Dr Vincent Ma: CTGTAC's 10-3 Vote on RP1/Nivo Is “Encouraging”

Following the Cellular, Tissue, and Gene Therapies Advisory Committee 10-3 vote on the clinical meaningfulness of the IGNYTE trial (NCT03767348), Vincent Ma, MD, associate professor in the Department of Medicine at the University of Wisconsin School of Medicine and Public Health, described the outcome as encouraging and a significant development, though he was careful not to frame it as a dismissal of the FDA’s concerns raised during the meeting and in the 2 prior reviews of the application.

Ma said the vote instead reflects the committee's recognition that RP1 in combination with nivolumab (Opdivo) appears to produce a meaningful treatment signal, particularly in a population that has proven difficult to treat: patients with anti-PD-1–refractory advanced melanoma who represent a substantial unmet medical need.

He pointed to the depth and durability of responses observed in patients enrolled in the IGNYTE trial as a key driver of the committee's view, singling out the durable complete responses seen in some patients as evidence that is hard to overlook despite the FDA’s concerns over the single-arm trial’s evaluability. In his assessment, these outcomes gave the committee grounds to weigh the therapy's potential benefit seriously, even against the backdrop of the FDA's reservations on study design and response criteria.

Ma also credited the committee with striking an appropriate balance in its deliberations, noting that panel members considered the strength of the efficacy data alongside the feasibility and safety profile of the RP1-nivolumab combination, rather than focusing on one dimension in isolation.

Overall, Ma suggests that although questions about trial design and the ability to isolate RP1's specific contribution to the observed responses were not erased by the vote, the committee ultimately found the clinical signal, especially the complete responses and durability data from IGNYTE, compelling enough to support a favorable read on the combination's benefit-risk profile in this refractory melanoma population while the confirmatory IGNYTE-3 trial (NCT06264180) is ongoing.