Injecting HIV drugs every month or two is as effective in suppressing the virus as taking daily medications, according to an eight-month clinical trial reported in Pharmabiz and conducted by ViiV Healthcare in collaboration with Janssen Sciences Ireland (one of the Janssen: Pharmaceutical Companies of Johnson & Johnson). Monthly injections could also improve adherence rates by reducing the potential of skipped doses.
"Going from many pills a day — like 10, 20 pills a day — to now one pill, to now one injection every two months is I think a huge medical technical achievement," said Paul Stoffels, Johnson & Johnson’s chairman of pharmaceuticals, in a conference call with reporters. "Despite great progress in HIV treatments, the burden of treating HIV patients remains high. Long-acting injectable drug formulations may offer another option for HIV maintenance therapy."
Just 32-weeks into the 96-week phase 2b trial, known as LATTE 2, researchers were so impressed with results they announced them to the press and are presenting them in an upcoming conference. The study compared a long-acting injectable combination of two separate drugs (cabetogravir and rilpivirine ) with a three-drug daily pill regime (which paired cabotegravir with two nucleoside reverse transcriptase inhibitors).
Once HIV enters T4 white blood cells, the virus uses an enzyme, called reverse transcriptase, to copy parts of its RNA into the cell’s human DNA via a process called "reverse transcription." Rilpivirine blocks that reverse transcription process by binding to and blocking the enzyme. Meanwhile cabetogravir attacks HIV at another point in the virus's lifecycle. After the virus transcribes its RNA into DNA, it then must integrate that DNA into the white blood cell’s DNA. It does this with the help of another enzyme, integrase, which cabetogravir blocks from doing its job.
Patricipants in the clinical trials where either virally suppressed on antiretroviral therapy (ART) or were HIV-positive and not previously on medication (what researchers call “ART-naïve” or "treatment-naïve"). After reaching virologic suppression on oral therapy the patients were subsequently randomized to one of three studies to receive either the injections every 4 or 8 weeks or continue on the oral treatments.
Regardless of frequency of the shots, patients receiving intramuscular injections of the long-acting formulation had viral suppression rates comparable with daily combination therapy. However, patients on monthly injections reported more pain at the injection site then those receiving the shots every two months.
Overall, injection site pain was also the most commonly reported side effect, and it was extreme enough lead a minority of participants to withdraw from the study due to “injection intolerance.”
John C Pottage, Jr., chief scientific and medical officer at ViiV Healthcare focused on the trials' positives, saying, in a written statement, “These initial phase IIb data investigating long-acting cabotegravir and rilpivirine are promising and build on the results we have seen to date. We look forward to seeing further results as we move into phase III.”
As currently formulated, the drug must remain refrigerated and would need to be administered by a medical professional as it requires too large a dose to be prescribed for at-home injections.
Stoffels acknowledged that there is still work to be done. But the pharmaceutical executive highlighted how far the fight against HIV has come since he began his career in Africa. “Back in the late ’80s in Africa when the HIV epidemic was in full growth, it was devastating,” Stoffels recalled.
It may be another five years until it’s available but an injectable, monthly HIV treatment could free people living with HIV from an endless regime of daily pills, while reducing medication fatigue and increasing adherence. Thats a win win to many advocates.