Avidity Biosciences has reported positive initial analysis data from the Phase I/II MARINA clinical trial of AOC 1001 in adults with myotonic dystrophy type 1 (DM1).

The double-blind, randomised, placebo-controlled trial is designed to evaluate the safety and tolerability of intravenously given, single and multiple ascending doses of AOC 1001.

It is anticipated to enrol nearly 44 adult DM1 patients.

According to the trial findings, AOC 1001 offered small interfering ribonucleic acid (siRNA) to skeletal muscles, which is said to be the first successful targeted delivery.

The treatment also induced a decline in DMPK in all trial subjects, with a 45% mean DMPK reduction following one dose of 1mg/kg or two doses of 2mg/kg.

In trial subjects, initial signs of clinical activity were seen, with improvement in myotonia on receiving the treatment.

In addition, most of the adverse events (AEs) reported were found to be mild or moderate.

A lead product candidate of the company, AOC 1001 leverages its antibody oligonucleotide conjugate (AOC) platform to address DM1’s root cause. 

It comprises a monoclonal antibody that attaches to the transferrin receptor 1 (TfR1), conjugated with an siRNA that acts on DMPK messenger RNA. 

The company plans to report top-line results from the trial next year.

Avidity Biosciences president and CEO Sarah Boyce said: “We are very pleased with this early data set of AOC 1001 from the Marina trial. We have demonstrated the cascade of delivery to muscle DMPK reduction and splicing improvements with AOC 1001, and are seeing early signs of clinical activity with improvement in myotonia, just weeks after only one or two doses of AOC 1001.

“AOC 1001 has the potential to deliver on the promise of the AOC platform and significantly impact the underlying disease mechanism of DM1, a devastating disease where there are currently no approved therapies.”

The US Food and Drug Administration (FDA) placed a partial clinical hold on the enrolment of new subjects in the trial in September this year.

The move comes after a serious adverse event was reported in a subject in the 4mg/kg dose cohort of the trial.

Avidity is currently working to resolve the partial hold soon.

Cell & Gene Therapy coverage on Clinical Trials Arena is supported by Cytiva.

Editorial content is independently produced and follows the highest standards of journalistic integrity. Topic sponsors are not involved in the creation of editorial content.