Novel single-pill HIV treatment may be on the way

the Clinical Advisor take:

A single-pill treatment for the human immunodeficiency virus (HIV) proved less toxic than a regimen using separate drugs, according to research presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy held in Washington, D.C.

Both treatments contained the protease inhibitor darunavir, boosted with cobicistat and emtricitabine. The difference between the regimens was in the fourth drug: one treatment contained tenofovir disoproxil (TDF), a nucleotide analog reverse transcriptase inhibitor, and the other contained the investigational drug tenofovir alafenamide (TAF).

“Both are prodrugs of the active form, but TAF puts more tenofovir in target cells and less in the plasma than tenofovir disoproxil,” said Anthony Mills, MD, of the Southern California Men’s Medical Group in Los Angeles, and colleagues. Lower levels of TAF allowed the researchers to co-formulate with the other three drugs.

To determine the efficacy of the single-pill regimen, the scientists randomly assigned 153 previously untreated patients to receive the single-pill or the multiple-pill treatment. Patients were followed for 48 weeks and each active treatment was accompanied by placebos to match the other treatment.

The primary endpoint for the drug trial was the proportion of patients with a plasma viral load of less than 50 copies of HIV RNA per milliliter after 24 weeks of treatment. Cellular and plasma levels of active tenofovir and renal and bone safety markers were followed as well.

Virological response was similar, with 75% of single-pill and 74% of multi-pill treatments meeting the primary endpoint.

The results of this phase II trial warrant moving the single-pill regimen into a phase III trial, concluded Mills and associates.