Gilead Sciences has presented more late-stage data on its four-drug HIV treatment Quad, which shows that it worked as well as the US firm's big-selling combo Atripla.

Gilead has announced full Phase III results from its pivotal Study 102 demonstrating that Quad, a fixed-dose, single-tablet regimen made up of the firm's investigational drugs elvitegravir and cobicistat combined with the two active ingredients in Truvada (emtricitabine and tenofovir), is non-inferior to Atripla (efavirenz/tenofovir/emtricitabine) after 48 weeks of therapy in treatment-naive adults. At the end of the trial, 88% of patients who took Quad had achieved HIV RNA levels (viral load) of less than 50 copies/ml, ie no detectable levels of HIV in their blood, compared with 84% for those on the three-drug combination pill.

In terms of side effects, patients on Quad experienced more nausea than those taking Atripla, though less dizziness, insomnia and abnormal dreams. Rashes were also less likely to occur among Quad patients.

Gilead quoted Paul Sax of the Brigham and Women’s Hospital in Boston, and principal investigator of Study 102, as saying that Quad's safety profile was comparable to that of Atripla, and was better tolerated in terms of "key neurological side effects". As such, he believes it could "represent a potentially important new treatment regimen for a wide range of HIV patients initiating therapy".

Gilead submitted a US New Drug Application for Quad in October last year and has been given a Prescription Drug User Fee Act action date of  August 27. The combo was filed in Europe in November.

AHF asks FDA to delay/deny Truvada to prevent HIV

Meantime, the AIDS Healthcare Foundation (AHF), the USA’s largest and oldest AIDS support organisation, has filed a citizen’s petition with the US Food and Drug Administration, asking the agency to "delay or deny" approval of an application by Gilead for expedited review of Truvada for expanded use as a method of preventing HIV in non-infected people.

In February, the FDA accepted the firm's supplemental NDA and granted a six-month priority review for once-daily Truvada for pre-exposure prophylaxis (PrEP) to reduce the risk of HIV-1 infection among uninfected adults. The drug was approved by the agency in 2004 for the treatment of HIV-1 infection and is now the most-prescribed antiretroviral in the USA.

The AHF argues that such a use would actually increase HIV infections, and note recent research linking one of the components of Truvada - tenofovir - to a significant risk of kidney disease and damage. Michael Weinstein, AHF’s president, says that "the idea of giving healthy people a toxic drug that will damage their kidneys in order to possibly prevent HIV – when simple condom use is 95% effective – is the height of irresponsibility and corporate greed”.

He added that “widespread use of PrEP has all the makings of a public health disaster – increased HIV infections, drug resistant strains of HIV, and tens of thousands of damaged kidneys". Mr Weinstein concluded by saying that the FDA, "in expediting its review and limiting further research, appears hell-bent on bringing this about as quickly as possible.”