Pembrolizumab trial in refractory melanoma reports no responses

ClinicalTrials.gov posted results on 16 September 2026 for a terminated Phase 2 trial of pembrolizumab plus rigosertib in patients with unresectable or metastatic melanoma refractory to PD-1 inhibitors. The study enrolled 7 participants; the posted data recorded 0 participants with an overall response and a median progression-free survival of 1.88 months.

Background

The trial evaluated the combination of rigosertib and pembrolizumab in patients with clinical stage III or IV cutaneous melanoma, metastatic melanoma, refractory melanoma, or unresectable melanoma. Participants had disease that had not responded to previous treatment with PD-1 or PD-L1 inhibitors. The supplied record describes pembrolizumab as an immunotherapy with monoclonal antibodies and states that rigosertib was being tested with pembrolizumab in this setting. It does not provide information about prior approvals, prevalence, or a separate pembrolizumab treatment history.

Trial design

This Phase 2 study, identified as NCT05764395, enrolled 7 participants and had an overall status of terminated. The listed interventions were rigosertib and pembrolizumab. The record lists no primary-outcome entries and does not identify a comparator arm. Posted measurements included overall response rate, median progression-free survival, progression-free survival at one year, and treatment-related adverse-event incidence.

Key results

The treatment group recorded 0 participants with an overall response. Median progression-free survival was 1.88 months, with no confidence-interval value supplied. Progression-free survival at one year was reported as 14% of participants, also without a confidence-interval value.

The posted treatment-related adverse-event measurements listed counts of 1 participant, 1 participant, 0 participants, 0 participants, 0 participants, 5 participants, 0 participants, 1 participant, and 0 participants. The supplied record does not identify the adverse-event categories associated with these counts or provide a separate adverse-event summary.

What this means

In this terminated, seven-participant Phase 2 study, the posted data showed no recorded overall responses, a median progression-free survival of 1.88 months, and 14% progression-free survival at one year. Because the record lists no primary outcomes, no comparator arm, and no confidence intervals, these results do not establish comparative efficacy. The adverse-event counts cannot be interpreted by event type from the supplied data.

Source

Source: ClinicalTrials.gov, registry results for the terminated Phase 2 study “Rigosertib Plus Pembrolizumab in Treating Patients With Unresectable/Metastatic Melanoma Refractory to PD-1 Inhibitors,” posted 16 September 2026. Available at clinicaltrials.gov/study/NCT05764395.