FDA approval sought for frameless, flexible IUD
April 1, 1999
FDA approval sought for frameless, flexible IUD
The options for intrauterine devices (IUDs) in the United States may be expanded as a Belgian company plans to seek federal Food and Drug Administration (FDA) approval of a frameless, flexible IUD.
Contrel, based in Knokke-Heist, Belgium, is preparing an Investigational New Drug application to initiate studies for FDA approval of its GyneFix IUD, according to Dirk Wildemeersch, MD, Contrel’s founder and chairman. The Gyne Fix is available in Austria, Belgium, France, Hung ary, the Netherlands, People’s Republic of China, Spain, Switzerland, and the United Kingdom.
Other IUDs already on U.S. market
Two IUDs are now available to U.S. women: the ParaGard TCu 380A from Ortho-McNeil Pharma ceu tical of Raritan, NJ, and the Progestasert from Alza Pharmaceuticals of Palo Alto, CA.
The ParaGard is a T-shaped IUD with copper bands wrapped around the arms and copper thread wound around its stem. The Progestasert, also a T-shaped device, releases small amounts of progesterone from its built-in reservoir.
The design of the GyneFix differs from the ParaGard and the Progestasert in design and implantation. The device consists of six copper sleeves on a non-biodegradable surgical nylon thread. A knot in the upper extremity of the thread serves as an anchor. It’s implanted into the fundal myometrium with a specially designed insertion instrument. By suspending the copper sleeves on suture material, the Gynefix device is designed to reduce the problems with expulsion and removal for pain or bleeding that have been associated with the plastic frame of conventional IUDs.
The clinical development of GyneFix began in the 1980s by gynecologists working at the Univer sity of Ghent, Belgium. The group, led by Wilde meersch, published preliminary results on the device (then known as the Copper-Fix or Cu-Fix IUD) in 1988.1 The Special Programme of Research, Development, and Research Training in Human Reproduction of Geneva, Switz erland, initiated a multicenter randomized comparative trial of the Cu-Fix (FlexiGard) and the TCu 380A in 1989.
Interim results from the multinational trial were published in 1995.2 The three-year pregnancy rates for the two devices were similar (1.6 and 1.9 per 100 women, respectively), but the FlexiGard’s three-year expulsion rate was 7.4 women per 100, compared with the TCu 380A’s rate of 4.4 per 100 women.
There were 2,184 successful insertions of the TCu 380A, and 2,102 of the FlexiGard, but researchers reported 53 insertion failures for the FlexiGard and only one for the TCu 380A. If the FlexiGard’s nylon thread was not properly implanted in the fundal myometrium, it could be inadvertently removed when providers withdrew the inserter tube or expulsed a few weeks after implantation, researchers surmised.
Comparing effectiveness
A separate randomized international two-year clinical trial also compared the TCu 380A and the Cu-Fix.3 It found that while both IUDs provide highly effective protection against pregnancy, the TCu 380A had a lower expulsion rate.
Wildemeersch and his colleagues modified the insertion technique and inserter tube and reported an improved rate: two insertion failures in 527 attempts (0.4%) in a multicenter trial, compared with the 2.5% rate in the HRP trial.4
While the GyneFix implant is the same as the Cu-Fix and the FlexiGard, its insertion system has been enhanced for easier use and greater reliability, thereby reducing the number of failed insertion rates, says Wildemeersch. "Failed insertion due to shortcomings of the FlexiGard inserter was a major problem in the FlexiGard studies. This problem is now solved."
Training important step
Training is an important component of prop -er insertion of the GyneFix, observes Michael Rosenberg, MD, MPH, clinical professor of obstetrics/gynecology and epidemiology at the University of North Carolina and president of Health Decisions, a private medical research firm, both in Chapel Hill. He served as head of the second multinational study of the device. Just as women who use oral contraceptives well have considerably better success with the method than women who do not, individuals well-trained in the insertion and anchoring of the GyneFix can do much better with training than those who are not, Rosenberg says.
Providers at the Margaret Pyke Family Planning Centre in London have been inserting GyneFix for about 18 months, reports its medical director, John Guillebaud, MA, FRCSE, FRCOG, MFFP. He also sees training as an important component to proper insertion of the device.
Guillebaud says the GyneFix seems to share practically all the strengths of the TCu 380 PLUS, and it offers a reduced expulsion rate. It removes the possibility of frame-related pain and reduces the risk of malpositioning within the uterus, he says. Good training is essential, however, for proper placement of the device, he says.
Contrel continues to work with designers in further modifying the inserter, which should further reduce the learning curve for providers, Wildemeersch says.
References
1. Wildemeersch D, van der Pas H, Thiery M, et al. The Copper-Fix (Cu-Fix): A new concept in IUD technology. Adv Contracept 1988; 4:197-205.
2. UNDP, UNFPA, and WHO Special Programme of Research, Development and Research Training in Human Reproduction, World Bank: IUD Research Group. The TCu 380A IUD and the frameless IUD "the FlexiGard": Interim three-year data from an international multicenter trial. Contraception 1995; 52:77-83.
3. Rosenberg MJ, Foldesy R, Mishell DR Jr, et al. Performance of the TCu380A and Cu-Fix IUDs in an international randomized trail. Contraception 1996; 53:197-203.
4. Wildemeersch D, Van Kets H, van der Pas H, et al. IUD tolerance in nulligravid and parous women; optimal acceptance with the frameless CuFix implant system (GyneFix). Longterm results with a new inserter. Brit J Fam Plann 1994; 20:2-5.
Resources
For more on intrauterine devices (IUDs), contact:
• Contrel (Gynefix IUD) in Belgium. E-mail: [email protected]. World Wide Web: http://www.gynefix.com.
• Ortho Pharmaceutical Corp. (ParaGard T380A IUD), Medical Affairs, P.O. Box 300, Raritan, NJ 08869. Telephone: (800) 682-6532. World Wide Web: http://www.ortho-mcneil.com.
• Alza Pharmaceuticals (Progestasert IUD), Medical Information, 950 Page Mill Road, P.O. Box 10950, Palo Alto, CA 94303-0802. Telephone: (800) 634-8977. World Wide Web: http://www.alza.com.
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