Finally, the moment many have been waiting for has come. On January 21, 2021 the US Food and Drug Administration (FDA) approved Cabanuva, an injectable form of combination therapy for treatment of HIV infection. The two components of Cabanuva are Cabotegravir, a drug from the powerful integrase inhibitor class which includes elvitegravir, dolutegravir, and bictegravir, and Rilpivirine, a drug in the same class as Efavirenz, Etravirine (Intellence), and Doravirine. The dosing requires an injection of both cabotegravir and rilpivirine in the muscle (usually in the buttocks) once a month! Yes, you read that correctly……once a month. The treatment has also been shown to be effective administered on every two months, but for now, it is only approved for once-monthly dosing. I should mention that the development and clinical trials of this product through Viiv Pharmaceuticals was directed by Kimberly Smith M.D., an African-American infectious diseases specialist and formerly, a professor at Rush University Medical School.
So what’s the big deal with long-acting therapy and why have I been obsessed with it for so long? Well, you tell me; would you prefer to take pills every day, or get an injection once a month? Many people would prefer the monthly option. But it’s more than just a matter of preference. HIV treatments are incredibly effective when they are taken as prescribed! We call this adherence. When they are not properly taken, the medicines cannot control the virus and it can start reproducing in the body and damage the immune system. But even more serious is that when the amount of drug in the body is too low to completely suppress the virus, the virus can develop resistance to the drugs. This means those drugs are no longer effective against the virus and different drugs will be needed to control the virus. This is our biggest challenge to controlling HIV long-term!
Long-acting combinations make it easier for some people to maintain their treatment, particularly for people who aren’t good at taking medicines every day.
Well, what”s the downside? The biggest complaint from taking the long-acting treatment is experiencing pain in the injection site. The injection must be given in the muscle (like your coronavirus vaccination). For the overwhelming majority, the pain is mild and usually dissipates after a day. In clinical studies, researchers closely monitored patient attitudes about getting the injection. Greater than 90% of trial participants were happy to tolerate the pain for once-a-month dosing. Importantly, study participants highly preferred the once-monthly injections to taking daily pills.
So how does this work if you want to use Cabanuva? First, you cannot have any resistance from drugs in the integrase class (for Cabotegravir) and no resistance from the non-nucleoside class (for Rilpivirine). Discuss it with your medical provider. You would first start taking Cabotegravir/Rilpivirine tablets for 30 days. This 30-day lead-in is to make sure you don’t have side-effects or reactions to the drug: after it is injected, it can’t be reversed. Once it is clear that you tolerate the medicines, then you receive the injections every month.
What if you can’t make into your provider’s office for your scheduled dose? If the dose isn’t given as scheduled, the amount of drug in the body could drop too low to suppress the HIV virus. To protect against this happening, you will be given a supply of tablets that can be taken from the time you are due for a dose until you are able to make it in for your next injection.
What if you don’t want to go into your medical provider’s office every month to get the injection? You may not have to. A Pharmacist at a nearby pharmacy may be able to administer your Cabanuva dose, just as they administer vaccinations. This may be more convenient than going into the office or clinic.
Welcome to the future! There will be other options for long-acting treatment and prevention coming down the pike.