A Phase III, single-arm study of LNG-IUS 8, a low-dose levonorgestrel intrauterine contraceptive system (total content 13.5mg) in postmenarcheal adolescents

OBJECTIVE: To assess the safety profile of the low-dose levonorgestrel intrauterine system (LNG-IUS) total content 13.5mg (average approximate release rate 8μg/24h over the first year; LNG-IUS 8; Jaydess®) in adolescents.

STUDY DESIGN: In a Phase III study in 36 European centers, 304 healthy nulliparous or parous postmenarcheal adolescents (12-17years) received LNG-IUS 8 for 12months. The primary outcome was the incidence of treatment-emergent adverse events (TEAEs). Secondary outcomes included: serious TEAEs, adverse events of special interest, overall user satisfaction, discontinuation rate at 12months, and Pearl Index.

RESULTS: LNG-IUS 8 placement was successful in 303/304 participants (99.7%). Overall, 82.6% of participants reported TEAEs, and serious TEAEs and serious study drug-related TEAEs were reported by 7.6% and 1.0% of participants, respectively. No cases of pelvic inflammatory disease, ectopic pregnancy, or uterine perforation were reported. No pregnancies were reported during the 12-month study. At Month 12/study end, the overall user satisfaction rate was 83.9%. Overall, 51 participants (16.8%) prematurely discontinued the study before 12months; 13.8% of participants discontinued owing to TEAEs.

CONCLUSIONS: No new or unexpected safety events were associated with the low-dose LNG-IUS 8. The safety profile of LNG-IUS 8 in adolescents was consistent with that previously reported in adults. The high overall user-satisfaction rate at study end and the low discontinuation rate over 12months demonstrate that LNG-IUS 8 is a highly acceptable contraceptive method among adolescents.

IMPLICATIONS: This study is the first to assess the low-dose levonorgestrel intrauterine system LNG-IUS 8 (average approximate release rate 8μg/24h over the first year and total content 13.5mg) specifically in females<18years of age and confirms the safety and efficacy of LNG-IUS 8 in an adolescent population.