Dr Tarhini on Neoadjuvant Pembrolizumab Plus Vidutolimod in Resectable Melanoma

“The study met its primary end point of improved pathologic complete response [with pembrolizumab plus vidutolimod vs pembrolizumab monotherapy], which was 71% on the combination arm.”

Ahmad A. Tarhini, MD, PhD, a tenured senior member in the Departments of Cutenaous Oncology and Immunology; the director of Cutaneous Clinical and Translational Research; leader of the Neoadjuvant and Adjuvant Translational Science Program at Moffitt Cancer Center; and a professor of oncologic sciences at the University of South Florida Morsani College of Medicine, discussed data from the phase 2 ECOG-ACRIN EA6194 trial (NCT04708418) presented during the 2025 ASCO Annual Meeting.

ECOG-ACRIN EA6194 evaluated pembrolizumab (Keytruda) with or without vidutolimod for the treatment of patients with high-risk resectable melanoma. The primary end point of the trial was pathologic complete response (pCR) rate.

Among all enrolled patients, those who received the combination (n = 28) achieved a pCR rate of 71% (95% CI, 51%-87%), meeting the primary end point, Tarhini said. Comparatively, patients who received pembrolizumab monotherapy (n = 29) achieved a pCR rate of 48% (95% CI, 29%-67%).

The overall response rate (ORR) in the combination arm was 43%, including a complete response (CR) rate of 7%. These respective rates were 50% and 4% in the monotherapy group.

The major pathologic response (MPR) rate among patients who were treated with the combination was 79%, Tarhini added. The MPR rate in the monotherapy arm was 58%. At a median follow-up of 19 months (range, 2-36), the 1-year event-free survival rates were 89% (95% CI, 78%-100%) and 75% (95% CI, 59%-91%), respectively, he added. In addition to comparing favorably to the monotherapy arm, the efficacy data compared well with historical controls, he noted.

In terms of safety, no grade 5 adverse effects (AEs) were reported. Grade 3 or 4 AEs were reported at rates of 25% in the monotherapy arm and 29% in the combination arm. Any-grade treatment-related AEs (TRAEs) in the monotherapy arm included fatigue (39%), maculopapular rash (32%), and nausea (29%). In the combination arm, common any-grade TRAEs consisted of fatigue (68%), maculopapular rash (43%), and increased aspartate aminotransferase and/or alanine aminotransferase levels (39%).