Trial results for a Phase 1/2 study evaluating pembrolizumab in combination with radiation therapy for non-small cell lung cancer (NSCLC) were posted on ClinicalTrials.gov on 2026-05-15. One cohort receiving pembrolizumab with stereotactic body radiation therapy or wide-field radiation therapy plus low dose XRT achieved an overall response rate of 100%.
Background
The study investigated pembrolizumab in treating patients with non-small cell lung cancer, specifically those with metastatic lung non-small cell carcinoma and Stage IV Lung Non-Small Cell Cancer AJCC v7.
Trial design
The Phase 1/2 study (NCT02444741) enrolled 124 participants with non-small cell lung cancer, including those with malignant solid neoplasm, metastatic lung non-small cell carcinoma, and Stage IV Lung Non-Small Cell Cancer AJCC v7. The trial investigated pembrolizumab in various combinations with stereotactic body radiation therapy (SBRT) or non-stereotactic wide-field radiation therapy (WFRT), including concurrent and sequential approaches, as well as pembrolizumab alone.
Key results
The trial reported the following overall response rates (ORR) across different treatment groups:
- For Phase II, Group 1: SBRT + Pembrolizumab, the ORR was 38%.
- For Phase II, Group 2: Pembrolizumab Alone (if PD Then SBRT + Pembrolizumab), the ORR was 33%.
- For Phase II, Group 3: WFRT + Pembrolizumab (+/- Salvage Traditional RT), the ORR was 10%.
- For Phase II, Group 4: Pembrolizumab Alone (if PD Then WFRT + Pembrolizumab), the ORR was 17%.
- For Phase II, Group V: SBRT or WFRT + Pembrolizumab + Low Dose XRT, the ORR was 100%.
Median progression-free survival (PFS) was also reported:
- In the Phase I Pembrolizumab + RT Arm, median PFS was 7.7 months.
- For Phase 1, Group 2: WFRT + Pembrolizumab SBRT Arm, median PFS was 6.1 months.
- In the Phase II: Pembrolizumab + Concurrent SBRT Arm, median PFS was 9.1 months.
- For the Phase II: Pembrolizumab Arm (+/- Salvage SBRT), median PFS was 5.1 months.
- In the Phase II: Pembrolizumab Arm + Concurrent Traditional RT(+/- Salvage Traditional RT), median PFS was 9.1 months.
- For the Phase II: Pembrolizumab Arm (+/- Salvage Traditional RT), median PFS was 5.1 months.
- In Phase II, Group V: SBRT or WFRT + Pembrolizumab + Low Dose XRT, median PFS was 12.2 months.
What this means
The results suggest that combining pembrolizumab with radiation therapy, particularly with low-dose XRT, may lead to high response rates and extended progression-free survival in patients with non-small cell lung cancer. The 100% ORR and 12.2 months median PFS observed in Phase II, Group V highlight a potentially effective combination strategy. Other combinations also showed varying degrees of response and PFS, indicating that the specific radiation therapy approach and timing with pembrolizumab could influence outcomes. These findings warrant further investigation into optimized combination regimens for this patient population.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for the study NCT02444741, titled "Pembrolizumab and Stereotactic Body Radiation Therapy or Non-Stereotactic Wide-Field Radiation Therapy in Treating Patients With Non-small Cell Lung Cancer", were posted on 2026-05-15 on clinicaltrials.gov.