PURINETHOL (mercaptopurine) was synthesized and developed by Hitchings, Elion, and associates at the Wellcome Research Laboratories. It is one of a large series of purine analogues which interfere with nucleic acid biosynthesis and has been found active against human leukemias.
PURINETHOL (mercaptopurine) is indicated for remission induction and maintenance therapy of acute lymphatic leukemia. The response to this agent depends upon the particular subclassification of acute lymphatic leukemia and the age of the patient (pediatric patient or adult).
Acute Lymphatic (Lymphocytic, Lymphoblastic) Leukemia: Given as a single agent for remission induction, PURINETHOL induces complete remission in approximately 25% of pediatric patients and 10% of adults. However, reliance upon PURINETHOL alone is not justified for initial remission induction of acute lymphatic leukemia since combination chemotherapy with vincristine, prednisone, and L-asparaginase results in more frequent complete remission induction than with PURINETHOL alone or in combination. The duration of complete remission induced in acute lymphatic leukemia is so brief without the use of maintenance therapy that some form of drug therapy is considered essential. PURINETHOL, as a single agent, is capable of significantly prolonging complete remission duration; however, combination therapy has produced remission duration longer than that achieved with PURINETHOL alone.
Acute Myelogenous (and Acute Myelomonocytic) Leukemia: As a single agent, PURINETHOL will induce complete remission in approximately 10% of pediatric patients and adults with acute myelogenous leukemia or its subclassifications. These results are inferior to those achieved with combination chemotherapy employing optimum treatment schedules.
Central Nervous System Leukemia: PURINETHOL is not effective for prophylaxis or treatment of central nervous system leukemia.
Other Neoplasms: PURINETHOL is not effective in chronic lymphatic leukemia, the lymphomas (including Hodgkins Disease), or solid tumors.
Published Studies Related to Purinethol (Mercaptopurine)
Randomized trial to compare LSA2L2-type maintenance therapy to daily 6-mercaptopurine and weekly methotrexate with vincristine and dexamethasone pulse for children with acute lymphoblastic leukemia. [2010.08]
CONCLUSIONS: There were no differences in the EFS between the different maintenance therapies in each risk group; however, grade IV liver toxicity occurred more often in the patients receiving 6-MP/MTX with VCR and DEX therapy than in patients receiving LSA2L2. (c) 2010 Wiley-Liss, Inc.
Azathioprine or 6-mercaptopurine for induction of remission in Crohn's disease. [2010.06.16]
CONCLUSIONS: Azathioprine and 6-mercaptopurine are effective therapy for inducing remission in active Crohn's disease. Adverse events were more common among patients on active therapy.
Benefits of the intermittent use of 6-mercaptopurine and methotrexate in maintenance treatment for low-risk acute lymphoblastic leukemia in children: randomized trial from the Brazilian Childhood Cooperative Group--protocol ALL-99. [2010.04.10]
PURPOSE To describe event-free survival (EFS) and toxicities in children with low-risk acute lymphoblastic leukemia (ALL) assigned to receive either continuous 6-mercaptopurine (6-MP) and weekly methotrexate (MTX) or intermittent 6-MP with intermediate-dose MTX, as maintenance treatment... Boys treated with the intermittent schedule had significantly better EFS.
Oral 6-mercaptopurine versus oral 6-thioguanine and veno-occlusive disease in children with standard-risk acute lymphoblastic leukemia: report of the Children's Oncology Group CCG-1952 clinical trial. [2010.04.08]
The Children's Cancer Group 1952 (CCG-1952) clinical trial studied the substitution of oral 6-thioguanine (TG) for 6-mercaptopurine (MP) and triple intrathecal therapy (ITT) for intrathecal methotrexate (IT-MTX) in the treatment of standard-risk acute lymphoblastic leukemia...
Azathioprine or 6-mercaptopurine for induction of remission in Crohn's disease. 
CONCLUSIONS: Azathioprine and 6-mercaptopurine are effective therapy for
Clinical Trials Related to Purinethol (Mercaptopurine)
Pilot Comparative Bioavailability Study of 6Mercaptopurine (Delayed Release vs. Purinethol) in Crohns Disease Patients [Completed]
The study is being conducted to evaluate the pharmacokinetic parameters (Cmax, Tmax and AUC)
of the new delayed release, lowered dose, 40 mg 6MP test formulation as compared to standard
6MP (100 mg Purinethol) in 12 patients with Crohn's Disease.
The study is being undertaken to prove that the new test formulation is indeed
delayed-release and targeted to the ileum, and that the levels of 6MP in the blood following
local absorption are lower than that seen following standard Purinethol dosing. This should
result in lower, safer mercaptopurine dosing, allowing for uninterrupted treatment with
fewer side effects.
Multicenter Clinical Efficacy and Safety Study of Delayed Release 6MP in Crohn's Disease [Terminated]
The study is designed to evaluate the clinical efficacy and safety of daily treatment for 12
weeks of oral administration of a delayed release, locally delivered 6MP (mercaptopurine)
drug (80 mg), as compared to standard Purinethol (at a dose of 1-1. 5 mg/kg/body weight), in
alleviating the clinical, immunological and mucosal signs and symptoms of moderately active
Study on Two Different Formulations of 6-mercaptopurine. Tablet Versus Oral Liquid [Recruiting]
Acute lymphoblastic leukemia (ALL) accounts for 30 % of all childhood malignancies. The
patients undergo four phases of treatment, finishing with a late maintenance phase in which
6-mercaptopurine and Methotrexate are essential components. Insufficient treatment intensity
in this phase is associated with increased risk of relapse. Excessive variation in the
bioavailability of 6-mercaptopurine has been observed which can cause both risks of
undertreatment/relapse as well as overtreatment with severe side effects.
In the attempt to achieve individualized 6-mercaptopurine dosing different approaches have
been pursued. Nonetheless variation in bioavailability remains a problem.
Earlier, oral tablets of 50 mg (Purinethol) were the only administration form of
6-mercaptopurine and it was primarily designed for adult patients. Challenges with accurate
dosing and getting the children to swallow the tablets have been a widespread problem,
forcing the caregivers to divide or crush the tablets as well as having to administer
different dosages over 2-3 days. Due to these problems, an oral liquid formulation of
6-mercaptopurine (Xaluprine) has been developed. However this oral liquid has only been
tested on healthy adult volunteers, and not on the target group, childhood patients. This
project will assess the bioavailability and plasma kinetics of oral liquid and tablet
formulation of 6-mercaptopurine in children with acute lymphoblastic leukemia.
The investigators hypothesize to observe comparable plasma kinetics, in children with acute
lymphoblastic leukemia when treated with 6-mercaptopurine in the form of a tablet and oral
liquid formulation, as previously observed in healthy adults.
Comparative Pharmacokinetics of a Compounded 6-mercaptopurine Liquid Formulation Preparation and Tablets [Recruiting]
The purpose of this study is to compare the pharmacokinetics of a routinely used compounded
liquid formulation of 6-mercaptopurine (6-MP) with commercially available tablets in
patients who are receiving treatment with 6-MP as part of their clinical treatment for acute
lymphoblastic leukemia (ALL).
Bioequivalence of An Oral Mercaptopurine Suspension 100 Mg / 5 Ml Versus Tablet in Healthy Male Subjects Under Fasting Conditions [Completed]
The primary objective of this study is to determine whether the test product, mercaptopurine
oral 100 mg/5 mL suspension, and the reference product, Purinethol® 50 mg tablets are
bioequivalent. For this purpose the PK profile of 6-mercaptopurine (6-MP) will be compared
after administration of a single dose of each of the two formulations, under fasting
conditions. The secondary objective is to assess the safety and tolerability of the test
product, mercaptopurine oral 100 mg/5 mL suspension.
Reports of Suspected Purinethol (Mercaptopurine) Side Effects
Crohn's Disease (7),
Drug Ineffective (6),
Abdominal Pain (5),
Rectal Haemorrhage (5),
Post Procedural Infection (5),
Hepatosplenic T-Cell Lymphoma (4),
Weight Decreased (3),
Cholestasis (3), more >>
Page last updated: 2013-02-10