Evaluation of Co-formulated Pembrolizumab/Quavonlimab (MK-1308A) Versus Other Treatments in Participants With Microsatellite Instability-High (MSI-H) or Mismatch Repair Deficient (dMMR) Stage IV Colorectal Cancer (CRC) (MK-1308A-008/KEYSTEP-008). (NCT04895722)

Check every box below. If you can check all of them, you may meet the study's basic screening requirements (final eligibility is confirmed by the site team).

1. Has a histologically confirmed diagnosis of Stage IV CRC adenocarcinoma (as defined by American Joint Committee on Cancer \[AJCC\] version 8)
2. Has locally confirmed dMMR/MSI-H
3. Has a life expectancy of at least 3 months
4. Female participants are eligible to participate if not pregnant or breastfeeding, and not a woman of childbearing potential (WOCBP), or if a WOCBP then uses a contraceptive method that is highly effective or is abstinent on a long-term and persistent basis, during the intervention period and for at least 120 days after the last dose of study intervention
5. Has measurable disease per RECIST 1.1 as assessed by the site and verified by BICR
6. Submit an archival (within 5 years of Screening) or newly obtained tumor tissue sample that has not been previously irradiated; formalin-fixed, paraffin embedded (FFPE) blocks are preferred to slides.
7. Has adequate organ function Cohort A: \- Has been previously treated for their Stage IV dMMR/MSI-H CRC and radiographically progressed on or after or could not tolerate standard treatment, which must include all of the following agents if approved and locally available in the country where the participant is randomized:
8. Fluoropyrimidine, irinotecan and oxaliplatin (capecitabine is acceptable as equivalent to fluorouracil in prior therapy)
9. With or without an anti-vascular endothelial growth factor (VEGF) monoclonal antibody (e.g., bevacizumab)
10. At least one of the anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (cetuximab or panitumumab) for rat sarcoma viral oncogene homolog (RAS) wild-type participants with left-sided tumors. Prior EGFR therapy is optional for patients with right sided RAS Wild-type (WT) tumors. Cohort B: \- Has untreated Stage IV dMMR/MSI-H CRC with no prior chemotherapy or immunotherapy for this disease

🔍 Extracted verbatim from the official NIH eligibility criteria. Always confirm with the study coordinator.

📍 All Participating Trial Locations (109 Sites)

• Mid Florida Cancer Center ( Site 1519) — Orange City, Florida
• University Cancer & Blood Center, LLC ( Site 1521) — Athens, Georgia
• University of Chicago Medical Center-Medicine - Section of Hematology/Oncology - Gastrointestinal P — Chicago, Illinois
• Icahn School of Medicine at Mount Sinai ( Site 1528) — New York, New York
• Hematology Oncology Associates of Rockland ( Site 1525) — Nyack, New York
• UPMC Hillman Cancer Center ( Site 1516) — Pittsburgh, Pennsylvania
• The West Clinic, PLLC dba West Cancer Center ( Site 1576) — Germantown, Tennessee
• Vanderbilt University Medical Center-Vanderbilt-Ingram Cancer Center ( Site 1509) — Nashville, Tennessee
• UT Southwestern Medical Center ( Site 1551) — Dallas, Texas
• Baylor Scott & White Medical Center - Temple-Division of Hematology/Oncology ( Site 1549) — Temple, Texas
• Northwest Medical Specialties, PLLC ( Site 1546) — Tacoma, Washington
• UZ Brussel ( Site 0105) — Brussels, Bruxelles-Capitale, Region de
• Cliniques universitaires Saint-Luc-Medical Oncology ( Site 0104) — Brussels, Bruxelles-Capitale, Region de
• Université Catholique de Louvain-Namur - Centre Hospitalier -Oncology ( Site 0102) — Yvoir, Namur
• UZ Leuven ( Site 0101) — Leuven, Vlaams-Brabant
• AZ Delta vzw ( Site 0106) — Roeselare, West-Vlaanderen
• The Moncton Hospital-Oncology ( Site 0307) — Moncton, New Brunswick
• Sunnybrook Research Institute - Odette Cancer Centre ( Site 0316) — Toronto, Ontario
• McGill University Health Centre-CIM - Oncology ( Site 0306) — Montreal, Quebec
• Instituto de Cancerología ( Site 1610) — Medellín, Antioquia
• Fundación Colombiana de Cancerología Clínica Vida ( Site 1606) — Medellín, Antioquia
• Clinica de la Costa S.A.S. ( Site 1608) — Barranquilla, Atlántico
• Clinica Colsanitas S.A, Sede Clínica Universitaria Colombia ( Site 1611) — Bogotá, Bogota D.C.
• Sociedad De Oncologia Y Hematologia Del Cesar-Oncology ( Site 1601) — Valledupar, Cesar Department
• Oncomédica S.A.S ( Site 1602) — Montería, Departamento de Córdoba

💰 Cost, Insurance & Patient Rights

• 100% Free Items: The investigational treatment and protocol-required procedures are supplied at zero cost by the sponsor.
• Routine Patient Care: Under federal law (ACA § 2709) and many state statutes, routine care costs are covered during participation.
• Voluntary Participation: You may withdraw at any time without affecting your standard medical care.