Avidity’s siRNA Muscular Dystrophy Drug Improves Mobility, Boosts Muscle Energy

Avidity Biosciences’ antibody-oligonucleotide conjugate improved mobility and muscle power in a sort of muscular dystrophy in an early-stage trial, and the FDA is open to receiving an software for accelerated approval of the drug, the San Diego–based mostly biotech revealed Monday.

“As we speak’s updates are considerably constructive for [Avidity],” BMO Capital Markets analysts wrote in a observe Monday, including that the “FDA’s “endorsement of [delpacibart braxlosiran] AA pathway is an enormous win.”

Nonetheless, Avidity’s shares declined greater than 11% to $32.14 as of 11:17 a.m. ET.

Avidity plans to launch a world confirmatory Part III examine referred to as FORWARD for facioscapulohumeral muscular dystrophy (FSHD) to assist the submission, in response to a separate announcement on Monday. That is on prime of an ongoing registrational examine to acquire extra biomarker knowledge.

The corporate plans to file a biologics license software for delpacibart braxlosiran in FSHD within the second half of 2026.

Monday’s topline knowledge come from the Part I/II FORTITUDE examine of sufferers with FSHD, a variant of muscular dystrophy that primarily weakens muscle tissue within the face and higher physique however can unfold to the remainder of the physique. Sufferers who obtained delpacibart braxlosiran noticed enhancements in mobility and muscle power throughout numerous assessments, together with the 10-meter walk-run check, timed up and go and quantitative muscle testing, in comparison with sufferers who obtained placebo.

Sufferers who obtained delpacibart braxlosiran additionally had diminished ranges of KHDC1L and creatine kinase, biomarkers of muscle injury. The trial had no discontinuations and no severe or extreme opposed results had been reported.

The corporate will current extra particulars on the thirty second Annual FSHD Society Worldwide Analysis Congress, June 12-13 in Amsterdam.

FSHD is attributable to irregular expression of a protein referred to as DUX4. Utilizing related ideas to an antibody-drug conjugate, Delpacibart braxlosiran makes use of an antibody to focus on a transferrin receptor that delivers an siRNA molecule that targets and destroys DUX4 mRNA. Delpacibart braxlosiran is the primary remedy designed to deal with this underlying reason behind FSHD, in response to Avidity.

A much-watched firm within the muscular dystrophy area, Avidity’s pipeline additionally contains an exon-skipper, delpacibart zotadirsen, for Duchenne muscular dystrophy, which in August 2024 boosted dystrophin manufacturing by an “unprecedented” 25% in a Part I/II trial. Additionally final yr, the FDA granted breakthrough standing to its myotonic dystrophy sort I therapy, and in 2023 Bristol Myers Squibb wager as much as $2.3 billion that Avidity’s antibody-oligonucleotide know-how may very well be utilized to 5 completely different cardiovascular targets.