Cohort study to evaluate efficacy, safety and acceptability of a two-rod contraceptive implant during third, fourth and fifth year of product use in China

Can a 3 months treatment with oral Desogestrel prior to insertion of the etonogestrel-releasing contraceptive implant improve continuation rate at 1 year? A randomized trial

OBJECTIVE

To evaluate if daily oral 75 µg of Desogestrel (DSG) for 3 months prior to the insertion of etonogestrel-releasing contraceptive implant (ENG-IMPLANT) might help reduce its premature discontinuation.

RESULTS

A total of 66 women were randomized in the ENG-IMPLANT group (26) and in the DSG + ENG-IMPLANT group (40), respectively, in the Geneva University Hospitals and Basel University Hospital, from August 15th, 2016 through September 30th, 2019. In the DSG + ENG-IMPLANT group, patients were given a 3 months' supply of 75 µg of DSG before the insertion of the ENG-IMPLANT. All women were seen after 3 months for bleeding and satisfaction evaluation, and at 12 months post ENG-IMPLANT insertion. Higher levels of satisfaction at 12-months were found in the ENG-IMPLANT group compared to the DSG + ENG-IMPLANT group (8.5 ± 1.7 vs. 6.6 ± 2.9, p = 0.012). There were no statistically significant differences regarding tolerance (7.8 ± 2.5 vs 6.8 ± 2.6, p = 0.191) and contraceptive continuation (80% vs 72.4%, p = 0.544) between groups.

CONCLUSION

DSG prior to insertion of the ENG-IMPLANT did not improve its continuation rate neither its satisfaction at 1 year. Trial registration NCT05174195. Retrospectively registered, the 30th December 2021.

Levonorgestrel release rates measured through analysis of two-rod contraceptive explants

Objective

The objective was to characterize and compare in vivo rates of levonorgestrel (LNG) release from Sino-implant (II) and Jadelle® contraceptive implants.

Study design

We sampled 48 Sino-implant (II) and 49 Jadelle® explant sets for residual LNG content from participants treated for up to 51 months in a randomized contraceptive efficacy trial in the Dominican Republic (DR). Additional Sino-implant (II) explants were obtained from 8 women who became pregnant in the DR trial and 10 who contributed 3 to 5 years of use in a cohort study in China. Baseline LNG loads were estimated from five unused implant sets per device type. Release profiles were estimated using mixture models that captured initial burst fractions and compared with efficacy and pharmacokinetics data from the DR trial.

Results

Estimated baseline LNG loads for Sino-implant (II) and Jadelle® were 142.8 mg and 150.5 mg, respectively (vs. the labeled 150 mg). There was an initial burst release of drug (5.6% and 7.9%, respectively) followed by an exponential decrease in LNG content evident for each device. Release rates were significantly lower for Sino-implant (II) throughout the treatment period, with estimated rates after 3 years of 24.2 mcg/day and 29.0 mcg/day for Sino-implant (II) and Jadelle®, respectively. The estimated Sino-implant (II) rate after 3 years was similar to the predicted rate after 5 years (23.6 mcg/day) for Jadelle® (rate ratio: 1.03; 95% confidence interval: 0.92-1.13).

Conclusions

Sino-implant (II) LNG release rates were significantly lower than Jadelle® with Sino-implant (II) rates through year 3 comparable to Jadelle® rates through year 5. These results reinforce the 3-year duration of action for which Sino-implant (II) was prequalified by the World Health Organization.

Implications

This analysis confirms the WHO prequalification of Sino-implant (II) for 3 years of use and supports different durations of action for Jadelle® and Sino-implant (II). It provides additional evidence that this approach can complement efficacy trials in determining duration of action of hormonal contraceptives in general.

Randomized trial to evaluate contraceptive efficacy, safety and acceptability of a two-rod contraceptive implant over 4 years in the Dominican Republic

Objective

Sino-implant (II) is a contraceptive implant that had a commodity price one-third of the competing products a decade ago. To make Sino-implant (II) more widely available, we conducted a trial to collect safety and efficacy data required for World Health Organization (WHO) prequalification, a quality standard allowing global donors to procure a pharmaceutical product.

Study design

This was a randomized controlled trial allocating 650 participants to either Sino-implant (II) or Jadelle®. Participants were seen at 1 and 6 months, and then semiannually. The primary efficacy measure was the pregnancy Pearl Index [number of pregnancies per 100 women-years (WY) of follow-up] in the Sino-implant (II) group during up to 4 years of implant use.

Results

For the primary outcome, Sino-implant (II) had a 4-year Pearl Index of 0.74 (95% confidence interval, 0.36-1.37) compared to 0.00 (95% confidence interval, 0.00-1.04) for Jadelle®. The Sino-implant (II) pregnancy rate was significantly higher in the fourth year (3.54 per 100 WY) than in the first 3 years combined (0.18 per 100 WY; p <.001). Total levonorgestrel concentrations were equivalent between groups at month 12, but were 19%, 22% and 32% lower in the Sino-implant (II) group at months 24, 36 and 48, respectively (p <.001 at each time point). Safety and acceptability of the two products were similar, while providers documented significantly higher breakage rates during removal of Sino-implant (II) (16.3% vs. 3.1%; p <.001).

Conclusion

Based on these results, WHO prequalified Sino-Implant (II) with a 3-year use label in June 2017, 2 years shorter than the 5-year duration of Jadelle®.

Implications

WHO prequalification allows global donors to procure Sino-implant (II), which means women in many low resource countries will have greater access to highly effective and acceptable contraceptive implants. Our study noted important clinical differences, including shorter duration of high effectiveness with Sino-implant (II) when compared to the other available two-rod system, Jadelle®. Introduction strategies should include appropriate training on these differences.