18 January 2017


Liège, Belgium – Mithra Pharmaceuticals (Euronext Brussels: MITRA), a company focused on women’s health, today announces that the United States Patent and Trademark Office (USPTO) has issued a Notice of Allowance for U.S. Application Serial Number 14/238,310, a patent which covers the use of Estetrol (E4) as an emergency contraceptive.

The patent specifically covers E4, a naturally occurring estrogen, as a potential new emergency contraception option where E4 is used alone. This new method differs from currently approved emergency contraceptives which include progestin only pills and combined estrogen-progestin pills.

“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 estrogen receptors in some tissues while in other tissues it acts as an anti-estrogen due to its ability to activate the nuclear estrogen receptor and to block the membrane estrogen receptor1. The inhibition of the membrane estrogen receptor has been shown to play a key role in suppressing ovulation. This was shown in a study carried out by Adlanmerini et al. in 2014 who demonstrated that transgenic mice with inactivating mutation of the membrane estrogen receptor did not ovulate2. This further supports E4’s potential as an emergency contraceptive option.”

Professor Jean-Michel Foidart

Scientific Comittee Member

“With an improved safety profile compared to the current generation of estrogens, E4 has the potential to revolutionalize 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.”

Francois Fornieri

CEO of Mithra Pharmaceuticals

1 Abot A., C Fontaine, M. Buscato, R Solinhac, G Flouriot, A Fabre, A Drougard, S Rajan, M Laine, A Milon, I Muller, D Henrion, M Adlanmerini, MC Valéra, A Gompel, C gerard, C pequeux, M Mestdagt, I Raymond-Letron, C Knauf, F Ferriere, P Valet, P Gourdy, B Katzenellenbogen, F Lenfant, G Greene, JM Foidart, JF Arnal (2014). "The uterine and vascular actions of estetrol delineate a distinctive profile of estrogen receptor α modulation, uncoupling nuclear and membrane activation." EMBO Molecular Medicine 6 (10): 1328-1346. Read more

2 Adlanmerini M., R Solinhac, A Abot, A Fabre, I Raymond-Letron, A Guihot, F Boudou, L Sautier, E Vessières, Q Hoon Kim, P Lière, C Fontaine, A Krust, JA Katzenellenbogen, P Gourdy, PW Shaul, D Henrion, JF Arnal, F Lenfant (2014). “Mutation of the palmitoylation site of estrogen receptor α in vivo reveals tissue-specific roles for membrane versus nuclear actions” PNAS 111 (2): E283-E290.

For more information, please contact:


Julie Dessart
Chief Communication Officer
+32 4 349 28 22 / +32 475 86 41 75

Investor Relations 

François Fornieri, CEO
+32 4 349 28 22

Consilium Strategic Communications
Jonathan Birt, Sue Stuart, Hendrik Thys
+44 2 037 095 700

About Mithra

Mithra Pharmaceuticals SA, founded in 1999 as a spin-off of the University of Liège by Mr. François Fornieri and Prof. Dr. Jean-Michel Foidart, is a Euronext listed pharmaceutical company (MITRA) focused on Women’s Health. Mithra’s mission is to improve every stage of women’s life with innovative and accessible pharmaceutical solutions. As such the Company aims to become a worldwide leader in women’s health by developing, manufacturing and commercialising proprietary, innovative and differentiated drugs and complex therapeutical solutions in four therapeutic fields of women’s health: fertility and contraception, menopause and osteoporosis, gynecological infections and female cancers.

Mithra has an approximate headcount of 141 staff members and is headquartered in Liège, Belgium. Further information can be found at: www.mithra.com

Important information

The contents of this announcement include statements that are, or may be deemed to be, "forward-looking statements". These forward-looking statements can be identified by the use of forward-looking terminology, including the words "believes", "estimates," "anticipates", "expects", "intends", "may", "will", "plans", "continue", "ongoing", "potential", "predict", "project", "target", "seek" or "should", and include statements the Company makes concerning the intended results of its strategy. By their nature, forward-looking statements involve risks and uncertainties and readers are cautioned that any such forward-looking statements are not guarantees of future performance. The Company's actual results may differ materially from those predicted by the forward-looking statements. The Company undertakes no obligation to publicly update or revise forward-looking statements, except as may be required by law. 

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