474P Pharmacokinetic (PK) and updated survival data from the Canadian cancer trials group IND.226 study of durvalumab ± tremelimumab in combination with platinum-doublet chemotherapy

Background In this phase Ib multicenter study, we sought to characterize the PK, safety and tolerability of durvalumab (D), an anti-PD-L1 antibody, ± tremelimumab (T), an anti-CTLA-4 antibody, in combination with one of four standard platinum-doublet chemotherapy regimens. We will present the PK, and update overall survival data. Methods Regardless of tumour PD-L1 status, patients were enrolled into one of four cohorts: pemetrexed, gemcitabine, etoposide (each with cisplatin or carboplatin) or nab-paclitaxel (with carboplatin), each of which were evaluated in one of six dose levels [Table]. Dose escalation followed a Rolling Six type design. Concurrent enrollment of cohorts was allowed. Limited PK was collected ≤1hour pre-dose and ≤10minutes post-dose on day 1 of cycles 1-3 as well as week 6 or 8 post chemotherapy. Results One hundred and thirty-six patients (median age=62 (range 30-83); males:females=67:69; ECOG PS 0/1=32%/68%). The majority of patients had non-small cell (53.7%) or small cell (13.2%) lung cancer. Immune-related adverse events (irAEs) that were considered related to D or T were mainly