A phase III trial of Allergan’s uterine fibroid drug ulipristal acetate has met its targets, setting up a possible filing in 2017.
Ulipristal acetate is a selective progesterone receptor modulator that could be a safer and more effective pharmacological treatment for uterine fibroids than existing drugs such as AbbVie’s Lupron (leuprolide acetate), a synthetic gonadotropin-releasing hormone (GnRH).
Uterine fibroids are a common form of benign tumour – estimated to affect around 40% of women – although in most cases they cause no symptoms. In some women however they can cause very heavy uterine bleeding, severe abdominal pain and increased urination, and severe cases can cause infertility.
The main therapy for symptomatic fibroids is surgery, although this can be associated with serious complications including infertility. Meanwhile, while Lupron is used to control symptoms in some women and as an alternative to surgery, it can cause menopausal symptoms such as hot flushes and is generally only prescribed for a few months.
Fibroids are the leading cause of hysterectomies in the US, costing around $34bn a year, according to Allergan, which notes that the withdrawal of some surgical devices used in these procedures has reduced surgical options for patients.
The company is developing ulipristal acetate for fibroids in collaboration with Gedeon Richter, which has sold the drug in Europe as Esmya since 2012, although only as a pre-treatment for women undergoing surgery. Allergan has already launched the drug in Canada under the Fibristal brand name.
In the US Allergan and Gedeon Richter are seeking a broader indication, not just pre-surgery, so the FDA has required them to conduct additional trials.
The 157-patient VENUS I trial is the first of these, and met its primary and secondary endpoints with ulipristal achieving statistically significant results over placebo on measures such as bleeding rates as well as time to absence of bleeding.
The second trial – Venus II – is due to be completed this year with top-line results expected in the first half of 2017.
A recent analysis by EvaluatePharma suggested the drug could become the biggest-selling drug for uterine fibroids with sales of nearly $520m by 2020.
Other companies working on new therapies for uterine fibroids include Bayer, which has a candidate called vilaprisan in mid-stage clinical development.