PO-412 Effectiveness and safety of anti-PD1 (Nivolumab) as second line treatment of advanced non-small cell lung cancer (NSCLC) elderly and heavy smokers patients (PTS) with unknown PD-1 status

Introduction PD1 (Programmed cell death) is a receptor expressed on activated T cells, produces down regulation of T cell when interacts with ligands PDL1-PDL2 of the tumour cells. Anti-PD1 therapy (Nivolumab) has shown tumoral activity in the treatment of advanced NSCLC pts. Nivolumab is a fully human IgG4 PD-1 immune-checkpoint–inhibitor antibody, interrupts PD-1–mediated signalling and may restore antitumor immunity. PDL-1 expression in the tumour tissue shows a predictive association between PDL-1 expression level and clinical benefit from anti-PD1 treatment. However, clinical benefit is seen regardless of the PDL-1 status. Material and methods Eighteen pts with metastatic NSCLC were treated at our institution with Nivolumab monotherapy as second line after platinum progression. Non-squamous and squamous cell carcinoma were fourteen and four respectively. Nivolumab at dose of 240 mg intravenous infusion was given every 2 weeks (w) until progression or unacceptable toxicity. Tumour response was assessed with the use of the Response Evaluation Criteria in Solid Tumours, version 1.1. Clinical adverse events were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0. Results and discussions Median age was 75 years old and median ECOG performance status (PS) was 1 (0–2). Fourteen pts were male. Pts had previously progressed to a first line of chemotherapy based on platinum. Sixteen patients were heavy smokers or former smokers with a median of 40-pack year. PDL1- status was negative in one and unknown in the rests of the pts. No activating mutations were detected in eight and 10 pts were unknown. A radiological response was achieved in 66% (twelve pts.), complete 11% (two pts.), partial response 33% (six pts.), stable disease 22% (four pts.) and progression disease was observed in 33% (six pts). After a median follow-up of 12 months, 3–20 median time to progression (TTP) and OS were 50% and 84% respectively. Grade (G) 1–2 asthenia was the most frequent toxicity (20%). Other observed G2 toxicities were hypertransaminasemia and diarrhoea in two pts. No grade 3–4 toxicity was observed. Conclusion In our small cohort of patients Nivolumab was very active in elderly and heavy smokers patients with metastatic NSCLC with unknown PDL-1 status.