A Phase 3 interventional study of Petosemtamab and Cetuximab in Colorectal Cancer, sponsored by Genmab. Recruiting at 6 sites in 2 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-12.
Sponsored by Genmab · Phase 3, Interventional, and Treatment
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Among 2,338 studies in Colorectal Neoplasms with a site in United States — 419 open to participants now, 628 under way, 30 of them phase 3. Colorectal Neoplasms · United States.
Among the 2,338 studies in Colorectal Neoplasms with a site in United States, this one is the 250th largest by planned enrollment of the 1,931 interventional ones that give a count, is one of 117 that started in 2026, is one of 117 in phase 3, reaches primary completion later than 522 of the 626 other live ones, and was the 2,314th registered.
6,545 studies on the registry are indexed under Colorectal Neoplasms; 1,664 are open to participants now.
Browse Colorectal Neoplasms studies →419 of the 2,338 studies in Colorectal Neoplasms with a site in United States are open now. Recruiting first, the newest first:
National Cancer Institute (NCI) · Sites in United States
Ages 18+
City of Hope Medical Center · Sites in United States
Ages 18+
Exelixis · Sites in United States
Ages 18+
City of Hope Medical Center · Sites in United States
Ages 40–80 · Men only
University of Pennsylvania · Sites in United States
Ages 18+
A study can be open while its sites in United States have not opened yet or have stopped. Only those recruiting at a site in United States →
Of the 1,181 Colorectal Neoplasms studies recruiting now, 764 (65%) set no upper age limit and 264 (22%) stop at 75 or younger; 48 take children under 18; 123 take healthy volunteers.
This study: 18 Years and older · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
2,338 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 817 · Phase 2 790 · Phase 3 132 · Phase 4 19
First in 1981; this study’s year is marked. 117 started in 2026.
By drug class, each counting the studies that test any of its medicines:
This study's planned enrollment of 600 is above the median of 76 across 4,802 interventional studies indexed under Colorectal Neoplasms.
Median enrollment 64 across the 1,931 interventional studies, 221 across the 324 observational. Of the 1,563 that completed or were terminated, 549 (35%) have results posted.
This tab as a report to print or save as PDF → With an account.
885 of 2,338 have an industry lead sponsor. The 10 most frequent:
Genmab is the lead sponsor of 72 studies on the registry; 15 are open to participants now.
Of its 23 completed or terminated interventional studies of FDA-regulated products, 13 (57%) have results posted.
Genmab has 8 studies filed under Colorectal Neoplasms — fewer than ten, so there is no comparison to draw.
227 of the studies in Colorectal Neoplasms with a site in United States that are under way reach primary completion within a year, 4 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT05141721Phase 3Seattle Project CorporationA Study of a Patient-Specific Neoantigen Vaccine in Combination With Immune Checkpoint Blockade for Patients With Metastatic Colorectal Cancer | 2027-03 |
| NCT04428905Phase 3City of Hope Medical CenterSelf-Management Survivorship Care in Stage I-III Non-small Cell Lung Cancer or Colorectal Cancer | 2027-03-31 |
| NCT02997228Phase 3National Cancer Institute (NCI)Testing the Addition of Atezolizumab to Combination Chemotherapy or Atezolizumab Alone for Metastatic Colon or Rectal Cancer, the COMMIT Study | 2027-06-01 |
| NCT01349881Phase 3SWOG Cancer Research NetworkS0820, Adenoma and Second Primary Prevention Trial | 2027-09-15 |
| NCT03796884Sidney Kimmel Comprehensive Cancer Center at Thomas Jefferson UniversityLinaclotide in Treating Patients With Stages 0-3 Colorectal Cancer | 2026-11 |
Add all 227 to your calendar (.ics) → With an account.
Among the 2,338 studies in Colorectal Neoplasms with a site in United States, from their registry updates:
This tab as a report to print or save as PDF → With an account.
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.
This is a Phase 3, randomized, open-label, global, multicenter, interventional trial to evaluate the efficacy and safety of petosemtamab in combination with investigator's choice (IC) chemotherapy (fluorouracil + leucovorin [calcium folinate] + irinotecan [FOLFIRI] or 5-FU, leucovorin [calcium folinate], and oxaliplatin [mFOLFOX6]; Arm A) versus IC cetuximab or bevacizumab in combination with IC chemotherapy (FOLFIRI or mFOLFOX6; Arm B) as second line (2L) treatment for participants with KRAS, NRAS, and BRAF wild type (wt), recurrent, unresectable or metastatic colorectal cancer (CRC).
Key Inclusion Criteria:
Key Exclusion Criteria:
Note: Other protocol-defined Inclusion and Exclusion criteria may apply.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.
“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.
HER2 is a protein, made from the ERBB2 gene, that drives the growth of some cancers. A study may look for a level of the protein, extra copies of the gene, or a particular change in it.
In breast cancer, protein tests are read as HER2-positive, HER2-low or HER2-negative; other cancers use their own rules. Check which test result the study requires.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Line of therapy
A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.
“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HER2
HER2 is a protein, made from the ERBB2 gene, that drives the growth of some cancers. A study may look for a level of the protein, extra copies of the gene, or a particular change in it.
In breast cancer, protein tests are read as HER2-positive, HER2-low or HER2-negative; other cancers use their own rules. Check which test result the study requires.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive petosemtamab 1500 milligrams (mg) once every 2 weeks (Q2W) + IC chemotherapy (FOLFIRI or mFOLFOX6) Q2W.
Drug: Petosemtamab · Drug: 5-FU · Drug: Leucovorin (Calcium Folinate) · Drug: Oxaliplatin · Drug: Irinotecan
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: Cetuximab · Drug: Bevacizumab · Drug: 5-FU · Drug: Leucovorin (Calcium Folinate) · Drug: Oxaliplatin · Drug: Irinotecan
Intravenous (IV) infusion.
Also known as: MCLA-158, GEN1158
IV infusion.
IV infusion.
IV infusion.
Also known as: Fluorouracil
IV infusion.
IV infusion.
IV infusion.
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 2.5 years
Objective Response Rate (ORR) per RECIST v1.1 as Assessed by BICR
Time frame: Up to approximately 2.5 years
Overall Survival (OS)
Time frame: Up to approximately 3.5 years
Duration of Response (DOR) per RECIST v1.1 as Assessed by BICR
Time frame: Up to approximately 3.5 years
Disease Control Rate (DCR) per RECIST v1.1 as Assessed by BICR
Time frame: Up to approximately 3.5 years
Progression-free Survival after First Subsequent Therapy (PFS2)
Time frame: Up to approximately 3.5 years
Curative Resection (R0) Rate
Time frame: Up to approximately 3.5 years
Number of Participants with Treatment-emergent Adverse Events (TEAEs)
Time frame: Up to approximately 3.5 years
Change from Baseline in Symptoms and Functioning, as Measured by European Organisation for Research and Treatment of Cancer (EORTC) Quality-of-life Questionnaire (QLQ)-F17
Time frame: Baseline up to approximately 3.5 years
Change from Baseline in Symptoms and Functioning, as Measured by EORTC QLQ-CR29
Time frame: Baseline up to approximately 3.5 years
Time to Worsening in Symptoms and Functioning, as Measured by EORTC QLQ-F17
Time frame: Baseline up to approximately 3.5 years
Time to Worsening in Symptoms and Functioning, as Measured by EORTC QLQ-CR29
Time frame: Baseline up to approximately 3.5 years
Overall Side Effect Burden, as Measured by EORTC Item 168
Time frame: Baseline up to approximately 3.5 years
Plan to share: No
No publications or documents are linked to this record.
Started Oct 2026 (actual). Primary completion is estimated for Mar 2029, 29 months after the start.
Of 69 industry-sponsored phase 3 interventional studies under Colorectal Neoplasms, half reached primary completion within 43 months of starting (the median), counting those still running; a quarter within 26 and three quarters within 54. This study's planned 29 months is below that.
Counting every sponsor, half of 175 studies reached it within 50 months; a quarter within 35 and three quarters within 79.
Start moved twice since we started tracking on Sep 25, 2026: Sep 2026 → Oct 2026, last on Oct 9, 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
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Studies of the drug tested here: Petosemtamab