Neoadjuvant dostarlimab for locally advanced dMMR/MSI‑H rectal cancer in routine practice

Real-world Efficacy and Safety of Neoadjuvant Dostarlimab in Patients With dMMR/MSI-H Locally Advanced Rectal Cancer

National Cancer Institute, Naples · NCT07269249

This project will try neoadjuvant dostarlimab in adults with dMMR/MSI‑H stage II–III rectal cancer to see how well it works and how safe it is in real-world clinical care.

Quick facts

Study typeObservational
Enrollment50 (estimated)
Ages18 Years and up
SexAll
SponsorNational Cancer Institute, Naples (other)
Drugs / interventionsdostarlimab
Locations2 sites (Naples and 1 other locations)
Trial IDNCT07269249 on ClinicalTrials.gov

What this trial studies

This is a multicentre, observational retrospective‑prospective study enrolling patients entered in the Italian AIFA monitoring registry who received neoadjuvant dostarlimab beginning in November 2023. The primary outcome is objective response rate by RECIST 1.1, with central radiology review planned for objective responses. Secondary outcomes include clinical complete and near‑complete response rates at 6 and 12 months, time to and duration of responses, surgical and pathological response rates, safety using CTCAE v5.0, and longer‑term outcomes such as event‑free survival, organ preservation at 3 years, time to distant recurrence, and overall survival. Data will be collected across participating Naples centers to describe real‑world effectiveness and toxicity outside a controlled trial setting.

Who should consider this trial

Good fit: Adults (age ≥18) with histologically confirmed stage II–III rectal cancer that is confirmed dMMR/MSI‑H and who received or will receive neoadjuvant dostarlimab and are entered in the AIFA monitoring registry are eligible.

Not a fit: Patients without dMMR/MSI‑H tumors, those with metastatic disease, those not treated with dostarlimab, or those not included in the AIFA registry are not expected to benefit from this study's findings.

Why it matters

Potential benefit: If successful, the results could clarify how often dostarlimab produces tumor shrinkage and enables organ preservation in routine practice, potentially helping more patients avoid major surgery.

How similar studies have performed: Early single‑center and small prospective series of neoadjuvant PD‑1 blockade in dMMR rectal cancer have reported very high clinical response rates, but evidence remains limited and needs confirmation in larger real‑world cohorts.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Signed informed consent form
* Age \> 18 years
* Histologically confirmed stage II-III rectal cancer
* dMMR/MSI status assessed locally by Immunohistochemistry, next-generation sequencing or PCR

For the retrospective part of the study:

* At least one dose of neoadjuvant dostarlimab from November 2023 (i.e. within the period of AIFA dostarlimab monitoring registry activation for the indication in rectal cancer, which is reimbursed according to the Italian law 648/1996, GU n.252 as of 27/10/2023)
* Eligible deceased or unreachable patients will also be included to avoid selection biases, in respect of the article 110 bis, paragraph 4 of the Italian Privacy Code (a Data Protection Impact Assessment will be produced and published on the Sponsor website before study initiation, and patients explicitly unwilling before death will be not included).

For the prospective part of the study:

\- Inclusion in the AIFA dostarlimab monitoring registry for the indication in rectal cancer, to receive dostarlimab according to the Italian law 648/1996, GU n.252 as of 27/10/2023

Exclusion Criteria:

* \- Distant metastasis
* Major cognitive dysfunction or psychiatric disorders
* Any previous systemic or local treatment for rectal cancer
* Dostarlimab received within an interventional clinical trial

Where this trial is running

Naples and 1 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: Locally Advanced Rectal Cancer, dostarlimab, mismatch repair-deficient LARC, real-world, retrospective-prospective study, neoadjuvant setting

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.