Efficacy and safety of a 28-day oral contraceptive with 7 days of low-dose estrogen in place of placebo

Efficacy and safety of a 21/7-active combined oral contraceptive with continuous low-dose ethinyl estradiol

OBJECTIVE

Substituting low-dose ethinyl estradiol (EE) for the hormone-free interval in combined oral contraceptives (COCs) may enhance ovarian suppression and improve tolerability. This noncomparative phase 3 study evaluated the efficacy and safety of a 21/7-active COC regimen including 21days of desogestrel (DSG)/EE followed by 7days of EE.

STUDY DESIGN

This multicenter, open-label, phase 3, single-arm study enrolled sexually active women aged 18-40years at risk for pregnancy. Women received up to 1year, or 13 consecutive 28-day cycles, of DSG 150mcg/EE 20mcg for 21days and EE 10mcg alone for 7days. Participants kept diaries to record compliance, bleeding/spotting and other contraceptive use. Efficacy was measured using the Pearl Index (PI) and life-table approach. Safety and tolerability were assessed primarily through reported adverse events (AEs).

RESULTS

A total of 2858 women enrolled and 1680 completed the study. Forty-six pregnancies in 2401 women aged 18-35years occurred after COC initiation and up to 7days after last DSG/EE or EE-only tablet was taken. When cycles in which another contraceptive method was used were excluded, the PI was 2.68 [95% confidence interval (CI), 1.96-3.57]. The cumulative pregnancy rate after 1year of treatment was 2.47% (95% CI, 1.85-3.29) for all users aged 18-35years. When only cycles during which women considered compliant were included, the PI was 2.00 (95% CI, 1.39-2.80). AEs were similar to those seen with other oral contraceptives.

CONCLUSIONS

This 21/7-active DSG/EE COC with 7days of low-dose EE was efficacious and well tolerated for pregnancy prevention.

IMPLICATIONS STATEMENT

This phase 3 open-label study demonstrated that a 21/7-active COC regimen including 21days of DSG 150mcg/EE 20mcg and 7days of EE 10mcg was efficacious and well tolerated for pregnancy prevention.

Efficacy and safety of an ascending-dose, extended-regimen levonorgestrel/ethinyl estradiol combined oral contraceptive

OBJECTIVE

To evaluate the efficacy and safety of an ascending-dose, extended-regimen (ADER) combined oral contraceptive consisting of levonorgestrel (LNG) 150 mcg/ethinyl estradiol (EE) 20 mcg for 42 days, LNG 150 mcg/EE 25 mcg for 21 days, LNG 150 mcg/EE 30 mcg for 21 days and EE 10 mcg for 7 days.

STUDY DESIGN

This was a multicenter, open-label, phase 3, single-arm study. Sexually active women aged 18-40 years were enrolled and received ADER for up to 1 year (4 consecutive 91-day cycles). Participants kept diaries to record adherence, bleeding/spotting and other contraceptive use. Efficacy was measured using the Pearl Index and the life-table method; safety and tolerability were assessed through reported adverse events (AEs).

RESULTS

A total of 3701 women were enrolled and 2144 completed the study. The Pearl Index was 3.19 [95% confidence interval (CI), 2.49-4.03], based on 70 pregnancies that occurred after ADER initiation and ≤ 7 days after the last LNG/EE or EE-only pill in women aged 18-35 years, excluding cycles in which another contraceptive method was used. Life-table pregnancy rate was 2.82% (95% CI, 2.23%-3.57%) for all users aged 18-35 years. Unscheduled bleeding/spotting decreased with increasing EE doses within each cycle and decreased after cycle 1. No unexpected AEs or changes in laboratory parameters were reported.

CONCLUSION

This study demonstrated that ADER effectively prevented pregnancy with a favorable safety and tolerability profile.

The creeping Pearl: Why has the rate of contraceptive failure increased in clinical trials of combined hormonal contraceptive pills?

BACKGROUND

Despite several drawbacks, the Pearl Index continues to be the most widely used statistical measure of contraceptive failure. However, Pearl indices reported in studies of newer hormonal contraceptives appear to be increasing.

STUDY DESIGN

We searched PubMed and Medical Intelligence Solutions databases for prospective trials evaluating oral contraceptive (OC) efficacy to examine potential factors that could contribute to increasing Pearl indices.

RESULTS

Numerous potential factors were identified, including an increased rate of failures of newer OCs, deficiencies in methods of calculating contraceptive failure rates, differences in study design and changes in patient populations resulting in increased rates of contraceptive failures due to the inappropriate or inconsistent use of the method.

CONCLUSIONS

The two most likely important contributors to the increase in Pearl indices are more frequent pregnancy testing with more sensitive tests and less adherent study populations. Because study populations appear to be increasingly representative of the likely actual users once the product is marketed, we can expect to see even higher failure rates in ongoing and future studies. This result poses challenges for companies and regulatory agencies.

Oral contraceptives in migraine therapy

Even if sometimes combined oral contraceptives (COCs) can initiate or aggravate headaches, in particular migraine, the headaches generally tend to improve after the first months of COC use. If migraine persists, in many patients the attacks are more likely to occur during the pill-free week, and an oral contraceptive-induced menstrual migraine (OCMM) occurs. In case of OCMM, some hormonal manipulations are available, by eliminating or reducing the hormone-free interval (HFI), in order to prevent this estrogen-withdrawal headache. It is possible to use a continuous COCs regimen, to shorten the HFI to less than the traditional 7 days, to use a low-dose estrogen supplementation after the 21 days of COCs or to prescribe a progestogen-only pill (POP). Interestingly, the use of a POP is a safe option also for women suffering from migraine with aura (in which COCs are absolutely contraindicated) and a recent trial suggests that its use can reduce the frequency of migraine attacks and the duration of aura symptoms too.