BioMarin Pharmaceutical's (NASDAQ:BMRN) PEG-PAL (pegvaliase) if approved has most experts noting that it will initially remain second-line as an option for adult standard of care (SOC) for phenylketonuria (PKU) versus Kuvan (sapropterin). Kuvan’s preferable side-effect profile and physician experience, among other reasons, will have it maintain its first-line status, they said.
Analysts state pegvaliase’s efficacy in a greater number of patients than the SOC, and its possibility of freeing patients from a restrictive low-protein diet that often accompanies Kuvan, will see its rapid adoption among adults. However, most experts said BioMarin’s Kuvan will continue to be the first-line therapy for patients but noted responsiveness to Kuvan is so low that the majority of treatable patients will subsequently switch to pegvaliase. That said, a fourth doctor said he would prescribe pegvaliase to all his patients as a first-line treatment due to Kuvan’s low efficacy chances and the possibility of allowing a normal diet.
Experts also noted patients’ desire to abandon low-protein diets – necessary in combination with Kuvan in some patients -- will also spur pegvaliase popularity, but one questioned the quality of data suggesting pegvaliase is efficacious without a low-protein diet.