A Study of mDCF in Combination or Not With Atezolizumab in Advanced Squamous Cell Anal Carcinoma

SCARCE is a non-comparative randomized, 2:1 phase II study. The purpose of this study is to assess the progression-free survival rate at 12 months. (evaluation according with RECISTv1.1 criteria). For all patients, CT scan will be planned at baseline, and every 8 weeks until 12 months from randomization (or disease progression), and every 12 weeks thereafter. PET scan will be performed at baseline, at the end of mDCF treatment, and at 12 months after randomization (in absence of disease progression). CT scan and PET scan will be collected for a centralized review.