Left-sided Colorectal CancerPhase 3NCT07702032
Study of Petosemtamab Plus Chemotherapy Versus Cetuximab Plus Chemotherapy in RAS and BRAF Wild-type, Unresectable or Metastatic, Left-sided Colorectal Cancer (LiGeR-CRC1)
A Phase 3 study testing Petosemtamab, Cetuximab and FOLFIRI in people with Left-sided Colorectal Cancer, run by Genmab at 12 sites in 3 countries.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Left-sided Colorectal Cancer
- What is being tested?
- Petosemtamab, Cetuximab and FOLFIRI
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 960 participants
- Where
- 12 sitesin 3 countries
- Study dates
- 11 Aug 2026to Sep 2031
- Phase
- Phase 3
- 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 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.
Who cannot join
- 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.
Trial locations and contacts
12 sites in 3 countries. Contact the study team or a site near you to ask about taking part.
12 sites in 3 countries
United States9 sites, 9 recruiting
- Recruiting
New York Cancer and Blood Specialists - Babylon Medical Oncology
Babylon, New York, 11702
- Recruiting
Genesis Cancer Center
Hot Springs, Arkansas, 71913
- Recruiting
Hematology-Oncology of Indiana, P.C.
Indianapolis, Indiana, 46260
- Recruiting
Valkyrie Clinical Trials - Los Angeles
Los Angeles, California, 90067
- Recruiting
Vista Oncology
Olympia, Washington, 98502
- Recruiting
Low Country Cancer Care Associates_Savannah_1
Savannah, Georgia, 31405
- Recruiting
Oncology Hematology Associates - Springfield_Springfield_2
Springfield, Missouri, 65807
- Recruiting
Washington University Saint Louis
St Louis, Missouri, 63110
- Recruiting
Central Georgia Cancer Care - Warner Robins Office
Warner Robins, Georgia, 31088
Australia2 sites, 2 recruiting
- Recruiting
GenesisCare - St Andrew's ADELAIDE
Adelaide, South Australia, 5000
- Recruiting
GenesisCare - Campbelltown CAMPBELLTOWN
Campbelltown, New South Wales, 2560
About this study
Official title: A Randomized, Open-label, Phase 3 Trial of Petosemtamab in Combination With mFOLFOX6 or FOLFIRI Versus Cetuximab in Combination With mFOLFOX6 or FOLFIRI as First-line Treatment for Participants With RAS and BRAF Wild-type, Unresectable or Metastatic, Left-sided Colorectal Cancer
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.
Read more
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.
Read the detailed description
This Phase 3, randomized, open-label, global trial is designed to assess the efficacy and safety of petosemtamab plus investigator's choice (IC) chemotherapy (fluorouracil + leucovorin (calcium folinate) + oxaliplatin [mFOLFOX6] or fluorouracil + leucovorin (calcium folinate) + irinotecan [FOLFIRI]) versus standard of care (SOC) (ie, cetuximab + IC chemotherapy [mFOLFOX6 or FOLFIRI]) as 1L therapy in participants with unresectable or metastatic left-sided colorectal cancer.
- Conditions
- Left-sided Colorectal Cancer
- Being tested
- Petosemtamab, Cetuximab, FOLFIRI, mFOLFOX6
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PetosemtamabDrug
Intravenous infusion
CetuximabDrug
Intravenous infusion
FOLFIRIDrug
Fluorouracil + leucovorin (calcium folinate) + irinotecan via intravenous infusion.
mFOLFOX6Drug
Fluorouracil + leucovorin (calcium folinate) + oxaliplatin via intravenous infusion.
| Study group | Role | What they receive |
|---|---|---|
| Petosemtamab + IC Chemotherapy | Experimental | Participants will receive petosemtamab and IC chemotherapy (mFOLFOX6 or FOLFIRI). Receives: Drug: Petosemtamab; Drug: FOLFIRI; Drug: mFOLFOX6 |
| Cetuximab + IC Chemotherapy | Active comparator | Participants will receive cetuximab + IC chemotherapy (mFOLFOX6 or FOLFIRI). Receives: Drug: Cetuximab; Drug: FOLFIRI; Drug: mFOLFOX6 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Progression-free Survival (PFS) per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 as Assessed by Blinded Independent Central Review (BICR)
Measured: Up to approximately 35 months
Objective Response Rate (ORR) per RECIST v1.1 as Assessed by BICR
Measured: Up to approximately 35 months
Secondary outcomes (11)
Overall Survival (OS)
Measured: Up to approximately 62 months
Duration of Response (DOR) per RECIST v1.1 as Assessed by BICR
Measured: Up to approximately 62 months
Disease Control Rate (DCR) per RECIST v1.1 as Assessed by BICR
Measured: Up to approximately 62 months
Progression-free Survival after First Subsequent Therapy (PFS2)
Measured: Up to approximately 62 months
Curative Resection (R0) Rate
Measured: Up to approximately 62 months
Number of Participants with Adverse Events (AEs)
Measured: Up to approximately 62 months
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
Measured: Baseline up to approximately 62 months
Change from Baseline in Symptoms and Functioning, as Measured by EORTC QLQ-CR29
Measured: Baseline up to approximately 62 months
Time to Worsening in Symptoms and Functioning, as Measured by EORTC QLQ-F17
Measured: Up to approximately 62 months
Time to Worsening in Symptoms and Functioning, as Measured by EORTC QLQ-CR29
Measured: Up to approximately 62 months
Overall Side Effect Burden, as Measured by EORTC Item 168
Measured: Up to approximately 62 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jul 2026
- Study start11 Aug 2026
- Primary completionJul 2029 (estimated)
- Study completionSep 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Left-sided Colorectal CancerStudies of the same condition, open and under way.
- More trials run by GenmabThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 960 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Genmab
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Study Official, Study director, Genmab
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07702032
- Sponsor's protocol ID
- GCT1158-08
- Other IDs
- 2026-525883-17
- Status last verified
- Nov 2026
- First submitted
- 9 Jul 2026
- Last updated
- 3 Nov 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized, Open-label, Phase 3 Trial of Petosemtamab in Combination With mFOLFOX6 or FOLFIRI Versus Cetuximab in Combination With mFOLFOX6 or FOLFIRI as First-line Treatment for Participants With RAS and BRAF Wild-type, Unresectable or Metastatic, Left-sided Colorectal Cancer
- ClinicalTrials.gov ID
- NCT07702032
- Acronym / sponsor ID
- GCT1158-08
- Conditions
- Left-sided Colorectal Cancer
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 960 participants (estimated)
- Lead sponsor
- GenmabIndustry (pharma, biotech, devices)
- Study start
- 11 Aug 2026 (actual)
- Primary completion
- Jul 2029 (estimated)
- Study completion
- Sep 2031 (estimated)
- First posted
- 14 Jul 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
This Phase 3, randomized, open-label, global trial is designed to assess the efficacy and safety of petosemtamab plus investigator's choice (IC) chemotherapy (fluorouracil + leucovorin (calcium folinate) + oxaliplatin [mFOLFOX6] or fluorouracil + leucovorin (calcium folinate) + irinotecan [FOLFIRI]) versus standard of care (SOC) (ie, cetuximab + IC chemotherapy [mFOLFOX6 or FOLFIRI]) as 1L therapy in participants with unresectable or metastatic left-sided colorectal cancer.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Petosemtamab + IC Chemotherapy | Experimental | Drug: Petosemtamab, Drug: FOLFIRI, Drug: mFOLFOX6Participants will receive petosemtamab and IC chemotherapy (mFOLFOX6 or FOLFIRI). |
| Cetuximab + IC Chemotherapy | Active comparator | Drug: Cetuximab, Drug: FOLFIRI, Drug: mFOLFOX6Participants will receive cetuximab + IC chemotherapy (mFOLFOX6 or FOLFIRI). |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- 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 (6 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PetosemtamabIntravenous infusion | Drug | Petosemtamab + IC Chemotherapy |
| CetuximabIntravenous infusion | Drug | Cetuximab + IC Chemotherapy |
| FOLFIRIFluorouracil + leucovorin (calcium folinate) + irinotecan via intravenous infusion. | Drug | Cetuximab + IC Chemotherapy, Petosemtamab + IC Chemotherapy |
| mFOLFOX6Fluorouracil + leucovorin (calcium folinate) + oxaliplatin via intravenous infusion. | Drug | Cetuximab + IC Chemotherapy, Petosemtamab + IC Chemotherapy |
Primary outcome
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
11 secondary outcomes
Overall Survival (OS)
Time frame: Up to approximately 62 months
Duration of Response (DOR) per RECIST v1.1 as Assessed by BICR
Time frame: Up to approximately 62 months
Disease Control Rate (DCR) per RECIST v1.1 as Assessed by BICR
Time frame: Up to approximately 62 months
Progression-free Survival after First Subsequent Therapy (PFS2)
Time frame: Up to approximately 62 months
Curative Resection (R0) Rate
Time frame: Up to approximately 62 months
Number of Participants with Adverse Events (AEs)
Time frame: Up to approximately 62 months
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 62 months
Change from Baseline in Symptoms and Functioning, as Measured by EORTC QLQ-CR29
Time frame: Baseline up to approximately 62 months
Time to Worsening in Symptoms and Functioning, as Measured by EORTC QLQ-F17
Time frame: Up to approximately 62 months
Time to Worsening in Symptoms and Functioning, as Measured by EORTC QLQ-CR29
Time frame: Up to approximately 62 months
Overall Side Effect Burden, as Measured by EORTC Item 168
Time frame: Up to approximately 62 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Nov 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Study Official study director
Genmab
12 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Petosemtamab, Cetuximab and FOLFIRI in people with Left-sided Colorectal Cancer, run by Genmab at 12 sites in 3 countries.
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 4 inclusion and 6 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: looking for participants now, as of the sponsor's last update on 3 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 12 sites in United States, Australia, Puerto Rico. Whether a site is taking part right now should be confirmed with that site. See every site.
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 phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
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 Genmab Trial Information (+4570202728, clinicaltrials@genmab.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the 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). 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?
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 3 Nov 2026.