Single-center phase 1 trial of cemiplimab for advanced cutaneous squamous cell carcinoma in kidney transplant recipients

Cemiplimab (anti-PD-1) is approved for treating locally advanced or metastatic cutaneous squamous cell carcinoma. Solid organ transplant recipients have been excluded from immunotherapy trial, given concern for allograft rejection. Chronic immunosuppression is necessary to prevent organ rejection but may attenuate antitumor response with PD-1 inhibitors. A phase 1 trial at Dana-Farber Cancer Institute (Boston, MA) evaluated cross-taper to mTOR inhibitor with pulsed dose prednisone to prevent kidney allograft rejection in recipients receiving cemiplimab for aCSCC. Among twelve included patients, no kidney rejection or loss was observed (primary end point). A response to cemiplimab was observed in five of eleven evaluable patients (46%; 90% CI 22-73), including two with durable responses beyond a year. Treatment-related grade 3 or greater adverse events occurred in five of twelve patients (42%); one patient died of angioedema and anaphylaxis attributed to mTOR-inhibitor cross-taper. The authors conclude that use of an mTOR inhibitor plus pulsed dose prednisone may be a novel method to prevent kidney allograft rejection in transplant recipients receiving immunotherapy for advanced cutaneous squamous cell carcinoma.