Esophageal chemoradiotherapy with concurrent nivolumab: Pilot results in the palliative treatment of oligometastatic disease.

Aims: Many patients diagnosed with esophageal cancer have dysphagia from their primary tumor and de novo metastatic disease. The purpose of this study was to test the safety and efficacy of nivolumab given concurrently with hypofractionated chemoradiotherapy to patients with oligometastatic and obstructing esophageal tumors.

Methods: Patients were enrolled in a planned single-arm, phase 2 clinical trial. Eligible participants had previously untreated oligometastatic (≤5 metastases on fludeoxyglucose-18 positron emission tomography scan outside the primary tumor radiotherapy field) esophageal or gastroesophageal carcinoma, dysphagia, and Eastern Cooperative Oncology Group performance status 0-1. Treatment was with 2 weeks of concurrent hypofractionated radiotherapy (30 Gy/10#) to the primary tumor, weekly carboplatin AUC2, weekly paclitaxel 50 mg/m, and q2weekly nivolumab 240 mg, followed by nivolumab 480 mg continuing q4weekly until disease progression or 24 months total. A single metastasis was treated with stereotactic radiotherapy (SBRT) (24 Gy/3#) in week 7.

Results: Five patients were recruited before trial closure to new participants for logistical reasons. Existing participants continued treatment per protocol as a pilot study at one center. All five patients completed chemoradioimmunotherapy and SBRT. All patients derived an improvement in their dysphagia. Two patients completed 24 months of nivolumab without disease progression. Grade 3 adverse events (AEs) occurred in 3 patients, however, there were no grade 4 AEs, AEs due to SBRT, or AEs of special interest as defined by the protocol.

Conclusion: Pilot results from five patients at one center found that treatment was well tolerated and effective for dysphagia relief. The efficacy of hypofractionated chemoradiotherapy with concurrent checkpoint inhibition should be tested in a multicentre study.