GSK’s Cabenuva made history in 2020 as the world’s first complete, long-acting HIV regimen. But the injectable drug is approved in various countries only as a switch therapy for patients who already have undetectable HIV levels in the blood.
Trying to reach tough-to-treat patients who have difficulty controlling the virus with existing daily oral therapies, GSK’s ViiV Healthcare is getting creative.
To seek an approval for Cabenuva in patients who aren’t virologically suppressed while on oral drugs, GSK’s ViiV is exploring running a clinical trial using a historical control group.
This would replace the standard practice of randomizing some patients in the study to receive standard-of-care oral meds, ViiV’s R&D head Kimberly Smith, M.D., said during a recent interview. (Listen to the interview on The Top Line)
The FDA in February unveiled draft guidance laying out the considerations for the use of external control groups in clinical trials to prove a drug’s safety and efficacy. The gist is, as Smith summed up, the FDA would need to see data from an outside group of people from the past who compare to the current trial population.
ViiV plans to talk to regulatory agencies and seek such a path for Cabenuva, Smith said.
“I would love for Cabenuva to be able to be used in more folks that have difficulty with consistent adherence because I really do think that’s the only way we’re going to get to the end of the [HIV] epidemic,” Smith said.
Some viremic patients are hard to treat because they have difficulty taking daily meds. So giving oral meds to a population that’s known to have adherence issues doesn’t make sense and could be dangerous. Taking HIV drugs inconsistently increases the risk of developing drug resistance, Smith explained.
For people who’re already suppressed, Cabenuva’s bimonthly dosing interval offers a convenience edge over daily meds as well as a relief from the emotional challenges and anxiety related to taking a pill every day, Smith said.
For adherence-challenged patients, a long-acting therapy could mean improved treatment effectiveness. And ViiV has seen some promising data that suggest Cabenuva could be that drug.
During the Conference on Retroviruses and Opportunistic Infections in February, researchers from Ward 86, the HIV clinic at University of California, San Francisco, presented promising data (PDF) in viremic patients who received Cabenuva. The single-site study enrolled 133 patients, including 66% who were unstably housed.
Among 57 viremic patients, all but two had their HIV successfully suppressed by Cabenuva after a median half year of follow-up. The virological failure rate was similar to that observed from Cabenuva’s registrational clinical trials in switch patients, the researchers noted.
After its FDA approval in early 2021, Cabenuva has become a growth driver for GSK’s HIV portfolio. The drug generated 127 million pounds sterling ($162 million) in the first three months of 2023. But the requirement to seek a healthcare professional every two months to get the injection could still be a tough ask for some patients.
Through a drug delivery technology partnership with Halozyme, GSK is exploring the potential to increase Cabenuva’s dosing interval to as long as six months.
Elsewhere, Gilead Sciences’ twice-yearly Sunlenca recently received FDA approval to be used alongside other HIV meds for people with multidrug-resistant HIV. Gilead is testing various combos to make a full long-acting regimen.