FDA fast tracks novel drug for rare form of muscular dystrophy
The FDA recently granted fast-track designation to Resolaris, the first known therapeutic candidate for limb girdle muscular dystrophy 2B, according to aTyr, its manufacturer.
The company said that the FDA also removed a partial clinical hold on limiting the dosing of the drug in clinical trials.
"This fast track designation … represents another step forward for our first product candidate based on the Physiocrine pathway,” John Mendlein, PhD, CEO, aTyr Pharma, said in a press release. “Combined with our Phase 1b/2 data in [limb girdle muscular dystrophy 2B (LGMD2B)], adult facioscapulohumeral muscular dystrophy (FSHD) and early onset FSHD patients, we believe we are building a clinical and regulatory foundation for future development of Resolaris to treat patients across multiple rare genetic myopathies with an immune component.”
In clinical trials already completed, Resolaris showed a favorable safety profile without signs of immuno-suppression of circulating immune cells, according to aTyr. In the trial, 78% of the patients with LGMD2B indicated increases in muscle function at 14 weeks as measured by a manual muscle test (MMT). When compared to baseline, the patients with LGMD2B had a mean increase of MMT scores of 6.2%.
"We … believe that during our safety and dose ranging Phase 1b/2 clinical trials we have potentially identified a dose for the next phase of clinical development with a favorable safety profile and potential clinical activity across different rare muscle indications,” Sanjay Shukla, MD, MS, chief medical officer, aTyr Pharma, said in a release.
The company also stated in a previous press release that Resolaris continues to demonstrate a well-tolerated safety profile in all trials.
Resolaris is derived from a naturally occurring protein released by human skeletal muscle cells and is the first known therapeutic candidate for LGMD2B to receive the fast track designation, the company stated.
NIH’s website states that LGMD2B is a rare, genetic disorder that affects the voluntary muscles of the hips and shoulders, and is characterized by atrophy and early weakness of the pelvic and shoulder girdle muscles in adolescence or young adulthood. According to aTyr, there are approximately 3,000 cases of LGMD2B in the United States.
Disclosure: Mendelein and Shukla work for aTyr Pharma.