The FDA's new pathway for rare disease drugs, based on causal biology, is scientifically promising. However, the name "plausible mechanism" is a critical flaw. The term sounds weak, creating doubt for patients and giving payers powerful leverage to deny coverage by implying a lower standard of evidence.

Despite massive turnover and internal dysfunction at the FDA, biotech investors have largely shrugged off the regulatory uncertainty. This disconnect suggests the market believes the negative impacts, like drug review delays, are a lagging indicator that won't materialize immediately, creating a potential future risk for the sector.

Amidst growing turmoil at the FDA, a viable strategy is to "invest around" the risk. This involves prioritizing companies whose drugs show clear data on well-understood, validated endpoints, as these are most likely to navigate the current political environment successfully, regardless of leadership changes.

Unicure's setback with its Huntington's gene therapy demonstrates a new political risk at the FDA. A prior agreement on a trial's design can be overturned by new leadership, especially if the data is not overwhelmingly definitive. This makes past regulatory alignment a less reliable indicator of future approval.

An ideologically driven and inconsistent FDA is eroding investor confidence, turning the U.S. into a difficult environment for investment in complex biologics like gene therapies and vaccines, potentially pushing innovation to other countries.

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.

Renowned gene therapy pioneer Jim Wilson was forced to spin out ultra-rare disease programs into a new company after his initial venture failed to attract VC funding. This demonstrates that even elite scientific leadership cannot overcome investor disinterest in this segment without powerful, predictable government incentives like transferable priority review vouchers.

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.

Venture capital for US seed and Series A cell and gene therapy companies has collapsed from a historical high of 17-21% of deals to only 7% this year. The sharp decline is driven by a confluence of factors including patient deaths, persistent manufacturing challenges, and growing regulatory uncertainty.