P2.04-21 Real World Experience of Immune Checkpoint Inhibitors In NSCLC: Our First 10 Months Experience at Leeds Cancer Centre, UK

Abstract

Pembrolizumab and Nivolumab are monoclonal antibodies to the PD-1 receptor and have shown significant overall survival(OS) and progression free survival(PFS) in the second line setting compared to chemotherapy in non-small cell lung cancer(NSCLC). Pembrolizumab has shown significant OS and PFS in the first line setting in high PD-1 expressors(>50%). In January 2017, immune checkpoint inhibitors became standard of care in the UK initially in the second line setting and subsequently first line later that year. Studies report fewer treatment-related adverse events in the checkpoint inhibitor arm Vs chemotherapy (10-20% Vs 54%). We report our first 10 months experience with routine use of checkpoint inhibitors in NSCLC at Leeds Cancer Centre(LCC), UK. All patients receiving pembrolizumab and nivolumb between 1/1/17 and 31/10/17 at LCC, UK were included. Retrospective review of medical notes was performed and outcomes recorded including: checkpoint inhibitor received; time to response; OS and treatment-related adverse effects. Kaplan-Meier survival curves were used to assess survival outcomes. Thirty-six patients received checkpoint inhibitors during this period. Median age was 68 years. Eleven patients received first line therapy with a response rate of 90% (n=10). Twenty-five patients received second line therapy with a response rate of 32% (n=8). For the whole cohort, median time to response was 52days. Median time to progression in responding patients was not reached. Median PFS was 152days (95%CI 57-232). Median OS was 467days (95% CI 194-not reached). Pseudoprogression occurred in one patient. Treatment-related adverse effects occurred in 58% (n=21). Of these, 57% (n=12) were non-autoimmune and 43% (n=9) were autoimmune. Grade 3-5 toxicities occurred in 8% (n=3), all were autoimmune mediated on pembrolizumab. In all cases, treatment was stopped. Thirty-one percent (n=11) remain on check-point inhibitors. Overall response rate to immune checkpoint inhibitors in this small cohort was better than reported data in both the first and second line setting (90% Vs 45% and 32% Vs 19% respectively). Time to response was comparable to previous trials (1.7months Vs 2.1months). Median PFS and OS were in keeping with large randomised controlled trials (PFS - 5months Vs 2.3-10.3months and OS - 15months Vs 12.2months). Frequency of treatment-related adverse effects and grade 3-5 effects were lower in this cohort at 58% and 8% respectively, compared to 69-73.4% and 10-26.6% in trials. In conclusion, our initial results in this real world cohort show immune checkpoint inhibitors are a safe, effective treatment in this group of patients.