New HIV drug cuts viral load, boosts immunity: Study

A new HIV drug may effectively reduce viral replication and increase immune cells in patients with advanced, drug-resistant infection, a study has found.

Used in combination with existing human immunodeficiency virus (HIV) medications, the drug is a promising strategy for patients who have run out of effective treatment options, according to researchers at Yale University in the US.

The study, published in the New England Journal of Medicine, enrolled patients with multi-drug-resistant HIV.

Patients received a dose of ibalizumab, which is delivered intravenously, in addition to their failing regimen, for one week, said Brinda Emu, assistant professor at Yale.

Ibalizumab is a drug that targets the primary receptor for HIV entry into immune cells known as CD4 T cells.

After that period, they received ibalizumab in combination with optimised treatment regimens for six months.

The researchers found that after one week on ibalizumab, the majority of the 40 patients (83 per cent) enrolled in the study experienced decrease in viral load, which refers to the amount of HIV detected in the blood.

After 25 weeks, nearly half of patients saw viral load suppression dip below the level of detection.

The researchers also reported an increase in CD4 T cells, which are a marker for immune strength.

A single individual experienced an adverse event, which was felt to be ibalizumab-related and resulted in withdrawal from the study, the researchers said.

The results were notable for this drug-resistant population of patients studied, said Emu.

"These patients had extremely advanced HIV and resistant virus with limited options. To see viral suppression in a significant percentage of these patients at six months is heartening," said Emu.

"The result represents a much-needed new mechanism of action for patients who have highly resistant HIV," she said.

As the first monoclonal antibody approved to treat HIV, ibalizumab is a promising option for individuals who have tried several other drug therapies, Emu said.

"It should be considered for patients that have multi-drug resistance given the efficacy seen this study," she said.