Background

The addition of Pembrolizumab to platinum doublet regimes resulted in significant improvements to progression-free survival (PFS) and overall survival (OS) in the Keynote-189 and -407 studies; hence the approval for first-line treatment of advanced non-small cell lung cancer (NSCLC). This audit assessed patient outcomes at two non-tertiary UK cancer centres.

Method

Retrospective analysis of all 43 patients with advanced NSCLC, without a targetable driver mutation, who received first-line palliative chemoimmunotherapy since December 2018, at two cancer centres in Essex and Suffolk. Primary outcomes were PFS and OS. All patients received pembrolizumab plus platinum doublet chemotherapy (carboplatin and pemetrexed or carboplatin and paclitaxel, for nonsquamous or squamous cell carcinoma (SCC), respectively).

Results

The median age was 66 years (range 48-78 years). Median follow-up 5.8 months. 35 (81%) patients had adenocarcinoma, 7 (16%) SCC and 1 (2%) patient had mixed adenosquamous cell carcinoma. 16 (37%) patients had stage IV-A and 23 (53%) stage IV-B disease. PD-L1 expression: 23 (53%) patients <1%, 5 (12%) patients 1-49% , and 12 (28%) patients >50%, 3 (7%) patients unknown expression. Performance status: 19 (44%) patients 0, 23 (53%) patients 1, and 1 (2%) patient 2. 26 (60%) patients, at the time of data analysis, had completed 4 cycles of introduction chemoimmunotherapy. Median PFS was 7.62 months (95% CI 7.57-7.87 months). Estimated OS at 12 months was 75.9%. Median PFS for nonsquamous carcinoma was 7.50 months (95% CI 7.32-7.68 months). Median PFS for SCC was not reached. Median OS for both nonsquamous and SCC was not reached. No apparent differences in PFS or OS based on PD-L1 expression, but statistical analysis not possible due to small numbers. 23% patients experienced grade 3 toxicity or higher. There was no treatment-related mortality.

Conclusion

Benefits observed in the phase 3 landmark studies, Keynote-189 and -407, continue to manifest in a non-trial setting for patients receiving first-line palliative chemoimmunotherapy for advanced NSCLC with comparable survival data, but nearly a quarter of patients experienced grade 3 toxicities or higher.

Impact statement

First-line palliative chemoimmunotherapy for advanced NSCLC is an effective treatment and real-world data suggests comparable outcomes with better than expected toxicity profiles.