New Treatment Can Potentially Reduce HIV Drug Resistance

Ibalizumab caused 83% of HIV-positive patients to achieve a virologic response.

A new investigational biologic drug shows promise treating patients with multidrug resistant HIV, results from a recent study suggests.

Ibalizumab, a monoclonal antibody, works by coating the immune system to protect the cells from HIV. It is the first biologic drug being used to treat the virus.

In a phase 3 study presented at IDWeek 2016, 83% of patients with multi-drug resistant HIV had a virologic response to the drug. Approximately 10,000 HIV-positive individuals have multi-drug resistance.

Some patients with multi-drug resistant HIV are infected with the strain, but a majority develop the resistance over time due to nonadherence to antiretroviral therapy.

“This is the first drug in a long time for patients with multidrug resistance,” said lead author of the study Jacob Lalezari, MD. “This therapy showed good activity in patients who were resistant to everything else, which is very exciting for these vulnerable patients and those who care for them.”

Ibalizumab is administered intravenously every 2 weeks, and is the first of long-acting anti-viral treatments, according to the study. A majority of antiretroviral therapies must be taken daily, and can cause problems with treatment adherence.

Long-acting antiretroviral therapies can offer patients a treatment option they have to take less frequently, which has the potential to boost adherence, according to the study.

“There’s higher compliance because they have a place where they can go and are cared for, and it really works for them,” said Dr. Lalezari.

Included in the study were 40 patients with multi-drug resistant HIV who were treated with multiple medications, with more than 1 in 4 patients who received 10 or more medications. All patients were treated with ibalizumab.

A majority of patients benefitted from the medication after only 7 days from treatment initiation. The investigators reported that 60% achieved a decrease in viral load of 1.0 log10 or more, and 83% of patients achieved a decrease in viral load of 0.5 log10, according to the study.

After a week, the average decrease was 1.1 log10. Prior to treatment, only 1 patient achieved a decreased viral load from an existing antiretroviral therapy regimen.

All patients continued taking ibalizumab, and began taking optimizing HIV medications as part of their treatment regimen, according to the study. Each patients’ treatment varied.

“This drug benefits a small but challenging population of HIV patients who are highly treatment experienced,” said Daniel R. Kuritzkes, MD, chief of the Division of Infectious Diseases at Brigham and Women’s Hospital and professor of medicine at Harvard Medical School, Boston. “This will not be a first- or second-line therapy for those who are infected with HIV, but it may be helpful for certain patients.”