Recruiting
Phase 3

Petosemtamab & Chemotherapy

Sponsor:

Genmab

Code:

NCT07702032

Conditions

Left-sided Colorectal Cancer

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Petosemtamab

Cetuximab

FOLFIRI

mFOLFOX6

Study Details

Brief summary:

The purpose of this trial is to evaluate how well petosemtamab in combination with chemotherapy works against colorectal cancer located on the left side of the colon 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 standard-of-care cetuximab + doctor's choice of 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.

Conditions

Left-sided Colorectal Cancer

Study ID

NCT07702032

Start date

Aug 11, 2026

Status verified date

Oct, 2026

Completion date

Sep, 2031

Anticipated

Primary completion date

Jul, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Key Inclusion Criteria:

  • Histologically or cytologically confirmed left-sided colorectal adenocarcinoma that is unresectable or metastatic.
  • Must have documented KRAS and NRAS wild type (wt) colorectal cancer (CRC), as determined by medical record of results from local testing or as assessed by central testing. Local testing must have been conducted in accordance with local guidelines using an Food and Drug Administration (FDA)-approved test or a laboratory-developed test that is validated in a Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory (sites in the United States) or an accredited local laboratory (sites outside of the United States). Next-generation sequencing (NGS)-based test results from tumor tissue are required for determining eligibility. Polymerase chain reaction (PCR)-based tests, sanger sequencing, or pyrosequencing test results are not allowed.
  • Has not received any prior systemic therapy for unresectable or metastatic CRC.
  • Must be eligible for treatment with mFOLFOX6 (if assigned to receive mFOLFOX6) or FOLFIRI (if assigned to receive FOLFIRI) according to local regulatory approvals and SOC guidelines.

Key Exclusion Criteria:

  • BRAF mutation, and/or microsatellite instability-high (MSI-H)/deficient mismatch repair (dMMR) and/or protocol specified 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).
  • 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 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 adenocarcinomatous disease.

Note: Other protocol-defined Inclusion and Exclusion criteria may apply.

Study Design

Enrollment

960 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Petosemtamab + IC Chemotherapy

Participants will receive petosemtamab and IC chemotherapy (mFOLFOX6 or FOLFIRI).

active comparator: Cetuximab + IC Chemotherapy

Participants will receive cetuximab + IC chemotherapy (mFOLFOX6 or FOLFIRI).

Interventions

Petosemtamab

Intravenous infusion

Cetuximab

Intravenous infusion

FOLFIRI

Fluorouracil + leucovorin (calcium folinate) + irinotecan via intravenous infusion.

mFOLFOX6

Fluorouracil + leucovorin (calcium folinate) + oxaliplatin via intravenous infusion.

Primary outcome measure

  • Progression-free Survival (PFS) per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 as Assessed by Blinded Independent Central Review (BICR) [ Time Frame: Up to approximately 35 months ]
  • Objective Response Rate (ORR) per RECIST v1.1 as Assessed by BICR [ Time Frame: Up to approximately 35 months ]

Central Contacts and Locations

Central contacts

Genmab Trial Information

+4570202728clinicaltrials@genmab.com

Locations

Genesis Cancer Center

Recruiting

Hot Springs, Arkansas, United States, 71913

Valkyrie Clinical Trials - Los Angeles

Recruiting

Los Angeles, California, United States, 90067

Low Country Cancer Care Associates_Savannah_1

Recruiting

Savannah, Georgia, United States, 31405

Central Georgia Cancer Care - Warner Robins Office

Recruiting

Warner Robins, Georgia, United States, 31088

Hematology-Oncology of Indiana, P.C.

Recruiting

Indianapolis, Indiana, United States, 46260

Oncology Hematology Associates - Springfield_Springfield_2

Recruiting

Springfield, Missouri, United States, 65807

Vista Oncology

Recruiting

Olympia, Washington, United States, 98502

More Information

Sponsor

Genmab

Last update posted

Oct 6, 2026

Last verified

Oct, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-24. This information was provided to ClinicalTrials.gov by Genmab on 2026-10-06. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.