Clinical trial · Interventional
A Study of Dostarlimab in Untreated dMMR/MSI-H Locally Advanced Rectal Cancer
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
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Summary
Brief summary (as posted)
The purpose of this study is to investigate dostarlimab monotherapy in participants with locally advanced Mismatch-repair deficient (dMMR)/Microsatellite instability-high (MSI-H) rectal cancer who have received no prior treatment. Participants who achieve complete clinical response (cCR) following dostarlimab treatment will undergo non-operative management (NOM), including close surveillance for recurrent disease. The goal of the study is to determine if Dostarlimab therapy alone is an effective treatment that can allow participants to avoid chemotherapy, radiation, and surgery.
Conditions
Conditions (1)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Neoplasms, Rectal | Rectal Neoplasm | ONTOLOGY_EXACT | 0.98 |
Interventions
Interventions (1)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Dostarlimab | Biological | Dostarlimab | ALIAS |
Design
Arms and outcomes
Arms (1)
- type
- EXPERIMENTAL
- label
- Dostarlimab monotherapy
- interventionNames
- Biological: Dostarlimab
Primary outcomes (1)
- measure
- Number of Participants with Sustained Complete Clinical Response for 12 Months (cCR12) as assessed by Independent Central Review (ICR)
- timeFrame
- 18 Months
- description
- cCR12 is achieved when a participant maintains complete clinical response (cCR) as assessed by ICR for 12 months following their post-intervention disease assessment (PIDA)
Secondary outcomes (20)
- measure
- Number of Participants with Sustained Complete Clinical Response for 24 Months (cCR24) as assessed by ICR
- timeFrame
- 30 Months
- description
Eligibility
Eligibility (as posted)
- Sex
- All
- Minimum age
- 18 Years
Show eligibility criteria text
Inclusion Criteria: * Participant has histologically confirmed Stage II to III (T3-T4, N0, or T any, N+), locally advanced rectal cancer * Participant has radiologically and endoscopically evaluable disease. * Participant has a tumor which can be categorized as dMMR or MSI-H by local or central assessment Exclusion Criteria: * Participant has distant metastatic disease. * Participant has received prior radiation therapy, systemic therapy, or surgery for management of rectal cancer. * Participant has any history of interstitial lung disease or pneumonitis * Participant has experienced any of the following with prior immunotherapy: any imAE of 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 (Stevens-Johnson Syndrome, toxic epidermal necrolysis, or DRESS syndrome), or myocarditis of any grade. Non clinically significant laboratory abnormalities are not exclusionary. * Participant has a known additional malignancy that progressed or required active treatment within the past 2 years. Exceptions include adequately treated superficial skin cancers, superficial bladder cancers, and other in situ cancers. * Participant has an active autoimmune disease that has required systemic treatment in the past 2 years (i.e., with use of disease-modifying agents, corticosteroids, or immunosuppressive drugs). Replacement therapy (e.g., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency) is not considered a form of systemic treatment. * Participant has a history of severe allergic and/or anaphylactic reactions to chimeric, human or humanized antibodies, fusion proteins, or has known allergies to dostarlimab or its excipients. * Has received or plans to receive an organ or stem cell transplant that uses donor stem cells (allogeneic stem cell transplant).
References
Publications (0)
Data not yet available