TY - JOUR
T1 - Endoxifen, an Estrogen Receptor Targeted Therapy
T2 - From Bench to Bedside
AU - Jayaraman, Swaathi
AU - Reid, Joel M.
AU - Hawse, John R.
AU - Goetz, Matthew P.
N1 - Publisher Copyright:
© 2021 The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
PY - 2021/12/1
Y1 - 2021/12/1
N2 - The selective estrogen receptor (ER) modulator, tamoxifen, is the only endocrine agent with approvals for both the prevention and treatment of premenopausal and postmenopausal estrogen-receptor positive breast cancer as well as for the treatment of male breast cancer. Endoxifen, a secondary metabolite resulting from CYP2D6-dependent biotransformation of the primary tamoxifen metabolite, N-desmethyltamoxifen (NDT), is a more potent antiestrogen than either NDT or the parent drug, tamoxifen. However, endoxifen's antitumor effects may be related to additional molecular mechanisms of action, apart from its effects on ER. In phase 1/2 clinical studies, the efficacy of Z-endoxifen, the active isomer of endoxifen, was evaluated in patients with endocrine-refractory metastatic breast cancer as well as in patients with gynecologic, desmoid, and hormone-receptor positive solid tumors, and demonstrated substantial oral bioavailability and promising antitumor activity. Apart from its potent anticancer effects, Z-endoxifen appears to result in similar or even greater bone agonistic effects while resulting in little or no endometrial proliferative effects compared with tamoxifen. In this review, we summarize the preclinical and clinical studies evaluating endoxifen in the context of breast and other solid tumors, the potential benefits of endoxifen in bone, as well as its emerging role as an antimanic agent in bipolar disorder. In total, the summarized body of literature provides compelling arguments for the ongoing development of Z-endoxifen as a novel drug for multiple indications.
AB - The selective estrogen receptor (ER) modulator, tamoxifen, is the only endocrine agent with approvals for both the prevention and treatment of premenopausal and postmenopausal estrogen-receptor positive breast cancer as well as for the treatment of male breast cancer. Endoxifen, a secondary metabolite resulting from CYP2D6-dependent biotransformation of the primary tamoxifen metabolite, N-desmethyltamoxifen (NDT), is a more potent antiestrogen than either NDT or the parent drug, tamoxifen. However, endoxifen's antitumor effects may be related to additional molecular mechanisms of action, apart from its effects on ER. In phase 1/2 clinical studies, the efficacy of Z-endoxifen, the active isomer of endoxifen, was evaluated in patients with endocrine-refractory metastatic breast cancer as well as in patients with gynecologic, desmoid, and hormone-receptor positive solid tumors, and demonstrated substantial oral bioavailability and promising antitumor activity. Apart from its potent anticancer effects, Z-endoxifen appears to result in similar or even greater bone agonistic effects while resulting in little or no endometrial proliferative effects compared with tamoxifen. In this review, we summarize the preclinical and clinical studies evaluating endoxifen in the context of breast and other solid tumors, the potential benefits of endoxifen in bone, as well as its emerging role as an antimanic agent in bipolar disorder. In total, the summarized body of literature provides compelling arguments for the ongoing development of Z-endoxifen as a novel drug for multiple indications.
KW - CYP2D6
KW - antiestrogen
KW - breast cancer
KW - endoxifen
KW - hormone therapy
KW - tamoxifen
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U2 - 10.1210/endocr/bqab191
DO - 10.1210/endocr/bqab191
M3 - Review article
C2 - 34480554
AN - SCOPUS:85116610073
SN - 0013-7227
VL - 162
JO - Endocrinology (United States)
JF - Endocrinology (United States)
IS - 12
M1 - bqab191
ER -