PD-1 Blockade in Mismatch Repair-Deficient, Locally Advanced Rectal Cancer (prospective phase 2 study of single-agent dostarlimab)
Phase 2NCT04165772
- Population
- Patients with mismatch repair-deficient stage II or III rectal adenocarcinoma
- Design
- Prospective single-arm phase 2 study. Single-agent dostarlimab was given every 3 weeks for 6 months to patients with mismatch repair-deficient stage II or III rectal adenocarcinoma, to be followed by standard chemoradiotherapy and surgery; patients with a clinical complete response after dostarlimab proceeded without chemoradiotherapy and surgery. The 2025 report adds a second cohort of non-rectal dMMR solid tumours (not summarised here) and analyses the rectal cohort (cohort 1; 49 patients completed treatment) for sustained clinical complete response at 12 months; its figures are recorded as milestone facts because they are counts without percentages in the abstract.
- Primary endpoint
- Sustained clinical complete response at 12 months
- Arms
- Dostarlimab (rectal cohort) (experimental): Dostarlimab every 3 weeks for 6 months
- People
- Cercek A, senior author Diaz LA Jr
Show the numbers
| Endpoint | Analysis | Dostarlimab (rectal cohort) | Control | Effect |
|---|---|---|---|---|
| Clinical complete responsePatients who had completed dostarlimab and had at least 6 months of follow-up (12 patients)Clinical complete response after dostarlimab, defined in the abstract as no evidence of tumour on MRI, FDG-PET, endoscopic evaluation, digital rectal examination or biopsy | interimCercek 2022 | 100% (74–100%) | — | 12 of 12 patients. At the time of the report no patient had received chemoradiotherapy or surgery, no progression or recurrence had been reported (follow-up range 6 to 25 months) and no adverse events of grade 3 or higher had been reported. |
| Endpoint | Analysis | Dostarlimab (rectal cohort) | Control | Effect |
|---|---|---|---|---|
| Clinical complete responsePatients who had completed dostarlimab and had at least 6 months of follow-up (12 patients)Clinical complete response after dostarlimab, defined in the abstract as no evidence of tumour on MRI, FDG-PET, endoscopic evaluation, digital rectal examination or biopsy | interimCercek 2022 | 100% (74–100%) | — | 12 of 12 patients. At the time of the report no patient had received chemoradiotherapy or surgery, no progression or recurrence had been reported (follow-up range 6 to 25 months) and no adverse events of grade 3 or higher had been reported. |