ABSTRACT
BACKGROUND: Phenylketonuria (PKU) leads to an accumulation of phenylalanine (Phe) in the blood and subsequent neurologic, cognitive, psychiatric, and behavioral dysfunction. Many patients report social isolation and decreased quality of life. Pegvaliase is an enzyme substitution therapy that reduces blood Phe levels in patients with PKU and is associated with a risk of hypersensitivity reactions. OBJECTIVE: To define the minimum acceptable benefit (MAB) of pegvaliase, i.e., the minimum probability of achieving a blood Phe level <360⯵mol/L, which patients require to tolerate the risks of hypersensitivity associated with pegvaliase. METHODS: Adult, pegvaliase-naïve patients with blood Phe levels >600⯵mol/L participated in a patient-preference web survey using two surveys: adapted swing-weighting and thresholding. Participants were asked to make ordinal choices between varying clinical benefit and severity levels for hypersensitivity. Disease effects and treatment satisfaction were also assessed. RESULTS: Among 45 participants, the mean (standard deviation) self-reported blood Phe level was 976.9 (429.9) µmol/L; only 28.8% reported satisfaction with their current treatment. Most (84.4%) indicated difficulty in following a PKU diet; 60% reported that the PKU diet was burdensome, and 58% reported feeling socially isolated. Most (≥69%) reported their MAB to be less than the expected clinical benefit provided by pegvaliase; the mean MAB was 22.7% and 34.4% in the swing-weighting and thresholding surveys, respectively. CONCLUSION: Most participants felt the burden of PKU on their daily lives, were dissatisfied with current treatments, and were willing to accept the risks of hypersensitivity reactions to achieve recommended blood Phe levels with pegvaliase treatment.
ABSTRACT
The care of patients with cystic fibrosis (CF) has improved over the past 30 years, and most patients now survive well into adulthood. As a result, clinicians other than pediatricians are more likely than in the past to see CF patients and manage their respiratory, gastrointestinal, pancreatic, and reproductive complications.
