A Single Centre Study to Assess Outcomes and Toxicity Profiles in Patients with Non-Small Cell Lung Cancer Receiving Pembrolizumab Therapy


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Wing Kin Liu1,Stephen Robinson1,David Chao2
1North Middlesex Hospital,2Royal Free Hospital

Abstract

Background

Pembrolizumab has been associated with improved survival and better toxicity profile compared to chemotherapy  in advanced non-small cell lung cancer (NSCLC). However, these findings are based on a highly selected population in clinical trials. We provide data from a busy District General Hospital for comparison.

Method

All patients treated with pembrolizumab for NSCLC up to 01/12/2017 were identified from Chemocare. Basic patient demographics, tumour characteristics, treatments and survival data were collected retrospectively from case-notes and laboratory records. Descriptive statistical analysis and Kaplan-Meier analysis were performed using SPSS.

Results

22 patients received pembrolizumab (median age, 67; 73% male). All were performance status 0-1. First line (1L) pembrolizumab was used in 59%. 27% had pre-treatment neuroimaging.

The clinical benefit rate was 62% in 1L and 33% in second line (2L). Median 6.5 cycles (range 1-17) and 10 patients remained on pembrolizumab, including all 1L patients with stable disease or better at time of response assessment.

Median PFS was 15.7 months (95% CI not available) for 1L, compared to 8.2 months (95% CI 1.0 to 15.4 months) with 2L (p=0.024). 1-year PFS was 67% for 1L and 17% for 2L. Median OS was not reached, 1-year OS was 77% for 1L and 64% for 2L (p=0.673). 9% progressed intra-cranially, none of whom had pre-treatment neuroimaging.

Toxicity was experienced by 27% (4.5% grade 3+), with more toxicity (31%) in 1L compared to 2L (22%).

Conclusion

Our cohort’s outcomes are comparable to the clinical trials KEYNOTE-010 and -024, suggesting pembrolizumab is safe and effective in a less selected population. Neuroimaging pre-immunotherapy requires standardisation, although currently there is a lack of trial data on the benefit of immunotherapy for brain metastases in lung cancer. Moving forwards, improving the therapeutic ratio through prediction of responders is key, with tumour mutational burden as a potential biomarker.