4-hydroxytamoxifen

Afimoxifene is a selective estrogen receptor modulator (SERM) of the triphenylethylene group and the major active metabolite of tamoxifen. The drug is under development under the tentative brand name TamoGel as a topical gel for the treatment of hyperplasia of the breast. It has completed a phase II clinical trial for cyclical mastalgia, but further studies are required before afimoxifene can be approved for this indication and marketed. Afimoxifene is a selective estrogen receptor modulator (SERM) of the triphenylethylene group and the major active metabolite of tamoxifen. The drug is under development under the tentative brand name TamoGel as a topical gel for the treatment of hyperplasia of the breast. It has completed a phase II clinical trial for cyclical mastalgia, but further studies are required before afimoxifene can be approved for this indication and marketed. In addition to its antiestrogenic and estrogenic activity, afimoxifene has been found to act as an antagonist of the estrogen-related receptors (ERRs) ERRβ and ERRγ.