Bristol-Myers Squibb Company and Gilead Sciences, Inc. announced the US Food and Drug Administration (FDA) has granted approval of Atripla (efavirenz 600 mg/ emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg) for the treatment of HIV-1 infection in adults.

Atripla is the first-ever once-daily single tablet regimen (STR) for HIV intended as a stand-alone therapy or in combination with other antiretrovirals.

The product combines Sustiva (efavirenz), manufactured by Bristol-Myers Squibb, and Truvada (emtricitabine and tenofovir disoproxil fumarate), manufactured by Gilead Sciences. Truvada itself is a fixed-dose product that contains two of Gilead's anti-HIV medications, Viread (tenofovir disoproxil fumarate) and Emtriva (emtricitabine), in a single once-daily tablet for use as part of combination therapy. Atripla will be available in the United States within seven business days, a BMS press release stated.

"The availability of Atripla marks the culmination of ten years of efforts to simplify dosing while helping to achieve and maintain effective viral suppression for adults infected with HIV-1," said John G. Bartlett, MD, Johns Hopkins University.

The collaboration between Bristol-Myers Squibb and Gilead is the first of its kind in the 25-year history of the AIDS epidemic. On December 20, 2004 the companies established a US joint venture to develop and commercialize the single tablet regimen.

"We appreciate the recognition by the FDA of this important therapeutic advance, and with their approval of Atripla in just over two months, patients will now have rapid access to the first once-daily single tablet regimen for the treatment of HIV-1 infection in adults," said John C. Martin, PhD, President and CEO of Gilead Sciences. "We are proud to have worked closely with Bristol-Myers Squibb in this precedent-setting collaboration to simplify therapy for physicians and patients."

"With the approval of Atripla, Bristol-Myers Squibb continues two decades of progress in the development and commercialization of medications to treat HIV. Partnering with Gilead, we are able to address another area of need for adults infected with HIV-1," said Anthony C. Hooper, President, US Pharmaceuticals, Bristol-Myers Squibb. "Atripla is an important step forward as we continue our focus on discovering, developing and providing innovative treatments for serious diseases."

The once-daily single tablet regimen contains three medicines from two classes of anti-HIV drugs. Atripla contains 600 mg of efavirenz, a non-nucleoside reverse transcriptase inhibitor (NNRTI), 200 mg of emtricitabine and 300 mg of tenofovir disoproxil fumarate, both nucleoside reverse transcriptase inhibitors (NRTIs). All three active ingredients work by blocking reverse transcriptase, an enzyme necessary for HIV replication.

Clinical data support the use of the three-drug regimen contained in Atripla in HIV treatment-naïve patients. An ongoing randomized, open label, active-controlled, multicenter, non-inferiority study, Study 934, compares a once-daily regimen of Viread, Emtriva and Sustiva, the components of Atripla, with twice-daily Combivir (lamivudine and zidovudine) and once-daily Sustiva in treatment-naïve patients with HIV. Through 48 weeks, 84 per cent of patients in the Viread/Emtriva/Sustiva group (n=244) compared to 73 per cent of patients in the Combivir/Sustiva group (n=243) achieved and maintained HIV-1 RNA less than 400 copies/mL. This difference largely results from the higher number of discontinuations in the Combivir/Sustiva group due to adverse events (9 per cent vs. 4 per cent in the Viread/Emtriva/Sustiva group) and other reasons including lost to follow-up, patient withdrawal, non-compliance and protocol violation (14 per cent vs. 10 per cent in the Viread/Emtriva/Sustiva group). In addition, 80 per cent and 70 per cent of patients in the Viread/Emtriva/Sustiva group and the Combivir/Sustiva group, respectively, achieved and maintained HIV-1 RNA less than 50 copies/mL. The mean increase from baseline in CD4 cell count was 190 cells/mm3 in the Viread/Emtriva/Sustiva group and 158 cells/mm3 in the Combivir/Sustiva group. Selected adverse events observed in greater than or equal to 5 per cent of patients in the Viread/Emtriva/Sustiva group include dizziness, nausea, diarrhoea, fatigue, headache and rash.

Guidelines issued by the US Department of Health and Human Services (DHHS) list efavirenz, emtricitabine and tenofovir disoproxil fumarate among the preferred agents for use in an NNRTI-based treatment regimen in appropriate patients who have never taken anti-HIV medicines. Efavirenz should not be used during the first trimester of pregnancy due to the potential harm to the foetus. Pregnancy should be avoided by women receiving efavirenz.