Two regulatory moves this week signaled a broader rejiggering of FDA expectations for approvals. First, FDA leadership articulated a new default that could allow marketing authorization based on a single adequate, well‑controlled trial for some novel drugs; the policy prompted debate about global harmonization and payer acceptance. Second, the agency proposed a 'plausible mechanism' framework intended to speed personalized genomic and ultrarare disease development by relaxing some evidentiary requirements when mechanistic rationale is clear. Industry groups and global regulators flagged concerns that these shifts could complicate international development strategies and reimbursement decisions. The FDA characterized both initiatives as efforts to accelerate patient access while requesting further stakeholder input on implementation and safeguards.