Segesterone acetate/ethinyl estradiol 12-month contraceptive vaginal system safety evaluation

Abstract

Objectives: To evaluate safety outcomes from clinical studies of a 12-month contraceptive vaginal system (CVS) releasing an average of segesterone acetate (SA) 150 mcg and ethinyl estradiol (EE) 13 mcg daily.

Study design: We integrated clinical safety data from nine studies in which women used the CVS for 21 consecutive days and removed it for 7 days of each 28-day cycle. Four studies used the final manufactured CVS, including a 1-year pharmacokinetic study, two 1-year phase 3 trials and a second-year treatment extension study. We assessed safety by evaluating adverse events women reported in a daily diary. We also included data from focused safety studies evaluating endometrial biopsies, vaginal microbiology and liver proteins from one of the phase 3 studies.

Results: The combined studies included 3052 women; 2308 women [mean age 26.7±5.1 years; mean body mass index (BMI) 24.1±3.7 kg/m²] received the final manufactured CVS, of whom 999 (43.3%) completed 13 cycles of use. Women using the final CVS most commonly reported adverse events of headache (n=601, 26%), nausea (n=420, 18%), vaginal discharge/vulvovaginal mycotic infection (n=242, 10%) and abdominal pain (n=225, 10%). Few (<1.5%) women discontinued for these complaints. Four (0.2%) women experienced venous thromboembolism (VTE), three of whom had risk factors for thrombosis [Factor V Leiden mutation (n=1); BMI>29 kg/m² (n=2)]. During 21,482 treatment cycles in the phase 3 studies evaluable for expulsion, women reported partial expulsions in 4259 (19.5%) cycles and complete expulsions in 1509 (7%) cycles, most frequently in the initial cycle [499/2050 (24.3%) and 190/2050 (9.3%), respectively]. Safety-focused studies revealed no safety concerns.

Conclusion: The 1-year SA/EE CVS has an acceptable safety profile. Additional studies are warranted in obese women at higher risk of VTE.

Implications: This 1-year contraceptive vaginal system represents a new long-term, user-controlled and procedure-free option with a safety profile similar to other combination hormonal contraceptives. The same precautions currently used for combination hormonal contraceptive prescriptions apply to this new contraceptive vaginal system.

Keywords: Adverse events; Contraceptive vaginal system; Ethinyl estradiol; Nestorone; Segesterone acetate.