Results from a Phase 2 trial evaluating pembrolizumab (Keytruda) for central nervous system metastases were posted on 2026-06-26. The study reported an intracranial benefit rate of 33.3% for previously untreated brain metastases and 43.8% for progressive brain metastases.
Background
The trial investigated pembrolizumab as a possible treatment for metastases in the central nervous system, specifically focusing on brain metastases.
Trial design
This was a Phase 2 trial (NCT02886585) titled "Pembrolizumab In Central Nervous System Metastases". The study enrolled 101 participants with brain metastases. The research studied pembrolizumab as a possible treatment for metastases in the central nervous system (brain and spinal cord).
Key results
The trial reported key measurements for different cohorts:
- For the Previously Untreated Brain Metastases-Cohort A, the Intracranial Benefit Rate was 33.3%.
- For the Progressive Brain Metastases-Cohort B, the Intracranial Benefit Rate was 43.8%.
- For the Neoplastic Meningitis-Cohort C, Overall Survival at Three Months was a 0.60 proportion of patients.
- For the Neoplastic Meningitis-Cohort C, the Intracranial Response Rate was 0 Participants.
- For the combined Previously Untreated Brain Metastases-Cohort A and Progressive Brain Metastases-Cohort B, the Extracranial Response Rate was 7.5%.
- For the Neoplastic Meningitis-Cohort C, the Extracranial Response Rate was 0%.
What this means
The posted results indicate that pembrolizumab showed varying levels of activity across different central nervous system metastatic conditions. While intracranial benefit rates were observed in patients with previously untreated and progressive brain metastases (33.3% and 43.8% respectively), the intracranial and extracranial response rates for neoplastic meningitis were reported as 0%. The overall survival at three months for neoplastic meningitis was 0.60 proportion of patients.
Source
The trial results were posted on 2026-06-26 on ClinicalTrials.gov, an official database of clinical studies. The full details are available on clinicaltrials.gov under the identifier NCT02886585.