AstraZeneca’s Alexion unit has reported divergent outcomes from its late-stage program testing Ultomiris (ravulizumab) in patients with thrombotic microangiopathy following hematopoietic stem cell transplant (HSCT-TMA), a rare and dangerous complication affecting fewer than 6,000 people annually in the US.
In the adult and adolescent study (ALXN1210-TMA-313), involving 146 participants across 18 countries, the drug fell short of statistical significance on its main goal—event-free survival at 26 weeks versus placebo—though investigators noted a favorable directional signal. By contrast, the pediatric trial (ALXN1210-TMA-314) delivered stronger news: an open-label design showed survival rates of roughly 87% at six months and 73% at one year, reinforcing earlier findings.
Based on the pediatric data and supporting evidence from an external comparator study, Alexion is moving ahead with regulatory submissions for children. For the adult population, the company says it will keep working with regulators, incorporating real-world evidence as it weighs next steps.
Written By: Sayan Das
Graphics by: Pramit Hazra
