# Toremifene

Source: https://onco.cc/drugs/toremifene/  
OnCo record `toremifene` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Toremifene (Fareston) is a tamoxifen-like tablet for postmenopausal women with hormone-sensitive breast cancer that has spread.

## Summary

Toremifene was approved by the FDA in May 1997 for metastatic breast cancer in postmenopausal women with oestrogen receptor-positive or unknown tumours, on three randomised trials (North American, Eastern European and Nordic) that showed response rates and time to progression similar to tamoxifen; the EU authorised Fareston in 1996 for first-line hormonal treatment of hormone-dependent metastatic breast cancer. It never displaced tamoxifen and aromatase inhibitors then moved ahead of both. QT prolongation carries a boxed warning; hot flushes, sweating and vaginal discharge are the common effects, with thromboembolism and endometrial changes as class risks.

## Fields

- Kind: Treatment
- Status: approved
- Last checked: 2026-09-10
- Tags: nci-list
- Brand: Fareston
- Modality: Selective oestrogen receptor modulator (triphenylethylene)
- Mechanism: Chlorinated tamoxifen analogue that binds the oestrogen receptor and acts as an antagonist in breast tissue with partial agonist effects elsewhere.
- Approvals: US 1997: Metastatic breast cancer in postmenopausal women with ER-positive or unknown tumours; EU 1996: First-line hormonal treatment of hormone-dependent metastatic breast cancer in postmenopausal women

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Toremifene
- US label (DailyMed): https://dailymed.nlm.nih.gov/dailymed/search.cfm?labeltype=all&query=toremifene
- NCI drug page: https://www.cancer.gov/about-cancer/treatment/drugs/toremifene
- EPAR: https://www.ema.europa.eu/en/medicines/human/EPAR/fareston

## Connected records

- drugs: [Tamoxifen](https://onco.cc/drugs/tamoxifen/)
- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/)
- technologies: [Endocrine therapy (SERMs, AIs, SERDs)](https://onco.cc/technologies/endocrine-therapy/)
- targets: [Estrogen receptor (ERα)](https://onco.cc/targets/estrogen-receptor/)
- companies: [GTx](https://onco.cc/companies/gtx/), [Kyowa Kirin](https://onco.cc/companies/kyowa-kirin/)
- trials: [Adjuvant Toremifene With or Without Goserrelin in Premenopausal Women With Stage I-IIIA, Hormonal Receptor Positive Breast Cancer Accompanied With or Without Chemotherapy Induced Amenorrhoea](https://onco.cc/trials/nct02132390/), [Efficacy of Tamoxifen Versus Toremifene in CYP2D6 IM/PM of Premenopausal Patients With ER-positive Early Breast Cancer](https://onco.cc/trials/nct03351062/), [Toremifene Citrate for Prevention of Bone Fractures in Men With Prostate Cancer on Androgen Deprivation Therapy](https://onco.cc/trials/nct00129142/)

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JSON: https://onco.cc/api/v1/entities/toremifene.json