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.
Mercaptopurine Tablets are 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, mercaptopurine induces complete remission in approximately 25% of pediatric patients and 10% of adults. However, reliance upon mercaptopurine 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 mercaptopurine 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. Mercaptopurine, as a single agent, is capable of significantly prolonging complete remission duration; however, combination therapy has produced remission duration longer than that achieved with mercaptopurine alone.
Acute Myelogenous (and Acute Myelomonocytic) Leukemia
As a single agent, mercaptopurine 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
Mercaptopurine is not effective for prophylaxis or treatment of central nervous system leukemia.
Mercaptopurine is not effective in chronic lymphatic leukemia, the lymphomas (including Hodgkin’s Disease), or solid tumors.
Published Studies Related to 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. [2009.10.07]
CONCLUSIONS: Azathioprine and 6-mercaptopurine are effective therapy for inducing remission in active Crohn's disease. The OR of response increases after > 17 weeks of therapy, suggesting that there is a minimum length of time for a trial of azathioprine or 6-mercaptopurine therapy. Adverse events were more common among patients on active therapy.
Clinical Trials Related to Mercaptopurine
Multicenter Clinical Efficacy and Safety Study of Delayed Release 6MP in Crohn's Disease [Recruiting]
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
Bioequivalence of An Oral Mercaptopurine Suspension 100 Mg / 5 Ml Versus Tablet in Healthy Male Subjects Under Fasting Conditions [Recruiting]
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.
Open Label Extension Study to Protocol C2/13/DR-6MP-02 [Not yet recruiting]
The open label extension study (Protocol C2/13/DR-6MP-02 EXT) is designed to evaluate the
clinical efficacy and safety of 80 mg DR-6MP test formulation for an additional 12 weeks in
subjects who already completed 12 weeks of Protocol C2/13/DR-6MP-02. Crohn's disease (CD)
therapy is aimed at reducing inflammation via induction of remission after a flare-up and
maintenance of the remission for as long as possible. The questions being asked in this
extension study are:
1. For subjects who received 80 mg DR-6MP for 12 weeks: Can the clinical efficacy and
safety status achieved following 12 weeks of treatment be maintained or improved
following an additional 12 weeks of DR-6MP treatment?
2. For subjects who received oral Purinethol (1-1. 5 mg/kg daily) for 12 weeks: Can the
clinical efficacy and safety at 12 weeks be maintained or improved following the
introduction of 12 weeks of 80 mg DR-6MP treatment?
A Clinical Trial in Patients With BRCA Defective Tumours [Recruiting]
This study will evaluate the efficacy and safety of 6MP in combination with methotrexate in
patients with breast or ovarian cancer who are known to have a BRCA mutation. 6MP is used
instead of 6TG as it is converted to the same cytotoxic moiety as 6TG, ie. thioguanine
nucleotides, but with reduced toxic effects. Low dose methotrexate is used in combination
with 6MP as it promotes the formation of thioguanine nucleotides.
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).
Reports of Suspected Mercaptopurine Side Effects
Acute Myeloid Leukaemia (26),
OFF Label USE (24),
Maternal Exposure During Pregnancy (15),
Hepatosplenic T-Cell Lymphoma (15), more >>
PATIENT REVIEWS / RATINGS / COMMENTS
Based on a total of 1 ratings/reviews, Mercaptopurine has an overall score of 8. The effectiveness score is 8 and the side effect score is 8. The scores are on ten point scale: 10 - best, 1 - worst.
Mercaptopurine review by 37 year old female patient
|Overall rating:|| || |
|Effectiveness:|| || Considerably Effective|
|Side effects:|| || Mild Side Effects|
|Condition / reason:|| || Crohn's disease|
|Dosage & duration:|| || 100 mg taken 1 time every evening for the period of three years +|
|Other conditions:|| || High cholesterol, depression|
|Other drugs taken:|| || Niaspan, Wellbutrin|
|Benefits:|| || I was prescribed the drug Mercaptopurine after two previous treatment drugs had begun to prove less effective than before. The doctor started on a higher course of the medicine, but the dose is currently 100mg (2 pills) every evening. There was a significant reduction in Crohn's disease symptoms, particularly general intestinal cramping. This was particularly helpful for cramping that tended to occur as I was relaxing to go to sleep. |
|Side effects:|| || Though the Crohn's disease in itself makes me tired, and I feel that the addition of the Mercaptopurine has added to my general fatigue. The fatigue abated somewhat as the dose was lowered (the doctor started at a more aggressive dose). I also seem to catch every bug that is going around. By suppressing my immune system I believe the Mercaptopurine makes it easier for seasonal illnesses to set up shop.|
|Comments:|| || I was diagnosed with Crohn's disease about eight years ago. The doctor started with a series of Remicade and a prescription of Prednisone. This combination made it possible for me to eat again - hurray! As for maintenance drugs, I have been on several, including Asacol and Pentasa. There were probably others, but those are the two that I definitely remember. It seemed as though my body would react well to a drug, but then the drug eventually lost that initial effectiveness. I have been on Mercaptopurine for 3-4 years now, and am getting ready to ask to move to a new drug. Mercaptopurine seems to be continuing to do a good job as a drug, but I'd like to find one that may be less deleterious to my liver.|
Page last updated: 2010-10-05