Trial results for the Phase 1 study (NCT02642809) investigating pembrolizumab with locally delivered radiation therapy for metastatic esophageal cancers were posted on ClinicalTrials.gov on 2026-03-18. The study reported 1 participant with Grade 3 or higher treatment-related adverse events and a mean percent change in esophageal tumor length of -4.0%.
Background
Pembrolizumab (Keytruda) is an immunotherapy drug. This study investigated its use in combination with locally delivered radiation therapy for the treatment of metastatic esophageal cancers.
Trial design
The study (NCT02642809) was a Phase 1 trial that enrolled 16 participants with metastatic esophageal cancers. The intervention involved treating patients with two fractions of brachytherapy followed by pembrolizumab. The trial aimed to examine the hypothesis that radiotherapy could induce an immune response augmented by pembrolizumab treatment.
Key results
The trial evaluated safety and changes in tumor length in participants receiving pembrolizumab and brachytherapy.
- For "Safety as Measured by Number of Participants With Grade 3 or Higher Treatment Related Adverse Events," 1 participant was reported in the Pembrolizumab and Brachytherapy group.
- For "Mean Percent Change in Esophageal Tumor Length as Measured by Endoscopy," the mean change was -4.0 percent change in the Pembrolizumab and Brachytherapy group.
What this means
The results from this Phase 1 study provide initial safety data for the combination of pembrolizumab with locally delivered radiation therapy in patients with metastatic esophageal cancers. The observation of 1 participant experiencing Grade 3 or higher treatment-related adverse events suggests a manageable safety profile in this small cohort. Additionally, the mean percent change in esophageal tumor length of -4.0% indicates a potential signal of activity, which could warrant further investigation in larger clinical trials. These findings support the rationale for exploring this combination therapy further.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT02642809, titled "Pembrolizumab With Locally Delivered Radiation Therapy for the Treatment of Metastatic Esophageal Cancers," were posted on 2026-03-18 on clinicaltrials.gov.