Gene therapy has had its commercial struggles in the past year. The cost to patients is in the millions and fewer are stepping forward for treatment than companies would like. While development continues in this game-changing field, some have struggled with regulatory authorities during development while others have just stepped away altogether.

The U.S. FDA’s green lighting of Omeros Corp.’s Yartemlea (narsoplimab) makes it the first approved treatment for hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA), a life-threatening complication of hematopoietic stem cell (HSC) transplantation. The BLA for narsoplimab, a fully human monoclonal antibody that inhibits the enzyme mannan-binding lectin-associated serine protease-2, had a Dec. 26 PDUFA date.

The U.S. FDA’s final rule for regulation of lab-developed tests was destined to be controversial at best and exceptionally susceptible to legal challenge according to more than one legal opinion. The inevitable legal challenge succeeded wildly in a decision rendered in district court in March 2025, marking one of the rare instances in which the courts thwarted FDA rulemaking and thus is easily the regulatory story of the year for 2025. Attempts to regulate AI in the U.S. and Europe also dominated the regulatory landscape.