Late-stage Angelman syndrome trial misses main goal
Shares of Ultragenyx Pharmaceutical RARE.O fall 45.5% to $14.4 premarket.
The company’s drug apazunersen failed to meet its main goal in a late-stage trial for Angelman syndrome, a condition that affects the nervous system and impairs typical brain development in childhood.
The drug did not show meaningful improvement in children's cognitive abilities or overall development compared with placebo.
Ultragenyx said it reviews the future of the apazunersen program.
The readout is "unambiguously negative" and the failure "raises risk for competitors" like Ionis IONS.O, which has its own similar late-stage Angelman trials ongoing.
As of last close, the stock was up 15.4% year to date.
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