BioMarin Pharmaceutical’s drug for the rare, inherited disease phenylketonuria (PKU) produced mixed results in an eight-week Phase 3 study, the company announced Monday.
The daily injection, pegvaliase, met the main study goal of reducing toxic-buildup levels of phenylalanine (Phe) in the blood of PKU patients by 62 percent compared with a placebo. However, the drug did not show significant cognitive improvement in attentiveness or mood.
BioMarin shares fell 4 percent in premarket trading on Monday.
PKU is a genetic disorder that increases the levels of the amino acid, phenylalanine, found in most protein-containing food. If PKU is not treated, phenylalanine can build up to harmful levels in the body, causing intellectual disability and other serious health problems.
Currently, PKU is managed with a strict diet of limited protein and by taking a PKU formula — a special nutritional supplement — for life to ensure necessary protein intake (without phenylalanine). BioMarin’s currently approved pill, Kuvan, is also used in conjunction with a restrictive diet to manage the disorder.
The new injectable, pegvaliase, is designed to be more potent than Kuvan and is intended to eliminate this dietary component.
BioMarin said it is encouraged by additional study data showing improved neurocognitive symptoms in those treated with pegvaliase for a longer time period. The company said it expects to submit a marketing application for the daily injectable later this year, subject to more discussions with the FDA.
“Treatment with pegvaliase has resulted in dramatic phenylalanine decreases down to within normal levels which have not been achievable in the past with other PKU treatment options,” said Hank Fuchs, M.D., chief medical officer at BioMarin.
About 40 percent of patients treated with pegvaliase experienced hypersensitivity reactions compared with 14 percent of placebo patients. There were no reported cases of anaphylaxis reported during the Phase 3 study (however, anaphylaxis was reported in 8 percent of patients across the entire Phase 3 program).
PKU is diagnosed in about 50,000 patients in the developed world, and affects around 20,000 people in the U.S.
Filed Under: Drug Discovery