Trial results for a Phase 2 study (NCT02562625) investigating pembrolizumab in combination with radiotherapy for melanoma were posted on ClinicalTrials.gov on 2026-04-23. The study was terminated, and results showed mixed findings for progression-free survival (PFS) and overall survival (OS) between the combination and monotherapy arms.
Background
Pembrolizumab (Keytruda) is an immunotherapy drug. The trial aimed to investigate its use, both alone and with radiotherapy, in patients with melanoma. Melanoma is a serious form of skin cancer, with around 13,000 diagnoses in the UK each year. Approximately 20% of patients experience recurrence after initial treatment, and new therapeutic approaches are needed to improve outcomes.
Trial design
The Phase 2 study, NCT02562625, titled "Trial of Pembrolizumab and Radiotherapy in Melanoma," was designed to evaluate the effectiveness and safety of pembrolizumab combined with radiotherapy. The trial enrolled 17 participants with melanoma and was ultimately terminated. It compared outcomes in patients receiving pembrolizumab alone versus those receiving pembrolizumab plus radiotherapy.
Key results
The trial reported several outcome measurements:
- For the objective to evaluate if radiotherapy enhances pembrolizumab efficacy by induction of an abscopal effect, 1 participant was reported in the Pembrolizumab Alone group and 3 participants in the Pembrolizumab Plus Radiotherapy group.
- For evaluating response rates by RECIST v1.1 post treatment, 1 participant was reported in the Pembrolizumab Alone group and 3 participants in the Pembrolizumab Plus Radiotherapy group.
- Regarding Progression Free Survival (PFS), the percentages of participants (with 95% Confidence Intervals) were reported as:
- For Pembrolizumab Alone: 25.0%, 25.0%, and 0%.
- For Pembrolizumab Plus Radiotherapy: 44.4%, 33.3%, and 33.3%.
- For Overall Survival (OS), the percentages of participants (with 95% Confidence Intervals) were reported as:
- For Pembrolizumab Alone: 100.0%.
- For Pembrolizumab Plus Radiotherapy: 77.8%.
What this means
The results from this Phase 2 trial, despite its termination and small enrollment of 17 participants, provide preliminary data on pembrolizumab in melanoma. While the combination of pembrolizumab plus radiotherapy showed higher percentages for Progression Free Survival compared to pembrolizumab alone in several measurements, the pembrolizumab alone arm reported a higher Overall Survival rate. The limited participant numbers and the trial's termination mean these findings should be interpreted with caution and do not allow for definitive conclusions regarding the efficacy of the combination therapy.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT02562625, titled "Trial of Pembrolizumab and Radiotherapy in Melanoma," were posted on 2026-04-23 on clinicaltrials.gov.