NEW YORK – The US Food and Drug Administration has cleared Aro Biotherapeutics' investigational new drug application for a short-interfering RNA (siRNA) drug it's developing for late-onset Pompe disease (LOPD), clearing the way for it to begin clinical testing in the US, the company said Wednesday.
The Philadelphia-based biotech is developing ABX1100 as a treatment for LOPD, a rare neuromuscular disorder caused by mutations in the GAA gene, which typically produces an enzyme called acid alpha-glucosidase that breaks down glycogen. ABX1100 aims to address this problem by reducing glycogen levels.
ABX1100 is designed to deliver an siRNA payload to muscle tissue to block production of GYS1, an enzyme that's necessary for synthesizing glycogen.
Investigators already are evaluating ABX1100 within an open-label Phase I trial of patients with LOPD in Canada.
In a completed Phase I trial of healthy volunteers, ABX1100 led to durable knockdown of GYS1 mRNA and protein in the muscle, according to Aro. The drug exhibited dose- and time-dependent GYS1 mRNA and protein reduction in muscle biopsy samples compared to baseline levels and was well tolerated with no serious adverse events.
Aro said data from these healthy volunteers supports its rationale for quarterly maintenance treatment after an initial regimen of loading doses.