Sanofi, in collaboration with the US National Institute of Health, is developing an antibody HIV treatment that can kill 99% of strains.
Human immunodeficiency virus (HIV) is notoriously difficult to treat as it mutates so quickly. Some patients develop ‘broadly neutralizing antibodies’ that attack fundamental parts of the virus, and are therefore very powerful tools. Researchers at Sanofi and the US National Institute of Health combined three of these antibodies to produce a treatment with 99% coverage of all HIV strains. Experiments in monkeys demonstrate its efficacy, and clinical trials will begin next year.
HIV infects immune cells, which impairs their function. The immune system deteriorates over time until it can no longer effectively fight infection and disease. At this point, the individual is at risk of opportunistic infections, which take advantage of the weakened immune system. When an individual has had one or more opportunistic infections or HIV-related cancers, they have acquired immunodeficiency syndrome (AIDS).
A single broadly neutralizing antibody can have up to 90% coverage of HIV strains. By engineering these antibodies, they can now interact with three determinants of the virus’ envelope protein, which is essential for the fusion with, and infection of human cells. Sanofi’s treatment combines three of these antibodies, to form an even more powerful ‘tri-specific antibody’.
Current treatments are based on the use of antiretroviral therapy (ART), which slows the rate of HIV multiplication. Although these helped to reduce the number of deaths per year by 45% between 2005 and 2015, the number of new cases and deaths remains high. To tackle this, a lot of innovative research across Europe is underway to find an effective therapy.
For example, Abivax’s HIV treatment completely removes the virus and prevents it from coming back. On average, a 40% decrease in viral load was observed during a Phase IIa trial. Immunocore’s ImmTAV TCR-based technology, which received $40M (€33M) from the Bill & Melinda Gates Foundation, and Mologen’s DNA molecule, lefitolimod, both modulate the immune system to enhance its HIV-killing capacity.
The fact that so much work is being carried out offers hope to the field. An HIV cure has been long sought after, so if one of these groups could pull it off, it would change the lives of millions. What is particularly exciting about Sanofi’s work is its potential as a preventative measure, which would obviously be the best possible approach.
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