Some breast cancer types are characterized by the presence of hormone receptors in the cells that act to drive tumor growth
Advanced breast cancer involves disease that is either metastatic (or is growing outside the breast and lymph nodes) or has locally recurred and cannot be surgically removed. Breast cancer types are frequently characterized by the presence of hormone receptors in the cells (such as estrogen or progesterone receptors) that act to drive tumor growth and therefore make good targets to inhibit as a treatment strategy. Androgen receptors are also frequently found on breast cancer tumor cells, and medical practice had included the use of steroidal androgens to treat patients with advanced breast cancer with favorable response rates.
We have evaluated enobosarm in women with two different subtypes of breast cancer:
- ER+/AR+ breast cancer – tumors with measurable level of estrogen and androgen receptors
- AR+ TNBC – tumors with measureable level of androgen receptors (AR positive) but unmeasurable levels of estrogen, progesterone and HER2 receptors, referred to as triple negative breast cancer
The current clinical development landscape has seen treatment paradigms shifting to immunotherapies and/or combination therapies. GTx has decided not to conduct the necessary clinical trials for approval in this indication at this time.