Currently Enrolling Trials
Natazia is an estradiol-based oral contraceptive combining estradiol valerate with the progestin dienogest. Combination oral contraceptives lower the risk of becoming pregnant primarily by suppressing ovulation.
Natazia is specifically indicated for use by women to prevent pregnancy.
Natazia is supplied as a tablet for oral administration. Natazia should be taken in the order directed on the blister pack in order to achieve maximum effectiveness. The first Natazia tablet should be taken orally on Day 1 of the menstrual cycle. A non-hormonal contraceptive should be used as back-up during the first 9 days.
Clinical ResultsFDA Approvals
The FDA approval of Natazia was based on two multicenter phase III clinical trials in North America and Europe. The Pearl Index (PI) was the primary efficacy endpoint used to assess contraceptive reliability and was assessed in each the two studies, assuming all subjects were at risk of pregnancy unless a back-up contraceptive was used. The PI is based on pregnancies that occurred after the onset of treatment and within 7 days after the last pill intake.
This trial enrolled 490 healthy subjects between 18 and 35 years of age with a mean weight of 62.5 kg and a mean BMI of 23.3 kg/m2. The subjects were treated for up to 28 cycles of 28 days each. There were 5 pregnancies within 13 Cycles and 7 days after last treatment. The estimated PI for the North American study was 1.64 and the contraceptive failure rate at the end of the first year was 0.016.
European Study (Germany, Austria and Spain)
This study enrolled 1,377 healthy subjects between the ages of 18 and 50 years with an mean weight of 63.8 kg and a mean BMI of 22.8 kg/m2. The subjects were treated for 20 cycles of 28 days each. There were 9 pregnancies within 13 Cycles and 7 days after last treatment. The estimated PI for the European study was 1.04 and the contraceptive failure rate at the end of the first year was 0.010.
Adverse events associated with the use of Natazia may include, but are not limited to, the following:
- Headache (including migraines)
- Metrorrhagia and irregular menstruation
- Breast pain, discomfort or tenderness
- Nausea or vomiting
- Increased weight
Mechanism of Action
Natazia is an estradiol-based oral contraceptive combining estradiol valerate with the progestin dienogest. This is the first in a new class of oral contraceptives to deliver estradiol, the estrogen identical to the one produced by the female body. Combination oral contraceptives lower the risk of becoming pregnant primarily by suppressing ovulation. Other possible mechanisms may include cervical mucus changes that inhibit sperm penetration and endometrial changes that reduce the likelihood of implant ation.
Ahrendt HJ, Makalová D, Parke S, Mellinger U, Mansour D Bleeding pattern and cycle control with an estradiol-based oral contraceptive: a seven-cycle, randomized comparative trial of estradiol valerate/dienogest and ethinyl estradiol/levonorgestrel. Contraception 2009 Nov;80(5):436-44
Hoy SM, Scott LJ Estradiol valerate/dienogest: in oral contraception. Drugs 2009 Aug 20;69(12):1635-46
For additional information regarding Natazia or contraceptives, please visit the Natazia web page.