DC-ATA personal dendritic cell vaccine + PD-1/LAG-3 blockade produced responses in all 6 response-evaluable patients with metastatic melanoma.

Personal DC-ATA is an autologous dendritic-cell vaccine loaded ex vivo with lysate from a short-term autologous tumor cell line (autologous tumor antigens), given here concurrently with standard immune checkpoint inhibitors (pembrolizumab or nivolumab/relatlimab; anti-CTLA-4 excluded) in the Phase Ib NCT03743298 trial. In 8 treated patients with advanced melanoma (mean age 75; stages III recurrence–M1C), 6 had measurable disease and the RECIST ORR was 100% (2 CR, 4 PR; 95% CI 54%–100%) with OS from enrollment ranging 11+ to 56+ months; this is far above typical first-line anti–PD-1 monotherapy ORR (~33%–40%) and even above nivo/relatlimab ORR ~44% in RELATIVITY-047 (cross-trial, small-n caveat). Safety looked additive/minimal: no grade 3–4 AEs, universal injection-site reactions, and 1 discontinuation for persistent rash/pruritus that began on pembrolizumab (not clearly attributable to DC-ATA); 61/64 planned vaccine doses were delivered.