Shares of Avidity Biosciences are soaring following reported early signs of clinical activity and improvement in patients with myotonic dystrophy type 1 (DM1) treated with its RNA-based therapeutic.
Avidity CEO Sarah Boyce/Company Courtesy
Shares of Avidity Biosciences are soaring following reported early signs of clinical activity and improvement in patients with myotonic dystrophy type 1 (DM1) treated with the company’s experimental RNA-based therapeutic and lead clinical program, AOC-1001.
Avidity announced preliminary data on Tuesday from its Phase I/II MARINA trial assessing AOC-1001 for DM1, a progressive neuromuscular disease for which there are no approved treatments. The early data shows AOC-1001 successfully delivered siRNA to skeletal muscle and demonstrated a “meaningful DMPK reduction in 100% of participants,” the San Diego-based company reported.
The DMPK gene is responsible for making the protein myotonic dystrophy protein kinase, which plays an important role in muscle, heart, and brain cells.
Preliminary data from the MARINA study also showed AOC-1001 produced a 45% mean reduction in DMPK following a single dose at 1mg/kg or two doses of 2 mg/kg. The preliminary assessment includes biomarker data six weeks after dosing, Avidity noted in its announcement.
Trial participants who were treated with AOC 1001 showed early signs of clinical activity with improvement in myotonia, or the inability to relax the impaired muscle, which is a hallmark symptom of DM1.
In a call with investors on Wednesday, Avidity Chief Medical Officer Steven Hughes stressed the data remains early and the information shared is only from lower doses. Over time, Hughes said the company hopes to have stronger longer-term data and data from higher doses.
Chief Executive Officer Sarah Boyce said during the call that the early data from the MARINA study shows AOC-1001 can significantly impact the underlying disease mechanism of DM1. She added the data is “exciting and encouraging” for the DM1 community.
The data was also exciting for Avidity investors. The company stock soared more than 40% in premarket trading to $15.05. The stock closed at $10.98 on Tuesday.
Boyce stressed that the MARINA data shows targeted delivery of siRNA to muscle tissue, which was previously untreatable with existing RNA therapeutics, she said. That opens the door for potentially using this approach in other tissue types, Boyce added.
Before additional data is reported, Hughes said Avidity will have to address a partial clinical hold placed on the MARINA study in September by the FDA. The hold on enrollment was put in place due to a serious adverse event suffered by a patient.
Despite that adverse event, Hughes added the preliminary data from patients treated with lower doses of AOC-1001 shows a favorable safety and tolerability profile. He said the company anticipates sharing more data by the end of the first quarter in 2023. Topline data remains on track for the end of 2023, he added.
Beyond DM1, Avidity also has two other programs in clinical development. One is a treatment for Duchenne Muscular Dystrophy and the other is for facioscapulohumeral muscular dystrophy.
