Warnings and Precautions

Myelosuppression
Monitor complete blood count (CBC) and adjust the dose of PURIXAN for excessive myelosuppression. Consider testing in patients with severe myelosuppression or repeated episodes of myelosuppression for thiopurine S-methyltransferase (TPMT) or nucleotide diphosphatase (NUDT15) deficiency. Patients with homozygous-TPMT or homozygous-NUDT15 deficiency may require a dose reduction.

Hepatotoxicity
Monitor transaminases, alkaline phosphatase and bilirubin. Withhold PURIXAN at onset of hepatotoxicity.

Immunosuppression
Response to all vaccines may be diminished and there is a risk of infection with live virus vaccines. Consult immunization guidelines for immunocompromised pediatrics.

Treatment Related Malignancies
Aggressive and fatal cases of hepatosplenic T-cell lymphoma have occurred.

Macrophage Activation Syndrome
Monitor for and treat promptly; discontinue PURIXAN.

Embryo-Fetal Toxicity
Can cause fetal harm. Advise patients of reproductive potential of the potential risk to a fetus and to use effective contraception.

Adverse Reactions

Adverse Reactions – Clinical Studies Experience
The most common adverse reaction occurring in > 20% of patients was myelosuppression, including anemia, neutropenia, lymphopenia and thrombocytopenia. Adverse reactions occurring in 5% to 20 % of patients included anorexia, nausea, vomiting, diarrhea, malaise, and rash. Adverse reactions occurring in < 5 % of patients included urticaria, hyperuricemia, oral lesions, elevated transaminases, hyperbilirubinemia, hyperpigmentation, infections, and pancreatitis. Oral lesions resemble thrush rather than antifolic ulcerations. Delayed or late toxicities include hepatic fibrosis, hyperbilirubinemia, alopecia, pulmonary fibrosis, oligospermia and secondary malignancies.

Adverse Reactions – Postmarketing Experience
The following adverse reactions have been identified during postapproval use of PURIXAN. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. These reactions include: photosensitivity, hypoglycemia, and portal hypertension.

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