The CREST trial's positive primary endpoint, assessed by investigators in an open-label setting, was rendered negative upon review by a blinded independent committee. This highlights the critical risk of confirmation bias and the immense weight regulators place on blinded data to determine a drug's true efficacy, especially when endpoints are subjective.

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Unicure's experience reveals a significant regulatory risk: the FDA can reverse its position on a pre-agreed Statistical Analysis Plan (SAP). Despite prior alignment on using a natural history control, the agency later told the company this approach was merely 'exploratory,' invalidating their filing strategy and shocking investors.

A blinded central radiology review is not the absolute gold standard for assessing patient progression. Expert clinicians argue their holistic assessment, incorporating the patient's clinical status and other biomarkers alongside scans, provides critical context that a disconnected reviewer lacks.

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.

To combat confirmation bias, withhold the final results of an experiment or analysis until the entire team agrees the methodology is sound. This prevents people from subconsciously accepting expected outcomes while overly scrutinizing unexpected ones, leading to more objective conclusions.

The FDA's critique of both CREST and Potomac trials highlights that while event-free survival (EFS) endpoints were met, the lack of improvement in overall survival or prevention of muscle-invasive disease makes the risk/benefit profile questionable for an early-stage cancer, where treatment-related harm is a primary concern.

The lack of a placebo arm in some adjuvant trials is not necessarily a fatal flaw. One expert view is that it mirrors real-world practice where treatments are known. This perspective places trust in the investigators' ability to assess disease progression accurately without blinding.

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.

Praxis Interactive's essential tremor drug succeeded in Phase 3 despite an earlier data monitoring committee (DMC) recommendation to stop for futility. This rare outcome shows that interim analyses on a small fraction of patients can be misleading due to high variance, and continuing a trial against DMC advice can be a winning strategy.

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.