Active — Not RecruitingPhase 2

A Study of Dostarlimab in Untreated dMMR/MSI-H Locally Advanced Rectal Cancer

United States, Canada, France154 participantsStarted 2023-04-03

Plain-language summary

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.

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

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., …

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Number of Participants with Sustained Complete Clinical Response for 12 Months (cCR12) as assessed by Independent Central Review (ICR)

Timeframe: 18 Months

Trial details

NCT IDNCT05723562

SponsorGlaxoSmithKline

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2026-11-02

View on ClinicalTrials.gov More Neoplasms, Rectal trials