The following is a summary of “Safety and Efficacy of Dostarlimab in Patients With Recurrent/Advanced Non–small Cell Lung Cancer: Results from Cohort E of the Phase I GARNET Trial” published in the November 2022 issue of Clinical Lung Cancer by Moreno et al.

In the ongoing Phase I multi-center, open-label, 2-part (dose escalation and cohort expansion) GARNET study, the anti-programmed cell death protein-1 antibody dostarlimab is being tested on recurrent or advanced solid tumors, such as non-small cell lung cancer (NSCLC) (NCT02715284). Here, researchers show an interim analysis of patients with recurrent or advanced NSCLC who got worse after platinum-based chemotherapy. First, patients were given dostarlimab (500 mg IV every 3 weeks [Q3W] for Cycles 1–4, then 1000 mg every 6 weeks [Q6W]) until the disease got worse or the side effects were too bad for more than 2 years. The main goals were safety and immune-related objective response rate (irORR) as measured by irRECIST.

As of July 8, 2019, 67 patients with recurrent or advanced NSCLC were enrolled and treated with dostarlimab. Most of the patients had PD-L1 tumor proportion score (TPS) less than 1% (35.8% of patients) or PD-L1 TPS 1%-49% (29.9% of patients); 7.5% of patients had PD-L1 TPS 50%, and 26.9% did not know their PD-L1 TPS status. The average follow-up time was 13.8 months (range: 0.0-22.6). irORR was 26.9%, with 2 full answers and 16 partial responses. The average time to respond was 11.6 months (range: 2.8-19.4). Responses were seen in 2 of 24 patients (16.7%) with PD-L1 TPS less than 1%, 4 of 20 patients (20%) with PD-L1 TPS 1%-49%, and 2 of 5 patients (40.0%) with PD-L1 TPS more than equal to 50%. Fatigue (4.5%) was the most common treatment-related treatment-emergent adverse event (TRAE) of grade greater than or equal to 3 or higher. All grades of immune-related TRAEs were seen in 28.4% of patients.

Dostarlimab showed promising antitumor activity in advanced/recurrent NSCLC that got worse after platinum-based chemotherapy, even in all PD-L1 subgroups, and it is safe.