HIV drug resistance slashed in Europe

The number of people who were able to keep HIV under control after original drugs failed has tripled in a decade, European researchers have found.

Since 1998, doctors have recommended that all HIV patients in western Europe start antiretroviral treatment with three or more drugs of two different types to reduce the amount of virus in their blood.

More treatments have recently become available to help those who developed resistance to the three original drugs. The Pursuing Later Treatment Option II trial, or PLATO II, was designed to find out whether the newer treatments actually helped reduce resistance.

In Monday's online edition of the journal Lancet Infectious Diseases, Dr. Dominique Costagliola of France's medical research institute in Paris and her co-authors found almost one in five patients achieved undetectable levels of HIV in 2000, which increased to nearly three in five patients in 2009. "Overall, we showed substantial improvements between 2000 and 2009 in virological suppression in people who had virological failure to drugs from the three original classes of antiretrovirals, and accompanying decreases in rates of AIDS," the study's authors concluded.

The analysis involved more than 91,000 adults in western Europe, including 2,476 who developed resistance to the three original classes of HIV drugs. The positive trends probably related to improvements in people taking their medications as prescribed to prevent resistance, and greater availability of new drugs, the researchers said. Whether the improving trend can be sustained is unclear, they said, and will depend on developing new drugs.

Other factors likely contributed to the positive trend, Jens Lundgren of Copenhagen University Hospital said in a journal commentary. These included:

• Genome technologies emerged around the year 2000 that allowed doctors and scientists to understand the role of true drug resistance compared with poor drug compliance
• HIV clinics began to focus on educating patients to improve compliance
• New drugs allowed patients to take fewer drugs on a more flexible schedule

Lundgren cautioned against complacency, noting the number of people with resistant HIV infection will increase as the number of people receiving antiretroviral therapy increases since the virus can change its genome to become resistant to drugs.

The study was funded by the U.K. Medical Research Council.