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About Purixan™

Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is a cancer that affects blood producing cells in the bone marrow. The word ‘acute’ means developing quickly, while ‘lymphoblastic’ refers to the type of white blood cell affected by the condition. ALL accounts for a third of all cancers inflicting children and is also the most common form of leukemia in children. Incidence of the disease peaks in childhood, but it can affect teenagers and young adults too; it then becomes increasingly more common in people over the age of 50.

ALL is a fast growing disease and so it is very important to receive effective therapy soon after diagnosis. Fortunately, most children respond very well to treatment and survival rates are very high. Over the last several decades, advances in the treatment and supportive care of children with ALL have dramatically increased its 5 year survival rates to more than 90%.

ALL is treated according to a treatment plan (also known as a ‘protocol’) and involves a number of phases of treatment; induction, consolidation and maintenance. A combination of chemotherapy drugs that have been carefully selected are given in each phase. The drugs may be given in several different ways: by mouth (tablets or liquid), into a blood vessel (intravenously), into a muscle (intramuscularly), or into the fluid around the spine and brain (intrathecally).The total length of treatment is around 2.5 years for girls and 3.5 years for boys.

PURIXAN (mercaptopurine) oral suspension is an essential drug in combination chemotherapy and is administered in all phase of treatment but is particularly important in the maintenance phase to prevent the disease returning (relapse).

More information on Acute Lymphoblastic Leukemia can be found on several oncology websites provided here.


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How to use Purixan®


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PURIXAN® is indicated for the treatment of patients with acute lymphoblastic leukemia (ALL) as part of a combination chemotherapy maintenance regimen.



Warnings and Precautions


The most consistent, dose-related adverse reaction of PURIXAN is myelosuppression, manifested by anemia, leukopenia, thrombocytopenia, or any combination of these. Monitor CBC and adjust the dosage of PURIXAN for excessive myelosuppression.
Consider testing for thiopurine S-methyltransferase (TPMT) or nucleotide diphosphatase (NUDT15) deficiency in patients with severe myelosuppression or repeated episodes of myelosuppression. TPMT genotyping or phenotyping (red blood cell TPMT activity) and NUDT15 genotyping can identify patients who have reduced activity of these enzymes. Patients with homozygous TPMT or NUDT15 deficiency may require a dose reduction.
Myelosuppression can be exacerbated by coadministration with allopurinol, aminosalicylates or other products that cause myelosuppression. Reduce the dosage of PURIXAN when coadministered with allopurinol.


Mercaptopurine is hepatotoxic. There are reports of deaths attributed to hepatic necrosis associated with the administration of mercaptopurine. Hepatic injury can occur with any dosage but seems to occur with greater frequency when the recommended dosage is exceeded. In some patients, jaundice has cleared following withdrawal of mercaptopurine and reappeared with rechallenge.
Usually, clinically detectable jaundice appears early in the course of treatment (1 to 2 months); however, jaundice has been reported as early as 1 week and as late as 8 years after starting mercaptopurine. The hepatotoxicity has been associated in some cases with anorexia, diarrhea, jaundice and ascites. Hepatic encephalopathy has occurred.
Monitor serum transaminase levels, alkaline phosphatase, and bilirubin levels at weekly intervals when first beginning therapy and at monthly intervals thereafter. Monitor liver tests more frequently in patients who are receiving PURIXAN with other hepatotoxic drugs or with known pre-existing liver disease. Withhold PURIXAN at onset of hepatotoxicity.


Mercaptopurine is immunosuppressive and may impair the immune response to infectious agents or vaccines. Due to the immunosuppression associated with maintenance chemotherapy for ALL, response to all vaccines may be diminished and there is a risk of infection with live virus vaccines. Consult immunization guidelines for immunocompromised patients.

Treatment Related Malignancies

Hepatosplenic T-cell lymphoma has been reported in patients treated with mercaptopurine for inflammatory bowel disease (IBD), an unapproved use. Mercaptopurine is mutagenic in animals and humans, carcinogenic in animals, and may increase the risk of secondary malignancies.
Patients receiving immunosuppressive therapy, including mercaptopurine, are at an increased risk of developing lymphoproliferative disorders and other malignancies, notably skin cancers (melanoma and non-melanoma), sarcomas (Kaposi's and non-Kaposi's) and uterine cervical cancer in situ. The increased risk appears to be related to the degree and duration of immunosuppression. It has been reported that discontinuation of immunosuppression may provide partial regression of the lymphoproliferative disorder.
A treatment regimen containing multiple immunosuppressants (including thiopurines) should therefore be used with caution as this could lead to lymphoproliferative disorders, some with reported fatalities. A combination of multiple immunosuppressants, given concomitantly increases the risk of Epstein-Barr virus (EBV)-associated lymphoproliferative disorders.

Macrophage Activation Syndrome

Macrophage activation syndrome (MAS) (hemophagocytic lymphohistiocytosis) is a known, life-threatening disorder that may develop in patients with autoimmune conditions, in particular with inflammatory bowel disease (IBD), and there could potentially be an increased susceptibility for developing the condition with the use of mercaptopurine (an unapproved use). If MAS occurs, or is suspected, discontinue PURIXAN. Monitor for and promptly treat infections such as EBV and cytomegalovirus (CMV), as these are known triggers for MAS.

Embryo-Fetal Toxicity

PURIXAN can cause fetal harm when administered to a pregnant woman. An increased incidence of miscarriage has been reported in women who received mercaptopurine in the first trimester of pregnancy. Adverse embryo-fetal findings, including miscarriage and stillbirth, have been reported in women who received mercaptopurine after the first trimester of pregnancy. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with PURIXAN and for 6 months after the last dose. Advise males with female partners of reproductive potential to use effective contraception during treatment with PURIXAN and for 3 months after the last dose.

Adverse Reactions

Based on multicenter cooperative group ALL trials, 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% 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.


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To report SUSPECTED ADVERSE REACTIONS, contact Rare Disease Therapeutics, Inc., at 1-844-472-7389, or FDA at 1-800-FDA-1088 or

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