Internal sources revealed that FDA's top cancer drug regulator intervened late in the review process of Replimune’s melanoma therapy RP1, significantly influencing its final rejection despite internal support. The agency has been undergoing leadership turmoil and staff disruptions, contributing to contentious decisions including this one. The high-profile case underscores complexities in regulatory oversight and decision-making dynamics for novel cancer therapeutics. Industry observers note shifts in FDA priorities and leadership impact on cell and gene therapy approvals.