Astellas takes another punt at tricky muscular condition despite past patient deaths

Astellas has been haunted by patient deaths in a previous trial for a tricky neuromuscular condition, but that hasn’t stopped the Japanese Big Pharma from seeking out another gene therapy to target the same indication.

Its latest potential solution is KT430, a preclinical asset the company has acquired the exclusive rights to from Kate Therapeutics for an undisclosed upfront payment and milestones. KT430 is designed to use a MyoAAV capsid to deliver a functional copy of the MTM1 gene to treat the rare and potentially fatal neuromuscular disease called X-linked myotubular myopathy (XLMTM).

Astellas Chief Strategy Officer Adam Pearson said in a release Thursday morning that adding a second potential XLMTM treatment to the company’s portfolio “further enhances our commitment to this patient community and dedication to delivering transformative medicines.”

The pharma is likely hoping that the new asset enjoys a smoother journey through the clinic than the other XLMTM therapy, called AT132. Acquired as part of the $3 billion buyout of Audentes in 2019, AT132 endured a clinical hold from the FDA and other troubles related to four patient deaths linked to liver failure. The hold was eventually lifted, but not before Astellas notched up a $540 million impairment loss for its troubles.

That wasn’t the only costly legacy of the Audentes acquisition. Last year, Astellas was forced to drop a suite of Duchenne muscular dystrophy candidates after the most advanced of the three assets failed to deliver the goods in a preclinical study. That brought a further $170 million impairment loss.

For Kate’s part, today’s deal marks a triumphant launch for the newly minted biotech. The muscular-dystrophy-focused company has debuted with $51 million in series A funds that will go toward advancing the remainder of Kate’s portfolio of muscle and heart disease programs.

Backed up by a capsid platform sprung from the lab of co-founder and Chief Scientific Officer Sharif Tabebordbar, Ph.D., key focuses of the San Diego-based biotech are myotonic dystrophy type 1 and facioscapulohumeral muscular dystrophy—two of the leading causes of adult-onset muscular dystrophy.