Phase III Estelle study of Estelle meets primary endpoint in contraception.- Mithra

Mithra announced that its Phase III Estelle study of Estelle (Estetrol (E4) 15 mg and drospirenone (DRSP) 3 mg) conducted in the United States and Canada successfully met its primary efficacy endpoint in contraception. Efficacy is well in line with expectations, similar to a recently FDA approved combined hormonal contraceptive (Annovera PI 2.98 [95% Confidence Interval 2.13-4.06]) per 100 woman-years of use) and to Lo-Loestrin (PI 2.92 [95% Confidence Interval 1.94-4.21]).

Amongst women aged 16-50 years old at study entry, results showed a PI of 2.30 (95% confidence interval 1.67-3.64) during 15,797 cycles, with in the absence of other contraceptive methods. The PI corresponds to a 98% efficacy rate over one year of use, in line with the efficacy goals of the study. Cycle control and bleeding profile, which are essential to women�s adherance, showed an excellent regular bleeding pattern similar to patterns seen with oral contraceptives containing EE.

Safety, acceptability and general well-being of the subjects (measured by two questionnaires) were also analyzed. Results from the MDQ (menstrual distress questionnaire) and QoL (quality of life) questionnaire showed that Estelle is well tolerated by women, while their overall quality of life is maintained. The safety profile is supported by the unique Mode of Action of E4, which is a native estrogen with selective action in tissues.

Two earlier Phase II studies conducted by Mithra confirmed E4 has a minimal impact on liver cells and metabolic pathways, including on the coagulation parameters resulting in an overall beneficial hemostatic profile. These coagulation parameters are effected more negatively by Ethinyl-Estradiol (EE), present in most oral contraceptives, making Estelle a promising new contraceptive solution for women with a unique benefit/risk profile.