Dare Bioscience announces publication of pharmacokinetics study of DARE-VVA1
Dare Bioscience announced the article entitled "Vaginal tamoxifen for treatment of vulvar and vaginal atrophy: Pharmacokinetics and local tolerance in a rabbit model over 28 days" was published online in the International Journal of Pharmaceutics. The article highlights the positive findings from the animal study which include availability and local tolerability of vaginally delivered tamoxifen. DARE-VVA1 is a novel vaginal application of tamoxifen, the well-known and well-characterized selective estrogen receptor modulator, and is being developed by Dare as an alternative to estrogen-based therapies for the treatment of vulvar and vaginal atrophy in women with or at risk for hormone-receptor positive (HR+) breast cancer. In breast tissue, tamoxifen acts as an estrogen antagonist, while in other tissue, including vaginal tissue, tamoxifen has been reported to exert an estrogen-like response on vaginal cytology. The goal of the study was to evaluate tamoxifen at two dose levels administered intra-vaginally to female rabbits once-daily over a 28-day period to assess its pharmacokinetics, systemic exposure and local vaginal tolerance. The findings revealed that there was little to no vaginal or systemic accumulation of tamoxifen following once-daily dosing for 28 days and that vaginal irritation was minimal to none at both doses.VVA is an inflammation of the vaginal epithelium due to the reduction in levels of circulating estrogen. Commonly used therapies for VVA are estrogen-based and often contraindicated in HR+ breast cancer patients, or patients with a genetic predisposition or history of familial disease, because of the concern that estrogen use will promote recurrence of disease. Many breast cancer survivors experience menopausal symptoms as a direct consequence of cancer treatment. Breast cancer patients treated with aromatase inhibitors refer to VVA as one of the most unpleasant side effects of treatment. A prior study of DARE-VVA1 published in Clinical and Experimental Obstetrics and Gynecology, demonstrated that weekly vaginal administration of tamoxifen for three months in post-menopausal women with VVA showed improvements in vaginal pH and vaginal dryness without significant systemic absorption of tamoxifen.