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The PAL Clinic is a comprehensive clinical program specifically for patients with phenylketonuria (PKU) to receive enzyme substitution therapy. Pegvaliase (Palynziq) is currently the only approved enzyme therapy for PKU. Pegvaliase is a PEGylated recombinant phenylalanine ammonia lyase (PAL) enzyme product that has been effective in reducing blood phenylalanine levels while allowing many individuals with PKU to eat a regular diet.

Our clinic provides thorough education surrounding the safety and efficacy of pegvaliase before beginning therapy, as well as over the duration of treatment. We aim to provide ongoing patient education, support, and close monitoring and responsiveness to our patients. Using this approach, we have had improved expectation management, reduction of fear associated with side effects and self-injections, positive attitudes in our patients, and strong patient-provider relationships. As of August 2019, we have treated 48 individuals through the PAL Clinic.

Your visit to the PAL Clinic

Patients followed in the PAL Clinic are required to have had an appointment with Boston Children’s Hospital Metabolism program within 12 months prior to starting pegvaliase therapy. If it has been over a year since your last Metabolism appointment or you are new to our center, you can schedule a baseline appointment in the PAL Clinic with either Dr. Sacharow or Dr. Kritzer.

Patients interested in initiating treatment are also required to attend an information session to begin the process. These sessions are held monthly in the evening at Boston Children’s Hospital. This discussion includes managing expectations and potential side effects of the drug, including Risk Evaluation and Mitigation Strategies (REMS) training due to risk of anaphylaxis. Monthly group night-time information sessions allow us to educate, enroll and start treating people quickly and on a rolling basis.

PAL Clinic Dosing Schedule

Clinic visits:

  • Weekly visits for the first 4 weeks
  • Week 6
  • Week 10
  • Visits every 8 weeks afterwards

Dietitian: Every 3 months

Psychologist: Recommended visit at medication initiation and at 12-months after treatment initiation. Additional visits available based on clinical need.

Blood Phe testing: Monthly at a minimum

Metabolic Dietitian: Patients in PAL Clinic are followed closely by a metabolic dietitian experienced in pegvaliase therapy. While starting pegvaliase treatment, it is important to keep one’s diet stable, and patients should continue their same dietary restrictions, supplements, and medical food, if applicable. If/when blood Phe concentrations decrease while on pegvaliase, patients will receive specific instruction how to liberalize their diets.

Clinical Psychology: Neuropsychological assessments are an important component of PKU management due to PKU’s effect on mood/anxiety, attention, and executive function. Visits with our clinical psychologist will help to track cognitive and emotional impact of PKU while on Palynziq therapy.

Psychology services are an optional, but recommended, part of the PAL clinic. This service is not meant to replace ongoing or long-term mental health services.

The overall visit with our clinic psychologist will last around an hour and a half and includes a short interview (~20-25 min.), questionnaires on social and emotional functioning (~10 min.), and cognitive testing (~45 min.). Your visit will also include feedback based on your questionnaire responses and performance on the cognitive testing. The cognitive testing is a brief evaluation of areas that are often impacted by elevated Phe levels.

On a limited basis, talk therapy and video-talk therapy services are available upon request.

Resources for PAL Clinic patients