Trial results for the Phase 3 study (NCT03867175) investigating pembrolizumab with or without stereotactic body radiation therapy (SBRT) in patients with Stage IV Non-small Cell Lung Cancer were posted on ClinicalTrials.gov on 2025-06-13. This small trial, which enrolled 5 participants, showed 1 participant in the combination arm achieved progression-free survival and overall survival, compared to 0 in the pembrolizumab-only arm.
Background
Pembrolizumab (Keytruda) is an immunotherapy drug. The trial investigated its use in patients with Stage IV Non-small Cell Lung Cancer, a metastatic form of lung cancer. The study aimed to compare immunotherapy alone versus immunotherapy combined with stereotactic body radiation therapy (SBRT), a type of radiation treatment.
Trial design
The Phase 3 study, NCT03867175, titled "Immunotherapy With or Without SBRT in Patients With Stage IV Non-small Cell Lung Cancer," was a completed trial that enrolled a total of 5 participants. The trial investigated treatment for patients with Metastatic Lung Cancer and Stage IV Lung Cancer. Participants were assigned to one of two arms: Arm 1 received Stereotactic Body Radiation Therapy/Pembrolizumab, and Arm 2 received Pembrolizumab Only. The trial aimed to compare the efficacy of the combination therapy against immunotherapy alone after first-line systemic therapy.
Key results
Results for several outcomes were reported for the 5 enrolled participants:
- For "Number of Participants With Progression-free Survival (PFS) After Completion of First Line Standard of Care Systemic Therapy": 1 participant in the Arm 1 Stereotactic Body Radiation Therapy/Pembrolizumab group achieved PFS, compared to 0 participants in the Arm 2 Pembrolizumab Only group.
- For "Number of Participants With Overall Survival": 1 participant in the Arm 1 Stereotactic Body Radiation Therapy/Pembrolizumab group achieved overall survival, compared to 0 participants in the Arm 2 Pembrolizumab Only group.
- For "Number of Participants With Progression": 1 participant in the Arm 1 Stereotactic Body Radiation Therapy/Pembrolizumab group experienced progression, compared to 0 participants in the Arm 2 Pembrolizumab Only group.
- For "Number of Participants to Have a Rate of Failure": 1 participant in the Arm 1 Stereotactic Body Radiation Therapy/Pembrolizumab group had a rate of failure, compared to 0 participants in the Arm 2 Pembrolizumab Only group.
- For "Number of Participants With New Sites of Disease": 1 participant in the Arm 1 Stereotactic Body Radiation Therapy/Pembrolizumab group developed new sites of disease, compared to 0 participants in the Arm 2 Pembrolizumab Only group.
- For "Number of Participants With Adverse Events": 4 participants in the Arm 1 Stereotactic Body Radiation Therapy/Pembrolizumab group experienced adverse events, compared to 1 participant in the Arm 2 Pembrolizumab Only group.
What this means
The results from this Phase 3 trial, with an enrollment of only 5 participants, provide limited data for drawing definitive conclusions regarding the efficacy and safety of pembrolizumab with or without SBRT in Stage IV Non-small Cell Lung Cancer. While 1 participant in the combination arm showed progression-free and overall survival, compared to 0 in the monotherapy arm, the very small sample size prevents robust statistical interpretation. Additionally, the combination arm reported a higher number of participants with adverse events (4 vs 1), which also requires cautious interpretation due to the limited data.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT03867175, titled "Immunotherapy With or Without SBRT in Patients With Stage IV Non-small Cell Lung Cancer," were posted on 2025-06-13 on clinicaltrials.gov.