Atezolizumab as first-line therapy improved the overall survival (OS) of platinum-ineligible patients with non-small cell lung cancer (NSCLC), and twice as many patients were estimated to be alive at 2 years, compared to chemotherapy.

This data from a phase 3 trial was presented on Monday, September 12, 2022, at the European Society for Medical Oncology Congress in Paris, France, by first author, Siow Ming Lee, MD, department of oncology, University College London Hospitals NHS Foundation Trust, UCL Cancer Institute and CRUK Lung Cancer Centre of Excellence, London, Great Britain.

The global, multi-center, open-label, phase 3 trial enrolled 453 patients with locally advanced or metastatic NSCLC without driver mutations, who were ineligible for first-line platinum-doublet chemotherapy. Patients were randomized on a 2:1 basis to receive either 1200 mg atezolizumab intravenously every 3 weeks (n = 302) or single-agent chemotherapy (vinorelbine or gemcitabine) in 3- or 4-week cycles (n = 151). The primary end point was OS, with OS rates, progression-free survival (PFS), objective response rate (ORR), duration of response (DOR), and safety among the secondary end points.

At the data cutoff date of April 30, 2022, the median follow-up duration was 41 months. Atezolizumab significantly improved OS when compared to chemotherapy (stratified hazard ratio [sHR]: 0.78; 95% confidence interval [CI], 0.63 to 0.97; P =.028). This benefit was consistent across the key subgroups, including PD-L1 expression level, performance status, and histology. There was also improvement seen in the 2-year OS rate (24.3% [95% CI, 19.3 to 29.4] in the atezolizumab arm vs 12.4% [95% CI, 6.7 to 18.0] in the chemotherapy arm), ORR (16.9% [95% CI, 12.8 to 21.6] vs 7.9% [95% CI, 4.2 to 13.5], and median DOR (14.0 months [95%CI, 8.1 to 20.3] vs 7.8 months [95% CI, 4.8 to 9.7].)

In the atezolizumab arm, 16.3% of patients experienced a grade 3/4 treatment-related adverse event and 1% experienced a grade 5 treatment-related adverse event. In the chemotherapy arm, 33.3% of patients experienced a grade 3/4 treatment-related adverse event, and 2.7% experienced a grade 5 treatment-related adverse event.

Additionally, atezolizumab improved the time to confirmed deterioration of chest pain, appetite loss, and cough, compared to chemotherapy.

Source:

Lee SM, Schulz C, Prabhash K. “IPSOS: Results from a phase III study of first-line (1L) atezolizumab (atezo) vs single-agent chemotherapy (chemo) in patients (pts) with NSCLC not eligible for a platinum-containing regimen.” Presented at European Society for Medical Oncology Congress; September 9-13, 2022. Paris, France.