Safety, influence on the endometrium, sonographic changes and bleeding profile after 13 cycles with the new...

The primary objective of the present trial was to assess the endometrial safety of a new oral contraceptive containing 4 mg drospirenone for a total duration of 13 cycles of 28 days each: 24 days of active treatment followed by 4 days placebo treatment per treatment cycle.

This was a single-center, open-label, multiple-dose study on healthy female subjects at risk of pregnancy. Twenty one (= safety population set) pre-menopausal female Caucasian subjects started treatment with the study medication. The mean age was 29.0 years (range 19.0-36.0 years). Four subjects terminated the trial prematurely for the following reasons: on the subject's request (n=2), due to an adverse event (n=1) and due to loss of contact (n=1). Seventeen subjects completed the planned duration of 13 cycles of open treatment with the test product (each cycle of 28 days).

At visit 1 (pre-treatment), the biopsy result in the safety population set was proliferative in 14 cases and secretory in seven cases. At visit 7, four cases showed an inadequate result (insufficient tissue for diagnosis), 12 as proliferative and three as secretory. The number of biopsies with proliferative and secretory results reduced under treatment (safety population). The pre-post treatment changes in the endometrial biopsy results in the treatment completers set (n=17) showed almost no differences. At visit 1 (pre-treatment), the biopsy result was proliferative in 12 cases and secretory in five cases. At visit 7 (after 13 cycles of 28 days), four cases showed an inadequate result (insufficient tissue for diagnosis), 11 as proliferative, and two as secretory. The mean endometrial thickness in the safety population was reduced from 8.3 mm at visit 1 to 6.0 mm at visit 7. When comparing the endometrial thickness in the 21 subjects (safety population), the endometrial thickness showed a pre-post difference of 2.1 mm, whereas the endometrial thickness in the 17 study completers showed a pre-post difference of 2.5 mm (8.2 mm at visit 1-5.6 mm at visit 7).

Drospirenone 4 mg film-coated tablet in a dosage regime of 24/4 days is, regarding endometrial histology, a safe drug. Trial registration: EudraCT Register number: 2013-002300-13.