Proven pregnancy prevention*

Gwyn Lo efficacy, adhesion, and safety results from Study 1, a phase 3 study1

*Individual results may vary.

Gwyn Lo Study 1 overview

A phase 3, open-label, single-arm, multicenter study evaluated 1320 women aged 16-54 years who were sexually active and had regular menstrual cycles. Participants completed ~13 consecutive 28-day cycles of treatment.1†

†The treatment regimen was a 4-week treatment cycle, with 1 Gwyn Lo patch applied every 7 days for 3 consecutive weeks followed by a 1-week patch-free period.1

Proven pregnancy prevention

Gwyn Lo was evaluated in Study 1, a phase 3, open-label, single-arm, multicenter pivotal trial1

The primary efficacy analysis included 983 women (aged 16-35 years, BMI <30 kg/m2) completing 9105 evaluable cycles in which intercourse occurred with no additional contraception.1

Primary endpoint1

Pearl Index 4.14

(95% CI: 2.77-5.95)

There were no differences in efficacy by BMI category

  • Pearl Index for patients with BMI <25 kg/m2: 4.48 (95% CI: 2.61–7.17) after 4936 evaluable cycles
  • Pearl Index for patients with ≥25 to <30 kg/m2: 3.74 (95% CI: 1.93–6.54) after 4169 evaluable cycles

96% avoided pregnancy

When used as directed.1

Pearl Index values are not comparable across trials or products due to differences in methodology, population criteria, BMI, and pregnancy detection methods.3
BMI=body mass index; CI=confidence interval.

Highly adhesive

~99% remained attached

Of the 39,790 patches worn in a year-long phase 3 study, 1.3% fully detached over the 7-day wear period.1

94%

of 342 patches worn in 4 additional studies had ≥75% surface area adhesion when evaluated throughout the 7-day wear period across various application sites and conditions.1

Additional safety and tolerability information

Venous events

Gwyn Lo is contraindicated in women with a BMI ≥30 kg/m2. The use of CHCs increases the risk of VTEs, such as deep vein thrombosis and pulmonary embolism. Risk factors for VTEs include smoking, obesity, and personal and/or family history of VTE, in addition to other factors that contraindicate use of CHCs. The risk of VTE may be greater with transdermal CHCs in women with a BMI ≥30 kg/m2 compared to women with a lower BMI.1

  • During Study 1, one thromboembolic event (pulmonary embolism), syncope, and seizure were reported in a female who had been using Gwyn Lo for 42 days and had a BMI of 27.6 kg/m2

Other serious adverse reaction

This serious adverse reaction occurred in <1% of women who received Gwyn Lo: suicidal ideation in 3 women with psychiatric histories, 1 of whom also experienced exacerbation of depression.1

Discontinuation due to adverse reactions

  • Discontinuation due to an adverse reaction occurred in 7.2% of women1
  • Discontinuation due to menstrual disorders occurred in 1.6% of women1
    • Menstrual disorders included intercycle and heavy withdrawal bleeding, menometrorrhagia, abnormal uterine bleeding, dysmenorrhea, and vaginal hemorrhage
  • The most common adverse reaction leading to discontinuation was application site irritation (1.2%)1
    • <1% of patients reported severe local application site reactions2
  • Overall, 0.9% of women discontinued due to psychiatric disorders2
    • Psychiatric disorders experienced in the clinical study included depression, anxiety, suicidal ideation, altered mood, depressed mood, and irritability
  • 0.2% of women discontinued due to weight gain2

    CHC=combined hormonal contraceptive; VTE=venous thromboembolism. 

    Most common adverse reactions

    Reported by ≥2% of women treated with Gwyn Lo in the pivotal clinical trial1

    Adverse reaction
    Gwyn Lo (n=1272)
    General disorders and administration site conditions
    Application site irritation 4.8%
    Application site erythema 3.7%
    Application site pruritus 3.7%
    Reproductive system and breast disorders
    Intercycle bleeding 3.9%
    Heavy withdrawal bleeding 2.0%
    Gastrointestinal disorders
    Nausea 2.0%

    Unscheduled bleeding/spotting

    Proportion of women reporting breakthrough bleeding1‡
    Mean number of unscheduled bleeding and/or spotting days1‡

    ‡Percent reporting based on any unscheduled bleeding/spotting per 28-day cycle via e-diary.1