aTyr Pharma’s Resolaris secures FDA fast track status

In addition, the FDA removed its partial clinical hold on a dosing ceiling for Resolaris in clinical trials.

John Mendlein, PhD, CEO of aTyr Pharma, said: "This Fast Track designation, which is granted to drug candidates addressing serious conditions and that demonstrate the potential to address unmet medical needs, represents another step forward for our first product candidate based on the Physiocrine pathway.

"Combined with our Phase1b/2 data in 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."

aTyr previously announced results from a completed Phase 1b/2 open-label, intra-patient dose escalation trial testing doses of Resolaris up to 3.0 mg/kg biweekly in patients with LGMD2B. 

Based on the clinical trials completed to date, Resolaris has demonstrated a favorable safety profile without signs of immuno-suppression of circulating immune cells. 78% of the LGMD2B patients in the trial (7 of 9) recorded increases in their muscle function at 14 weeks as measured by manual muscle test (MMT), a validated assessment tool. Overall, the LGMD2B patients had a mean increase of MMT scores from baseline of 6.2%.

Sanjay Shukla, MD, MS, Chief Medical Officer of aTyr Pharma, said: "We appreciate the FDA's responsiveness to our request to remove the partial clinical hold that provides dosing flexibility based on our data for Resolaris.

"We also 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."

About Resolaris

aTyr Pharma is developing Resolaris as a potential first-in-class intravenous protein therapeutic for the treatment of rare myopathies with an immune component.

Resolaris is derived from a naturally occurring protein released by human skeletal muscle cells. aTyr believes Resolaris has the potential to provide therapeutic benefit to patients with rare myopathies with an immune component characterized by excessive immune cell involvement.

About LGMD2B

Limb girdle muscular dystrophy (LGMD) refers to a group of rare genetic myopathies, of which there are more than 20 different subtypes, none with approved therapies. LGMD affects an estimated 16,000 patients in the U.S., approximately 3,000 of whom have LGMD2B. LGMD2B is a recessive genetic disease caused by a toxic loss of function in the dysferlin gene.

Patients experience progressive debilitating muscle weakness and atrophy as well as immune cell invasion in the skeletal muscle.