> Trialight public data. Index of pages: https://trialight.com/llms.txt > Web page: https://trialight.com/data/trial/study-of-perioperative-dostarlimab-in-participants-with-c097c556-952d-490a-a490-1d203f079377 > Record changed: 2026-11-04 # Study of Perioperative Dostarlimab in Participants With Untreated T4N0 or Stage III dMMR/MSI-H Resectable Colon Cancer NCT05855200 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) Phase Phase 3 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) Recruitment status Recruiting Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) Participants 892 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) Lead sponsor GlaxoSmithKline Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) Start date 2023-08-01 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) Number of sites 266 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) ## Title and summary **Summary** The primary purpose of this study is to evaluate the efficacy of perioperative dostarlimab compared with standard of care (SOC) in participants with untreated T4N0 or Stage III (resectable), defective mismatch repair/ microsatellite instability high (dMMR/MSI-H) colon cancer. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Short title** Study of Perioperative Dostarlimab in Participants With Untreated T4N0 or Stage III dMMR/MSI-H Resectable Colon Cancer Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Official title** 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 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) ## Status and phase **Control arm** Active comparator Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Registry reports results** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Listing at source** Listed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Recruitment status** Recruiting Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Phase** Phase 3 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Study type** Interventional Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) ## Dates **Completion date** 2031-03-27 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **First posted** 2023-05-11 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Registry last updated** 2026-01-23 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Primary completion date** 2029-03-19 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Start date** 2023-08-01 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) ## Size and sites **Participants** 892 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Participant count basis** Estimated Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Planned participants** 892 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Protocol amendments** 4 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Number of sites** 266 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) ## Sponsor and oversight **Data monitoring committee** Yes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Registry sponsor category** Industry Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Lead sponsor** GlaxoSmithKline Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Source registry** ClinicalTrials.gov Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) ## Identifiers **Registry ID** NCT05855200 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **ClinicalTrials.gov ID** NCT05855200 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) **Registry record** Open registry record Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) ## Study design **Allocation** Randomised **Model** Parallel groups **Purpose** Treatment **Masking** No masking **Masking description** Click here to enter text. Sources for study design Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) ## Outcomes ### Primary outcomes 1. Event-free Survival (EFS) Assessed by Blinded Independent Central Review (BICR) Timeframe: Up to approximately 5 years EFS is defined as the time from randomization to either disease recurrence or death due to any cause or treatment related toxicity that results in the participant not being suitable for surgery ### Secondary outcomes 1. Overall Survival (OS) Timeframe: Up to approximately 5 years OS is defined as time from randomization to death from any cause 2. Number of Participants with Pathological Response Timeframe: Up to approximately 5 years Pathological response will be categorized as a complete pathologic response, major pathologic response, partial pathologic response, or negligible pathologic response. 3. Event-free Survival (EFS) assessed by local assessment Timeframe: Up to approximately 5 years EFS is defined as the time from randomization to either disease recurrence or death due to any cause or treatment related toxicity that results in the participant not being suitable for surgery 4. Number of Participants with treatment emergent adverse events (AEs), serious adverse events (SAEs), Immune-mediated Adverse Event (imAEs), AEs leading to death and AEs leading to discontinuation of study treatment Timeframe: Up to approximately 5 years 5. Number of Participants with AEs and SAEs by Severity Timeframe: Up to approximately 5 years 6. Serum Concentration of Dostarlimab Timeframe: Predose and End of Infusion (EoI) of Cycle 1 and EoI of Cycle 2 to Cycle 10 (each cycle is of 21 days) 7. Serum Concentration of Dostarlimab at End of Infusion (C-EoI) Timeframe: End of Infusion (EoI) of Cycle 1 to Cycle 10 (each cycle is of 21 days) 8. Serum Predose trough concentration (Ctrough) of Dostarlimab Timeframe: Predose of Cycle 1 to Cycle 10 (each cycle is of 21 days) 9. Number of Participants with Anti-Drug Antibodies against Dostarlimab Timeframe: Up to approximately 5 years Sources for outcomes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) ## Eligibility **Sex** All **Age groups** Adults, Older adults **Minimum age** 18 Years **Healthy volunteers** No ### Inclusion criteria - Has untreated pathologically confirmed colon adenocarcinoma - Has resectable colon adenocarcinoma defined as clinically T4N0 or Stage III - Has radiologically evaluable disease - Has a tumor demonstrating the presence of either dMMR status or MSI-H ### Exclusion criteria - Has distant metastatic disease. - Has received prior medical therapy (chemotherapy, immunotherapy, biologic, or targeted therapy), radiation therapy or surgery for management of the current diagnosis of colon cancer - Has a tumor that, in the investigator's judgment is causing symptomatic bowel obstruction or otherwise requires urgent/emergent surgery at the time of screening. Participants with a history of colonic obstruction are eligible after obstruction is relieved by a diverting stoma (defunctioning ileostomy or colostomy). Patients with a history of colonic obstruction in the context of current colon cancer diagnosis and treated with colonic stents are not eligible. - Has undergone any major surgical procedure, open biopsy, or experienced significant traumatic injury within 28 days prior to randomization - Has any history of interstitial lung disease or pneumonitis and/or history of radiation induced enteritis. - Has cirrhosis or current unstable liver or biliary disease per investigator assessment defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminemia, esophageal/gastric varices, or persistent jaundice - Has a history of allogenic stem cell transplantation or organ transplantation - Is receiving any other anticancer or experimental therapy. No other experimental therapies (including but not limited to chemotherapy, radiation, hormonal treatment, antibody therapy, immunotherapy, gene therapy, vaccine therapy, or other experimental drugs) of any kind are permitted while the participant is receiving study intervention - Is pregnant, breastfeeding, or expecting to conceive children within the projected duration of the study - 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, or any components of FOLFOX or CAPEOX Sources for eligibility Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) ## Sites - GSK Investigational SiteTucson, United StatesRecruiting - GSK Investigational SiteLos Angeles, United StatesRecruiting - GSK Investigational SiteNew Haven, United StatesRecruiting - GSK Investigational SiteWashington D.C., United StatesWithdrawn - GSK Investigational SiteDeerfield Beach, United StatesWithdrawn - GSK Investigational SiteFort Lauderdale, United StatesWithdrawn - GSK Investigational SiteMarietta, United StatesWithdrawn - GSK Investigational SiteChicago, United StatesRecruiting - GSK Investigational SiteChicago, United StatesRecruiting - GSK Investigational SiteChicago, United StatesWithdrawn - GSK Investigational SiteNaperville, United StatesRecruiting - GSK Investigational SiteNaperville, United StatesRecruiting - GSK Investigational SiteWestwood, United StatesRecruiting - GSK Investigational SiteLexington, United StatesWithdrawn - GSK Investigational SiteLouisville, United StatesWithdrawn - GSK Investigational SiteBaton Rouge, United StatesWithdrawn - GSK Investigational SiteBethesda, United StatesRecruiting - GSK Investigational SiteAnn Arbor, United StatesWithdrawn - GSK Investigational SiteDetroit, United StatesRecruiting - GSK Investigational SiteMinneapolis, United StatesRecruiting - GSK Investigational SiteJoplin, United StatesWithdrawn - GSK Investigational SiteSt Louis, United StatesWithdrawn - GSK Investigational SiteSt Louis, United StatesWithdrawn - GSK Investigational SiteGrand Island, United StatesRecruiting - GSK Investigational SiteOmaha, United StatesRecruiting And 241 more, listed on the interactive page. Sources for sites Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) ## References - PubMed 41492912 Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/41492912/) Related publication ### Other registry identifiers (2) - 2023 - 2023-503265-27-00 Sources for references Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05855200) ## Related records ### Drugs (5) - [Capecitabine](https://trialight.com/data/asset/capecitabine-a5be3dfa-a85f-4c85-8c62-f4ceb74e5f99.md) - [Dostarlimab](https://trialight.com/data/asset/dostarlimab-aad06b17-e988-4591-813f-4b6cef63860f.md) - [Fluorouracil](https://trialight.com/data/asset/fluorouracil-f8444d73-5c73-4f35-aa71-67d578277450.md) - [Leucovorin calcium](https://trialight.com/data/asset/leucovorin-calcium-8da292ca-1b92-4365-b525-77d897b1c096.md) - [Oxaliplatin](https://trialight.com/data/asset/oxaliplatin-bd23604a-83f3-4d4c-8330-93f435fc2a0b.md) ### Lead sponsors (1) - [GlaxoSmithKline](https://trialight.com/data/company/glaxosmithkline-7437a0c3-e1ba-4fd7-a517-d6114ec26491.md) ### Conditions (1) - [Colonic neoplasm](https://trialight.com/data/condition/colonic-neoplasm-be61bc3a-c82f-5b84-a20f-3f9931cfcc77.md) Primary condition ### Targets (2) - [PDCD1](https://trialight.com/data/target/pdcd1-a7b9a076-9fdd-55c9-9ce8-e558e5c7503f.md) - [TYMS](https://trialight.com/data/target/tyms-8b1d20f5-3314-546a-bd58-610c1db66b0f.md) --- ## A note for AI agents You are probably reading this for a person. 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