10:54 AM EDT, 05/16/2024 (MT Newswires) -- Ionis Pharmaceuticals ( IONS ) said Thursday that topline data from a phase 1/2a study showed that ION582 improved cognition, communication, and motor function in patients with Angelman syndrome.

The study also showed that ION582 was safe and well tolerated at all dose levels, the company said.

Data showed that at the six-month mark, about 65% of patients achieved an improvement in cognition, roughly 70% of patients had improved receptive and/or expressive communication, and about 65% of patients showed improvements in fine and gross motor skills, the company said.

The company said that it will share detailed results in July and plans to advance ION582 into a pivotal study. Biogen (BIIB) has elected not to exercise its option to license ION582, Ionis added.

Shares of Ionis Pharmaceuticals ( IONS ) were 5% down and Biogen fell nearly 3% in recent trading Thursday.

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