Palynziq

Dosage and Administration

Palynziq medicine is a clear to a bit opalescent, colorless to a pale yellow solution available in the form of injection as a prefilled syringe in the strengths of:

• 2.5 mg/0.5 ml single-dose
• 10 mg/0.5 ml single-dose
• 20 mg/ml single-dose.

One should consult such doctors who have experience in managing PKU disease, and administration of dosage is always according to the doctor’s prescription.

Doctors should obtain baseline blood phenylalanine concentration before starting the treatment.

The recommended initial induction dosage of the medicine is 2.5 mg via hypodermic injection once a week for 4 weeks.
One should titrate the medicine dosage step by step, according to the tolerability, over at least 5 weeks to achieve a 20 mg dose subcutaneously once a day.
To achieve a therapeutic response, titrate an effective maintenance dosage of the medicine to the patient. Professionals should use the lowest effective and tolerated dosage of the drug.
One should assess patient tolerability, blood phenylalanine concentrations, and dietary protein and phenylalanine intake during the treatment.
Discontinue the medicine pegvaliase in patients who have not achieved a response after 16 weeks of repeated treatment with the maximum dosage of 40 mg once a day.

Administration instructions

• Professionals recommend each prefilled syringe of Palynziq for use as a single hypodermic injection.
• Inspect the medicine visually for particulate matter and discoloration before administration. Palynziq is a clear to a bit opalescent, colorless to pale yellow solution. Discard the solution if discolored, cloudy, or if any particulate matter is present.
• Before the first dose of the medicine, professionals should prescribe auto-injectable epinephrine, instruct the patient on recognizing the symptoms of anaphylaxis, properly administer auto-injectable epinephrine, and seek immediate medical care after its use.
• Perform initial administration or re-administer of Palynziq for PKU after an anaphylaxis episode under the supervision of a healthcare professional experienced to manage anaphylaxis, and closely observe patients for at least 60 minutes after injection. Before self-injection, confirm the patient’s competency with self-administration.
• Professionals often advise having an adult observer for patients who may need assistance recognizing and managing anaphylaxis during the treatment. The observer should present during and for at least 60 minutes after each Palynziq administration and should be able to administer auto-injectable epinephrine.
• The recommended injection sites are: the front middle of thighs and the abdomen at least 2 inches away from the navel, the top of buttocks, and the back of the upper arms are also appropriate injection sites.
• Do not inject the medicine into moles, scars, birthmarks, bruises, rashes, and areas where the skin is hard, tender, red, damaged, burned, inflamed, and tattooed.
• Rotate sites for hypodermic injections. If the healthcare professional needs more than one injection for a single dose, the areas for injecting medicine should be at least 2 inches away from each other. And the second injection site can be on the same part or a different part of the body.

Side effects

Side effects of pegvaliase-pqpz injection for PKU are classified as:

Common
Injection site reactions, arthralgia, hypersensitivity reactions, headache, skin reactions, pruritus, nausea, abdominal pain, oropharyngeal pain, and fatigue are common side effects of treatment with Palynziq.

Uncommon
Vomiting, coughing, and diarrhea are uncommon side effects of the medicine.

Less frequent
Anxiety, alopecia, and nasal congestion are less frequent side effects of taking this medicine.

Note: Every patient doesn’t need to experience these symptoms.

Precautions and Warnings

Anaphylaxis
During induction/titration/maintenance of phenylketonuria treatment, 9% of patients experienced anaphylaxis. According to reports of clinical trials, symptoms of anaphylaxis are syncope, hypotension, hypoxia, dyspnea, wheezing, chest discomfort/chest tightness, tachycardia, angioedema, etc.

According to the patient’s tolerability, one should consider premedication with an H1-receptor antagonist, H2-receptor antagonist, or antipyretic before Palynziq administration.

Palynziq is available only via a restricted program under a REMS after phenylketonuria diagnosis.

Palynziq REMS program
Palynziq is available only via a restricted program under a REMS( Risk Evaluation and Mitigation Strategy) known as Palynziq REMS because of the risk of anaphylaxis in patients with phenylketonuria enzyme deficiency.
Requirements of the Palynziq REMS are:
The prescriber/professional must be certified with the program by enrolling in the program and completing training.
The prescriber must prescribe auto-injectable epinephrine with the medicine.
One should go for the certified pharmacies with the program, and the pharmacies must dispense only to patients authorized to receive it.
The patient must enroll in the program. One should educate the patient about the risk of anaphylaxis to ensure they understand the risks and benefits of treatment with the medicine.
The patient must have auto-injectable epinephrine available at all times while taking this medicine.

Other Hypersensitivity Reactions
Other than anaphylaxis, 69% of patients experienced different hypersensitive reactions during PKU treatment with pegvaliase. Healthcare professionals should consider premedication with an H1-receptor antagonist, H2-receptor antagonist, or antipyretic before the medicine administration based on the patient’s tolerability.
One should manage hypersensitivity reactions according to the severity of the response, recurrence of the reaction, and the patient’s clinical status, and may include dosage adjustment, temporary drug interruption, or treatment with antihistamines antipyretics, or corticosteroids.

Handling and storage

• Store the medicine in the refrigerator at 36°F- 46°F or 2°C – 8°C to protect it from light in its original carton only.
• Do not freeze or shake the medicine.
• For patients: If needed, store the medicine in the original carton at room temperature between 68°F-77°F or 20°C-25°C for 30 days only.

Note the date removed from refrigeration on the carton.
Once stored at room temperature, do not restore the product in the refrigerator.
The shelf-life of the medicine expires after storage at room temperature for 30 days or after the expiration date on the product carton