Phase II Study of Neoadjuvant Dostarlimab in Patients With Untreated T3-4N0-2 or Stage III pMMR/MSS Resectable Colon Cancer

NCT06830239 | Recruiting Phase 2

• 2 other identifiers: S688822024-512499-36-00
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

Brief Summary

Dostarlimab belongs to a class of drugs called PD-1 inhibitors that use your own immune system to treat cancer (immunotherapy). It is designed to stop cancer from growing by helping your immune system recognize and fight the cancer. This investigational medicinal product (IMP) has been approved by the Belgian authorities, but not for the treatment of colon cancer. It is known that a small number of patients with pMMR/MSS colon cancer may have significant response to medication of this type (immunotherapy) depending on each person's biology. Trial intervention for all patients will be neo-adjuvant dostarlimab 500 mg IV, given alone by intravenous infusion. Two administrations of dostarlimab are foreseen, at three weeks interval, before surgery for your colon cancer. It has not yet been proven that this treatment can cure, improve or stabilise your disease or condition. The study aims to investigate specific molecular changes in tumour and blood after dostarlimab monotherapy administered and before surgery which could be associated with improved response to conventional treatment in some patients. If you decide to participate, as the duration of treatment with dostarlimab is 6 weeks, surgery may be slightly delayed compared to patients that are not treated with dostarlimab and go directly for surgery. It remains uncertain if this is beneficial in your personal situation but some patients might experience significant response. The risks have been carefully assessed and the potential benefits for some patients are considered important and justify undertaking the treatment. Subsequent therapy after surgery remains at the discretion of the treating physician. The duration of a patient on trial will last up to 4 months from the first dose of dostarlimab and afterwards 2 years of follow up is applicable.

Conditions

Colon Cancer Stage III

Keywords

Colon Cancer; Neoadjuvant; pMMR/MSS; Resectable

Outcome Measures

Primary Outcomes (1)

• Multi-omic exploration

  Data generation through multi-omic exploration of blood and tissue derived products (see Sampling and Lab manual). Correlation of molecular-biological features identified with pathological response. The presence or absence of specific molecular characteristics in blood and tissue will be correlated in each patient with the degree of tumour response to therapy evaluated by a pathologist.

  From enrollment to the last FU visit of the patient for blood (2 years). From baseline to surgery for tissue (12-15 weeks). Data will be reported at the final study report (max 3 years from study start).

Secondary Outcomes (3)

• Safety analysis

  Continuous

• Pathological response

  Pathological tumor staging and response assessment is at surgery

• Survival

  From enrollment till last FU visit of patient (2 years). Data will be reported at the final study report (max 3 years from study start).

Study Arms (1)

Dostarlimab monotherapy

EXPERIMENTAL

Dostarlimab should be administered by intravenous infusion using an intravenous infusion pump over 30 minutes at a dose of 500 mg once every 3 weeks (Q3W), for 2 cycles (6 weeks in total).

Drug: Dostarlimab

Interventions

Dostarlimab DRUG

Dostarlimab \[Jemperli GlaxoSmithKline (GSK)\] is a humanized IgG4 monoclonal antibody that binds with high affinity and specificity to PD-1, resulting in inhibition of binding to PD-L1 and PD-L2. Dostarlimab is in clinical development for the treatment of subjects with solid tumors, including those with recurrent/advanced dMMR/MSI-H solid tumors who have progressed on standard of care chemotherapy, as monotherapy or in combination with other agents.

Also known as: Jemperli

Dostarlimab monotherapy

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• at least 18 years of age and capable of giving informed consent
• primary adenocarcinoma colon cancer than can be removed surgically, staged cT3-4, cN0-2, cM0 or stage III
• tumour expresses an MMR proficient/microsatellite stable called MSS
• tissue samples from tumour and colon mucosa available for molecular analyses
• capable of receiving immunotherapy
• adequate general health status and organ function (blood tests)

You may not qualify if:

• no prior cancer treatment
• not pregnant and using effective contraception if applicable

Sponsors & Collaborators

• Universitaire Ziekenhuizen KU Leuven: lead

Study Sites (1)

UZLeuven

Leuven, 3000, Belgium

RECRUITING

MeSH Terms

Conditions

Colonic Neoplasms

Interventions

dostarlimab

Condition Hierarchy (Ancestors)

Colorectal Neoplasms; Intestinal Neoplasms; Gastrointestinal Neoplasms; Digestive System Neoplasms; Neoplasms by Site; Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Colonic Diseases; Intestinal Diseases

Study Officials

• Sabine Tejpar, MD

  Universitaire Ziekenhuizen KU Leuven

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Sabine Tejpar, MD

CONTACT

+32 16 34 42 25; sabine.tejpar@uzleuven.be

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 10, 2024
• First Posted: February 17, 2025
• Study Start: April 3, 2025
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2028
• Last Updated: February 12, 2026

Record last verified: 2026-02

Locations

BE (1)