By Michael Dabaie


Biogen Inc. said the Phase 2/3 Xirius study of cotoretigene toliparvovec as a one-time therapy for patients with X-linked retinitis pigmentosa didn't meet its primary objective.

The company said that data indicated positive trends in several prespecified secondary endpoints, such as a clinically relevant measure of visual acuity.

XLRP is a rare, inherited retinal disease that is associated with progressive vision loss as the light-sensing cells of the retina gradually deteriorate.

The study didn't meet its primary endpoint of demonstrating a statistically significant improvement in the proportion of treated study eyes with >=7 dB improvement from baseline at >=5 of the 16 central loci of the 10-2 grid assessed by macular integrity assessment microperimetry, the company said.

"Although the Phase 2/3 Xirius study of cotoretigene toliparvovec did not meet its primary endpoint, we are encouraged by positive trends in other pre-specified clinically relevant endpoints, such as a measure of visual acuity under low light conditions," said Katherine Dawson, head of the therapeutics development unit at Biogen.

Biogen said it will communicate next steps for the program after analyzing the complete data set.


Write to Michael Dabaie at


(END) Dow Jones Newswires

May 14, 2021 08:14 ET (12:14 GMT)

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