NuvaRing’s contraceptive efficacy and tolerability are comparable to an
oral contraceptive
K. Oddsson (1), C. Verhoeven (2)
Women’s Health Associates, Kopavogur, Iceland (1); Department of
Clinical Development, NV Organon, Oss, The Netherlands (2)
Introduction: Oral contraceptives (OCs) are the most frequently used
form of hormonal contraception, but require daily dosing. NuvaRing is a
once-a-month contraceptive vaginal ring that is used for 3 weeks followed by a
1-week ring free period. This large comparative trial was conducted to compare
NuvaRing’s contraceptive efficacy and tolerability with that of an OC
containing levonorgestrel 150 µg and ethinylestradiol 30 µg daily.
Design and methods: This open-label, randomized, comparative, 1-year
trial was conducted in 11 countries and involved healthy women (>18 years),
seeking contraception. Subjects received either NuvaRing (n=512) or the OC
(n=518) for 13 cycles, and used diary cards to record daily ring and pill use.
Assessments and adverse event reports were made at clinic visits after cycles 3,
6, 9 and 13.
Results: A total of 149 women in each group discontinued: 70.9% of the
NuvaRing group and 71.2% of the OC group completed the trial. The main reasons
for discontinuation were adverse events (AEs) (11.3% NuvaRing vs 8.7% OC) and
lost to follow up (6.4% for both groups). There were 5 in-treatment pregnancies
in both the NuvaRing and OC groups; the Pearl Index for both groups was 1.2.
Cycle control data were significantly better for NuvaRing compared with the OC (presented
separately at this meeting). Both treatments were well tolerated and similar
numbers of subjects experienced AEs in the NuvaRing (57.6%) and OC (54.3%)
groups. A slightly greater proportion of subjects experienced treatment-related
AEs with NuvaRing (28.9%) than with the OC (22.1%). Treatment-related AEs of the
female reproductive disorders class were more common with NuvaRing (18.0%) than
the OC (4.6%), mainly due to a higher incidence of local events (e.g. vaginitis,
leukorrhea, ring-related events) with NuvaRing. Treatment-related events such as
headache, nausea and breast pain were comparable for NuvaRing and the OC (7.2%
vs 5.8%; 2.7% vs 4.0%; 3.1 vs 1.3%, respectively). There were 11 (2.1%) serious
adverse events (SAEs) with NuvaRing and 7 (1.3%) with the OC; one SAE in each
treatment group was considered to be treatment related. There were no relevant
differences between the two groups for vital signs or body weight.
Conclusions: This study shows that NuvaRing has comparable efficacy
and tolerability to an OC containing 150 mg levonorgestrel and 30 mg
ethinylestradiol and supports previous findings that NuvaRing is effective with
a good safety profile. Thus, NuvaRing offers contraceptive efficacy in a
convenient formulation that only requires monthly dosing.
