Europe says no — again. The EMA's CHMP has reaffirmed its refusal to authorize narsoplimab (Yartemlea) for a serious post-transplant blood vessel complication called TA-TMA. After re-examination, regulators found the evidence still too weak to confirm the drug actually works — leaving European patients without an approved option, even as the FDA gave it the green light late last year.
Europe doubles down on narsoplimab rejection for post-transplant complication
The European Medicines Agency's (EMA) Committee for Medicinal Products for Human Use (CHMP) has upheld its refusal to authorize narsoplimab (Yartemlea) for hematopoietic stem cell transplant (HSCT)-associated thrombotic microangiopathy (TA-TMA) — a rare but potentially life-threatening complication that damages small blood vessels following transplant. The decision, confirmed on October 15, 2026, came after drug maker Omeros requested a re-examination of the committee's initial June 2026 rejection.
The CHMP's core concern: the evidence just doesn't hold up. The main study enrolled only 28 adults, had no comparator group, and patients received other treatments alongside narsoplimab — making it impossible to attribute any improvements to the drug itself. Pediatric data were too thin to support dosing or safety conclusions, and the committee noted that published literature showed similar outcomes with other TA-TMA treatments.
Key Takeaways
Why it matters: With the FDA having approved Yartemlea in December 2025, the transatlantic regulatory divide leaves European TA-TMA patients without an authorized treatment. Omeros is winding down its EU compassionate-use program, and current patients will only receive enough supply to complete existing treatment courses.
