FDA Say It Needs an Additional Three Months to Review BioMarin’s PKU Drug

Rare Daily Staff

BioMarin Pharmaceutical said that the U.S. Food and Drug Administration will require additional time to complete its review of its application to market pegvaliase, its experimental therapeutic to treat adults with phenylketonuria, a genetic enzyme deficiency that prevents people from metabolizing an amino acid meat and other protein in their diet.

Phenylketonuria, or PKU, affects about 50,000 diagnosed patients in the developed world and is caused by a deficiency of the enzyme PAH. This enzyme is required for the metabolism of Phe, an essential amino acid found in most protein-containing foods. If the active enzyme is not present in sufficient quantities, Phe accumulates to abnormally high levels in the blood and becomes toxic to the brain, resulting in a variety of complications including severe intellectual disability, seizures, tremors, behavioral problems and psychiatric symptoms.

As a result of newborn screening efforts implemented in the 1960s and early 1970s, virtually all individuals with PKU under the age of 40 in developed countries are diagnosed at birth and treatment is implemented soon after. PKU can be managed with a Phe-restricted diet, which is supplemented by low-protein modified foods and Phe-free medical foods; however, the strict diet is difficult for most patients to adhere to the extent needed for achieving adequate control of blood Phe levels. 

Pegvaliase is a PEGylated recombinant phenylalanine ammonia lyase enzyme product, to reduce blood Phe, levels in adult patients with phenylketonuria who have uncontrolled blood Phe levels on existing management.

In a notice from the FDA to BioMarin, the agency said it would extend the Prescription Drug User Fee Act Goal Date for pegvaliase by three months to May 28, 2018. Due to the Memorial Day weekend, the Action Goal Date will be May 25, 2018. 

At the end of August, when the FDA accepted BioMarin’s application and granted priority review status, the company announced that the FDA had requested additional information on Chemistry, Manufacturing and Controls, which was likely to be classified as a major amendment to its application and result in a three-month extension of the PDUFA date. As expected, the FDA designated the receipt of this additional information as a major amendment to the application thus extending the PDUFA action date by three months. 

“We appreciate the FDA’s ability to expedite review through priority designation, particularly for this complex disease and treatment,” said Hank Fuchs, president of worldwide research and development at BioMarin. “We continue to work closely with the FDA and look forward to the possibility of bringing this important treatment to patients.”

December 26, 2017

Photo: Hank Fuchs, president of worldwide research and development at BioMarin