Nafoxidine (; developmental code names U-11,000A) or nafoxidine hydrochloride () is a

nonsteroid A nonsteroidal compound is a drug that is not a steroid nor a steroid derivative. Nonsteroidal anti-inflammatory drugs (NSAIDs) are distinguished from corticosteroids as a class of anti-inflammatory agents. List of nonsteroidal steroid receptor ...

selective estrogen receptor modulator Selective estrogen receptor modulators (SERMs), also known as estrogen receptor agonist/antagonists (ERAAs), are a class of drugs that act on the estrogen receptor (ER). A characteristic that distinguishes these substances from pure ER agonists a ...

(SERM) or

partial Partial may refer to: Mathematics * Partial derivative, derivative with respect to one of several variables of a function, with the other variables held constant ** ∂, a symbol that can denote a partial derivative, sometimes pronounced "partial ...

antiestrogen of the triphenylethylene group that was developed for the treatment of advanced breast cancer by

Upjohn The Upjohn Company was a pharmaceutical manufacturing firm founded in 1886 in Hastings, Michigan, by Dr. William E. Upjohn who was an 1875 graduate of the University of Michigan medical school. The company was originally formed to make ''friabl ...

in the 1970s but was never marketed. It was developed at around the same time as tamoxifen and clomifene, which are also triphenylethylene derivatives. The drug was originally synthesized by the fertility control program at Upjohn as a

postcoital contraceptive Emergency contraception (EC) is a birth control measure, used after sexual intercourse to prevent pregnancy. There are different forms of EC. Emergency contraceptive pills (ECPs), sometimes simply referred to as emergency contraceptives (ECs), o ...

, but was subsequently repurposed for the treatment of breast cancer. Nafoxidine was assessed in clinical trials in the treatment of breast cancer and was found to be effective. However, it produced side effects including ichthyosis, partial hair loss, and phototoxicity of the skin in almost all patients, and this resulted in the discontinuation of its development. Nafoxidine is a long-acting estrogen receptor ligand, with a

nuclear retention In the field of molecular biology, nuclear receptors are a class of proteins responsible for sensing steroids, thyroid hormones, vitamins, and certain other molecules. These receptors work with other proteins to regulate the expression of specif ...

in the range of 24 to 48 hours or more.

References

{{Estrogen receptor modulators Abandoned drugs Hormonal antineoplastic drugs Phenol ethers Pyrrolidines Selective estrogen receptor modulators Triphenylethylenes