First-line atezolizumab improves overall survival (OS), compared with chemotherapy, in patients with stage IIIB/IV non-small cell lung cancer (NSCLC) who are ineligible for platinum-containing therapy, according to results from the phase 3 IPSOS trial.

In this trial, the 24-month OS rate was 24.3% with atezolizumab and 12.4% with single-agent chemotherapy. 

“IPSOS is the first randomized study to show that first-line treatment with atezolizumab improves overall survival in this poor-prognosis NSCLC population with no EGFR or ALK alterations, regardless of histology, PD-L1 status, and ECOG performance status,” said Siow Ming Lee, PhD, of University College London Hospitals in London, UK.


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Dr Lee presented results from IPSOS (ClinicalTrials.gov Identifier: NCT03191786) at ESMO Congress 2022. 

The trial included 453 patients with stage IIIB/IV NSCLC who were ineligible for platinum-containing treatment and did not have EGFR or ALK alterations. They were randomly assigned to receive atezolizumab (n=302) or single-agent chemotherapy with vinorelbine or gemcitabine (n=151). 

At baseline, the median age was 75 years in each treatment arm. More than 80% of patients in each arm had an ECOG performance status of 2 or 3, close to 60% had non-squamous histology, and nearly 90% were current or former smokers. 

At a median follow-up of 41.0 months, there was a significant improvement in OS with atezolizumab. The median OS was 10.3 months in the atezolizumab arm and 9.2 months in the chemotherapy arm (hazard ratio [HR], 0.78; 95% CI, 0.63-0.97; P =.028). 

The 12-month OS rate was 43.7% in the atezolizumab arm and 38.6% in the chemotherapy arm. The 24-month OS rates were 24.3% and 12.4%, respectively.

There was no significant difference in progression-free survival (PFS) between the treatment arms. The median PFS was 4.2 months in the atezolizumab arm and 4.0 months in the chemotherapy arm (HR, 0.87; 95% CI, 0.70-1.07). 

The 12-month PFS rate was 19.7% in the atezolizumab arm and 14.2% in the chemotherapy arm. The 24-month PFS rates were 8.9% and 1.6%, respectively.

The overall response rate was 16.9% in the atezolizumab arm and 7.9% in the chemotherapy arm. The median duration of response was 14.0 months and 7.8 months, respectively. The proportion of patients who went on to subsequent anticancer therapy was 20.2% in the atezolizumab arm and 29.8% in the chemotherapy arm. 

Grade 3-4 adverse events (AEs) related to study treatment were reported in 16.3% of patients in the atezolizumab arm and 33.3% of patients in the chemotherapy arm. Serious treatment-related AEs occurred in 11.7% and 15.6%, respectively. 

Fatal treatment-related AEs occurred in 3 patients in the atezolizumab arm and 4 patients in the chemotherapy arm.

Atezolizumab was associated with stabilization of health-related quality of life functioning domains, while deterioration was observed in the chemotherapy arm. In particular, confirmed time-to-deterioration rates of chest pain were improved in the atezolizumab arm compared with the chemotherapy arm (HR, 0.51; 95% CI, 0.27-0.97).

Disclosures: This research was supported by F. Hoffmann-La Roche, Ltd. Some of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Reference

Lee SM, Schulz C, Prabhash K, et al. 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 ESMO 2022; September 9-13, 2022. Abstract LBA11.

This article originally appeared on Cancer Therapy Advisor