NCT07775287

Brief Summary

The purpose of this trial is to evaluate how well petosemtamab in combination with chemotherapy works against colorectal cancer that has recurred after previous treatment and that cannot be safely removed by surgery or has spread to other parts of the body. Participants will receive either petosemtamab + doctor's choice of chemotherapy (mFOLFOX6 or FOLFIRI) or doctor's choice of standard-of-care (SOC) cetuximab or bevacizumab + chemotherapy (mFOLFOX6 or FOLFIRI). No participants will be given placebo. The treatment duration will be different for every participant. If a participant's cancer stays the same or gets better, and there are not any serious problems, participants can keep getting study treatment for as long as the study is open. Participants will be asked to attend 2 visits at the study clinic for each cycle (duration of cycle is 4 weeks). During visits, there will be various tests (such as blood draws) and procedures (such as imaging) to monitor whether the study treatment is safe and effective. The overall study duration (including screening, treatment, and follow-up) will be different for every participant.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
600

participants targeted

Target at P50-P75 for phase_3 colorectal-cancer

Timeline
40mo left

Started Sep 2026

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress1%
Sep 2026Jan 2030

First Submitted

Initial submission to the registry

August 13, 2026

Completed
7 days until next milestone

First Posted

Study publicly available on registry

August 20, 2026

Completed
26 days until next milestone

Study Start

First participant enrolled

September 15, 2026

Completed
2.5 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 30, 2029

Expected
10 months until next milestone

Study Completion

Last participant's last visit for all outcomes

January 31, 2030

Last Updated

September 10, 2026

Status Verified

September 1, 2026

Enrollment Period

2.5 years

First QC Date

August 13, 2026

Last Update Submit

September 9, 2026

Conditions

Outcome Measures

Primary Outcomes (2)

  • Progression-free Survival (PFS) per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 as Assessed by Blinded Independent Central Review (BICR)

    Up to approximately 2.5 years

  • Objective Response Rate (ORR) per RECIST v1.1 as Assessed by BICR

    Up to approximately 2.5 years

Secondary Outcomes (11)

  • Overall Survival (OS)

    Up to approximately 3.5 years

  • Duration of Response (DOR) per RECIST v1.1 as Assessed by BICR

    Up to approximately 3.5 years

  • Disease Control Rate (DCR) per RECIST v1.1 as Assessed by BICR

    Up to approximately 3.5 years

  • Progression-free Survival after First Subsequent Therapy (PFS2)

    Up to approximately 3.5 years

  • Curative Resection (R0) Rate

    Up to approximately 3.5 years

  • +6 more secondary outcomes

Study Arms (2)

Arm A: Petosemtamab + IC Chemotherapy (FOLFIRI or mFOLFOX6)

EXPERIMENTAL

Participants will receive petosemtamab 1500 milligrams (mg) once every 2 weeks (Q2W) + IC chemotherapy (FOLFIRI or mFOLFOX6) Q2W.

Drug: PetosemtamabDrug: 5-FUDrug: Leucovorin (Calcium Folinate)Drug: OxaliplatinDrug: Irinotecan

Arm B: IC Cetuximab or Bevacizumab + IC Chemotherapy (FOLFIRI or mFOLFOX6)

ACTIVE COMPARATOR

Participants will receive IC cetuximab 500 milligrams per meter squared (mg/m\^2) or bevacizumab 5 milligrams per kilogram (mg/kg) Q2W + IC chemotherapy (FOLFIRI or mFOLFOX6) Q2W.

Drug: CetuximabDrug: BevacizumabDrug: 5-FUDrug: Leucovorin (Calcium Folinate)Drug: OxaliplatinDrug: Irinotecan

Interventions

Intravenous (IV) infusion.

Also known as: MCLA-158, GEN1158
Arm A: Petosemtamab + IC Chemotherapy (FOLFIRI or mFOLFOX6)

IV infusion.

Arm B: IC Cetuximab or Bevacizumab + IC Chemotherapy (FOLFIRI or mFOLFOX6)

IV infusion.

Arm B: IC Cetuximab or Bevacizumab + IC Chemotherapy (FOLFIRI or mFOLFOX6)
5-FUDRUG

IV infusion.

Also known as: Fluorouracil
Arm A: Petosemtamab + IC Chemotherapy (FOLFIRI or mFOLFOX6)Arm B: IC Cetuximab or Bevacizumab + IC Chemotherapy (FOLFIRI or mFOLFOX6)

IV infusion.

Arm A: Petosemtamab + IC Chemotherapy (FOLFIRI or mFOLFOX6)Arm B: IC Cetuximab or Bevacizumab + IC Chemotherapy (FOLFIRI or mFOLFOX6)

IV infusion.

Arm A: Petosemtamab + IC Chemotherapy (FOLFIRI or mFOLFOX6)Arm B: IC Cetuximab or Bevacizumab + IC Chemotherapy (FOLFIRI or mFOLFOX6)

IV infusion.

Arm A: Petosemtamab + IC Chemotherapy (FOLFIRI or mFOLFOX6)Arm B: IC Cetuximab or Bevacizumab + IC Chemotherapy (FOLFIRI or mFOLFOX6)

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Histologically or cytologically confirmed colorectal adenocarcinoma that is recurrent, unresectable or metastatic.
  • Must have documented KRAS and NRAS wt CRC, as determined by medical record of results from local testing or as assessed by central testing. Next-generation sequencing-based test results from tumor tissue are required for determining eligibility. At a minimum, local testing must have assessed the mutational status of KRAS and NRAS G12/G13, A59, Q61, K117, and A146 codons.
  • Has received no more than 1 line of prior systemic therapy for unresectable or metastatic CRC, with documented disease progression. First line (1L) regimen must be fluoropyrimidine- and oxaliplatin- (if 2L choice of backbone is FOLFIRI) or irinotecan- (if 2L choice of backbone is fluorouracil + leucovorin (calcium folinate) + oxaliplatin \[FOLFOX\]) based. Prior anti-vascular endothelial growth factor receptor (VEGF) treatment is allowed.
  • Must be eligible for treatment with mFOLFOX6 (if assigned by the investigator to receive mFOLFOX6) or FOLFIRI (if assigned by the investigator to receive FOLFIRI) according to local regulatory approvals and standard of care (SOC) guidelines.

You may not qualify if:

  • BRAF V600 mutation (eg, V600E) and/or microsatellite instability-high/deficient mismatch repair tumor status and/or ERBB2/human epidermal growth factor receptor 2 (HER2) positive/amplified tumor status as documented by local test results in the medical record or from central testing or known documented activating HRAS mutation identified prior to enrollment from local testing results in the medical record, if available .
  • Prior exposure to any agents that target epidermal growth factor receptor (EGFR) (including but not limited to protein products, monoclonal antibodies, tyrosine kinase inhibitors, or antisense oligonucleotide therapy).
  • Prior exposure to irinotecan (for participants assigned to FOLFIRI) or oxaliplatin (for participants assigned to FOLFOX) in the metastatic setting.
  • Known complete dihydropyrimidine dehydrogenase (DPD) deficiency or known homozygous/compound heterozygous dihydropyrimidine dehydrogenase gene (DPYD) variants associated with complete loss of DPD activity. Testing for DPD deficiency should be performed per local guidelines.
  • For a participant who is to receive FOLFIRI: known to be homozygous for the uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1)\*28 or \*6 alleles or compound or double heterozygous for the UGT1A1\*28 and \*6 alleles. Testing for UGT1A1 should be done in accordance with local guidelines.
  • Participants with non-colorectal adenocarcinumatous disease.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

PanOncology

Manati, 00674, Puerto Rico

RECRUITING

MeSH Terms

Conditions

Colorectal Neoplasms

Interventions

CetuximabBevacizumabFluorouracilLeucovorinOxaliplatinIrinotecan

Condition Hierarchy (Ancestors)

Intestinal NeoplasmsGastrointestinal NeoplasmsDigestive System NeoplasmsNeoplasms by SiteNeoplasmsDigestive System DiseasesGastrointestinal DiseasesColonic DiseasesIntestinal DiseasesRectal Diseases

Intervention Hierarchy (Ancestors)

Antibodies, Monoclonal, HumanizedAntibodies, MonoclonalAntibodiesImmunoglobulinsImmunoproteinsBlood ProteinsProteinsAmino Acids, Peptides, and ProteinsSerum GlobulinsGlobulinsUracilPyrimidinonesPyrimidinesHeterocyclic Compounds, 1-RingHeterocyclic CompoundsFormyltetrahydrofolatesTetrahydrofolatesFolic AcidPterinsPteridinesHeterocyclic Compounds, 2-RingHeterocyclic Compounds, Fused-RingCoenzymesEnzymes and CoenzymesCoordination ComplexesOrganic ChemicalsCamptothecinAlkaloids

Study Officials

  • Study Official

    Genmab

    STUDY DIRECTOR

Central Study Contacts

Genmab Trial Information

CONTACT

Study Design

Study Type
interventional
Phase
phase 3
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

August 13, 2026

First Posted

August 20, 2026

Study Start

September 15, 2026

Primary Completion (Estimated)

March 30, 2029

Study Completion (Estimated)

January 31, 2030

Last Updated

September 10, 2026

Record last verified: 2026-09

Data Sharing

IPD Sharing
Will not share

Locations