In March 2020, the 28th annual Conference on Retroviruses and Oportunistic Infections (CROI) was held virtually. HIV is in the family of Retroviruses and this conference has long been considered the top research meeting for presenting cutting-edge research in HIV Science, Clinical research and Epidemiology.
It also presents important research on Sars-Cov-2 coronavirus, viral hepatitis, tuberculosis, and other infections. This article and the next series will present some updates from the conference that you might find interesting.
Lenacapravir is a truly remarkable drug for many reasons. The first feature is that this drug works in a totally new way, different from all the many other HIV drugs.
Lenacapravir is the first drug in a class called capsid inhibitors. Capsid is a very important protein for HIV replication. These capsid proteins are linked together to form a pouch that stores and protects the HIV virus’s genetic material. When the virus infect a cell, the capsid protein must unravel to release the genetic material in order to make new viruses.
Lenacapravir can bind to the capsid protein and prevent it from unraveling and releasing the virus’s genetic material. The virus is, therefore, unable to make more viruses. Also, the binding of Lenacapravir to capsid protein prevents new viruses from being assembled and spreading to infect more of our white blood cells.
This double action effect of Lenacapravir makes it a potent drug in suppressing HIV that works even better when combined with other HIV drugs.
Because Lenacapravir works a new way, it is a very important drug.
While it could work effectively for any patient, there are some patients who have been infected for many years, even decades and there are very few drugs available that they can be treated with. So, this feature of the drug led to a special clinical trial using Lenacapravir that was presented at CROI.
In this study, subjects were recruited who were failing their HIV regimen. These patients were on HIV medicines that were no longer working for them but they had few treatment options to switch to.
They had detectable virus in their blood. In the first part of the study, Lenacapravir was added to the failing HIV regimen. By simply adding Lenacapravir, the patients got on average 100-fold reduction in the amount of HIV in the blood at the end of two weeks.
This allowed the researchers to observe how powerful Lenacapravir was as a single drug against HIV.
The regimen was then strengthened by adding other HIV drugs that might still have some effectiveness to the Lenacapravir. In starting this phase of the study, we find another remarkable feature of Lenacapravir.
The drug can be taken every 6-months…….not every six days, not every 6 weeks but every six months! At the end of 6-months on treatment, 73% of the patients were undetectable, that is, completely suppressed.
Lenacapravir doesn’t have many side-effects or major toxicities (at least so far). It could be a real game changer for folks who are running low on options for treatment or folks who don’t do well taking pills every day.
We have already approved our first long-acting combination injectable that can be dosed on a monthly basis (see my article on Cabanuva).
It seems like we are getting more and more options for powerful medicines that are easier to take. You’ll be hearing a lot more about Lenacapravir so stay tuned.