Last reviewed 2026-04-20 · How we verify

Palynziq

Palynziq, developed by Emory University, is a marketed drug for the treatment of classical phenylketonuria. Its key strength lies in its unique mechanism of action, which differentiates it in the market. The primary risk is the key composition patent expiry in 2028, which could lead to increased competition from generics.

At a glance

Approved indications

• Classical phenylketonuria

Common side effects

• Injection site reactions
• Arthralgia
• Hypersensitivity reactions
• Headache
• Generalized skin reactions lasting at least 14 days
• Nausea
• Abdominal pain
• Vomiting
• Cough
• Oropharyngeal pain
• Pruritus
• Diarrhea

Serious adverse events

• Anaphylaxis
• Angioedema
• Hypersensitivity reactions

Key clinical trials

• A Long-term, Post-marketing Safety Study of Palynziq in Patients With PKU (PALace)
• A Global, Multicenter Study to Assess Maternal, Fetal and Infant Outcomes of Exposure to Palynziq® (Pegvaliase) During Pregnancy and Breastfeeding
• A Long Term, Post-marketing Study of Immune Response in Patients Receiving Palynziq Treatment for PKU (PALisade)
• Immune Modulation During Palynziq® Treatment in Adults (IMPALA) (PHASE4)
• Nutritional Impacts of Palynziq on Patients With Phenylketonuria (PKU)
• Preliminary Study of Brain Effects of Palynziq-Related Changes in Phenylalanine in Individuals With PKU
• Rapid Drug Desensitization Study in Adults Experiencing Hypersensitivity Reactions to Palynziq (PHASE4)
• Nutrition Status of Adults Treated With Pegvaliase

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Palynziq CI brief — competitive landscape report
• Palynziq updates RSS · CI watch RSS
• Emory University portfolio CI