Mercaptopurine (Mercaptopurine) - Summary

MERCAPTOPURINE SUMMARY

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.

Other Neoplasms

Mercaptopurine is not effective in chronic lymphatic leukemia, the lymphomas (including Hodgkin’s Disease), or solid tumors.

See all indications & dosage >>

NEWS HIGHLIGHTS

Published Studies Related to Mercaptopurine

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.

Toxicity and efficacy of 6-thioguanine versus 6-mercaptopurine in childhood lymphoblastic leukaemia: a randomised trial. [2006.10.14]
BACKGROUND: 6-mercaptopurine has been a standard component of long-term continuing treatment for childhood lymphoblastic leukaemia, whereas 6-thioguanine has been mainly used for intensification courses. Since preliminary data have shown that 6-thioguanine is more effective than 6-mercaptopurine, we compared the efficacy and toxicity of the two drugs for childhood lymphoblastic leukaemia... INTERPRETATION: Compared with 6-mercaptopurine, 6-thioguanine causes excess toxicity without an overall benefit. 6-mercaptopurine should remain the thiopurine of choice for continuing therapy of childhood lymphoblastic leukaemia.

Intravenous 6-mercaptopurine decreases salvage after relapse in childhood acute lymphoblastic leukemia: a report from the Children's Cancer Group study CCG 1922. [2005.07]
PURPOSE: To compare outcomes of patients with NCI standard risk acute lymphoblastic leukemia (ALL) who relapsed after being randomized to receive either oral or intravenous 6-mercaptopurine (6MP) in the Children's Cancer Group study CCG 1922... CONCLUSION: Treatment with intravenous 6MP during a brief period of total therapy had a significant negative impact on the prognosis in childhood ALL even though oral 6MP was used during maintenance.

Value of intravenous 6-mercaptopurine during continuation treatment in childhood acute lymphoblastic leukemia and non-Hodgkin's lymphoma: final results of a randomized phase III trial (58881) of the EORTC CLG. [2005.05]
Between November 1990 and November 1996, EORTC Children Leukemia Group conducted a randomized trial in de novo acute lymphoblastic leukemia and lymphoblastic non-Hodgkin's lymphoma patients using a Berlin-Frankfurt-Munster protocol to evaluate the monthly addition of intravenous 6-mercaptopurine (i.v...

more studies >>

Clinical Trials Related to Mercaptopurine

Fasting Study of Mercaptopurine 50 mg and Purinethol® Tablets 50 mg [Completed]
The objective of this study was to investigate the bioequivalence of Mylan's mercaptopurine 50 mg tablets to Gate's Purinethol® 50 mg tablets following a single, oral 50 mg (1 x 50 mg) dose administered under fasting conditions.

Bioequivalence Study of 6-Mercaptopurine Under Fasting Conditions [Completed]
The objective of this study was to assess the bioequivalence of a potential generic 6-mercaptopurine 50 mg tablet formulation compared with GlaxoSmithKline Purinethol® (mercaptopurine) 50-mg scored tablets following a single 50 mg oral dose administered in the fasted state.

Pilot Comparative Bioavailability Study of 6Mercaptopurine (Delayed Release vs. Purinethol) in Crohns Disease Patients [Not yet recruiting]
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.

ALL2008 Protocol for Childhood Acute Lymphoblastic Leukemia (ALL) - 6MP Consolidation Therapy [Recruiting]
The purpose of this study is to increase the fraction of patients, who become MRD-negative during consolidation for the non-HR ALL group through individualized intensification of the 6MP-dosage days 30-85.

Efficacy Study of Targeted, Local Delivery of Drugs to Treat Crohn's Disease [Recruiting]
The study is being undertaken to evaluate whether delayed-release medications, designed to begin to open in the lower intestinal tract, the main site of Crohn's Disease, are more effective than standard systemically delivered drugs to promote remission or response in CD patients. It is hypothesized that the delayed-release medications will go right to the injured tissue and heal the disease more quickly.

The delayed-release test drugs are 6-mercaptopurine (at a dose of 40 mg daily) or calcitriol (at a dose of 5 mcg three times a week) versus Purinethol (6-MP at a dose of 1-2 mg/kg body weight daily). Calcitriol is a synthetically manufactured replica of a natural substance in the body that is derived from Vitamin D. There is much medical evidence that shows that lack of Vitamin D can be a possible risk factor in developing autoimmune disorders, including Crohn's Disease. Moreover, calcitriol has been shown in animal models to improve the symptoms of Crohn's Disease.

more trials >>

PATIENT REVIEWS / RATINGS / COMMENTS

Mercaptopurine review by 37 year old female patient
		Rating
Overall rating:
Effectiveness:		Considerably Effective
Side effects:		Mild Side Effects
		Treatment Info
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
		Reported Results
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.