Safety and efficacy of checkpoint inhibitors in solid organ transplant recipients with cutaneous squamous cell carcinoma.

e22014 Background: Immune checkpoint inhibitors (ICI) are increasingly used in solid organ malignancies. However, data are limited regarding their safety and efficacy in solid organ transplant (SOT) recipients at risk for allograft rejection. The aim of this study was to review our experience with ICIs in SOT recipients at a large transplant center. Methods: A retrospective review of ICIs used in SOT recipients from April 2011 to September 2019 was undertaken. Patient clinical and demographic features, ICI regimen, immunosuppression, allograft function, and efficacy were reviewed. Results: There were 8 SOT recipients (3 kidney, 4 liver, 1 lung) with 7 diagnosed with metastatic head and neck (H&N) cutaneous squamous cell carcinoma (cSCC) and 1 with Merkel cell carcinoma. At a median of 150 months [79-219] post-transplant, 6 were treated with cemiplimab and 2 with pembrolizumab after minimizing calcineurin inhibitors (CNI). Overall tumor response was 37.5% at a median of 3.8 months [0-8] of follow-up. However, 3 died of tumor progression and 2 of other causes at a median of 55 days [8-214] after starting ICI. The only irAE reported was severe pneumonitis in one patient requiring intubation and ICI discontinuation but responded to steroids. Two patients received prophylactic steroids and have preserved allograft function and ongoing tumor response at month 6. Conclusions: Our data suggest that minimization of CNI along with judicious use of prophylactic steroids may allow for the safe use of ICIs in SOT recipients with advanced H&N cSCC. Short-term efficacy appears promising and prospective studies are warranted. [Table: see text]