Searchlight licenses Mithra’s menopause drug Donesta for Canadian market

Mithra Pharmaceuticals and Searchlight Pharma have entered a licensing agreement for Donesta, an investigational drug for treating menopausal symptoms.

The agreement grants Searchlight exclusive sales and marketing rights in Canada.

As per the agreement, Searchlight is responsible for regulatory approval of Donesta in Canada while Mithra would be entitled to licensing fees, Canadian sales royalties, and milestone-based payments totalling up to €17.05m ($18.8m).

Donesta is an orally administered estetrol (E4) hormone therapy that targets nuclear estrogen receptor alpha (ERα) and can potentially avoid the common side effects associated with hormonal therapies.

Mithra’s first estertrol (E4) therapy was a combination therapy Estelle (15mg estetrol and 3mg drospirenone), which is currently marketed in the US, Canada, and Europe.

The data from the two multicentre, randomised Phase III trials (C301 – NCT04209543, and C302 – NCT04090957) evaluating Donesta, demonstrated a reduction in vasomotor symptoms from baseline and compared to placebo.

Mithra has reported positive safety data in North America in the C302 Phase III trial, with primary safety data from Europe expected in H1 2024.

Mithra plans to file marketing authorisation with the US Food and Drug Administration (FDA) by the end of 2023, based on the safety and efficacy data from the C302 Phase III trial. Searchlight also plans to file for marketing authorisation with Health Canada in H1 2024.

Mithra has previously signed agreements with Searchlight for the licensing of an oral contraceptive Nextstellis (drospirenone and estetrol tablets), and a vaginal contraceptive Haloette, in Canada in 2021 and 2022, respectively.

Mithra CEO David Horn Solomon stated that the company intends to seek a partnership to market Donesta in the US.

Apart from the contraceptive and hormone therapy, Mithra is also developing a colony-stimulating factor 1 receptor (CSF-1R) kinase inhibitor with BCI Pharma for treating endometriosis, and certain oncology indications and inflammatory disorders.