USPTO issues Notice of Allowance for Mithra’s application for Estetrol patent

The US Patent and Trademark Office (USPTO) has issued patent allowance for Belgium-based Mithra Pharmaceuticals’ Estetrol (E4) for use as an emergency contraceptive.

The notice of allowance for the company’s US application serial number 14/238,310, covers a naturally occurring oestrogen known as E4 as a potential new emergency contraception option where it is used alone.

Mithra Pharmaceuticals CEO Francois Fornieri said: "With an improved safety profile compared to the current generation of estrogens, E4 has the potential to revolutionalise the contraceptive market.

"This patent allowance further strengthens our US intellectual property position and we look forward to further developing E4 in emergency oral contraceptive applications."

"With an improved safety profile compared to the current generation of estrogens, E4 has the potential to revolutionalise the contraceptive market."

The latest method is different from emergency contraceptives that are currently approved and include progestin only pills, as well as combined oestrogen-progestin pills.

The inhibition of the membrane oestrogen receptor is expected to play a vital role in suppressing ovulation, which was shown in a study carried out by Adlanmerini and others in 2014.

In this study, it was demonstrated that transgenic mice with inactivating mutation of the membrane oestrogen receptor did not ovulate, offering support to E4's potential as an emergency contraceptive option.

Scientific Committee Member professor Jean-Michel Foidart said: "The unique profile of E4 has been widely supported by academia and leading international institutions, including the University of Toulouse, the University of Rennes, the University of Chicago and the University of Illinois at Urbana-Champaign.

"Notably, it has been demonstrated in academic studies that E4 can activate oestrogen receptors in some tissues, while in other tissues it acts as an anti-oestrogen due to its ability to activate the nuclear oestrogen receptor and to block the membrane oestrogen receptor."