The U.S. Food and Drug Administration approved Palynziq (pegvaliase-pqpz) for adults with a rare and serious genetic disease known as phenylketonuria (PKU). Patients with PKU are born with an inability to break down phenylalanine (Phe), an amino acid present in protein-containing foods and high-intensity sweeteners used in a variety of foods and beverages. Palynziq is a novel enzyme therapy for adult PKU patients who have uncontrolled blood Phe concentrations on current treatment.
The most common adverse events reported in the Palynziq trials included injection site reactions, joint pain, hypersensitivity reactions, headache, generalized skin reactions lasting at least 14 days, pruritus (itchy skin), nausea, dizziness, abdominal pain, throat pain, fatigue, vomiting, cough and diarrhea. Hypersensitivity reactions occurred in most patients, likely due to formation of antibodies to the product.
The most serious adverse reaction in the Palynziq trials was anaphylaxis, which occurred most frequently during upward titration of the dose within the first year of treatment. Because of this serious risk, the labeling for Palynziq includes a Boxed Warning and the product is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called the Palynziq REMS Program. Notable requirements of the Palynziq REMS Program include the following:
- Prescribers must be certified by enrolling in the REMS program and completing training
- Prescribers must prescribe auto-injectable epinephrine with Palynziq
- Pharmacies must be certified with the program and must dispense only to patients who are authorized to receive Palynziq
- Patients must enroll in the program and be educated about the risk of anaphylaxis by a certified prescriber to ensure they understand the risks and benefits of treatment with Palynziq
- Patients must have auto-injectable epinephrine available at all times while taking Palynziq