Safety and acceptability of penile application of 2 candidate topical microbicides: BufferGel and PRO 2000 Gel: 3 randomized trials in healthy low-risk men and HIV-positive men.

Objectives: To assess safety and acceptability of penile application of BufferGel (ReProtect, Baltimore, MD) and PRO 2000 Gel (Indevus Pharmaceuticals, Lexington, MA)compared with placebo among low-risk sexually abstinent men and HIV-positive sexually abstinent men.

Design: Seventy-two healthy low-risk men (36 uncircumcised) and 25 HIV-positive men (12 uncircumcised) were enrolled in 3 double-blind, single-center studies as follows: 36 low-risk men in a study of BufferGel and K-Y Jelly (McNeil-PPC, Skillman, NJ) placebo; 36 low-risk men in a study of PRO 2000 Gel and vehicle placebo; and 25 HIV-positive men in a crossover study of BufferGel, PRO 2000 Gel, and K-Y Jelly placebo.

Methods: Participants applied product to the penis on 7 consecutive nights, kept study diaries, and were then interviewed and examined. Urine was tested for inflammation by leukocyte esterase.

Results: No serious adverse events (AEs) or urethral inflammation was detected. During use of BufferGel, 3 low-risk men (13%) reported 6 AEs and 2 HIV-positive men (8%) reported 3 AEs. During use of PRO 2000 Gel, 4 low-risk men (17%) reported 6 AEs and 1 HIV-positive participant (4%) had 1 AE. AE rates during use of BufferGel and PRO 2000 Gel use were not significantly different from rates observed during placebo. One low-risk man (4%) would object to his partners using BufferGel and 3 (13%) to PRO 2000 Gel. Two HIV-positive men (8%) reported they would object to partners using either BufferGel or PRO 2000 Gel.

Conclusions: Daily application of BufferGel and PRO 2000 Gel directly to the penis consecutively for 7 days was generally safe and well tolerated among healthy low-risk men and HIV-positive men. These microbicides have acceptable safety profiles to proceed with planned phase 3 vaginal microbicide trials.