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B.C. biotech Xenon partner abandons trials after Phase 2 failure

Xenon drug candidate failed to prove effective in treating epilepsy
Xenon CEO Ian Mortimer "disappointed" with outcome of Phase 2 trials for epilepsy drug candidate.

A licensing partner that had been testing a new drug candidate developed by B.C.’s Xenon Pharmaceuticals Inc. (Nasdaq:XENE) says it is abandoning further trials of the drug, after Phase 2 trials failed to prove efficacy in treating the targeted disorder.

Xenon is a clinical stage biopharmaceutical company focused on developing drugs to treat various neurological disorders.

Neurocrine Biosciences Inc. (Nasdaq: NBIX) had been licensing Xenon’s NBI-921352 and trialing it in adult patients for the potential treatment of focal onset seizures.

But Neurocrine today announced that Phase 2 trials failed to prove the drug’s efficacy in treating the neurological condition. 

In a press release, Neurocrine said NBI-921352, licensed from Xenon, “failed to demonstrate meaningful seizure frequency reduction in the Phase 2 dose finding study assessing the safety, efficacy, tolerability and pharmacokinetics as adjunctive therapy in adults with focal onset seizures. 

“No further development with NBI-921352 in Focal Onset Seizure (FOS) is planned at this time.”

“Although we are disappointed with the outcome of this clinical trial in focal onset seizures, we are grateful to the study participants and investigators, as well as our partner Neurocrine for running this proof-of-concept study,” Xenon CEO Ian Mortimer said in a press release.

“We intend to work closely with Neurocrine to review the data in depth to understand any potential implications for the second ongoing study with NBI-921352 in SCN8A-developmental epileptic encephalopathy."

Xenon’s NBI-921352 is one of four drug candidates in Xenon’s pipeline. Two are in Phase 3 clinical trials and one in Phase 2.

Xenon's stock was down by US$2.15 at close of markets today -- a 6.7 per cent decline in value.

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