- Adding pembrolizumab to chemotherapy with etoposide and platinum (EP) offered significantly better PFS than placebo+EP as firstline treatment for extensive-stage small-cell lung cancer (ES-SCLC).
Why this matters
- The standard treatment for ES-SCLC is chemotherapy with EP, even though response rates with the therapy are not durable and median OS is approximately 10 months.
- International, randomized, double-blind, placebo-controlled, phase 3 KEYNOTE-604 study.
- 453 patients with untreated ES-SCLC received pembrolizumab with EP (n=228) or placebo+EP (n=225).
- Funding: Merck & Co., Inc., Kenilworth, NJ, USA.
- Median PFS:
- 4.5 months with pembrolizumab+EP vs
- 4.3 months with placebo+EP.
- 12-month PFS estimates:
- 13.6% with pembrolizumab+EP vs
- 3.1% with placebo+EP.
- PFS was significantly better with pembrolizumab+EP (HR, 0.75; P=.0023).
- Median OS was not significantly different between groups (HR, 0.80; P=.0164).
- Objective response rate:
- 70.6% (95% CI, 64.2%-76.4%) with pembrolizumab+EP vs
- 61.8% (95% CI, 55.1-68.2) with placebo+EP.
- Median duration of response:
- 4.2 months with pembrolizumab vs
- 3.7 months with placebo.
- At 1 year, the estimated proportion of ongoing responses was 19.3% with pembrolizumab vs 3.3% with placebo.
- Rate of adverse events was similar between groups.
- Highly selected clinical trial population.
- Results presented at a conference without peer review.