On 18 March 2019, the FDA approved atezolizumab (Tecentriq®, Genentech) plus carboplatin and etoposide as front-line treatment of adult extensive-stage small cell lung cancer (ES-SCLC) patients.¹FDA website

IMpower133

The multicenter, double-blind, placebo-controlled IMpower133 (NCT02763579) trial randomised 403 ES-SCLC patients 1:1 to either receive four cycles of atezolizumab plus carboplatin and etoposide followed by maintenance atezolizumab or four cycles of placebo plus carboplatin and etoposide, followed by maintenance placebo. Eligible participants did not receive prior chemotherapy for extensive stage disease and had an ECOG performance status 0 or 1. The treatment was continued until disease progression or unacceptable toxicity. The efficacy outcome measures included the overall survival (OS) and the progression-free survival (PFS) by RECIST 1.1 in the intent-to-treat population as assessed by the investigator.

The median OS  for patients in the atezolizumab plus chemotherapy group was 12.3 months (10.8, 15.9) vs 10.3 months (9.3, 11.3) for those treated in the placebo plus chemotherapy group (HR=0.70; 95% CI, 0.54-0.91; P=0.0069). The median PFS measured 5.2 months (4.4-5.6) with atezolizumab plus chemotherapy vs 4.3 months (4.2-4.5) for placebo plus chemotherapy (HR=0.77; 95% CI, 0.62-0.96; P=0.0170).

Safety

Common adverse reactions in ≥ 20% of atezolizumab-treated patients in the IMpower133 included fatigue/asthenia, nausea, alopecia, constipation, and decreased appetite.

Full prescribing information Tecentriq®.