Christine Kalatma: The future of HIV treatment
What will HIV treatment look like in the near future? What developments are underway, and why is there still no HIV vaccine? The Medical Bulletin discussed these and other important issues with Professor Christine Kalatma of the University of the Sorbonne.
Professor Kalatma is the co-director of HIV clinic research at Pierre-Louis Institute of Public Health and Epidemiology (IPLESP), a research arm of the National Institute of Health and Medical Research of France (INSERM). She was part of the team that discovered the HIV-2 virus in 1986.
Four-day antiretroviral therapy (ART) regimens
Professor Kalatma spoke of a pilot study in France, in which patients are taking ART from Monday to Thursday - “4D” (four days a week). Experts comparing the effectiveness of the 4D regimen with standard daily ART in 600 said the results were “very convincing” and that the 4D regimen was almost as good as a traditional daily regimen.
According to one expert, this approach reduces the cost of treatment by almost 40% and, importantly, is popular with patients who can take pills during the week and take a break from therapy at the weekend. But Kalatma emphasised that this regimen is only applicable to people living with HIV (PLHIV) who have a completely suppressed viral load.
Can long-lasting injectables replace pills?
Whilst long-lasting agents, in the form of injections or implants, have promise it’s “too early” to put into practice right now as there are still questions and nuances to be worked out. For example, it requires a nurse or a doctor to perform the injections which may cause cost/resource/staffing implications for the clinic - making time for injection appointments might not be convenient for the PLHIV either. Some of these long-lasting injectables are also not suitable for people with resistance.
But, as the professor notes, this is an important step forward in HIV therapy and will suit lots of people, it’s important to consider and design treatments so that there’s a wide range of treatments suitable for all people and situations.
The future is definitely long-lasting drugs, however. These may be delivered in different ways such as injections, implants and orally. In 5-10 years the standard daily ART will be a thing of the past for many people, the professor believes.
Currently under development is lenakapavir, a new class of HIV therapy known as a ‘capsid inhibitor’. Lenakapavir has a long half-life and is administered every six months. When this drug passes all the necessary checks, tests and regulation it will be a “fantastic achievement” says Kalatma.
Where is the HIV vaccine?
Despite continuing advancements in the field of HIV treatment we’re still some time away from a marketable HIV vaccine. Currently work is underwear on a number of projects all aiming to produce the illusive immunisation against HIV.
The main problem with creating a HIV vaccine is how to initiate an immune response. There are few neutralising antibodies against HIV and they tend to be quite weak.
“HIV is a very smart virus” says Kalatma. It doesn’t attack the immune system in the same way as other viruses. For example, when a vaccine is administered on a run-of-the-mill adenovirus, HIV increases. Any stimulation of the immune system helps HIV because that’s where it lives - inside our immune cells.
“You’ll get much more than then Nobel Prize if you can create a HIV vaccine”, says Professor Christine Kalatma.
Still, she thinks we need to be optimistic. There are many public institutions and pharmaceutical firms working on the HIV vaccine - with some using the new mRNA platform that helped bring us the COVID-19 vaccines. For now we have effective HIV treatment, and plenty of other HIV prevention tools - such as PrEP.
