Novel Monoclonal Antibody Under Study in Phase III Trial of Nonsquamous NSCLC

By: Celeste L. Dixon
Posted: Friday, October 11, 2024

When combined with pemetrexed and platinum-based chemotherapy in the first-line setting in the phase III DOMAJOR trial, prolgolimab offered improved survival outcomes and a higher objective response rate than pemetrexed/chemotherapy plus placebo in patients with advanced nonsquamous non–small cell lung cancer (NSCLC). Prolgolimab is a monoclonal antibody directed against the negative immunoregulatory human cell receptor PD-1. Daniil L. Stroyakovsky, PhD, of Moscow City Oncology Hospital, and colleagues, presented their results during the International Association for the Study of Lung Cancer (IASLC) 2024 World Conference on Lung Cancer (Abstract OA11.05).

The trial combination was shown to have a favorable safety profile as well, noted the authors. The 292 participating patients, randomly assigned on a 1:1 basis to the experimental and placebo arms, all had previously untreated disease in which the driver mutations EGFR and ALK were not present. The level of PD-L1 expression did not seem to affect outcomes (P > .3). The patients were treated at 45 centers across Russia, China, and the European Union.

The study’s primary endpoint was overall survival in the intention-to-treat population. After a median follow-up of 18 months, the investigators said, the median overall survival was not reached in the experimental arm, although it was 14.6 months in the placebo arm (P = .0001). The estimated overall survival rate at 24 months was 59.0% with prolgolimab vs 36.3% without it.

The objective response rate was 50.3% with the prolgolimab combination therapy and 27.5% with the placebo combination (relative risk = 0.21), the authors noted; the median progression-free survival was 7.7 months in the experimental arm vs 5.5 months in the placebo arm (P = .0004). Additionally, adverse events related to study therapy were reported in 64.3% of the experimental group and 50% of the placebo arm. However, 9.8% and 8.8% of patients in those arms, respectively, discontinued treatment as a result of adverse events.

Disclosure: For full disclosure information of the study authors, visit wclc2024.iaslc.org.

2024 World Conference on Lung Cancer

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