FDA Grants Fast Track Designation to Synlogic’s Experimental Therapy for Phenylketonuria

Rare Daily Staff

The U.S. Food and Drug Administration has granted Fast Track designation to Synlogic’s experimental oral therapy, labafenogene marselecobac, for the treatment of phenylketonuria.

Phenylketonuria (PKU) is a rare, inherited metabolic disorder caused by a deficiency of the enzyme phenylalanine hydroxylase (PAH). This enzyme is required for the breakdown of phenylalanine (Phe), an amino acid found in all protein-containing foods. When PAH is deficient or defective, Phe accumulates to abnormally high levels in the blood, and if left untreated, these toxic levels of Phe in the blood can result in progressive and severe neurological impairment and neuropsychological complications.

Labafenogene marselecobac is an orally administered, non-systemically absorbed drug candidate being studied as a potential treatment for phenylketonuria (PKU) that is designed to reduce levels of Phe in people with PKU using precision genetic engineering of the well-characterized probiotic E. coli Nissle. Treatment options for PKU are currently limited due to efficacy and safety, and many of those who are treated need additional Phe-lowering.

Labafenogene marselecobac has also received Rare Pediatric Disease and Orphan Drug designations by the FDA and orphan designation from the European Medicines Agency.

“This milestone re-enforces our own urgency as we execute our pivotal study, Synpheny-3.,” said Aoife Brennan, president and CEO of Synlogic.

The FDA’s Fast Track process is designed to facilitate the development and expedite the review of drugs to treat serious conditions and fill an unmet medical need. To qualify, available clinical and non-clinical data need to demonstrate meaningful therapeutic potential. The benefits of Fast Track designation include opportunities for frequent meetings with the FDA to discuss trial design, development plans and data needed to support drug approval, as well as the ability to submit a registrational filing for approval on a rolling basis, and eligibility for priority review, if relevant criteria are met.

Aoife Brennan, president and CEO of Synlogic