Ok, you’re probably tired of me promising that long-acting antiretroviral therapy would soon be available through your doctor.
The product I’ve been talking about the most is a combination of the drugs cabotegravir and rilpivirine. Cabotegravir is an integrase inhibitor, in the same class as dolutegravir (in products like Triumeq, Dovato, Juluca ) and bictegravir (in Bictarvy). Ripivirine (in Complera and Juluca) is a non-nucleoside analogue in the same class as drugs like Efavirenz (in Atripla), Etravirine (Intellence) and Doravirine (Pilfeltro).
The medical community was really expecting the Food and Drug Administration to approve this long-acting therapy for once-monthly dosing in December; a sort of Christmas present. However, the approval was delayed but fortunately not related to issues of drug safety or effectiveness. In the meantime, there have been some positive developments.
A study presented in March at the Conference for Retroviruses and Opportunistic Infections , the top HIV research conference (presented as a virtual conference) had more good news. They showed that the injectable combination treatment was effective for two months from a single injection. The drug preparation is...
...administered intramuscularly, as an injection in the gluteus muscle, which can admittedly be a little painful. In the clinical trials, 90% of patients preferred the monthly injection compared to taking pills every day. An injection every two months only makes it better.
But what about long-acting HIV medicines for HIV prevention? I’ve written a lot about Pre-exposure Prophylaxis (PrEP), or the use of HIV medicines to protect against getting HIV infection. Fewer drugs are necessary to prevent HIV than to treat it. The two products that are currently approved in the US are combination pills taken daily, Truvada (Tenofovir + emtricitibine) and Descovy (tenofovir alafenamide + emtricitabine).
To study the effectiveness of long-acting injectable PrEP, two large studies were launched with one targeting predominantly gay men and another targeting African women. Injectable Cabotegravir as a single agent injected once every two months was compared with Truvada taken as one pill daily. The study in men released early results in mid-May, which recruited 4,750 men from different countries in Latin America, Southeast Asia, South Africa and the United States. Approximately half of those enrolled in the study in the U.S. were African American.
You May Also Like
The protection provided from daily Truvada was impressive with a rate of 1.2 percent of study participants getting infected. However, in the subjects who received the Cabotegravir, the infection rate was only 0.38 percent. Investigations are underway to determine the causes of why some people got infected while others didn’t.
In most studies of PrEP, people get infected when they are not taking the medicine and the drug levels in the blood are not adequate to protect against the virus. This is one reason why the injectable may provide better protection because people don’t have to worry about taking daily doses. But they do have to go in and receive the injection every two months and if they miss their clinic visit, they may not have adequate levels of Cabotegravir for protection. The studies in African women are ongoing in East and Southern Africa. Hopefully, those results will be as encouraging when they come out. Stay tuned!
