An observational study in Colorectal Cancer Metastatic and Microsatellite Instability-High Colorectal Cancer, sponsored by Federation Francophone de Cancerologie Digestive. Recruiting at 20 sites in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-10-06.
Sponsored by Federation Francophone de Cancerologie Digestive · Observational
The Keynote 117 phase III trial demonstrated the superiority of pembrolizumab (anti-PD1 monoclonal antibody) versus chemotherapy +/- targeted therapy in first-line treatment of dMMR/MSI metastatic colorectal cancer (mCRC). However, primary resistance to pembrolizumab was observed in approximately 20-30% of patients treated in the Keynote 177 study. Therefore, the identification of biomarkers predictive of resistance to immunotherapy for dMMR/MSI mCRC is necessary to better select patients who benefit the most from immunotherapy, and those for whom other therapeutic approaches should be favored.
The primary endpoint is the identification of predictive factors of resistance to pembrolizumab in first-line treatment of MSI and/or dMMR metastatic colorectal cancer
CORESIM is a retrospective and prospective multicenter national French cohort. National recruitment will be carried out in all French centers, including the FFCD, AGEO, GERCOR, and UNICANCER, representing more than 150 centers and most French sites, public and private hospitals.
In France, pembrolizumab for first-line treatment of patients with MSI mCRC was accessible via its compassionate use in February 2021, then its reimbursement was effective in June 2023 Patients treated with pembrolizumab will be included prospectively on the start date of the study, i.e. on February 2024; patients treated since February 2021 via compassionate use of pembrolizumab will be included retrospectively A total of 600 patients are expected. The theoretical duration of inclusion is set at 2 years. All patients will be followed up for 3 years.
6,541 studies on the registry are indexed under Colorectal Neoplasms; 1,667 are open to participants now.
This study's planned enrollment of 600 is above the median of 250 across 1,440 observational studies indexed under Colorectal Neoplasms.
Browse Colorectal Neoplasms studies →Federation Francophone de Cancerologie Digestive is the lead sponsor of 63 studies on the registry; 15 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Prospective inclusion of patients receiving first-line immunotherapy with pembrolizumab (as defined in the MA) for unresectable mCRC.
Patients who have received pembrolizumab in the same indication on a compassionate basis since February 2021 may also be retrospectively included in the cohort.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
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.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Registration of patients treated with pembrolizumab since February 2021. Collection of tumour sample archives will be associated
Recruitment of metastatic colorectal cancer patients with microsatellite instability prior to the first administration of pembrolizumab immunotherapy. Blood and tumour sampling will be combined.
This study also gives Pembrolizumab. No intervention listed here names it: that was found by reading the record.
Identification of predictive factors of resistance to pembrolizumab in first-line treatment of MSI and/or dMMR metastatic colorectal cancer
Primary resistance will be defined as immediate progression of the disease (at the time of the first assessment, excluding pseudoprogression) Secondary resistance will be defined as progression occurring after control of the disease.
Time frame: 2 years
Started Feb 2024 (actual). Primary completion is estimated for Feb 2029, 60 months after the start.
Of 528 non-industry observational studies under Colorectal Neoplasms, half reached primary completion within 56 months of starting (the median), counting those still running; a quarter within 27 and three quarters within 132. This study's planned 60 months is close to that.
Counting every sponsor, half of 645 studies reached it within 51 months; a quarter within 27 and three quarters within 104.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
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Federation Francophone de Cancerologie Digestive