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Colo-rectal CancerPhase 1/2NCT07900165

Study of Varsetatug Masetecan in Combination With Anti-Cancer Therapies in Colorectal Cancer

A Phase 1/2 study testing varsetatug masetecan, bevacizumab + 5-FU + leucovorin and bevacizumab in people with Colo-rectal Cancer, run by CytomX Therapeutics.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

This is a non-registrational Phase 1/2, multicenter, open-label trial to evaluate the efficacy and safety of varsetatug masetecan combined with anti-cancer therapies in participants with unresectable metastatic colorectal cancer in the second line treatment setting. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Colo-rectal Cancer
What is being tested?
varsetatug masetecan, bevacizumab + 5-FU + leucovorin and bevacizumab
Type of treatment
Injection or infusion
Could I receive a placebo?
No, everyone receives an active treatment
How many people
368 participants
Where
No sites listed yet
Study dates
Dec 2026to Feb 2029
Phase
Phase 1/2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Histologically or cytologically documented unresectable metastatic CRC
  • Documented progression during or following exactly one prior regimen of systemic therapy with or without targeted therapy for metastatic CRC
  • Measurable disease per RECIST v1.1
  • Eastern Cooperative Oncology Group performance status of 0-1
  • Adequate organ and marrow function
  • Additional inclusion criteria may apply

Who cannot join

  • Recent history (within last 2 years) of localized cancers that are not related to the current cancer being treated
  • Participants with prior CNS involvement with malignancy must have completed effective treatment of their CNS disease at least 4 weeks prior to first dose of trial intervention
  • Serious concurrent illness
  • Clinically significant proteinuria
  • Prior treatment with ADCs with Topo-I inhibitor payload
  • Prior treatment with irinotecan or Topo-I inhibitors
Show all 10Show fewer
  • Receipt of systemic anti-cancer treatment, radiotherapy, or investigational agent(s) within 14days prior to trial intervention initiation
  • Pregnant or breastfeeding
  • Surgery within 4 weeks prior to first dose of trial intervention
  • Additional exclusion criteria may apply

Trial locations and contacts

No sites are listed yet. Contact the study team or a site near you to ask about taking part.

Karen Deane contact

650-515-3185

ClinicalTrials@cytomx.com

About this study

Official title: A Trial of Varsetatug Masetecan in Combination With Anti-Cancer Therapies in Participants With Metastatic Colorectal Cancer

This is a non-registrational Phase 1/2, multicenter, open-label trial to evaluate the efficacy and safety of varsetatug masetecan combined with anti-cancer therapies in participants with unresectable metastatic colorectal cancer in the second line treatment setting.

Read the detailed description

The study is comprised of 2 parts. Part 1 (Phase 1) involves varsetatug masetecan dose finding to identify the recommended Phase 2 dose (RP2D) of varsetatug masetecan in combination with bevacizumab + 5-FU + leucovorin in the second line treatment setting. Part 2 (Phase 2) will further assess safety, tolerability and antitumor activity doses and schedules of varsetatug masetecan in combination with bevacizumab + 5-FU + leucovorin in this second line patient population, based on the dose finding results from Part 1 of this trial. In addition, Part 2 will also further evaluate dose and schedules of varsetatug masetecan in combination with bevacizumab (without 5-FU and leucovorin) in the second line treatment setting based on the dose finding results in the ongoing Phase 1 Study CTMX-2051-101 assessing the varsetatug masetecan combination with bevacizumab (NCT06265688).

Being tested
varsetatug masetecan, bevacizumab + 5-FU + leucovorin, bevacizumab
Medical subject headings
Colonic Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • varsetatug masetecanDrug

    Investigational Product

  • bevacizumab + 5-FU + leucovorinDrug

    IV infusion

  • bevacizumabDrug

    Also called Avastin

    IV infusion

Study groups in NCT07900165
Study groupRoleWhat they receive
varsetatug masetecan + bevacizumab + 5-FU + leucovorinExperimentalNot described
Receives: Drug: varsetatug masetecan; Drug: bevacizumab + 5-FU + leucovorin
varsetatug masetecan + bevacizumabExperimentalNot described
Receives: Drug: varsetatug masetecan; Drug: bevacizumab

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Part 1 - Safety and tolerability of varsetatug masetecan in combination with bevacizumab + 5-FU + leucovorin

    The number of participants experiencing a dose-limiting toxicity (DLT) as defined in the protocol, AEs (adverse events), and treatment-emergent adverse events (TEAEs) at any dose level

    Measured: 27 months

  2. Part 2 - Progression-free survival (PFS) based on blinded independent central review (BICR)

    PFS defined as the time from participant allocation to a trial intervention to the first documentation of objective disease progression, as determined by BICR according to Response Evaluation Criteria in Solid Tumors (RECIST) v1.1, or death due to any cause, whichever occurs first

    Measured: 27 months

Secondary outcomes (6)

  1. Objective Response Rate (ORR)

    ORR defined as the proportion of participants with a complete response (CR) or partial response (PR), as determined by BICR and Investigator assessment according to RECIST v1.

    Measured: 27 months

  2. Disease Control Rate (DCR)

    DCR defined as the proportion of participants with confirmed CR, PR, or stable disease (SD), as determined by BICR and Investigator assessment according to RECIST v1.1

    Measured: 27 months

  3. PFS based on Investigator assessment

    PFS defined as the time from participant allocation to a trial intervention to the first documentation of objective disease progression, as determined by Investigator assessment according to RECIST v1.1, or death due to any cause, whichever occurs first

    Measured: 27 months

  4. Overall Survival (OS)

    OS defined as the time from participant allocation to a trial intervention to death due to any cause

    Measured: 27 months

  5. Duration of Response (DOR)

    DOR for participants with a confirmed CR or PR, is defined as the time from the first occurrence of a documented objective response to disease progression or death due to any cause (whichever occurs first), as determined by BICR and Investigator assessment according to RECIST v1.1

    Measured: 27 months

  6. Duration of Disease Control (DODC)

    DODC for participants with a confirmed CR, PR, or SD, is defined as the time from the first occurrence of a documented CR, PR, or SD to disease progression or death due to any cause (whichever occurs first), as determined by BICR and Investigator assessment according to RECIST v1.1

    Measured: 27 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted28 Oct 2026
  2. Study startDec 2026 (estimated)
  3. Primary completionFeb 2029 (estimated)
  4. Study completionFeb 2029 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1/2
Primary purpose
Treatment
Allocation
Non-randomised
Intervention model
Sequential
Masking
None (open label)
Enrolment
368 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07900165
Sponsor's protocol ID
CTMX-2051-201
Status last verified
Oct 2026
First submitted
21 Oct 2026
Last updated
28 Oct 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing varsetatug masetecan, bevacizumab + 5-FU + leucovorin and bevacizumab in people with Colo-rectal Cancer, run by CytomX Therapeutics.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 28 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Karen Deane (650-515-3185, ClinicalTrials@cytomx.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Part 1 - Safety and tolerability of varsetatug masetecan in combination with bevacizumab + 5-FU + leucovorin (time frame: 27 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07900165.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Oct 2026.

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