Avanti polyurethane condom as effective as latex in preventing pregnancy -- NICHD trial.

AVANTI POLYURETHANE CONDOM EFFICACY COMPARABLE TO LATEX in a three-year study sponsored by the National Institutes of Health National Institute of Child Health & Human Development and conducted by the Los Angeles Regional Family Planning Council. The lead investigator was Anita Nelson, MD. The study, involving 805 monogamous, heterosexual couples ages 18-45, found an insignificant difference in pregnancy prevention between the Durex Avanti (thin version) polyurethane condom and the Ramses Sensitol latex condom. Both condoms are manufactured and marketed by London International Group. The company expects the study to be published in a peer-reviewed journal in 1997.

"The typical-use pregnancy rate after six complete menstrual cycles of use was 4.7 (+/-2.5) for the polyurethane condom compared to 6.8 (+/-2.9) for the latex condom," Nelson et al. state. When adjusted to reflect use of "emergency contraception" (the use of a "morning after pill"), the difference between rates remains statistically insignificant, at 5.3% and 7%.

London International has been marketing Durex Avanti male polyurethane condoms in U.S. drug and food chains since late 1994 with restricted labeling stating that the product is "intended for latex-sensitive condom users only," and "the risk of pregnancy and sexually transmitted diseases, including AIDS (HIV infection) are not known for this condom." Once study results are published, London International will be able to change the labeling without obtaining additional 510(k) device clearances from FDA, the firm said previously ("The Tan Sheet" March 17, p. 5). Avanti was cleared in 1991 via a 510(k) device premarket notification application submitted by San Diego, Calif.-based Apex Medical Technologies.

The randomized, controlled, double-masked trial randomly assigned the couples to either the polyurethane or the latex condom as their only method of birth control for six months. Subjects were instructed to complete a diary for each act of intercourse detailing their experiences with the condom and were contacted every three months, either through a clinic visit or a telephone interview, and at the conclusion, in a face-to-face exit interview.

In spite of the comparable six-month typical-use pregnancy rates for the two products, Avanti was found to have an increased risk of condom failure in a "slippage and breakage" study nested within the framework of the efficacy study.

In the initial five-use "slippage and breakage" trial, Avanti was reported either to have slipped off or broken during intercourse or withdrawal 5.3% of the time compared to .7% for the latex control. A breakdown of the 5.3% clinical failure rate reveals a breakage rate of 4%, which contrasts with a .4% rate for the latex product. London International said breakage rates for latex condoms are known to range between 1.3% and 6.7%.

"In general, participants who used the latex control condom expressed greater satisfaction with their device than participants who used the polyurethane condom," the study notes. Eighty-three percent of male and 85% of female type participants from the latex group said they would recommend or strongly recommend their condom type, compared to 62% of male and 67% of women whose partners used polyurethane condoms. "The early study discontinuation rate for reasons other than pregnancy were significantly higher...for the polyurethane group...than for the latex group," the researchers note. A total of 47 male partners who used the polyurethane product cited a condom-related reason for dropping out of the trial compared to 19 male latex condom users.

"However, the polyurethane condom fared better than the latex condom in several subjective characteristics including sensitivity and odor," the study says. Seventy percent of the polyurethane study participants, both male and female, reported the condom's odor to be more pleasant than latex, compared to 61% of male and 66% of female latex condom participants responding to the same question. The researchers did not find a statistically significant difference between the groups regarding their assessment of the "sensitivity" afforded by the polyurethane condom compared to previous experience using latex condoms.

Even with less restrictive labeling claims, London International may find it a challenge to grow Avanti's market share because the product costs roughly twice as much as many latex condoms, $6.30 for a three-pack and $10.40 for a six-pack. Avanti, the first commercially available non-latex condom, holds a 1%-2% share of the male condom market, the company said. London International has indicated it plans to launch an extensive national promotional campaign for the product, including television and print ads, which may focus on Avanti's thinness and corresponding increased sensitivity. Avanti is available in both "thin" and "super-thin" versions.