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Bayoumy AB, Simsek M, Seinen ML, Mulder CJJ, Ansari A, Peters GJ, De Boer NK. The continuous rediscovery and the benefit-risk ratio of thioguanine, a comprehensive review. Expert Opin Drug Metab Toxicol 2020; 16:111-123. [PMID: 32090622 DOI: 10.1080/17425255.2020.1719996] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Introduction: In the 1950s, thioguanine (TG), a thiopurine-derivative together with azathioprine (AZA) and mercaptopurine (MP), were developed for the treatment of childhood leukemia. Over the years, the use of TG was also explored for other, mainly immune-mediated and inflammatory, diseases such as in the field of dermatology and rheumatology (e.g. psoriasis, systemic lupus erythematosus (SLE)) and gastroenterology and hepatology (e.g. inflammatory bowel diseases (IBD), autoimmune hepatitis).Areas covered: This review provides a comprehensive overview of all the clinical uses of TG and describes its mechanism of action, pharmacokinetic/pharmacodynamic features, and toxicity.Expert opinion: Thioguanine has shown beneficial clinical effects in hematological (particularly leukemia) and several immune-inflammatory diseases including psoriasis, SLE, polycythemia vera, Churg-Strauss syndrome, IBD, collagenous sprue, refractory celiac disease, and autoimmune hepatitis. Thioguanine is not effective in treating solid-cancers. At relatively low dosages, i.e. 0.2- 0.3mg/kg/day or 20 mg/day, TG has a favorable risk-benefit ratio and is a safe and effective drug in the long-term treatment of amongst other IBD patients. Thioguanine toxicity, especially myelotoxicity, and hepatotoxicity, including nodular regenerative hyperplasia (NRH) of the liver, is limited when dosed adequately. The occurrence of NRH appears dose-dependent and has been especially described during high dose TG above 40 mg/day.
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Affiliation(s)
- Ahmed B Bayoumy
- Amsterdam UMC, Department of Gastroenterology and Hepatology, VU University Medical Center, Amsterdam, Netherlands
| | - Melek Simsek
- Amsterdam UMC, Department of Gastroenterology and Hepatology, VU University Medical Center, AG&M Research Institute, Amsterdam, Netherlands
| | - Margien L Seinen
- Amsterdam UMC, Department of Gastroenterology and Hepatology, VU University Medical Center, Amsterdam, Netherlands
| | - Chris J J Mulder
- Amsterdam UMC, Department of Gastroenterology and Hepatology, VU University Medical Center, Amsterdam, Netherlands
| | - Azhar Ansari
- Department of Gastroenterology, Surrey and Sussex NHS, Easy Surrey Hospital, Surrey, UK
| | - Godefridus J Peters
- Amsterdam UMC, VU University Medical Center, Laboratory Medical Oncology, Cancer Center Amsterdam, Amsterdam, Netherlands.,Department of Biochemistry, Medical University of Gdansk, Gdansk, Poland
| | - Nanne K De Boer
- Amsterdam UMC, Department of Gastroenterology and Hepatology, VU University Medical Center, AG&M Research Institute, Amsterdam, Netherlands
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Ward MG, Patel KV, Kariyawasam VC, Goel R, Warner B, Elliott TR, Blaker PA, Irving PM, Marinaki AM, Sanderson JD. Thioguanine in inflammatory bowel disease: Long-term efficacy and safety. United European Gastroenterol J 2016; 5:563-570. [PMID: 28588888 DOI: 10.1177/2050640616663438] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 07/17/2016] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Thioguanine (TG) is efficacious in inflammatory bowel disease (IBD), but its toxicity, particularly nodular regenerative hyperplasia (NRH) of the liver, has limited its use. We assessed the long-term clinical outcomes and safety of TG in patients whom were intolerant or refractory to conventional immunomodulators. METHODS This is a retrospective, single-centre study of IBD patients treated with TG from 2001-2013. Response was defined as clinical remission (Harvey-Bradshaw Index < 5 for Crohn's disease (CD), Simple Clinical Colitis Activity Index < 4 for ulcerative colitis (UC)) without corticosteroids or, if receiving anti-tumour-necrosis-factor (anti-TNF) therapy, absence of dose escalation. We recorded TG failure, withdrawal and adverse events. Patients were monitored with biochemistry, liver biopsy and/or magnetic resonance imaging (MRI). RESULTS 54 patients (47 CD and 7 UC) whom received TG (mean dose: 27 mg/d (range: 20-40 mg/d)) as monotherapy (n = 36) or concomitantly with anti-TNF (n = 18) for a median inter-quartile range of 16 (5-37) months (126 patient-years of follow-up). 32 (59%) patients responded to TG at 6 months and 23 (43%) at 12 months. Pancreatitis did not recur amongst the 19 patients with prior thiopurine-induced pancreatitis. 16 (30%) patients ceased TG due to intolerance or toxicity (four serious); NRH was not observed. 6-thioguanine nucleotide concentrations did not correlate with efficacy nor with toxicity. CONCLUSIONS TG was efficacious and well tolerated in one out of two patients who had previously failed conventional immunomodulators. NRH did not occur.
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Affiliation(s)
- Mark G Ward
- Department of Gastroenterology, Guy's and St. Thomas' Hospital, NHS Foundation Trust, London, UK
| | - Kamal V Patel
- Department of Gastroenterology, Guy's and St. Thomas' Hospital, NHS Foundation Trust, London, UK
| | - Viraj C Kariyawasam
- Department of Gastroenterology, Guy's and St. Thomas' Hospital, NHS Foundation Trust, London, UK
| | - Rishi Goel
- Department of Gastroenterology, Guy's and St. Thomas' Hospital, NHS Foundation Trust, London, UK
| | - Ben Warner
- Department of Gastroenterology, Guy's and St. Thomas' Hospital, NHS Foundation Trust, London, UK
| | - Tim R Elliott
- Department of Gastroenterology, Guy's and St. Thomas' Hospital, NHS Foundation Trust, London, UK
| | - Paul A Blaker
- Department of Gastroenterology, Guy's and St. Thomas' Hospital, NHS Foundation Trust, London, UK
| | - Peter M Irving
- Department of Gastroenterology, Guy's and St. Thomas' Hospital, NHS Foundation Trust, London, UK.,Diabetes and Nutritional Sciences Division, School of Medicine, King's College London, London, UK
| | - Anthony M Marinaki
- Purine Research Laboratory, Viapath, Guy's and St. Thomas' Hospital, London, UK
| | - Jeremy D Sanderson
- Department of Gastroenterology, Guy's and St. Thomas' Hospital, NHS Foundation Trust, London, UK.,Diabetes and Nutritional Sciences Division, School of Medicine, King's College London, London, UK
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Abstract
Sixty years ago, 6-thioguanine (6-TG) was introduced into the clinic. We suggest its full potential in therapy may not have been reached. In this paper, we contrast 6-TG and the more widely used 6-mercaptopurine; discuss 6-TG metabolism, pharmacokinetics, dosage and schedule; and summarize many of the early studies that have shown infrequent but nevertheless positive results with 6-TG treatment of cancers. We also consider studies that suggest that combinations of 6-TG with other agents may enhance antitumor effects. Although not yet tested in man, 6-TG has recently been proposed to treat a wide variety of cancers with a high frequency of homozygous deletion of the gene for methylthioadenosine phosphorylase (MTAP), often codeleted with the adjacent tumor suppressor CDKN2A (p16). Among the cancers with a high frequency of MTAP deficiency are leukemias, lymphomas, mesothelioma, melanoma, biliary tract cancer, glioblastoma, osteosarcoma, soft tissue sarcoma, neuroendocrine tumors, and lung, pancreatic, and squamous cell carcinomas. The method involves pretreatment with the naturally occurring nucleoside methylthioadenosine (MTA), the substrate for the enzyme MTAP. MTA pretreatment protects normal host tissues, but not MTAP-deficient cancers, from 6-TG toxicity and permits administration of doses of 6-TG that are much higher than can now be safely administered. The combination of MTA/6-TG has produced substantial shrinkage or slowing of growth in two different xenograft human tumor models: lymphoblastic leukemia and metastatic prostate carcinoma with neuroendocrine features. Further development and a clinical trial of the proposed MTA/6-TG treatment of MTAP-deficient cancers seem warranted.
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Affiliation(s)
- Pashna N Munshi
- Rutgers Robert Wood Johnson University Hospital and Rutgers Cancer Institute of New Jersey, Departments of Pharmacology, Biochemistry, and Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA; Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Martin Lubin
- Rutgers Robert Wood Johnson University Hospital and Rutgers Cancer Institute of New Jersey, Departments of Pharmacology, Biochemistry, and Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA; Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Joseph R Bertino
- Rutgers Robert Wood Johnson University Hospital and Rutgers Cancer Institute of New Jersey, Departments of Pharmacology, Biochemistry, and Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA; Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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