Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Original Manuscript
  • Published:

Pharmacodynamics and Pharmacogenomics

6-Mercaptopurine dosage and pharmacokinetics influence the degree of bone marrow toxicity following high-dose methotrexate in children with acute lymphoblastic leukemia

Abstract

Through inhibition of purine de novo synthesis and enhancement of 6-mercaptopurine (6MP) bioavailability high-dose methotrexate (HDM) may increase the incorporation into DNA of 6-thioguanine nucleotides (6TGN), the cytoxic metabolites of 6MP. Thus, coadministration of 6MP could increase myelotoxicity following HDM. Twenty-one children with standard risk (SR) and 25 with intermediate risk (IR) acute lymphoblastic leukemia (ALL) were studied. During consolidation therapy they received either three courses of HDM at 2 week intervals without concurrent oral 6MP (SR-ALL) or four courses of HDM given at 2 week intervals with 25 mg/m2 of oral 6MP daily (IR-ALL). During the first year of maintenance with oral 6MP (75 mg/m2/day) and oral MTX (20 mg/m2/week) they all received five courses of HDM at 8 week intervals. In all cases, HDM consisted of 5000 mg of MTX/m2 given over 24 h with intraspinal MTX and leucovorin rescue. Erythrocyte levels of 6TGN (E-6TGN) and methotrexate (E-MTX) were, on average, measured every second week during maintenance therapy. When SR consolidation (6MP: 0 mg), IR consolidation (6MP: 25 mg/m2), and SR/IR maintenance therapy (6MP: 75 mg/m2) were compared, white cell and absolute neutrophil count (ANC) nadir, lymphocyte count nadir, thrombocyte count nadir, and hemoglobin nadir after HDM decreased significantly with increasing doses of oral 6MP. Three percent of the HDM courses given without oral 6MP (SR consolidation) were followed by an ANC nadir <0.5 × 109/l compared to 50% of the HDM courses given during SR/IR maintenance therapy. Similarly, only 13% of the HDM courses given as SR-ALL consolidation induced a thrombocyte count nadir <100 × 109/l compared to 58% of the HDM courses given during maintenance therapy. The best-fit model to predict the ANC nadir following HDM during maintenance therapy included the dose of 6MP prior to HDM (β = −0.017, P = 0.001), the average ANC level during maintenance therapy (β = 0.82, P = 0.004), and E-6TGN (β = −0.0029, P = 0.02). The best-fit model to predict the thrombocyte nadir following HDM during maintenance therapy included only mPLATE (β = 0.0057, P = 0.046). In conclusion, the study indicates that reductions of the dose of concurrently given oral 6MP could be one way of reducing the risk of significant myelotoxicity following HDM during maintenance therapy of childhood ALL.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1
Figure 2

Similar content being viewed by others

References

  1. Lilleyman JS, Lennard L . Mercaptopurine metabolism and risk of relapse in childhood lymphoblastic leukemia Lancet 1994 343: 1188–1190

    Article  CAS  PubMed  Google Scholar 

  2. Schmiegelow K, Schrøder H, Gustafsson G, Kristinsson J, Glomstein A, Salmi T, Wranne L . Risk of relapse in childhood acute lymphoblastic leukemia is related to RBC methotrexate and mercaptopurine metabolites during maintenance chemotherapy. Nordic Society for Pediatric Hematology and Oncology J Clin Oncol 1995 13: 345–351

    Article  CAS  PubMed  Google Scholar 

  3. Waters TR, Swann PF . Cytotoxic mechanism of 6-thioguanine: hMutS-alfa, the human mismatch binding heterodimer, binds to DNA containing S6-methylthioguanine Biochemistry 1997 36: 2501–2506

    Article  CAS  PubMed  Google Scholar 

  4. Lennard L . The clinical pharmacology of 6-mercaptopurine Eur J Clin Pharmacol 1992 43: 329–339

    Article  CAS  PubMed  Google Scholar 

  5. Lennard L, Lilleyman JS . Variable mercaptopurine metabolism and treatment outcome in childhood lymphoblastic leukemia (published erratum appears in J Clin Oncol 1990; 8: 567) J Clin Oncol 1989 7: 1816–1823

    Article  CAS  PubMed  Google Scholar 

  6. Weinshilboum RM, Otterness DM, Szumlanski CL . Methylation pharmacogenetics; catechol O-methyltransferase, thiopurine methyltransferase and histamine N-methyltransferase Annu Rev Pharmacol Toxicol 1999 39: 19–52

    Article  CAS  PubMed  Google Scholar 

  7. Frankel LS, Wang YM, Shuster J, Nitschke R, Doering EJ, Pullen J . High-dose methotrexate as part of remission maintenance therapy for childhood acute lymphocytic leukemia: a Pediatric Oncology Group pilot study J Clin Oncol 1983 1: 804–809

    Article  CAS  PubMed  Google Scholar 

  8. Abromowitch M, Ochs J, Pui CH, Fairclough D, Murphy SB, Rivera GK . Efficacy of high-dose methotrexate in childhood acute lymphocytic leukemia: analysis by contemporary risk classifications Blood 1988 71: 866–869

    CAS  PubMed  Google Scholar 

  9. Pui CH . Childhood leukemias New Engl J Med 1995 332: 1618–1630

    Article  CAS  PubMed  Google Scholar 

  10. Rask C, Albertioni F, Bentzen SM, Schrøder H, Peterson C . Clinical and pharmacokinetic risk factors for high-dose methotrexate-induced toxicity in children with acute lymphoblastic leukemia – a logistic regression analysis Acta Oncol 1998 37: 277–284

    Article  CAS  PubMed  Google Scholar 

  11. Peeters M, Koren G, Jakubovicz D, Zipursky A . Physician compliance and relapse rates of acute lymphoblastic leukemia in children Clin Pharmacol Ther 1988 43: 228–232

    Article  CAS  PubMed  Google Scholar 

  12. Schmiegelow K . Prognostic significance of methotrexate and 6-mercaptopurine dosage during maintenance chemotherapy for childhood acute lymphoblastic leukemia (published erratum appears in Pediatr Hematol Oncol 1992; 9: 198) Pediatr Hematol Oncol 1991 8: 301–312

    Article  CAS  PubMed  Google Scholar 

  13. Relling MV, Hancock ML, Boyett JM, Pui CH, Evans WE . Prognostic importance of 6-mercaptopurine dose intensity in acute lymphoblastic leukemia Blood 1999 93: 2817–2823

    CAS  PubMed  Google Scholar 

  14. Balis FM, Holcenberg JS, Zimm S, Tubergen DG, Collins JM, Murphy RF, Gilchrist GS, Hammond D, Poplack DG . The effect of methotrexate on the bioavailability of oral 6-mercaptopurine Clin Pharmacol Ther 1987 41: 384–387

    Article  CAS  PubMed  Google Scholar 

  15. Bökkerink JPM, Bakker MAH, Hulscher TW, DeAbreu RA, Schretlen EDAM . Purine de novo synthesis as the basis of synergism of methotrexate and 6-mercaptopurine in human malignant lymphoblasts of different lineages Biochem Pharmacol 1988 37: 2321–2327

    Article  PubMed  Google Scholar 

  16. Gustafsson G, Kreuger A, Clausen N, Garwicz S, Kristinsson J, Lie SO, Moe PJ, Perkkio M, Yssing M, Saarinen PU . Intensified treatment of acute childhood lymphoblastic leukaemia has improved prognosis, especially in non-high-risk patients: the Nordic experience of 2648 patients diagnosed between 1981 and 1996. Nordic Society of Paediatric Haematology and Oncology (NOPHO) Acta Paediatr 1998 87: 1151–1161

    Article  CAS  PubMed  Google Scholar 

  17. Thomsen JB, Schrøder H, Kristinsson J, Madsen B, Szumlanski C, Weinshilboum R, Andersen JB, Schmiegelow K . Possible carcinogenic effect of 6-mercaptopurine on bone marrow stem cells – relation to thiopurine metabolism Cancer 1999 86: 1080–1086

    Article  CAS  Google Scholar 

  18. Bruunshuus I, Schmiegelow K . Analysis of 6-mercaptopurine, 6-thioguanine nucleotides, and 6- thiouric acid in biological fluids by high-performance liquid chromatography Scand J Clin Lab Invest 1989 49: 779–784

    Article  CAS  PubMed  Google Scholar 

  19. Kamen BA, Takach PL, Vatev R, Caston JD . A rapid, radiochemical-ligand binding assay for methotrexate Anal Biochem 1976 70: 54–63

    Article  CAS  PubMed  Google Scholar 

  20. Andersen JB, Szumlanski C, Weinshilboum RM, Schmiegelow K . Pharmacokinetics, dose adjustments, and 6-mercaptopurine/methotrexate drug interactions in two patients with thiopurine methyltransferase deficiency Acta Paediatr 1998 87: 108–111

    Article  CAS  PubMed  Google Scholar 

  21. Schmiegelow K, Pulczynska MK . Maintenance chemotherapy for childhood acute lymphoblastic leukemia: should dosage be guided by white blood cell counts? Am J Pediatr Hematol Oncol 1990 12: 462–467

    Article  CAS  PubMed  Google Scholar 

  22. Siegel S, Castellan NJ . Non-parametric Statistics for the Behavioral Sciences McGraw-Hill: Singapore 1988

    Google Scholar 

  23. SPSS statistical software for Windows release 10.0.5. SPSS Inc 1999

  24. Synold TW, Relling MV, Boyett JM, Rivera GK, Sandlund JT, Mahmoud H, Crist WM, Pui CH, Evans WE . Blast cell methotrexate-polyglutamate accumulation in vivo differs by lineage, ploidy, and methotrexate dose in acute lymphoblastic leukemia J Clin Invest 1994 94: 1996–2001

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  25. Evans WE, Relling MV, Rodman JH, Crom WR, Boyett JM, Pui C-H . Conventional compared with individualized chemotherapy for childhood acute lymphoblastic leukemia New Engl J Med 1998 338: 499–505

    Article  CAS  PubMed  Google Scholar 

  26. Balis FM, Holcenberg JS, Bleyer WA . Clinical pharmacokinetics of commonly used anticancer drugs Clin Pharmacokinet 1983 8: 202–232

    Article  CAS  PubMed  Google Scholar 

  27. White JC, Goldman ID . Mechanism of action of methotrexate. Free intracellular methotrexate required to suppress dihydrofolate reduction to tetrahydrofolate by Erlich ascites tumor cells in vitro Mol Pharmacol 1976 12: 711–719

    CAS  PubMed  Google Scholar 

  28. Chabner BA, Allegra CJ, Curt GA, Clendeninn NJ, Baram J, Kouzumi S . Polyglutamation of methotrexate: is methotrexate a prodrug? J Clin Invest 1985 76: 907–912

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  29. Innocenti F, Danesi R, Di Paolo A, Loru B, Favre C, Nardi M, Bocci G, Nardini D, Macchia P, Del Tacca M . Clinical and experimental pharmacokinetic interaction between 6-mercaptopurine and methotrexate Cancer Chemother Pharmacol 1996 37: 409–414

    Article  CAS  PubMed  Google Scholar 

  30. Frei E, Karon M, Levin RH, Freireich EJ, Taylor RJ, Hananian J, Selawry O, Holland JF, Hoogstraten B, Wolman IJ, Abir E, Sawitsky A, Lee S, Mills SD, Burgert EOJ, Spurr CL, Patterson RB, Ebaugh FG, James GW, Moon JH . The effectiveness of combinations of antileukemic agents in inducing and maintaining remission in children with acute leukemia Blood 1965 26: 642–656

    PubMed  Google Scholar 

  31. Lonsdale D, Gehan EA, Fernbach DJ, Sullivan MP, Lane DM, Ragab AH . Interrupted vs. continued maintenance therapy in childhood acute leukemia Cancer 1975 36: 341–352

    Article  CAS  PubMed  Google Scholar 

  32. Schmiegelow K, Schrøder H, Schmiegelow M . Methotrexate and 6-mercaptopurine maintenance chemotherapy for childhood acute lymphoblastic leukemia: dose adjustments by white cell counts or by pharmacokinetic parameters Cancer Chemother Pharmacol 1994 34: 209–215

    Article  CAS  PubMed  Google Scholar 

  33. Giverhaug T, Loennechen T, Aarbakke J . The interaction of 6-mercaptopurine (6-MP) and methotrexate (MTX) Gen Pharmacol 1999 33: 341–346

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

The commitment and skillful technical assistance of Jannie Gregers, Kristine Nielsen, and Michael Timm are greatly appreciated. The study has received financial support from The Carl and Ellen Hertz Foundation, The Danish Childrens Cancer Foundation, The Danish Cancer Society (grant Nos 91-048, 92-017, 93-017, 95-100-28), The JPC Foundation, The Lundbeck Foundation (38/99), and The Minister Erna Hamilton Foundation.

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Schmiegelow, K., Bretton-Meyer, U. 6-Mercaptopurine dosage and pharmacokinetics influence the degree of bone marrow toxicity following high-dose methotrexate in children with acute lymphoblastic leukemia. Leukemia 15, 74–79 (2001). https://doi.org/10.1038/sj.leu.2401986

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/sj.leu.2401986

Keywords

This article is cited by

Search

Quick links