CytomX Therapeutics, Inc.
For the period ended Mar 31, 2026. Filed May 7, 2026.
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A company's report for each of its first three quarters. The financial statements are not audited. It shows how the business has moved since the last annual report, and what management says changed.
Mar 31, 2026 · Filed May 7, 2026
CTMX$2.19+2.3%Stored close · as of Nov 6, 2026
What changed in Management’s Discussion and Analysis?
Read the current filingPrevious report: 10-Q
Period ended 2025-09-30; filed 2025-11-06.
0001193125-25-269477
Item 2. Management’s Discussion and Analysis of Financial Condition and Results of OperationsCurrent report: 10-Q
Period ended 2026-03-31; filed 2026-05-07.
0001193125-26-211868
Item 2. Management’s Discussion and Analysis of Financial Condition and Results of OperationsThe baseline is this issuer’s latest earlier reporting period of the same form that was filed before the current report. A previous 10-Q is a different quarter, not a year-over-year comparison. Amendments are excluded.
Compared 108 previous paragraphs and 116 current paragraphs.
37 unchanged; 24 reworded; 52 added; 44 removed; 3 previous and 3 current paragraphs rearranged.
Tables are not compared: 6 previous and 6 current tables excluded. Dates, whitespace, punctuation and numbering changes are ignored; changes to financial figures remain significant.
A changed paragraph is not evidence that risk increased or decreased. An unchanged paragraph does not establish that risk stayed the same.
Added paragraphs (52)
Current report
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:
Current report
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.
Current report
Indication: The significance of the clinical unmet need that may be addressed if the target could be targeted systemically and unlocked through masking.
Current report
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.
Current report
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.
Current report
Varsetatug Masetecan (Varseta-M)
Current report
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.
Current report
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.
Current report
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.
Current report
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.
Current report
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 rdline or later metastatic CRC, with the number expected to grow over the next decade.
Current report
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.
Current report
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.
Current report
Varsetatug Masetecan Development
Current report
Varsetatug Masetecan March 2026 Interim Data Update from Phase 1 Dose Expansions
Current report
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.
Current report
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.
Current report
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
Current report
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.
Current report
Table 1. Varseta-M Efficacy Summary by Phase 1 Expansion Dose
Current report
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.
Current report
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.
Current report
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).
Current report
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.
Current report
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
Current report
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).
Current report
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.
Current report
1 96% of patients with an evaluable biopsy had an H score by immunohistochemistry above 250 and all patients had H scores above 200.
Current report
2 Budesonide is a corticosteroid locally absorbed in the gastrointestinal (GI) tract.
Current report
3 8.6 mg/kg and 10 mg/kg dosed utilizing adjusted ideal body weight (AIBW).
Current report
4 Based on March 2, 2026 data snapshot.
Current report
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.
Current report
Varsetatug Masetecan Development Status
Current report
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.
Current report
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.
Current report
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.
Current report
Initiation of initial Phase 1 expansion cohort(s) in non-CRC indications is planned for the second half of 2026.
Current report
CX-801
Current report
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.
Current report
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.
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Removed paragraphs (44)
Previous report
We are a clinical-stage, oncology-focused biopharmaceutical company focused on developing novel, conditionally activated, masked biologics designed to be preferentially unmasked and activated in the tumor microenvironment. We aim to build a commercial enterprise to maximize our impact on the treatment of cancer. By pioneering a novel class of localized biologic drug candidates, powered by our PROBODY® therapeutic technology platform, we are a leader in the field of masked, conditionally activated oncology therapeutics and have established biologics localization as a strategic area of research and development in the biopharmaceutical industry. Our vision is to transform lives with safer, more effective therapies with the goal to address major unmet needs in oncology.
Previous report
We are employing our leading, masking platform technology to address some of the biggest challenges in oncology biologics research and development. These include the validation of potential new targets for antibody-drug conjugates (“ADCs”), increasing the therapeutic index for immune modulators such as cytokines, and opening therapeutic window for novel T-cell engagers (“TCEs”) targeting solid tumors.
Previous report
We have utilized our PROBODY therapeutic platform and masking technology to build a promising pipeline of potential first-in-class and best-in-class clinical-stage molecules. These are CX-2051, an investigational, conditionally activated ADC targeting epithelial cell adhesion molecule (“EpCAM”), and CX-801, an investigational, masked version of interferon alpha-2b (“IFNα2b”). Our current clinical-stage molecules address targets or mechanisms that have been previously validated as having anti-cancer activity but have been limited in their utilization due to toxicities in healthy tissues. We have incorporated our significant, multi-modality masking, conditional activation expertise and clinical learnings to optimize predicted therapeutic index and the clinical potential of these promising agents through tumor localized, conditional activation.
Previous report
A CX-2051 Phase 1 data update is expected to be provided in the first quarter of 2026. Additionally, the Company expects to initiate enrollment of a Phase 1b study of CX-2051 in combination with bevacizumab in the first quarter of 2026, data from which is intended to inform potential CX-2051 late phase development in earlier lines of CRC therapy. The Company also continues to evaluate additional non-CRC, EpCAM expressing indications for potential CX-2051 development.
Previous report
Restructuring
Previous report
On January 6, 2025, we announced a restructuring plan (the “2025 Restructuring Plan”) to streamline our organization and prioritize CX-2051, CX-801 and our activities to support our research collaborations. The restructuring plan resulted in a reduction of approximately 40% of our workforce and was substantially completed in the first quarter of 2025. We recorded total restructuring charges of approximately $2.8 million, 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 the nine months ended September 30, 2025.
Previous report
No revenue recognized under the BMS Agreement due to the completion of our performance obligations in the second quarter of 2025. BMS is responsible for the future research and development of the ongoing collaboration programs;
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A decrease in revenue under the Moderna Agreement driven by Moderna's budget considerations in 2025 where the $9.3 million of remaining deferred revenue is expected to be recognized primarily in 2026 and 2027; partially offset by
Previous report
An increase in revenue under the Astellas Agreement driven by continued progress of ongoing collaboration programs.
Previous report
A decrease in revenue under the Astellas Agreement primarily driven by higher preclinical milestone payments in the first quarter of 2024;
Previous report
A decrease in revenue under the Moderna Agreement driven by Moderna's budget considerations in 2025 where the $9.3 million of remaining deferred revenue is expected to be recognized primarily in 2026 and 2027; partially offset by
Previous report
An increase in revenue under the Amgen Agreement due to a cumulative adjustment from a change in estimate of $8.4 million resulting from Amgen terminating its license to the EGFR Product in March 2025, effective May 2025. The remaining deferred revenue was recognized upon completion of our performance obligations in the second quarter of 2025.
Previous report
Research and development expenses decreased by $6.1 million for the three months ended September 30, 2025, compared to the corresponding period of 2024 primarily due to:
Previous report
a reduction in CX-904 spend due to program deprioritization in 2025;
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lower CX-2051 manufacturing expenses partially offset by increased clinical spend; and
Previous report
reduced general research and development expenses after the restructuring announced in January 2025.
Previous report
Research and development expenses decreased by $21.1 million for the nine months ended September 30, 2025, compared to the corresponding period of 2024 primarily due to:
Previous report
a reduction in CX-904 spend due to program deprioritization in 2025;
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lower CX-2051 manufacturing expenses partially offset by increased clinical spend;
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reduced general research and development expenses as a result of the January 2025 restructuring;
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lower spend on preclinical programs; and
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a one-time royalty milestone payment of $5.0 million to ImmunoGen in 2024; partially offset by
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a one-time restructuring expenses of $1.7 million which were primarily included in internal costs.
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General and administrative expenses decreased by $1.5 million for the three months ended September 30, 2025, compared to the corresponding period of 2024, primarily driven by personnel related expenses as well as patent and legal expenses.
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Restructuring
Previous report
During the three and nine months ended September 30, 2025, we recognized aggregate restructuring cost (adjustment) of approximately ($0.1) million and $2.8 million, respectively, primarily related to severance and benefits. This included $1.7 million in research and development expenses and $1.1 million in general and administrative expenses. The total restructuring cost is expected to be approximately $2.8 million. The restructuring was substantially completed in the first quarter of 2025.
Previous report
Income Taxes
Previous report
The $0.1 million and $0.2 million of tax provision represented the interest accrued for the three and nine months ended September 30, 2025, respectively, related to the proposed assessment received from the state of California for the years 2017 and 2018.
Previous report
In the first quarter of 2025, we achieved the GLP toxicology studies for the second collaboration target nominated in March 2024 under the Astellas Agreement; as a result, we collected the $5.0 million milestone payment in March 2025.
Previous report
On January 6, 2025, we announced the 2025 Restructuring Plan to streamline our organization and prioritize CX-2051 investment and activities to support our research collaborations. The restructuring plan resulted in a reduction to our workforce by approximately 40% and was substantially completed in the first quarter of 2025.
Previous report
During the nine months ended September 30, 2025, cash used in operating activities was $52.3 million, which consisted of a net income of $9.1 million and non-cash charges of $7.5 million, adjusted by a net decrease of $68.9 million relating to the change of our net operating assets and liabilities. The non-cash charges primarily consisted of $4.8 million in stock-based compensation, $3.3 million in non-cash lease expense, $0.9 million in depreciation and amortization, partially offset by $1.5 million in accretion of discounts on investments.
Previous report
The change in our net operating assets and liabilities was primarily due to:
Previous report
a net decrease of $66.1 million in deferred revenue resulting from the continued recognition of deferred revenue from existing customers;
Previous report
a decrease of $3.9 million in accounts payable, accrued and other long-term liabilities primarily due to timing of payments; and
Previous report
a decrease of $0.4 million in cashflows from prepaid and other current assets primarily due to increase in advance payments, partially offset by
Previous report
an increase of $1.5 million in cashflows from accounts receivable primarily due to timing of collection of service revenue.
Previous report
During the nine months ended September 30, 2024, cash used in operating activities was $66.3 million, which consisted of a net income of $13.0 million and non-cash charges of $5.6 million, adjusted by a net decrease of $84.9 million relating to the change of our net operating assets and liabilities. The non-cash charges primarily consisted of $5.8 million in stock-based compensation, $3.0 million in non-cash lease expense, $1.3 million in depreciation and amortization, partially offset by $4.5 million in accretion of discounts on investments.
Previous report
The change in our net operating assets and liabilities was primarily due to:
Previous report
a net decrease of $82.7 million in deferred revenue resulting from the continued recognition of deferred revenue from existing customers;
Previous report
a decrease of $4.1 million in accounts payable, accrued and other long-term liabilities primarily due to timing of payments; offset by
Showing the first 40 of 44 passages. Open the source sections for the rest.
Reworded paragraphs (24)
Previous wording
Our proprietary, versatile, multi-modality PROBODY technology platform is designed to enable conditional activation of potent masked biologic therapeutic candidates within the tumor microenvironment while minimizing drug activity in healthy tissues and circulation. Our platform is built on a strong foundation of tumor biology expertise, including deep knowledge of tumor-associated enzymes known as proteases. Proteases are tightly controlled in normal tissues but often dysregulated and active in tumor microenvironments where they play important roles in cancer cell migration, invasion and metastasis. Leveraging our deep scientific knowledge, we conceived of and constructed our PROBODY therapeutic platform which allows us to genetically engineer biologic therapeutic candidates to contain protease-cleavable masks. 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.
Current wording
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.
Previous wording
CX-2051, a conditionally activated, PROBODY ADC, targets EpCAM. High expression of EpCAM has been documented in many tumor types, including colorectal cancer (“CRC”). The CX-2051 payload, a topoisomerase-1 inhibitor payload licensed from AbbVie (formerly ImmunoGen), is tailored to have anti-tumor activity against multiple EpCAM-expressing indications, including colorectal cancer. The payload-antibody linker we selected for CX-2051 is designed to drive bystander killing of neighboring tumor cells, contributing to anti-tumor activity. The design of CX-2051 is intended to establish a clinically meaningful therapeutic window for the systemic treatment of EpCAM-expressing cancers where previous industry efforts targeting EpCAM have not been successful due to dose-limiting toxicities. CX-2051 has demonstrated strong preclinical activity and tolerability in multiple preclinical models and encouraging initial Phase 1 data in late-line colorectal cancer.
Current wording
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.
Previous wording
The IND for CX-2051 was allowed to proceed by the FDA in January 2024 and a Phase 1 clinical trial of CX-2051 in patients with EpCAM expressing solid tumors, with an initial focus in CRC, was commenced in April 2024. No pre-screening of CRC patients based on tumor EpCAM expression has been conducted because of anticipated high and uniform EpCAM expression in CRC. As of May 2025, the Phase 1 study had reached the seventh dose escalation level.
Current wording
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.
Previous wording
In May 2025, the Company announced positive interim Phase 1 data as of an April 7, 2025 data cutoff in advanced metastatic colorectal cancer. The data encompassed results from 25 CRC patients treated with CX-2051 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.
Current wording
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.
Previous wording
As of the data cutoff, 25 patients were evaluable for safety. CX-2051 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, the Company 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. The Company 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 and enrollment which are ongoing.
Current wording
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.
Previous wording
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 every three weeks (Q3W) and are currently ongoing. In the third quarter of 2025, dose expansion enrollment continued with the goal of supporting a potential registrational study of CX-2051 monotherapy in advanced CRC. CX-2051 Phase 1 study enrollment is projected to reach approximately 100 patients by the first quarter of 2026.
Current wording
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.
Previous wording
CX-801 is our PROBODY interferon ("IFN") alpha(a)-2b clinical program. IFNα2b provides a potentially superior approach to activating anti-tumor immune responses. CX-801 is a dually masked, conditionally activated version of IFNα2b that has the potential to become a cornerstone of combination therapy for a wide range of tumor types. 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, CytomX 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.
Current wording
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.
Previous wording
Phase 1 CX-801 monotherapy biomarker data in melanoma patients will be presented at the Society of Immunotherapy of Cancer (SITC) 2025 Annual Meeting on November 8, 2025. The data to be presented indicate that CX-801 has been generally well tolerated to date and consistently increased expression of interferon-stimulated genes in paired tumor biopsies, suggesting preferential activity in tumors. 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. 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 in 2026.
Current wording
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.
Previous wording
In addition to PROBODY ADCs like CX-2051 and PROBODY cytokines like 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 partners such as Regeneron and Astellas and maintain significant research expertise. For example, at SITC 2025, we presented preclinical data for CX-908, a dually masked PROBODY T-cell Engager 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 T-cell engagers and view strategic partnering in this area as an important way to extend the reach of the PROBODY platform.
Current wording
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.
Previous wording
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.
Current wording
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.
Previous wording
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, 2024. There have been no material changes to our critical accounting policies and estimates for the three months ended September 30, 2025.
Current wording
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.
Previous wording
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 Amgen, Astellas, Bristol Myers Squibb, Regeneron, 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.
Current wording
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.
Previous wording
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, such as contract research organizations (“CRO”) and contract development and manufacturing organizations (“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.
Current wording
(“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.
Previous wording
The decrease in revenue of $27.5 million for the three months ended September 30, 2025, compared to the corresponding period of 2024 was primarily due to:
Current wording
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:
Previous wording
A decrease in revenue under the BMS Agreement driven by the completion of our performance obligations in the second quarter of 2025. BMS is responsible for the future research and development of the ongoing collaboration programs;
Current wording
A decrease in revenue under the BMS Agreement driven by the completion of our performance obligations in the second quarter of 2025;
Previous wording
No revenue recognized under the Amgen Agreement as a result of Amgen terminating its license to the EGFR Product effective May 2025;
Current wording
The recognition of all remaining deferred revenue under the Amgen Agreement resulting from Amgen terminating its license to the EGFR Products effective May 2025;
Previous wording
A decrease in revenue under the Regeneron Agreement driven by a primary focus on the most developed preclinical program in 2025; and
Current wording
The continued primary focus on the lead preclinical program in 2026 under the Regeneron Agreement; and
Previous wording
General and administrative expenses decreased by $1.6 million for the nine months ended September 30, 2025, compared to the corresponding period of 2024, primarily driven by personnel related expenses and legal and consulting related expenses, partially offset by $1.1 million of one-time restructuring expenses.
Current wording
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.
Previous wording
Interest income decreased by $0.1 million and $2.1 million during the three months and nine months ended September 30, 2025, respectively, compared to the corresponding period of 2024. The decrease was primarily driven by lower interest rates and the lower average cash and cash equivalents and short-term investments position.
Current wording
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.
Previous wording
As of September 30, 2025, we had cash, cash equivalents and short-term investments of $143.6 million and an accumulated deficit of $682.4 million, compared to cash, cash equivalents and short-term investments of $100.6 million and an accumulated deficit of $691.6 million as of December 31, 2024. 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 July 2023, we completed a private placement and issued pre-funded warrants to purchase an aggregate of 14,423,077 shares of common stock, 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. We received gross proceeds of approximately $30.0 million. In March 2024, we achieved a clinical candidate milestone for a second collaboration target as well as the GLP toxicology studies milestone for the first collaboration target nominated in January 2023 under the Astellas Agreement; as a result, we collected the two milestone payments totaling $10.0 million in April 2024.
Current wording
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.
Previous wording
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.
Current wording
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.
Previous wording
In February 2020, we initiated an at-the-market offering program (“ATM”) pursuant to a sales agreement with Jefferies, LLC (as amended on March 4, 2022 and August 9, 2024, the "Sales Agreement"). In 2024, we sold 3,925,202 shares at a weighted average price of $1.82 per share under our ATM offering for net proceeds of approximately $6.9 million after deducting sales commissions and related issuance cost. In
Current wording
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.
Previous wording
Based upon our current operating plan and liquidity requirements, we expect our existing capital resources will be sufficient to fund operations into the second quarter of 2027. 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 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 operation 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.
Current wording
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 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.
Previous wording
During the nine months ended September 30, 2024, cash provided by investing activities was $84.6 million, which consisted of $190.5 million of proceeds from the maturities of short-term investments partially offset by $105.7 million used in the purchase of short-term investments and $0.2 million of capital expenditures used to purchase property and equipment.
Current wording
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.
Rearranged current paragraphs (3)
Current report — wording carried from elsewhere
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.
Current report — wording carried from elsewhere
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
Current report — wording carried from elsewhere
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.
Rearranged previous paragraphs (3)
Previous report — wording carried elsewhere
The decrease in revenue of $24.5 million for the nine months ended September 30, 2025, compared to the corresponding period of 2024 was primarily due to:
Previous report — wording carried elsewhere
A decrease in revenue under the Regeneron Agreement driven by a primary focus on the most developed preclinical program in 2025;
Previous report — wording carried elsewhere
October 2025, we sold $4.3 million shares at a weighted average price of $3.43 per share under our ATM offering for net proceeds of approximately $14.4 million after deducting sales commissions and related issuance cost.