A single boosted protease inhibitor instead of the standard 3-drug "cocktail" for maintenance therapy may be an effective treatment for some HIV-infected patients, according to a U.S. study released on Sunday.

These encouraging findings, appearing in the Aug. 16 edition of the Journal of American Medical Association(JAMA), might lead to anti-AIDS regimens with less complexity, pill burden, long-term complications, and cost, said the researchers at the University of Nebraska Medical Center.

The study was also presented at the International AIDS Conference in Toronto, Canada.

Currently, three-drug "cocktail" regimens have been accepted as a standard therapy against HIV infection, but the cocktail therapy also leads to long-term adverse effects, high expenses, sustained adherence.

Earlier studies had tried treatment cessation, intermittent therapy, and induction-maintenance, which means a few months of triple therapy followed by simplified therapy, but most results were disappointing.

In the latest trial, the researchers found that a protease inhibitor named atazanavir could suppress the HIV virus level in some patients when atazanavir's effect is boosted by a small dose of ritonavir.

The study conducted between September 2004 and April 2006, included 36 HIV-infected adults with virologic suppression for 48 weeks or longer receiving their first protease inhibitor.

The participants switched to atazanavir-ritonavir at entry and discontinued other drugs. In the 34 patients that accepted final tests after 24 weeks of simplified therapy, the researchers found that 31 had showed suppressed virus level.

"The data suggest that simplified maintenance therapy with atazanavir-ritonavir alone in patients who have never experienced treatment failure may be efficacious in maintaining HIV-1 RNA suppression below 200 copies/milliliters for 24 weeks," wrote the researchers led by Susan Swindells.

"Maintenance therapy with a single boosted PI (protease inhibitor) offers a treatment strategy with potentially less complexity, pill burden, long-term complications, and cost," they concluded.

However, the researchers cautioned that although the findings were encouraging, their study had limitations such as the small number of participants.

"Larger, randomized trials comparing this approach with standard antiretroviral therapy are warranted," they added.

Source: Xinhua