O-022 A multi-institutional phase 2 study of single agent nivolumab in previously treated metastatic squamous cell carcinoma of the anal canal (SCCA)

Abstract

Introduction:Worldwide, it is estimated that SCCA will develop in > 27,000 patients ( pts). Twenty percent of pts will develop metastatic (met) disease for which there is no standard approach in the refractory setting.We have previously demonstrated that > 90% of metastatic SCCA is associated with HPV carcinogenesis. Nivolumab (Nivo), a monoclonal antibody targeting PD-1 on T cells, promotes immune-mediated anti-tumor activity of T cells against HPV-positive cells in vitro.We proceeded to conduct the first phase II trial of Nivo in previously treated met SCCA pts. Methods: All pts were required to be immunotherapy naïve; > 1 prior metastatic treatment; presence or absence of PD-L1 expression. If HIV +, CD4 count > 300/uL, a Simon two-stage phase II trial (Ho: p