Trial results for the combination of pembrolizumab and blinatumomab in adult patients with relapsed or refractory B-cell acute lymphoblastic leukemia (B-ALL) were posted on ClinicalTrials.gov on 2025-11-10. The study demonstrated that the combination therapy achieved a Complete Response Rate (CR) in 6 participants, compared to 0 participants receiving blinatumomab alone.
Background
The study investigated the combination of blinatumomab with pembrolizumab for adult patients diagnosed with relapsed or refractory B-lineage acute lymphoblastic leukemia (B-ALL). The primary objective was to assess if adding pembrolizumab to blinatumomab could improve the Complete Response Rate (CR) and Complete Remission with Partial Hematologic Recovery (CRh) in patients with high bone marrow lymphoblast percentage (>50% lymphoblasts) compared to blinatumomab alone.
Trial design
The study (NCT03160079) was a Phase 1/Phase 2 investigation that enrolled 16 adult participants with relapsed or refractory B-cell acute lymphoblastic leukemia. The trial evaluated the efficacy of blinatumomab in combination with pembrolizumab. The study aimed to determine if the addition of pembrolizumab to blinatumomab improved the Complete Response Rate (CR) and Complete Remission with Partial Hematologic Recovery (CRh) compared to blinatumomab alone in patients with high bone marrow lymphoblast percentage (>50% lymphoblasts).
Key results
The trial results included measurements for Complete Response Rate (CR) and Best Overall Response Rate (ORR).
- For the Complete Response Rate (CR):
- 6 participants in the Blinatumomab + Pembrolizumab group achieved a Complete Response Rate.
- 0 participants in the Blinatumomab Only group achieved a Complete Response Rate.
- For the Best Overall Response Rate (ORR):
- In the Blinatumomab + Pembrolizumab group, participant counts for Best Overall Response Rate (ORR) were reported as 6, 1, 1, 4, and 0 participants.
- In the Blinatumomab Only group, participant counts for Best Overall Response Rate (ORR) were reported as 0, 0, 0, 1, and 3 participants.
What this means
The results from this Phase 1/Phase 2 study suggest that the combination of pembrolizumab with blinatumomab may improve response rates in adult patients with relapsed or refractory B-cell acute lymphoblastic leukemia. Specifically, the observation of 6 participants achieving a Complete Response Rate (CR) in the combination arm compared to 0 participants in the blinatumomab alone arm indicates a potential benefit of adding pembrolizumab. These findings provide preliminary data for clinicians considering treatment strategies for this challenging patient population.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT03160079, titled "Blinatumomab & Pembrolizumab for Adults With Relapsed/Refractory B-cell ALL With High Marrow Lymphoblasts," were posted on 2025-11-10 on clinicaltrials.gov.