Real-world evidence of first-line pembrolizumab plus chemotherapy in metastatic non-squamous NSCLC: A single-centre experience.

Abstract

e21091 Background: Pembrolizumab plus chemotherapy is now the standard of care in previously untreated patients with metastatic non-squamous NSCLC post the results of KEYNOTE 189 trial. This study is to evaluate the real world outcomes and toxicity data in similar subset of patients treated with this protocol in a non-trial setting. Methods: We analysed 38 patients who were treated with Pembrolizumab plus Platinum-Pemetrexed from June 2019 to October 2021. We stratified the patients based on age, performance status, smoking habits, PDL1 results, presence of brain metastases. Our primary endpoint was to collect survival outcome (OS and PFS) and toxicity profile. Baseline patient and disease characteristics were compared using the chi-square test. PFS and OS were calculated by Kaplan-Meier method. Data was analyzed using R version 4.1.1. Results: At a median follow-up of 15.6 (10.35 – 27.33) months, the median PFS was 11.1 months (95% CI 8.31-18.4) and median OS was 15.6 months (95% CI 11-27.3). Median OS at 12 months was 60.3 %(95% CI41.9 – 74.5).63% patients had completed all 4 induction cycles and the median of 7 (1-19) maintenance cycles were given. 63% patients had an objective response to induction chemo (56% PR,7% SD).The main toxicity profiles were fatigue (35%), renal impairment (13%), hepatitis (28%), myelosuppression (13%), rash (18.9%), thyroid problems (24%).Grade 3 diarrhea was seen in 8% and pneumonitis in 2.7%.12 patients stopped treatment due to toxicity. Conclusions: In comparison with the seminal Keynote 189 trial, our median PFS was better (11.1 months vs 9 months), however our 12-month OS rates were worse (60.3 vs 69.2%), however this needs a longer follow-up in relation to maintenance treatment to accurately assess this outcome. In general the tolerance has been at par with the reported trials as is evident from the results.[Table: see text]