The Food and Drug Administration (FDA) has granted Fast Track designation to the investigational gene therapy BMN 307 (BioMarin Pharmaceutical) for the treatment of patients with phenylketonuria (PKU).

BMN 307 is an adeno-associated virus type 5 (AAV5)-phenylalanine hydroxylase (PAH) gene therapy designed to normalize blood phenylalanine (Phe) concentration levels in patients with PKU by inserting a correct copy of the PAH gene into liver cells.

The Company recently initiated an open-label phase 1/2 study (PHEARLESS) to evaluate the safety, efficacy and tolerability of a single intravenous administration of BMN 307 in adults with PKU with PAH deficiency. The study will assess whether a single dose of treatment can restore natural Phe metabolism, increase plasma Phe levels, and enable a normalization of diet in patients with PKU.

“Fast Track designation combined with our ability to conduct our clinical studies incorporating material manufactured using a commercial-ready process will further facilitate rapid clinical development of BMN 307 gene therapy,” said Hank Fuchs, MD, President, Worldwide Research and Development at BioMarin.  “We are looking forward to working closely with the FDA, as well as other health agencies, to evaluate the safety and efficacy of this promising investigational gene therapy as we continue our unwavering 15-year commitment to advance the standard of care for people with PKU.”  

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The FDA’s Fast Track designation allows for expedited review of therapies that are meant to treat serious or life-threatening conditions. Generally, the designation is granted to drugs that are expected to have an impact on factors such as survival and daily functioning.

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BioMarin, pioneer in phenylketonuria (PKU) and gene therapy, receives FDA Fast Track designation for PKU investigational gene therapy, BMN 307. Accessed October 5, 2020.