggregate $297.0 million in upfront and milestone payments under the agreement. The 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 approximately$1.2 billion in future development, regulatory, and commercial milestone payments. The Company is also eligible to receive tiered royalties from high-single digit to low-teen percentage rates of annual global net sales of any products that are commercialized under the Moderna Agreement.

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 wasno 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”).

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 and $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:

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.

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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.

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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 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 exercisedthe 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:

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:

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:

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")

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 henceno 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 henceno compensation cost was recorded for these awards through March 31, 2026.

Activities for the Company’s PSUs for the three months ended March 31, 2026, were as follows:

Stock-based Compensation

Total stock-based compensation recorded was as follows:

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 million 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.

11. Segment Disclosures

The Company operates as asingle 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):

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 ofresearch and development expenses and $1.1 million of general and administrative expenses that were recorded during 2025. The restructuring was completed as of March 31, 2026.