Mirum’s younger-child FOP results support a planned expansion filing

Mirum ($MIRM) reported new results for zilurgisertib in children aged six to under twelve with fibrodysplasia ossificans progressiva, a rare disease that causes abnormal bone formation. In the randomized Phase 2 PROGRESS cohort, twelve treated children had a mean 8.09-cubic-centimeter reduction in lesion volume after 24 weeks, while thirteen placebo recipients had a 9.14-cubic-centimeter increase. The comparison had a nominal p-value of 0.003.

No treated child developed a new lesion, compared with one on placebo, and no participant discontinued treatment during the blinded period. Mirum intends to seek an expanded US indication in the first half of 2027. Atebrioz is already approved for patients twelve and older; these small-cohort findings do not yet authorize use in the younger group. Further results and longer-term safety remain relevant to the filing.

Sources:

• Business Wire
• Issuer release via StockTitan