When leadership changes at the FDA, as with Vinay Prasad succeeding Peter Marks, a core tension emerges. The new head isn't obligated to follow prior agreements, but abruptly shifting regulatory expectations for companies mid-development creates industry whiplash and erodes trust in the agency's consistency.

The FDA publicly promotes regulatory flexibility for rare diseases, yet industry insiders perceive it as less permissive than prior administrations. This disconnect between the agency's messaging and its actual decisions is fueling widespread criticism, investor uncertainty, and accusations of 'moving the goalposts'.

The FDA publicly champions rare disease drug development, but its actions—frequent and inconsistent rejections—tell a different story. This disconnect between rhetoric and reality creates significant uncertainty, causing prominent investors like Rod Wong of RTW Investors to reduce their investments in the space.

The FDA issued guidance supporting minimal residual disease (MRD) as an approval endpoint in multiple myeloma. This directly contradicts the CBER division’s recent rejections of drugs based on single-arm response rates, creating a "schizophrenic" and unpredictable regulatory landscape for developers.

Unpredictable changes in FDA review processes are more destructive to biotech investment than consistently high approval standards. Investors can adapt to a stringent but stable regulatory bar, but constant changes undermine the multi-year planning and capital commitment required for drug development, causing investors to flee.

Moderna spent $1 billion on a trial based on FDA guidance that was later deemed unacceptable. This arbitrary "changing of the rules" after the fact makes long-term, capital-intensive investment in new medicines like vaccines extremely risky for pharmaceutical companies.

FDA CBER Director Vinay Prasad is reportedly overriding staff recommendations not just in his own center (vaccines), but also in CEDAR (drugs), as seen in the Disc Medicine case. This consolidation of decision-making power in one individual is making FDA approvals far more unpredictable for drug developers.

Recent events, like Moderna's rescinded 'refusal to file' letter, reveal that alignment with FDA staff on trial design is no guarantee. Senior leaders, notably Vinay Prasad, are reportedly overturning prior agreements, creating extreme uncertainty and making it impossible for companies to trust the regulatory guidance they receive.

Despite political chaos, most FDA work continues. However, companies are experiencing severe inconsistency, with different agency groups offering contradictory advice and major rejections being walked back, as seen with Atara Biotherapeutics. This demonstrates how top-level instability creates unpredictable regulatory hurdles for developers.