Brilanestrant (

INN Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway. Before the advent of motorized transportation, they also provided accomm ...

; developmental codes GDC-0810, ARN-810, RG-6046, and RO-7056118) is a

nonsteroidal 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 mo ...

combined

selective estrogen receptor modulator Selective estrogen receptor modulators (SERMs), also known as estrogen receptor agonists/antagonists (ERAAs), are a class of drugs that act on estrogen receptors (ERs). Compared to pure ER agonists–antagonists (e.g., full agonists and silent ...

(SERM) and

selective estrogen receptor degrader Selective may refer to: * Selective school, a school that admits students on the basis of some sort of selection criteria ** Selective school (New South Wales) See also * Selective breeding, the process of breeding for specific traits * Selection ...

(SERD) that was discovered by Aragon Pharmaceuticals and was under development by

Genentech Genentech, Inc. is an American biotechnology corporation headquartered in South San Francisco, California. It operates as an independent subsidiary of holding company Roche. Genentech Research and Early Development operates as an independent cent ...

for the treatment of locally advanced or

metastatic Metastasis is a pathogenic agent's spreading from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, ...

estrogen receptor Estrogen receptors (ERs) are proteins found in cell (biology), cells that function as receptor (biochemistry), receptors for the hormone estrogen (17β-estradiol). There are two main classes of ERs. The first includes the intracellular estrogen ...

(ER)-positive

breast cancer Breast cancer is a cancer that develops from breast tissue. Signs of breast cancer may include a Breast lump, lump in the breast, a change in breast shape, dimpling of the skin, Milk-rejection sign, milk rejection, fluid coming from the nipp ...

. Development of brilanestrant was discontinued by Roche in April 2017. It reached phase II

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...

s for the treatment of breast cancer prior to the discontinuation of its development.

Mechanism of action

Similarly to

tamoxifen Tamoxifen, sold under the brand name Nolvadex among others, is a selective estrogen receptor modulator used to prevent breast cancer in women and men. It is also being studied for other types of cancer. It has been used for Albright syndrome ...

, a SERM, brilanestrant shows some capacity to activate the ER in certain contexts and possesses weak estrogenic activity in the rat

uterus The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...

, and unlike

fulvestrant Fulvestrant, sold under the brand name Faslodex among others, is an antiestrogenic medication used to treat hormone receptor (HR)-positive metastatic breast cancer in postmenopausal women with disease progression as well as HR-positive, HER2-n ...

, which is currently the only SERD to have been marketed, brilanestrant is not a

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

and is

oral The word oral may refer to: Relating to the mouth * Relating to the mouth, the first portion of the alimentary canal that primarily receives food and liquid **Oral administration of medicines ** Oral examination (also known as an oral exam or ora ...

bioavailable In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. H ...

and does not need to be administered by

intramuscular injection Intramuscular injection, often abbreviated IM, is the medical injection, injection of a substance into a muscle. In medicine, it is one of several methods for parenteral, parenteral administration of medications. Intramuscular injection may be ...

. Brilanestrant has been found to be active in tamoxifen- and fulvestrant-resistant ''

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

'' models of human breast cancer.

Side effect In medicine, a side effect is an effect of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects. A drug or procedure usually use ...

s observed in clinical studies of brilanestrant thus far have included

diarrhea Diarrhea (American English), also spelled diarrhoea or diarrhœa (British English), is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration d ...

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...

, and

fatigue Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated wit ...

of mostly mild-to-moderate severity. Brilanestrant is a structural analogue of

etacstil Etacstil (developmental code names GW-5638, DPC974) is an orally active, nonsteroidal, combined selective estrogen receptor modulator (SERM) and selective estrogen receptor degrader (SERD) that was developed for the treatment of estrogen recept ...

, an earlier combined SERM and SERD that was abandoned in 2001 for commercial reasons.

References

External links

GDC-0810 (brilanestrant) - AdisInsight

Pipeline - Genentech
{{Estrogen receptor modulators Abandoned drugs Antiestrogens Chlorobenzene derivatives Fluorobenzene derivatives Hormonal antineoplastic drugs Indazoles Selective estrogen receptor degraders Selective estrogen receptor modulators Triphenylethylenes