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Therapeutic Drug Monitoring of Oral Anti-Hormonal Drugs in Oncology

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Abstract

Oral anti-hormonal drugs are essential in the treatment of breast and prostate cancer. It is well known that the interpatient variability in pharmacokinetic exposure is high for these agents and exposure–response relationships exist for many oral anti-hormonal drugs. Yet, they are still administered at fixed doses. This could lead to underdosing and thus suboptimal efficacy in some patients, while other patients could be overdosed resulting in unnecessary side effects. Therapeutic drug monitoring (TDM), individualized dosing based on measured blood concentrations of the drug, could therefore be a valid option to further optimize treatment. In this review, we provide an overview of relevant clinical pharmacokinetic and pharmacodynamic characteristics of oral anti-hormonal drugs in oncology and translate these into practical guidelines for TDM. For some agents, TDM targets are not well established yet and as a reference the median pharmacokinetic exposure could be targeted (exemestane: minimum plasma concentration (Cmin) 4.1 ng/mL and enzalutamide: Cmin 11.4 mg/L). However, for most drugs, exposure–efficacy analyses could be translated into specific targets (abiraterone: Cmin 8.4 ng/mL, anastrozole: Cmin 34.2 ng/mL, and letrozole: Cmin 85.6 ng/mL). Moreover, prospective clinical trials have shown TDM to be feasible for tamoxifen, for which the exposure–efficacy threshold of its active metabolite endoxifen is 5.97 ng/mL. Based on the available data, we therefore conclude that individualized dosing based on drug concentrations is feasible and promising for oral anti-hormonal drugs and should be developed further and implemented into clinical practice.

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References

  1. Siegel RL, Miller KD, Jemal A. Cancer statistics. CA Cancer J Clin. 2016;66:7–30.

    Article  Google Scholar 

  2. Committee for Medicinal Products for Human Use European Medicines Agency. Abiraterone European public assessment report. 2011. http://www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Product_Information/human/002321/WC500112858.pdf. Accessed 26 May 2018.

  3. Verheijen R, Yu H, Schellens J, Beijnen J, Steeghs N, Huitema A. Practical recommendations for therapeutic drug monitoring of kinase inhibitors in oncology. Clin Pharmacol Ther. 2017;102:765–76.

    Article  Google Scholar 

  4. Yu H, Steeghs N, Nijenhuis C, Schellens J, Beijnen J, Huitema A. Practical guidelines for therapeutic drug monitoring of anticancer tyrosine kinase inhibitors: focus on the pharmacokinetic targets. Clin Pharmacokinet. 2014;53:305–25.

    Article  CAS  Google Scholar 

  5. Beumer JH. Without therapeutic drug monitoring, there is no personalized cancer care. Clin Pharmacol Ther. 2013;93:228–30.

    Article  CAS  Google Scholar 

  6. Paci A, Veal G, Bardin C, Levêque D, Widmer N, Beijnen J, et al. Review of therapeutic drug monitoring of anticancer drugs part 1: cytotoxics. Eur J Cancer. 2014;50:2010–9.

    Article  CAS  Google Scholar 

  7. Widmer N, Bardin C, Chatelut E, Paci A, Beijnen J, Levêque D, et al. Review of therapeutic drug monitoring of anticancer drugs part two: targeted therapies. Eur J Cancer. 2014;50:2020–36.

    Article  CAS  Google Scholar 

  8. Fox P, Balleine RL, Lee C, Gao B, Balakrishnar B, Menzies AM, et al. Dose escalation of tamoxifen in patients with low endoxifen level: evidence for therapeutic drug monitoring: the TADE study. Clin Cancer Res. 2016;22:3164–71.

    Article  CAS  Google Scholar 

  9. De Wit D, Guchelaar HJ, Den Hartigh J, Gelderblom H, Van Erp NP. Individualized dosing of tyrosine kinase inhibitors: are we there yet? Drug Discov Today. 2015;20:18–36.

    Article  Google Scholar 

  10. US Food and Drug Administration. Center for Drug Evaluation and Research. Abiraterone clinical pharmacology and biopharmaceutics review. 2011. http://www.accessdata.fda.gov/drugsatfda_docs/nda/2011/202379Orig1s000ClinPharmR.pdf. Accessed 26 May 2018.

  11. James ND, de Bono JS, Spears MR, Clarke NW, Mason MD, Dearnaley DP, et al. Abiraterone for prostate cancer not previously treated with hormone therapy. N Engl J Med. 2017;377:338–51.

    Article  CAS  Google Scholar 

  12. Chi KN, Spratlin J, Kollmannsberger C, North S, Pankras C, Gonzalez M, et al. Food effects on abiraterone pharmacokinetics in healthy subjects and patients with metastatic castration-resistant prostate cancer. J Clin Pharmacol. 2015;55:1406–14.

    Article  CAS  Google Scholar 

  13. Carton E, Noe G, Huillard O, Golmard L, Giroux J, Cessot A, et al. Relation between plasma trough concentration of abiraterone and prostate-specific antigen response in metastatic castration-resistant prostate cancer patients. Eur J Cancer. 2017;72:54–61.

    Article  CAS  Google Scholar 

  14. Stuyckens K, Saad F, Xu XS, Ryan CJ, Smith MR, Griffin TW, et al. Population pharmacokinetic analysis of abiraterone in chemotherapy-naïve and docetaxel-treated patients with metastatic castration-resistant prostate cancer. Clin Pharmacokinet. 2014;53:1149–60.

    Article  CAS  Google Scholar 

  15. Attard G, Reid AHM, Yap TA, Raynaud F, Dowsett M, Settatree S, et al. Phase I clinical trial of a selective inhibitor of CYP17, abiraterone acetate, confirms that castration-resistant prostate cancer commonly remains hormone driven. J Clin Oncol. 2008;26:4563–71.

    Article  CAS  Google Scholar 

  16. Steven X, Charles X, Kim JR, Matthew S, Saad F, Griffin TW, et al. Modeling the relationship between exposure to abiraterone and prostate-specific antigen dynamics in patients with metastatic castration-resistant prostate cancer. Clin Pharmacokinet. 2017;56:55–63.

    Article  Google Scholar 

  17. Li Z, Bishop AC, Alyamani M, Garcia JA, Dreicer R, Bunch D, et al. Conversion of abiraterone to D4A drives anti-tumour activity in prostate cancer. Nature. 2015;523:347–51.

    Article  CAS  Google Scholar 

  18. Emamekhoo H, Li Z, Sharifi N. Clinical significance of D4A in prostate cancer therapy with abiraterone. Cell Cycle. 2015;14:3213–4.

    Article  CAS  Google Scholar 

  19. US Food and Drug Administration. Center for Drug Evaluation and Research. Enzalutamide clinical pharmacology and biopharmaceutics review. 2012. http://www.accessdata.fda.gov/drugsatfda_docs/nda/2012/203415Orig1s000ClinPharmR.pdf. Accessed 26 May 2018.

  20. Gibbons JA, Ouatas T, Krauwinkel W, Ohtsu Y, van der Walt J-S, Beddo V, et al. Clinical pharmacokinetic studies of enzalutamide. Clin Pharmacokinet. 2015;54:1043–55.

    Article  CAS  Google Scholar 

  21. Scher HI, Anand A, Rathkopf D, Shelkey J, Morris MJ, Danila DC, et al. Antitumour activity of MDV3100 in castration-resistant prostate cancer: a phase 1-2 study. Lancet. 2010;375:1437–46.

    Article  CAS  Google Scholar 

  22. Armstrong AJ, Saad F, Phung D, Dmuchowski C, Shore ND, Fizazi K, et al. Clinical outcomes and survival surrogacy studies of prostate-specific antigen declines following enzalutamide in men with metastatic castration-resistant prostate cancer previously treated with docetaxel. Cancer. 2017;123:2303–11.

    Article  CAS  Google Scholar 

  23. de Vries Schultink AHM, Zwart W, Linn SC, Beijnen JH, Huitema ADR. Effects of pharmacogenetics on the pharmacokinetics and pharmacodynamics of tamoxifen. Clin Pharmacokinet. 2015;54:797–810.

    Article  Google Scholar 

  24. Jager NGL, Rosing H, Schellens JHM, Linn SC, Beijnen JH. Tamoxifen dose and serum concentrations of tamoxifen and six of its metabolites in routine clinical outpatient care. Breast Cancer Res Treat. 2014;143:477–83.

    Article  CAS  Google Scholar 

  25. Borges S, Desta Z, Li L, Skaar TC, Ward BA, Nguyen A, et al. Quantitative effect of CYP2D6 genotype and inhibitors on tamoxifen metabolism: implication for optimization of breast cancer treatment. Clin Pharmacol Ther. 2006;80:61–74.

    Article  CAS  Google Scholar 

  26. Mürdter TE, Schroth W, Bacchus-Gerybadze L, Winter S, Heinkele G, Simon W, et al. Activity levels of tamoxifen metabolites at the estrogen receptor and the impact of genetic polymorphisms of phase I and II enzymes on their concentration levels in plasma. Clin Pharmacol Ther. 2011;89:1–10.

    Article  Google Scholar 

  27. Jager N, Koornstra R, Vincent A, van Schaik R, Huitema A, Korse C, et al. Hot flashes are not predictive for serum concentrations of tamoxifen and its metabolites. BMC Cancer. 2013;13:612.

    Article  Google Scholar 

  28. Madlensky L, Natarajan L, Tchu S, Pu M, Mortimer J, Flatt SW, et al. Tamoxifen metabolite concentrations, CYP2D6 genotype, and breast cancer outcomes. Clin Pharmacol Ther. 2011;89:718–25.

    Article  CAS  Google Scholar 

  29. de Vries Schultink AHM, Alexi X, van Werkhoven E, Madlensky L, Natarajan L, Flatt SW, et al. An antiestrogenic activity score for tamoxifen and its metabolites is associated with breast cancer outcome. Breast Cancer Res Treat. 2017;161(3):567–74.

    Article  Google Scholar 

  30. Neven P, Jongen L, Lintermans A, Van Asten K, Blomme C, Lambrechts D, et al. Tamoxifen metabolism and efficacy in breast cancer: a prospective multicentre trial. Clin Cancer Res. 2018;24(10):2312–8.

    Article  CAS  Google Scholar 

  31. Jin Y, Desta Z, Stearns V, Ward B, Ho H, Lee KH, et al. CYP2D6 genotype, antidepressant use, and tamoxifen metabolism during adjuvant breast cancer treatment. J Natl Cancer Inst. 2005;97:30–9.

    Article  CAS  Google Scholar 

  32. Dezentje V, den Hartigh J, Guchelaar H, Hessing T, van der Straaten T, Vletter-Bogaartz J. Association between endoxifen serum concentration and predicted CYP2D6 phenotype in a prospective cohort of patients with early-stage breast cancer. J Clin Oncol. 2011;15(Suppl.):562.

    Article  Google Scholar 

  33. US Food and Drug Administration. Center for Drug Evaluation and Research. Anastrozole clinical pharmacology and biopharmaceutics review. 2000. https://www.accessdata.fda.gov/drugsatfda_docs/nda/2000/20-541S006_Arimidex_biopharmr.pdf. Accessed 26 May 2018.

  34. US Food and Drug Administration. Center for Drug Evaluation and Research. Letrozole clinical pharmacology and biopharmaceutics review. https://www.accessdata.fda.gov/drugsatfda_docs/nda/97/20726_FEMARA 2.5MG_BIOPHARMR.PDF. Accessed 26 May 2018.

  35. US Food and Drug Administration. Center for Drug Evaluation and Research. Exemestane clinical pharmacology and biopharmaceutics review. 1999. https://www.accessdata.fda.gov/drugsatfda_docs/nda/99/20-753_Aromasin_biopharmr_P1.pdf. Accessed 26 May 2018.

  36. Kelly CM, Buzdar AU. Anastrozole. Expert Opin Drug Saf. 2010;9:995–1003.

    Article  CAS  Google Scholar 

  37. Pauwels S, Lintermans A, Neven P, Verhaeghe J, Jans I, Billen J, et al. Need for estradiol assays with a lower functional sensitivity in clinical studies examining postmenopausal women treated with aromatase inhibitors. J Clin Oncol. 2013;31:509.

    Article  Google Scholar 

  38. Ketha H, Girtman A, Singh RJ. Estradiol assays: the path ahead. Steroids. 2015;99:39–44.

    Article  CAS  Google Scholar 

  39. Ingle JN, Buzdar AU, Schaid DJ, Goetz MP, Batzler A, Robson ME, et al. Variation in anastrozole metabolism and pharmacodynamics in women with early breast cancer. Cancer Res. 2010;70:3278–86.

    Article  CAS  Google Scholar 

  40. Folkerd EJ, Dixon JM, Renshaw L, A’Hern RP, Dowsett M. Suppression of plasma estrogen levels by letrozole and anastrozole is related to body mass index in patients with breast cancer. J Clin Oncol. 2012;30:2977–80.

    Article  CAS  Google Scholar 

  41. Oberguggenberger A, Meraner V, Sztankay M, Beer B, Weigel G, Oberacher H, et al. Can we use gonadotropin plasma concentration as surrogate marker for BMI-related incomplete estrogen suppression in breast cancer patients receiving anastrozole? BMC Cancer. 2017;17:1–7.

    Article  Google Scholar 

  42. Ingle JN, Kalari KR, Buzdar AU, Robson ME, Goetz MP, Desta Z, et al. Estrogens and their precursors in postmenopausal women with early breast cancer receiving anastrozole. Steroids. 2015;99:32–8.

    Article  CAS  Google Scholar 

  43. Micheal F, Saranya S, Aparna N, Sridevi N, Chithra R, Judith MP. Concepts of bioequivalence and its impact on truncated area under curve (AUC) of drugs with long half life in point estimate and intra-subject variability. J Pharm Sci Res. 2012;4:1890–6.

    CAS  Google Scholar 

  44. Plourde P, Dyroff M, Dukes M. Arimidex: a potent and selective fourth-generation aromatase inhibitor. Breast Cancer Res Treat. 1994;30:103–11.

    Article  CAS  Google Scholar 

  45. Geisler J, King N, Dowsett M, Ottestad L, Lundgren S, Walton P, et al. Influence of anastrozole (Arimidex), a selective, non-steroidal aromatase inhibitor, on in vivo aromatisation and plasma oestrogen levels in postmenopausal women with breast cancer. Br J Cancer. 1996;74:1286–91.

    Article  CAS  Google Scholar 

  46. Mandic S, Kratzsch J, Mandic D, Debeljak Z, Lukic I, Horvat V, et al. Falsely elevated serum oestradiol due to exemestane therapy. Ann Clin Biochem. 2017;54(3):402–5.

    Article  CAS  Google Scholar 

  47. Hertz DL, Kidwell KM, Seewald NJ, Gersch CL, Desta Z, Flockhart DA, et al. Polymorphisms in drug-metabolizing enzymes and steady-state exemestane concentration in postmenopausal patients with breast cancer. Pharmacogenom J. 2017;17(6):521–7.

    Article  CAS  Google Scholar 

  48. Hertz DL, Speth KA, Kidwell KM, Gersch CL, Desta Z, Storniolo AM, et al. Variable aromatase inhibitor plasma concentrations do not correlate with circulating estrogen concentrations in post-menopausal breast cancer patients. Breast Cancer Res Treat. 2017;165(3):659–68.

    Article  CAS  Google Scholar 

  49. Wang Y, Chia Y, Nedelman J, Schran H, Mahon F, Molimard M. A therapeutic drug monitoring algorithm for refining the imatinib trough level obtained at different sampling times. Ther Drug Monit. 2009;31:579–84.

    Article  CAS  Google Scholar 

  50. Desta Z, Kreutz Y, Nguyen AT, Li L, Skaar T, Kamdem LK, et al. Plasma letrozole concentrations in postmenopausal women with breast cancer are associated with CYP2A6 genetic variants, body mass index, and age. Clin Pharmacol Ther. 2011;90:693–700.

    Article  CAS  Google Scholar 

  51. De Jonge ME, Huitema ADR, Schellens JHM, Rodenhuis S, Beijnen JH. Individualised cancer chemotherapy: strategies and performance of prospective studies on therapeutic drug monitoring with dose adaptation: a review. Clin Pharmacokinet. 2005;44:147–73.

    Article  Google Scholar 

  52. US Food and Drug Administration. Center for Drug Evaluation and Research. Guidance for industry: exposure–response relationships: study design, data analysis and regulatory applications. FDA Guide. 2003;1–25. https://www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation/guidances/ucm072109.pdf.

  53. van Nuland M, Hillebrand MJX, Rosing H, Schellens JHM, Beijnen JH. Development and validation of an LC–MS/MS method for the simultaneous quantification of abiraterone, enzalutamide, and their major metabolites in human plasma. Ther Drug Monit. 2017;39:243–51.

    Article  Google Scholar 

  54. de Krou S, Rosing H, Nuijen B, Schellens JHM, Beijnen JH. Fast and adequate liquid chromatography-tandem mass spectrometric determination of Z-endoxifen serum levels for terapeutic drug monitoring. Ther Drug Monit. 2017;39:132–7.

    Article  Google Scholar 

  55. van Nuland M, Rosing H, de Vries J, Ovaa H, Schellens JHM, Beijnen JH. An LC–MS/MS method for quantification of the active abiraterone metabolite Δ(4)-abiraterone (D4A) in human plasma. J Chromatogr B Anal Technol Biomed Life Sci. 2017;1068–10699:119–24.

    Article  Google Scholar 

  56. Shao R, Yu L, Lou H, Ruan Z, Jiang B, Chen J. Development and validation of a rapid LC–MS/MS method to quantify letrozole in human plasma and its application to therapeutic drug monitoring. Biomed Chromatogr. 2016;30:632–7.

    Article  CAS  Google Scholar 

  57. Yu J, He J, Zhang Y, Qin F, Xiong Z, Li F. Development of a liquid chromatography–tandem mass spectrometry method for determination of butoconazole nitrate in human plasma and its application to a pharmacokinetic study. Biomed Chromatogr. 2011;25:511–6.

    Article  CAS  Google Scholar 

  58. Wang L-Z, Goh S-H, Wong AL-A, Thuya W-L, Lau J-YA, Wan S-C, et al. Validation of a rapid and sensitive LC–MS/MS method for determination of exemestane and its metabolites, 17beta-hydroxyexemestane and 17beta-hydroxyexemestane-17-O-beta-d-glucuronide: application to human pharmacokinetics study. PLoS One. 2015;10(3):e0118553.

    Article  Google Scholar 

  59. Cardoso E, Csajka C, Schneider MP, Widmer N. Effect of adherence on pharmacokinetic/pharmacodynamic relationships of oral targeted anticancer drugs. Clin Pharmacokinet. 2018;57(1):1–6.

    Article  CAS  Google Scholar 

  60. Gervasini G, Jara C, Olier C, Romero N, Martinez R, Carrillo JA. Polymorphisms in ABCB1 and CYP19A1 genes affect anastrozole plasma concentrations and clinical outcomes in postmenopausal breast cancer patients. Br J Clin Pharmacol. 2017;83:562–71.

    Article  CAS  Google Scholar 

  61. Dowsett M, Cuzick J, Howell A. Jackson I; ATAC Trialists’ Group. Pharmacokinetics of anastrozole and tamoxifen alone, and in combination, during adjuvant endocrine therapy for early breast cancer in postmenopausal women: a sub-protocol of the “Arimidex™ and tamoxifen alone or in combination” (ATAC) trial. Br J Cancer. 2001;85:317–24.

    Article  CAS  Google Scholar 

  62. Hubalek M, Oberguggenberger A, Beer B, Meraner V, Sztankay M, Oberacher H, et al. Does obesity interfere with anastrozole treatment? Positive association between body mass index and anastrozole plasma levels. Clin Breast Cancer. 2014;14:291–6.

    Article  CAS  Google Scholar 

  63. Committee for Medicinal Products for Human Use European Medicines Agency. Public assessment report: scientific discussion exemestane. 2010. https://db.cbg-meb.nl/Pars/h104327.pdf%0A. Accessed 26 May 2018.

  64. Bisagni G, Cocconi G, Scaglione F, Fraschini F, Pfister C, Trunet PF. Letrozole, a new oral non-steroidal aromatase inhibitor in treating postmenopausal patients with advanced breast cancer: a pilot study. Ann Oncol. 1996;7:99–102.

    Article  CAS  Google Scholar 

  65. Binkhorst L, Kloth JSL, de Wit AS, de Bruijn P, Lam MH, Chaves I, et al. Circadian variation in tamoxifen pharmacokinetics in mice and breast cancer patients. Breast Cancer Res Treat. 2015;152:119–28.

    Article  CAS  Google Scholar 

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Correspondence to Stefanie L. Groenland.

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Remy B. Verheijen is currently a full-time employee of AstraZeneca, Cambridge, UK. Although Jan H. M. Schellens is involved in Modra Pharmaceuticals, this article does not contain information that poses a conflict of interest as it does not examine any product of Modra Pharmaceuticals or products related to this spinout company. Stefanie L. Groenland, Merel van Nuland, Jos H. Beijnen, Alwin D. R. Huitema, and Neeltje Steeghs have no conflicts of interest directly relevant to the content of this article.

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Groenland, S.L., van Nuland, M., Verheijen, R.B. et al. Therapeutic Drug Monitoring of Oral Anti-Hormonal Drugs in Oncology. Clin Pharmacokinet 58, 299–308 (2019). https://doi.org/10.1007/s40262-018-0683-0

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