Mithra studies the role of estrogen in Covid-19 treatment25/05/2020

Women are more likely than men to be spared by Covid-19, with less severe infections and lower mortality rates. Mithra, a company dedicated to Women's Health launches a research programme on Estetrol's effect in Covid-19 treatment. Protective role of estrogen against human coronaviruses already demonstrated during the SARS infection, and currently being tested in the U.S. among hospitalized patients.

Recent epidemiological studies in China, Italy and the United States indicate that Covid-19 affects more men than women and more severely. Italy has suffered four times as many male deaths as female deaths1. In the United States, twice as many men as women die from Covid-19. One explanation for this gender disparity is believed to be biological differences in the immune system. This immuno-sexual difference was already observed with other infectious diseases caused by human coronaviruses, such as Severe Acute Respiratory Syndrome (SARS).

An American study showed that male mice infected with the SARS virus developed more frequent, more severe and often more fatal infections than female mice2 . In addition, removal of the ovaries or administration of anti-estrogens in females aggravated infection and increased fatalities, demonstrating the protective role played by estrogen. Estrogen acts on a protein known as Angiotensin Converting Enzyme 2 (ACE2) and enables its expression to be reduced. This ACE2 protein specifically serves as a gateway for certain coronaviruses (such as the one that causes Covid-19) to enter human cells.

“It would be very interesting to investigate further the effect of estrogen, in particular Estetrol, on the immune response of patients affected by Covid-19," comments Jean-Louis Vincent, Professor of Intensive Care at the Belgian University ULB and intensive care physician at the Erasmus University Hospital in Brussels. "Pregnant women, naturally under increased influence of estrogens, are relatively unaffected. Furthermore, administering estrogen to patients over a short period of time would not pose any major safety concerns and would be of limited cost.”

"Studies are currently underway at two US hospitals to see if hormones can have an impact on the disease, especially in men," says Mitchell Creinin, Professor of Gynecology at UC Davis University, California. "Estetrol has unique properties and a profile of activity that is distinct from that of classical estrogens. It would therefore be interesting to explore its effect on Covid-19 and assess its impact on the blood vessels of infected patients, especially as the virus induces strokes among young patients."

"Men and women react differently to viral respiratory infections, due to different responses of innate immune cells," adds Professor Jean-Michel Foidart, Permanent Secretary of the Royal Academy of Medicine of Belgium. "Similarly, changes in estrogen levels in women at puberty, during pregnancy and menopause are associated with changes in their natural immunity. It is therefore considered useful to ascertain the favourable impact of natural human estrogen such as Estetrol, which has a higher safety profile than other classical estrogens. In Belgium, the death rate of women is lower than that of men up to the age of 74. This beneficial gender effect disappears in the 75-84 age group, before reversing after the age of 85. This is consistent with the hypothesis of the protective role of estrogens in women during their hormonal cycle and even up to 15-20 years after the natural menopause".

Following epidemiological and clinical data, Mithra has decided to launch a research program on the potential beneficial impact of Estetrol in the treatment of Covid-19. The protocol for this program is currently being developed in consultation with various international experts active in Covid-19 research. This Phase II study should be conducted in late 2020 on both male and female patients infected with the virus.

Mithra is a Belgian biotech company dedicated to transforming Women’s Health by offering new choices through innovation, with a particular focus on contraception and menopause. Active in more than 100 countries around the world, Mithra has an approximate headcount of 250 staff members and is headquartered in Liège, Belgium.


Press Contact :  Maud Vanderthommen: +32 473 58 61 04 –

+32 473 58 61 04 –

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