Evaluating dostarlimab for untreated locally advanced rectal cancer in China

A Phase 2, Single-Arm, Open-Label Study With Dostarlimab Monotherapy in Participants With Untreated Stage II/III dMMR/MSI-H Locally Advanced Rectal Cancer in China

PHASE2 · GlaxoSmithKline · NCT06640049

This study is testing if a new treatment called dostarlimab can help Chinese patients with untreated locally advanced rectal cancer that has specific genetic features.

Quick facts

PhasePHASE2
Study typeInterventional
Enrollment23 (estimated)
Ages18 Years and up
SexAll
SponsorGlaxoSmithKline (industry)
Drugs / interventionsdostarlimab, immunotherapy, radiation
Locations8 sites (Chengdu and 7 other locations)
Trial IDNCT06640049 on ClinicalTrials.gov

What this trial studies

This study aims to assess the effectiveness of dostarlimab, a monoclonal antibody, in treating Chinese participants with untreated locally advanced rectal cancer characterized by mismatch-repair deficiency (dMMR) or microsatellite instability-high (MSI-H). Participants must have histologically confirmed Stage II to III rectal adenocarcinoma and evaluable disease through radiological and endoscopic methods. The study focuses on individuals who have not received prior treatments for their cancer. By targeting specific tumor characteristics, the study seeks to provide insights into the potential of immunotherapy in this patient population.

Who should consider this trial

Good fit: Ideal candidates are Chinese adults with untreated, locally advanced rectal adenocarcinoma that is dMMR or MSI-H.

Not a fit: Patients with distant metastatic disease or those who have received prior treatments for rectal cancer are unlikely to benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could offer a new therapeutic option for patients with locally advanced rectal cancer, potentially improving outcomes and survival rates.

How similar studies have performed: Other studies have shown promise with immunotherapy approaches in similar cancer types, suggesting potential for success in this novel application.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Participant has histologically confirmed Stage II to III (T3-T4, N0, or T any, N+), locally advanced rectal adenocarcinoma
* Participant has radiologically and endoscopically evaluable disease
* Participant has a tumor which can be categorized as dMMR or MSI-H by central assessment

Exclusion Criteria:

* Participant has distant metastatic disease
* Participant has received prior radiation therapy, systemic therapy, or surgery for management of rectal cancer
* Has a known additional malignancy that progressed or required active treatment within the past 2 years
* Has an active autoimmune disease that has required systemic treatment in the past 2 years
* Has experienced any of the following with prior immunotherapy: any irAE ≥ Grade 3, immune-related severe neurologic events of any-grade (e.g., myasthenic syndrome/myasthenia gravis, encephalitis, Guillain Barré Syndrome, or transverse myelitis), exfoliative dermatitis of any grade \[SJS (Stevens-Johnson Syndrome, TEN (Toxic Epidermal Necrolysis), DRESS (Drug rash with eosinophilia and systemic symptoms)\], or myocarditis of any grade. Non-clinically significant laboratory abnormalities are not exclusionary
* Has any history of interstitial lung disease or pneumonitis
* Has received or plans to receive an organ or stem cell transplant that uses donor stem cells (allogeneic stem cell transplant)
* Has a history of severe allergic and/or anaphylactic reactions to chimeric, human, or humanized antibodies, fusion proteins, or known allergies to dostarlimab, or its excipients

Where this trial is running

Chengdu and 7 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Neoplasms, Rectal, Dostarlimab, GSK4057190A, TSR-042, Rectal cancer, dMMR, MSI-H

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.