Overview

• In a Phase 1/2 IGNYTE trial of 140 immunotherapy-resistant melanoma patients, the RP1–nivolumab regimen achieved at least 30% tumor reduction in about one-third and complete regression in nearly one-sixth.
• Uninjected tumors shrank or vanished at rates comparable to those directly injected with RP1, indicating systemic antitumor immune activation.
• The combination therapy was well tolerated, with most adverse events limited to mild fatigue and flu-like symptoms and no new safety concerns.
• RP1 is a gene-edited herpes simplex virus type 1 that selectively replicates in tumor cells, and nivolumab enhances its effect by blocking cancer’s immune-evasion mechanisms.
• The FDA granted priority review for the RP1–nivolumab combination in January and a global Phase 3 IGNYTE-3 trial is now enrolling over 400 patients to confirm these findings.