SCIENTISTS today presented “promising data” on what drugs could prove effective in the next generation of microbicides to stop the sexual transmission of HIV.

Dr Walid Heneine said that an integrase inhibitor (the compound L-870812) had protected two out of three monkey models from infection.

This is the first gel with an integrase inhibitor to be tested and it was found to offer the macaques significant protection.

Integrase inhibitors prevent the HIV integrase protein from inserting HIV genetic information into the infected cell’s own DNA.

Professor Robin Shattock from St George’s, University of London, spoke about the potential of several new drugs – tested in cell and tissue studies – for developing microbicides.

He said that those showing promise down the pipeline were the protease inhibitor darunavir and even further down the fusion inhibitor L’644.

Protease inhibitors block the maturation of new virus particles once they have infected the cell, preventing them from being passed on.

Daruvanir shows potential, particularly when combined with dapivirine, a non-nucleoside reverse transcriptase inhibitor, laboratary studies show.

The compound L’644 is coming first in the class of drugs known as fusion inhibitors – which act to stop the virus from binding to healthy target cells. They have already been used in treatment.

This drug is active even after being washed off the tissue, suggesting it locks on the cell surface and could offer a wider window of protection over time, said Shattock.