Of note, despite some safety concerns of lenalidomide in combination with PD-1/PD-L1 inhibitors in two phase III trials in patients with multiple myeloma, which reported excessive and unpredictable toxicity necessitating trial discontinuation, and an increased death rate, following treatment with an anti-PD-1 mAb and immunomodulatory agent (KEYNOTE-185: pembrolizumab/lenalidomide/dexamethasone; KEYNOTE-183: pembrolizumab/pomalidomide/dexamethasone) [ 36, 38 ], the addition of atezolizumab to G-len did not lead to an unacceptable increase in the incidence of immune-based toxicities in R/R FL patients in our study.