Multicenter Retrospective Study on Optimizing Combination Immunotherapy Strategies in MSS/MSI-L/pMMR Advanced Colorectal Cancer

Launched by YUE GOU · Feb 22, 2025

Keywords

ClinConnect Summary

This is a multicenter, retrospective study (looking back at medical records) to learn which immunotherapy-based treatment combinations work best for advanced colorectal cancer that is MSS, MSI-L, or mismatch repair–proficient (types that often respond less to immunotherapy). The study will compare four groups: immunotherapy alone; immunotherapy with bevacizumab (a drug that targets tumor blood vessels); immunotherapy with chemotherapy plus bevacizumab; and chemotherapy alone. Researchers will examine outcomes such as how often the cancer is controlled, how long patients live before the cancer advances, the rate of tumor shrinkage, and overall survival, in order to identify the most effective combinations and potential biomarkers that predict benefit.

Eligible participants are about 200 people with MSS/MSI-L/pMMR metastatic colorectal cancer who have received at least one immunotherapy-based treatment. Data will come from four centers in China (including Xiangya Hospital, Central South University, Changsha). This is an observational study, meaning treatments were given as part of routine care, not assigned by the study. No new procedures are required for the study beyond standard care, and information is collected from medical records with ethical oversight and privacy protections. The study started in 2019 and is currently enrolling by invitation, with an expected completion around May 2025; data sharing is not yet decided.

Gender

ALL

Eligibility criteria

• • Inclusion Criteria:1) study subjects were mCRC patients with explicitly stated MSS/MSI-L/pMMR status; 2) at least one cohort included immunotherapy treatment; 3); primary outcomes of this study were defined as Disease Control Rate (DCR) and Progression-Free Survival (PFS); secondary outcomes included Objective Response Rate (ORR), Overall Survival (OS), and Adverse Drug Reactions (ADRs) Exclusion Criteria: individuals lacking definitive pathological diagnosis, response evaluation, or pertinent follow-up data
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