Trial results for a Phase 2 study investigating pembrolizumab in combination with rituximab for Marginal Zone Lymphoma were posted on ClinicalTrials.gov on 2026-02-27. The single-arm study reported a median Time to Treatment Failure (TTF) of 18.5 months.
Background
Marginal Zone Lymphoma (MZL) patients, often of advanced age, frequently face challenges with chemotherapy-associated toxicity. While rituximab in combination with conventional chemotherapy is widely used for those who fail local therapy or do not qualify, it does not always prevent relapse, and toxicity remains a concern. This highlights the attractiveness of chemotherapy-free approaches for this patient group, although rituximab as a single agent has its own limitations.
Trial design
This Phase 2, single-arm, open-label, multicenter study (NCT04268277) was terminated and enrolled 22 participants with Marginal Zone Lymphoma. The intervention involved treatment with rituximab and pembrolizumab.
Key results
Key measurements from the trial included:
- The Complete Response (CR) Rate was observed in 3 Participants.
- For Response Rate, participant counts were 3, 10, 7, and 2 Participants.
- For Best Response, participant counts were 3, 11, and 8 Participants.
- The median Time to Best Response was 7.6 months (Full Range).
- The median Time to First Response was 6.9 months (Full Range).
- The Progression Free Survival (PFS) was a 0.941 probability (95% Confidence Interval).
- The median Time to Treatment Failure (TTF) was 18.5 months (95% Confidence Interval).
A key analysis using a one-sided one sample exact binomial test for the CRR value of 14.0 (with a 97.5% Confidence Interval lower bound of 3.0) yielded a p-value of 1.
What this means
The posted results provide data on the combination of pembrolizumab and rituximab in patients with Marginal Zone Lymphoma. While specific response counts and time-to-event metrics like a median Time to Treatment Failure of 18.5 months were reported, the statistical analysis for the Complete Response Rate showed a p-value of 1, indicating no statistical significance for the observed CRR. The trial's terminated status also suggests that further investigation under this specific design was halted.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT04268277, titled "Pembrolizumab in MarginalzoneLymphoma A MULTICENTER OPEN LABEL SINGLE-ARM PHASE II STUDY," were posted on 2026-02-27 on clinicaltrials.gov.