Pegvaliase therapy for phenylketonuria: Real-world safety, efficacy, and medication access outcomes in a pharmacist-led pegvaliase program.

Abstract

Purpose: Given the complexity and close monitoring needs of pegvaliase, we evaluated the real-life clinical outcomes of phenylketonuria (PKU) patients managed in a pharmacist-led pegvaliase pharmacotherapy program.

Methods: A review of 51 PKU patients initiated on pegvaliase at the PKU clinic of M Health Fairview, Minneapolis, MN, between May 2018 and May 2024 was conducted. Data collected included baseline characteristics, payer authorization outcomes, treatment history, phenylalanine levels, adverse events, and management strategies.

Results: At the 12-months, 55% of patients achieved Phe goal (360 umol/L), increasing to 77% at 24 months. Among patients on maintenance doses, 87% achieved ≥20% Phe reduction at 12 months, rising to 93.5% at 24 months. Combination therapy with sapropterin and pegvaliase was associated with faster Phe goal attainment compared to pegvaliase monotherapy (p=0.0599). Anaphylaxis occurred in 31% of patients, predominantly during the maintenance phase. All patients successfully initiated therapy without access barriers, though 35% required appeals for insurance approval. Common adverse events included injection site reactions (90%) and arthralgia (69%). Special populations, including one adolescent and two pregnant women were safely managed on pegvaliase.

Conclusions: Pegvaliase effectively reduced phenylalanine levels in PKU patients, though carried significant risks of anaphylaxis and other adverse events. A pharmacist-led program and interdisciplinary collaboration was crucial for prompt access and effective management.