The CREST trial showed benefit driven by patients with carcinoma in situ (CIS), while the Potomac trial showed a lack of benefit in the same subgroup. This stark inconsistency demonstrates that subgroup analyses, even for stratified factors, can be unreliable and are a weak basis for regulatory decisions or label restrictions.

A significant disconnect exists between the FDA leadership's public statements promoting flexibility and the stringent, delay-prone reality faced by companies. For areas like gene therapy, firms report feeling the "rug was pulled out," suggesting investors should be skeptical of the agency's accommodating PR.

Voyager CEO Al Sandrock supports the FDA's use of accelerated approval for severe diseases but argues it must be coupled with industry accountability. He praises Amelix for voluntarily pulling its ALS drug after a failed confirmatory trial, framing such responsible actions as essential for maintaining the FDA's willingness to be flexible with approvals based on surrogate endpoints.

A key tension is emerging in orphan drug development. While the FDA's approval standards appear to be rising and becoming more erratic, Congress has simultaneously created a powerful economic incentive by exempting orphan-only drugs from Medicare price negotiation, creating a complex strategic landscape.

After a decade on the market and multiple shifts in endpoints, Sarepta's definitive Phase 3 study for its DMD drugs failed. This outcome casts doubt on the entire accelerated approval framework for slowly progressive diseases, where surrogate endpoints may not translate to clinical benefit, leaving regulators and patients in a difficult position.

The FDA is predicted to approve new PARP inhibitors from trials like AMPLITUDE only for BRCA-mutated patients, restricting use to where data is strongest. This contrasts with the EMA's potential for broader approvals or denials. This highlights the diverging regulatory philosophies that create different drug access landscapes in the US and Europe.

In the CREST trial, the FDA's critique heavily emphasized an overall survival hazard ratio above one. Though statistically insignificant and based on immature data, this single figure created a powerful suggestion of potential harm that overshadowed the positive primary endpoint and likely contributed to the panel's divided vote.

The FDA's current leadership appears to be raising the bar for approvals based on single-arm studies. Especially in slowly progressing diseases with variable endpoints, the agency now requires an effect so dramatic it's akin to a parachute's benefit—unmistakable and not subject to interpretation against historical data.

The GLORA-IV trial is designed with a dual endpoint, evaluating both patient response rate and overall survival. This structure creates an alternative pathway for regulatory approval based on response rates, which can be assessed faster than survival, strategically de-risking the lengthy and expensive trial process.