New tenofovir gel study shows no effect on HIV prevention: Lower than expected gel use impact FACTS trial results
HIV prevention for women suffered a setback today when a study conducted by the Follow-on African Consortium for Tenofovir Studies (FACTS) reported that its results do not confirm the HIV protective effect of tenofovir gel shown previously in the CAPRISA 004 trial. The FACTS 001 trial involving 2059 South African women showed no overall HIV prevention benefit of the gel. However, a sub-group analysis based on gel use confirmed by tenofovir detection in genital fluid, showed a 52% reduction in HIV infection. The CAPRISA study had reported in 2010 that tenofovir, applied as a gel before and after sex, reduced HIV infection by 39% overall and by 54% in women who used the gel consistently.
The results of the FACTS 001 study, which was led by Professors Helen Rees and Glenda Gray, were markedly influenced by the large proportion of women who did not apply the gel consistently. This is similar to the experiences in the VOICE (Vaginal and Oral Interventions to Control the Epidemic) trial involving women from Uganda, South Africa and Zimbabwe. The VOICE study recently reported no impact of tenofovir gel on HIV prevention because many of the women in that trial did not adhere to the daily dosing regimen.
“ Tenofovir gel prevents HIV infection when it is used but most of the women in the FACTS study did not manage to apply the gel consistently when they had sex.” said Professor Quarraisha Abdool Karim, Associate Scientific Director of CAPRISA and leader of the CAPRISA 004 trial. “While the results are disappointing, the high HIV infection rates in this trial highlight the urgent need for continued efforts to find appropriate HIV prevention tools for women in Africa.”
Research on tenofovir gel is continuing. Tenofovir gel is currently being studied by the Microbicide Trials Network as a rectal application in men who have sex with men in several countries, including South Africa. CAPRISA is in the process of completing the CAPRISA 008 trial, which assesses gel adherence in women receiving tenofovir gel in conjunction with family planning. This real world implementation study may shed additional light on adherence when using a product that users know works. Further, a vaginal ring with both tenofovir and a contraceptive is being developed with the aim of improving tenofovir adherence in women who are also strongly motivated to prevent pregnancy.
Professor Salim S. Abdool Karim, Director of CAPRISA congratulated the FACTS 001 study team on this multicentre study and commented that, “CAPRISA remains fully committed to HIV prevention technologies that empower women to protect themselves from HIV. We are now undertaking research on newer long-acting agents such as our recently discovered broadly neutralising antibodies, which could potentially be used as a 3-monthly injection to prevent HIV.”
Women have a disproportionately high burden of HIV in Southern Africa. Within the KwaZulu-Natal province of South Africa where CAPRISA conducts its research, 5 sub-districts have HIV prevalence rates in pregnant women that exceed 40%. CAPRISA calls on AIDS researchers to re-double efforts, despite the recent disappointments, to find new HIV prevention technologies for women. Reducing the high infection rates among young women is key to controlling the epidemic, particularly in sub-Saharan Africa.
Enquiries: Smita Maharaj
Cell: +27 (0)82 806 9931