8507 Background: BMS-936558 is a fully human mAb that blocks the programmed death-1 (PD-1) co-inhibitory receptor expressed by activated T cells. This study describes the activity and safety of BMS-936558 in patients (pts) with previously treated advanced MEL and underscores the importance of the PD-1/PD-L1 pathway in MEL therapy. Methods: BMS-936558 was administered IV Q2WK to pts with various solid tumors at doses of 0.1 to 10 mg/kg during dose-escalation and/or cohort expansion. Pts received up to 12 cycles (4 doses/cycle) of treatment or until PD or CR. Clinical activity was assessed by RECIST 1.0. Results: Of 240 pts treated as of July 1, 2011, 95 MEL pts were treated with BMS-936558 at 0.1 (n=13), 0.3 (n=17), 1 (n=28), 3 (n=17), or 10 mg/kg (n=20). ECOG performance status was 0/1/2 in 56/36/3 pts. The majority of pts (60/95) had received prior immunotherapy (IT), primarily interferon-alpha or IL-2 (prior anti-CTLA-4 excluded). Prior B-raf inhibitor therapy was noted in 7/95 pts. The number of prior therapies was 1 (n=35), 2 (n=34), or ≥3 (n=26). Sites of metastatic disease included lymph node (n=60), liver (n=32), lung (n=55), and bone (n=10). Median duration of therapy was 15 wk (max 120 wk), with 40 pts still receiving treatment. The incidence of grade 3-4 related AEs was 19% and included gastrointestinal (4%), endocrine (2%), and hepatobiliary disorders (1%). There were no drug-related deaths in MEL pts. Clinical activity was observed at all dose levels (Table). Of 20 pts with OR at the time of data lock, 12 had OR duration ≥1 yr and 6 pts were on study with OR duration between 1.9 and 11.3 mo. OR were seen in pts with visceral or bone metastases. Several pts had prolonged SD. Some had a persistent decrease in overall tumor burden in the presence of new lesions and were not categorized as responders. Conclusions: BMS-936558 had durable clinical benefit in pts with advanced MEL, including those who had received prior IT. Further development of BMS-936558 in MEL is ongoing. [Table: see text]
Clinical Activity and Safety of the Anti–Programmed Death 1 Monoclonal Antibody Dostarlimab for Patients With Recurrent or Advanced Mismatch Repair–Deficient Endometrial Cancer
