Gilead's new once-daily, single pill HIV therapy Stribild has been rolled out in the UK this week, offering potential benefits in treatment adherence, a crucial aspect of treatment outcomes.

Stribild - a combination of elvitegravir, cobicistat, emtricitabine and tenofovir disoproxil - was approved just days ago by the European Commission for the treatment of HIV-1 infection in adults who have not received antiretroviral therapy or are infected with HIV-1 without the known mutations linked with resistance to antiretroviral agents in the product.

Clearance of the drug was given a helping hand by data from the pivotal Phase III Study 102, which showed the product to be non-inferior to Gilead's triple combination therapy Atripla (efavirenz/tenofovir/emtricitabine) after 48 weeks' treatment. 

At trial end, 88% of patients who took Stribild had achieved HIV RNA levels (viral load) of less than 50 copies/ml, i.e. no detectable levels of HIV in their blood, compared with 84% for those on the three-drug combo.

Also, on the tolerability front, while patients on Stribild experienced more nausea than those on Atripla, less dizziness, insomnia, abnormal dreams and rashes were observed. 

According to Anton Pozniak, Director, HIV Service, Chelsea and Westminster Hospital, London, Stribild is "an important advance for HIV patients in the UK" and one that, given the simplification of dosing regimen, may help to enhance patient adherence and thereby potentially improve long-term health benefits for patients.

The drug's label does however warn patients of the potential for lactic acidosis - a build-up of lactic acid in the blood - as well as severe liver problems, both of which can be fatal. 

Standalone approvals

Two of the medicines contained within Stribild have been approved for the first time in the UK as part of the product: elvitegravir, an integrase inhibitor, and the 'booster' cobicistat, which basically facilitates once-daily dosing.

Marketing applications for these drugs as standalone agents are currently under review in Europe, but they have suffered a setback in the US, after regulators issued Complete Response Letters refusing to approve them at this time, which the firm said it is now working to rectify.