Safety evaluation of nonoxynol-9 gel in women at low risk of HIV infection.
OBJECTIVE: To determine the safety of a vaginal microbicide, COL-1492, containing 52.5 mg nonoxynol-9, applied once daily for 14 days among healthy volunteers.
METHODS: A randomized, double-blind controlled trial with three arms, COL-1492 gel versus placebo gel versus no-treatment controls, was conducted. Outcomes of interest were reported genital symptoms, incidence of gynaecological signs, and incidence of genital lesions revealed by colposcopy. Participants were enrolled in four centres (Belgium, The Netherlands, and two in Thailand).
RESULTS: A total of 534 women participated in the study: 179 used COL-1492, 178 used placebo, and 177 were no-treatment controls. Study visits were scheduled 1 week prior to enrollment (day -7), day 0 (enrollment), day 8 and day 14. The most frequently reported genital symptom was vaginal discharge in both the COL-1492 and placebo groups. This appeared to be related to leakage of the product out of the vagina. The incidence of lesions associated with epithelial disruption (ulcers and abrasions) was very low (< 2%) and there was no statistically significant difference between the three groups. Of the lesions observed by colposcopy that did not involve epithelial disruption, petechial haemorrhage was the most frequently detected, with an incidence of 20.1, 9.0 and 7.3% in the COL-1492, placebo and control groups, respectively. COL-1492 users had a higher incidence of erythema (8.4 versus 2% in the other groups).
CONCLUSION: COL-1492 showed minimal toxicity when applied once daily. A Phase III trial to assess the product's effectiveness in HIV prevention is currently ongoing.