Article

Effectiveness of Cellulose Sulfate Vaginal Gel for the Prevention of HIV Infection: Results of a Phase III Trial in Nigeria

Tulane University, United States of America
PLoS ONE (Impact Factor: 3.23). 02/2008; 3(11):e3784. DOI: 10.1371/journal.pone.0003784
Source: PubMed

ABSTRACT

This trial evaluated the safety and effectiveness of 6% cellulose sulfate vaginal gel in preventing male-to-female vaginal transmission of HIV, gonorrhea and chlamydial infection.
This Phase III, double-blind, randomized, placebo-controlled trial was conducted between November 2004 and March 2007 in Lagos and Port Harcourt, Nigeria. We enrolled 1644 HIV-antibody negative women at high risk of HIV acquisition. Study participants were randomized 1:1 to cellulose sulfate or placebo and asked to use gel plus a condom for each act of vaginal intercourse over one year of follow-up. The participants were evaluated monthly for HIV, gonorrhea and chlamydial infection, and for adverse events.
The trial was stopped prematurely after the data safety monitoring board of a parallel trial concluded that cellulose sulfate might be increasing the risk of HIV. In contrast, we observed fewer infections in the active arm (10) than on placebo (13), a difference that was nonetheless not statistically significant (HR = 0.8, 95% CI 0.3-1.8; p = 0.56). Rates of gonorrhea and chlamydial infection were lower in the CS group but the difference was likewise not statistically significant (HR = 0.8, 95% CI 0.5-1.1; p = 0.19 for the combined STI outcome). Rates of adverse events were similar across study arms. No serious adverse events related to cellulose sulfate use were reported.
Cellulose sulfate gel appeared to be safe in the evaluated study population but we found insufficient evidence that it prevented male-to-female vaginal transmission of HIV, gonorrhea or chlamydial infection. The early closure of the trial compromised the ability to draw definitive conclusions about the effectiveness of cellulose sulfate against HIV.
ClinicalTrials.gov NCT00120770.

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Available from: Saïd Abdellati, Jul 14, 2014
    • "A: μ 30 y Invisible Condom ® formulations and applicator were well-tolerated when applied intravaginally bid for 2 w 70–86% compliance; however, only 20% of gel applications coincided with sex[23]Cellulose[Cotonou, Benin]gel use: 63% AWMP, 94% AWOP (last 7 d);[Kampala, Uganda]gel use: 60% AWMP, 85% AWOP (last 7 d);[Durban, South Africa]gel use: 91% AWMP, 95% AWOP (last 7 d);[Chennai, India]gel use: 38% AWMP, 91% AWOP (last 7 d);[24][25](Continued)[Isipingo, Durban, KwaZulu-Natal]Gel: μ 92% at LS (SELF); CLS: μ 58% (SELF); μ 55% covered acts[26][Masaka, Uganda]A: μ 32 y; E: 2% ≥ secondary; NP: 0% >1 partner (last 1 w); CF: median 1 APW; AI: <0.5% (last 4 w); CLS: 70%; FP: 27%;[Mwanza, Tanzania]A: μ 30 y; E: 5% ≥ secondary; NP: 3% >1 partner (last 1 w); CF: median 1 APW; AI: <0.5% (last 4 w); CLS: 33%; FP: 50%;[CF: median 2 APW; AI: 46% (ever); CLS: 61%; FP: 89%;[Kamwala, Zambia]A: μ 23 y; E: 9% ≥ secondary; NP: 3% >1; CF: median 3 APW; AI: 3% (ever); CLS: 77%; FP: 98%;[Chitungwiza, Zimbabwe]A: μ 26 y; E: 29% ≥ secondary; NP: 3% >1; CF: median 5 APW; AI: 1% (ever); CLS: 87%; F: 99%[Harare, Zimbabwe][31](Continued) "

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    • "Another polyanion, Ushercell (cellulose sulfate; Polydex Pharmaceuticals, Toronto, ON, Canada), a contraceptive product possessing anti-HIV activity by binding to the V3 loop of gp120 of the HIV-1 envelope can inhibit the entry of both CXCR4 and CCR5-tropic virus.45 However, different clinical trials indicated that it has no beneficial effect in curtailing the risk of HIV transmission and its use may increase the risk of HIV infection, possibly owing to toxicity of the active ingredient or the hyperosmolar gel vehicle (iso-osmolar placebo).46,47 "
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    • "Unfortunately, the clinical results were disappointing. One of the cellulose sulfate trials even showed higher HIV seroincidence in the cellulose sulfate arm [9], while another efficacy trial indicated no inhibitory effect of cellulose sulfate on the risk of HIV-1 transmission [10]. Efficacy trial of carrageenan demonstrated that carrageenan gel was safe, but lacked efficacy against HIV-1 transmission [11]. "
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