A new once-daily pill combining three Antiretovirals (ARTs) and a booster molecule has been found to be safe and effective alternative to two widely used drug regimens for newly diagnosed HIV positive adults, who have had no previous treatment.

The findings of two large international randomized trials to be published on Friday's Lancet says the new "Quad" pill is faster acting , doesn't have the neuropsychiatric side-effects associated with other combinations, and could improve compliance with treatment.

Patient adhearence to medication is vital, especially for patients with HIV, where missed doses can quickly lead to the virus becoming resistant to medication. Older HIV treatment regimens involve taking several pills multiple times a day. Paul Sax from Brigham and Women's Hospital, Harvard Medical School, lead author of the first study, said, "Our results provide an additional highly potent, well tolerated treatment option and highlight the simplicity of treatment resulting from combining several antiretrovirals in a single pill".

Sax said studies have shown that single pill treatments improve both adherence  and patient satisfaction and help prevent prescription errors, helping reducing the likelihood of treatment failure and drug resistance.

The first trial randomly assigned 700 patients from centers across North America to start treatment with two different single tablet regimens - either quad, combining the new integrase inhibitor elvitegravir (EVG) boosted with cobicistat  (a new pharma-coenhancer COBI) plus FTC/TDF, or a gold standard regimen approved by the FDA in 2006, combining EFV/FTC/TDF (also known as Atripla)

After 48 weeks of treatment, 88% of patients given Quad suppressed viral loads to undetectable levels (less than 50 copies per mL of blood), compared with 84% in the EFV/FTC/TDF group.