Phase 3 Study of Perioperative Dostarlimab in Participants with Untreated T4N0 or Stage III dMMR/MSI-H Resectable Colon Cancer

A Phase 3, Open-Label, Randomized Study of Perioperative Dostarlimab Monotherapy versus Standard of Care in Participants with Untreated T4N0 or Stage III dMMR/MSI-H Resectable Colon Cancer

Status

Recruiting

Phases

Phase 3

Study type

Interventional

Source

CTRI

Registry ID

CTRI/2025/07/092011

Enrollment

711

Registered

2025-07-30

Start date

Unknown

Completion date

Unknown

Last updated

2026-01-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Health Condition 1: C189- Malignant neoplasm of colon, unspecified

Interventions

Intervention1: Dostarlimab: Type - Biologic Dose Formulation - Solutiom for Infusion Unit DOse Strength - 500 mg Q3W for 4 Cycles before surgery and 1000 mg Q6W for 6 Cycles after surgery ROA - IV In

Eligibility

Inclusion criteria

Inclusion criteria: Confirmed Colon Adenocarcinoma Resectable colon adenocarcinoma clinically T4N0 or Stage 3 Radiologically evaluable disease Tumor demonstrating the presence of either -MMR status must be assessed by IHC for MMR protein expression (MLH1, 2, 6 and PMS2) MSi-H phenotype as determined by PCR or by tissue NGS, MSI-H determined by local Laboratory ECOG PS of 0 or 1 Provide tissue sample from initial diagnosis adequate organ function

Exclusion criteria

Exclusion criteria:

Design outcomes

Primary

Measure	Time frame
To evaluate the efficacy of perioperative dostarlimab compared with SOC in participants with untreated T4N0 or Stage III(resectable), dMMR/MSI-H colon cancerTimepoint: EFS with recurrence assessed by BICR Where an event is defined as: 1-Disease recurrence based on radiological assessment by BICR o Disease progression precluding surgery (local assessment). 2-Disease recurrence based on a pathological assessment of new lesions (local assessment). 3-Death due to any cause o Treatment-related toxicity that results in the participant not being suitable for surgery	—

Measure

Time frame

To evaluate the efficacy of perioperative dostarlimab compared with SOC in participants with untreated T4N0 or Stage III(resectable), dMMR/MSI-H colon cancerTimepoint: EFS with recurrence assessed by BICR Where an event is defined as: 1-Disease recurrence based on radiological assessment by BICR o Disease progression precluding surgery (local assessment). 2-Disease recurrence based on a pathological assessment of new lesions (local assessment). 3-Death due to any cause o Treatment-related toxicity that results in the participant not being suitable for surgery

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Secondary

Measure	Time frame
To further evaluate the efficacy of perioperative dostarlimab compared with SOC in participants with untreated T4N0 or Stage III (resectable), dMMR/MSI-H colon cancer.Timepoint: OS, defined as time from randomization to death from any cause;To evaluate the efficacy of neoadjuvant dostarlimab in participants with untreated T4N0 or Stage III (resectable), dMMR/MSI-H colon cancerTimepoint: Whenever there is a Pathological response determined by local assessment.;To evaluate the efficacy of perioperative dostarlimab compared with SOC in participants with untreated T4N0 or Stage III (resectable), dMMR/MSI-H colon cancerTimepoint: EFS event with recurrence evaluated by local assessment;To assess the safety & tolerability of dostarlimab compared with SOC in participants with untreated T4N0 or Stage III (resectable), dMMR/MSI-H colon cancerTimepoint: Whenever there are treatment emergent AEs SAEs imAEs & AEs leading to death or discontinuation of study intervention;To describe the PK of dostarlimab in participants with untreated T4N0 or Stage III (resectable), dMMR/MSI-H colon cancerTimepoint: Serum concentrations and relevant PK parameters (C-EoI and Ctrough) for dostarlimab;To determine the immunogenicity of dostarlimab in participants with untreated T4N0 or Stage III (resectable), dMMR/MSI-H colon cancerTimepoint: Incidence of ADA against dostarlimab	—

Measure

Time frame

To further evaluate the efficacy of perioperative dostarlimab compared with SOC in participants with untreated T4N0 or Stage III (resectable), dMMR/MSI-H colon cancer.Timepoint: OS, defined as time from randomization to death from any cause;To evaluate the efficacy of neoadjuvant dostarlimab in participants with untreated T4N0 or Stage III (resectable), dMMR/MSI-H colon cancerTimepoint: Whenever there is a Pathological response determined by local assessment.;To evaluate the efficacy of perioperative dostarlimab compared with SOC in participants with untreated T4N0 or Stage III (resectable), dMMR/MSI-H colon cancerTimepoint: EFS event with recurrence evaluated by local assessment;To assess the safety & tolerability of dostarlimab compared with SOC in participants with untreated T4N0 or Stage III (resectable), dMMR/MSI-H colon cancerTimepoint: Whenever there are treatment emergent AEs SAEs imAEs & AEs leading to death or discontinuation of study intervention;To describe the PK of dostarlimab in participants with untreated T4N0 or Stage III (resectable), dMMR/MSI-H colon cancerTimepoint: Serum concentrations and relevant PK parameters (C-EoI and Ctrough) for dostarlimab;To determine the immunogenicity of dostarlimab in participants with untreated T4N0 or Stage III (resectable), dMMR/MSI-H colon cancerTimepoint: Incidence of ADA against dostarlimab

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Countries

Argentina, Australia, Belgium, Brazil, Canada, China, Democratic People's Republic of Korea, Estonia, Finland, France, Germany, Greece, India, Italy, Japan, Mexico, Netherlands, Norway, Panama, Portugal, Spain, Sweden, Taiwan, Turkey, United Kingdom, United States of America

Contacts

Public ContactSwapnali Raut

GSK Pharma India Private Limited

gaurav.a.deshmukh@gsk.com7977659978

Outcome results

None listed

Source: CTRI (via WHO ICTRP) · Data processed: Feb 4, 2026