Ospemifene for vulvovaginal atrophy

Ospemifene 60 mg tablets are licensed for the treatment of moderate to severe symptomatic vulvar and vaginal atrophy (VVA) in postmenopausal women who are not candidates for vaginal oestrogen therapy.

• application for marketing authorisation included data from four phase 2 and 3 studies
• only one of the four co-primary outcome measures assessed over 12 weeks involved a clinical endpoint (reduction in severity of dyspareunia or vaginal dryness) (1)

Ospemifene 60 mg daily produced a statistically significant modest reduction in severity of dyspareunia over placebo in both studies in which it was assessed.

Ospemifene 60 mg daily produced a statistically significant modest reduction in severity of vaginal dryness over placebo in one of the two studies in which it was assessed.

In clinical trials, ospemifene was not directly compared with other active treatments for VVA (1)

Common adverse effects include vulvovaginal candidiasis, hot flushes, muscle spasms, headache, rash and vaginal/genital discharge. Uncommon adverse effects included endometrial hypertrophy and hypersensitivity reactions

• hot flashes were the most frequently reported side effects of ospemifene, with reported occurrence of 2% in the placebo group and 7.2% in the ospemifene group; however, it was not severe enough to lead to discontinuation (2)
  • incidence rates of thromboembolic and hemorrhagic stroke were 0.72 and 1.45 per 1,000 women, respectively, in the ospemifene group and 1.04 and 0 per 1,000 women, respectively, in the placebo group
  • incidence of deep vein thrombosis was 1.45 per 1,000 women in the ospemifene group and 1.04 per 1,000 women in the placebo group
  • ospemifene is contraindicated in women with active arterial thromboembolic disease or a history of these conditions
  • if feasible, ospemifene should be discontinued for at least 4 to 6 weeks prior to surgery, and before any procedure with an increased risk of thromboembolism or during periods of prolonged immobilization (2)

A systematic review and meta-analysis investigated the use of various treatments for genitourinary syndrome of the menopause (3):

• found vaginal oestrogen, vaginal dehydroepiandrosterone, oral ospemifene, & vaginal moisturizers may improve some genitourinary syndrome of menopause (GSM) symptoms in the short term.
• also noted that few long-term data exist on efficacy, tolerability, & safety of GSM treatments.

Notes:

• Selective estrogen receptor modulators (SERMs) have estrogenic or anti-estrogenic effects depending on the tissues
  • tamoxifen and toremifene are well-known SERMs for reducing the risk of breast cancer recurrence - however they have been associated with an increased risk of endometrial cancer due to having estrogenic effects on the endometrium
• Ospemifene is the first non-hormonal SERM that has been approved for the treatment of dyspareunia associated with VVA
• Ospemifene is a triphenylethylene, with a similar structure to tamoxifen and toremifene - however unlike the latter two agents, it does not contain an amino group

Reference:

1. Drug and Therapeutics Bulletin. Ospemifene for vulvar and vaginal atrophy (May 2019)
2. Shin JJ et al. Ospemifene: A Novel Option for the Treatment of Vulvovaginal Atrophy. J Menopausal Med. 2017 Aug; 23(2): 79-84
3. Elisheva R. Danan, Catherine Sowerby, Kristen E. Ullman, et al. Hormonal Treatments and Vaginal Moisturizers for Genitourinary Syndrome of Menopause: A Systematic Review. Ann Intern Med.[Epub 10 September 2024]