Dr Riess on the Initial Efficacy of the IO102-IO103 Vaccine Plus Pembrolizumab in Lung Adenocarcinoma

Jonathan Riess, MD, MS, is the medical director of Thoracic Oncology, an associate professor of Medicine, Division of Hematology & Oncology, University of California Davis Comprehensive Cancer Center, discusses preliminary results from a phase 2 trial (NCT05077709) of the IO102-IO103 immuno-modulating cancer vaccine plus pembrolizumab (Keytruda) in patients with metastatic non–small cell lung cancer (NSCLC) adenocarcinoma.

The multi-arm basket trial enrolled treatment-naïve patients with advanced and metastatic NSCLC who had lung adenocarcinoma histology, and a PD-L1 expression level of 50% or greater. A total of 15 patients were deemed efficacy evaluable and this was defined as patients who had a minimum of 2 treatment cycles and 2 confirming scans.

Initial results from the presentation were presented at the International Association for the Study of Lung Cancer (IASLC) 2023 World Conference on Lung Cancer. The overall response rate with first-line pembrolizumab given with the IO102-IO103 vaccine was 53.3% and was resulted in partial responses, Riess reports. Among responders, 26.7% achieved stable disease and 20.0% experienced disease progression. 

Further biomarker analysis of 2 responders showed undetectable levels of circulating tumor DNA (ctDNA), with a 94% reduction in ctDNA levels observed 21 days after the initial dose administration, he adds. T-cell expansion upon vaccination was also reported.

Overall, systemic adverse effects (AEs) associated with the combination therapy were consistent with immune-related AEs seen with pembrolizumab alone, Riess continues. The most common treatment-related AE was injection site reaction, which could be managed by changing the injection site, he notes.

Based on these data, the study continues to enroll more patients, with plans for extended follow-up to assess survival outcomes and response duration.