Phase 1 trial of nonoxynol-9 film among sex workers in South Africa

Objectives: To assess the acceptability and safety of a vaginal nonoxynol-9 film in a group of sex workers at a truck stop in South Africa. Design: A randomized double-blinded crossover trial was conducted between A pril 1995 and July 1995. Intervention: Seventy-twomg nonoxynol-9 film and an identical glycerine pla cebo film. Methods: Following informed consent, each study participant was randomly as signed the designated pre-coded film for 1 month. The second month was a fi lm-flee washout period and the participants used the alternate film in the third month. Besides measuring behavioural and clinical outcomes, colposcop y examination for genital lesions, serology and microbiology investigations for sexually transmitted diseases and semi-quantitative PCR for vaginal HI V load estimates were performed. Results: Twenty women participated in the study. The women reported, on ave rage, 19 sexual encounters per week. Vaginal intercourse was protected 25% of the time by condoms. On average, 11 vaginal Rims, either nonoxynol-9 or placebos were inserted per week. There were no statistically significant di fferences between the two treatment groups for genital lesions (P = 0.29), reported side effects (P = 0.73), and viral load (P = 0.9). However, the pr oportions of clinically detected genital lesions (six out of eight versus t wo out of eight) and self-reported side-effects (five out of eight versus t hree out of eight) were higher in the nonoxynol-9 group when compared with the placebo group. Incident sexually transmitted diseases occurred more fre quently in the placebo group. An increased viral load was associated with t he development of a genital lesion (relative risk, 6.0; 95% confidence inte rval, 0.81-44.4). Conclusions: The 72 mg film formulation of nonoxynol-9 was an acceptable pr oduct for use in this population of sex workers. Although no statistically significant differences in adverse outcomes were detected, clinically there appeared to be an increase in minor lesions and self-reported side-effects with nonoxynol-9 and less protection against sexually transmitted diseases with the placebo. Furthermore, HIV shedding was correlated with the presen ce of incident vaginal or cervical lesions. This brings into question the p otential narrow margin of safety for this product; additional Phase 2 studi es are therefore required. (C) 1999 Lippincott Williams & Wilkins.