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The manufacturer of Lea’s Shield, a "one-size-fits-all" vaginal contraceptive, plans to extend its present clinical studies following a Food and Drug Administration (FDA) advisory committee’s ruling of "a lack of adequate data on effectiveness."
The committee, comprising physicians and researchers outside the federal regulatory agency, voted 7-1 in October following presentations by YAMA Corp. of Millburn, NJ, and other organizations to obtain pre-market approval for the device. (For more information, see Contraceptive Technology Update, December 1996, p. 145.)
The FDA is not bound to follow the advisory panel’s recommendations, says Sharon Snider, agency spokeswoman. From reviewing previous actions, however, it is unlikely that the FDA will move to approve the device at this time.
There were a number of concerns expressed by the panel, but a major obstacle for members was the determination that the number of users included in the study was too small, says Snider.
"Basically, the panel’s main concern was that the manufacturer of this product only studied it in 55 couples," says Snider. "They felt they needed to see a much larger study in order to be sure that it was effective for women on a widespread scale."
The committee only focused on a portion of the study, says Shlomo Gabbay, MD, medical director for YAMA. A total of 106 women, out of 185 enrollees, completed the six-month study, according to data published in June 1996 in Contraception1 (and reviewed in Contraceptive Technology Update, September 1996, pp. 112-113.) Fifty-nine users of 106 included in the final analysis used the method with spermicide, while 47 used Lea’s Shield alone.
After controlling for age, center, and frequent prior use of barrier methods, the adjusted six-month life table pregnancy rates were 5.6 per 100 women for spermicide users and 9.3 per 100 women for non-spermicide users, which shows that use of spermicide lowered rates, but not at a significant rate.
Through standardization of parity between the Contraceptive Research and Development Program (CONRAD) study population and government-funded baseline studies conducted for the cap, diaphragm and sponge,2,3 results yielded unadjusted pregnancy rates of 2.2 and 2.9 per 100 users of spermicide and nonspermicide, respectively.
Although surprised and disappointed with the committee’s decision, YAMA plans to enlarge its current study to give the FDA the data it requests on the device’s efficacy, provided it can secure funding for the effort.
"If we put ourself to it, it can take a year to complete" a study of up to 200 women, Gabbay says.
The original study was performed by researchers at CONRAD in Arlington, VA, with data analysis performed by Family Health International (FHI) in Research Triangle Park, NC. Funding was provided by the National Institute of Child Health and Human Development, a division of the National Institutes of Health (NIH) in Bethesda, MD and the United States Agency for International Development (USAID) in Washington, DC.
"We would seriously consider funding a study along with NIH," says James Shelton, MD, senior medical scientist at USAID.
Even if the company completes its current study up to 200 women, it will take time to move through the regulatory process. It is unlikely that Lea’s Shield will be available to U.S. women even by the end of 1997, which is long past the originally anticipated December 1996 debut.
Some 14,000 women are now using the device, which is sold over the counter in Germany, Switzerland, Austria, and Canada. Made of silicone, Lea’s Shield is resistant to petroleum-based lubricants, does not absorb odors, and does not cause allergic reactions in users with latex sensitivity. Its unique design fills the posterior fornix to help keep it in place and prevent sperm from entering the cervical os. A loop offers ease of insertion and removal, and a one-way flutter valve prevents air from being trapped during and after insertion.
Unlike the diaphragm, the device does not have to be physician-fitted. YAMA plans to offer the device in one size in the United States, with physician prescription required.
Gabbay says he is frustrated by what he terms the committee’s inability to "listen to the science." The company also presented European-conducted studies of the device, but the committee chose to focus on the CONRAD/FHI research, he contends.
Despite the setback, the company will move forward toward obtaining FDA approval so the device can be distributed to American women, Gabbay vows.
"For YAMA, we probably will complete what we have up to 200 [women] and go and present it," he says. "The device is very good."
1. Mauck C, Glover LH, Miller E, et al. Lea’s Shield: A study of the safety and efficacy of a new vaginal barrier contraceptive used with and without spermicide. Contraception 1996 53(6):329-335.
2. Bernstein GS, Clark V, Coulson AH, et al. Use effectiveness of cervical caps. Final report. Washington DC: National Institute of Child Health and Human Development. Contract No. 1-HD-1-2804; 1986.
3. National Institutes of Health. Development and testing of vaginal contraceptives. Final report. Washington DC: National Institute of Child Health and Human Development. Contract No. 1-HD-1-2800; 1983.