A young girl visits her pediatrician in Kuala Lumpur. (Photo: Kevin Tachman)
The TREAT Asia Studies to Evaluate Resistance, Pediatrics (TASER-P), monitored how 270 Asian children and adolescents in Indonesia, Thailand, and Vietnam who had developed resistance to first-line antiretrovirals (ARV) responded and adhered to second-line treatment. The three-year long study, the first of its kind in the region, completed its core activities in December 2013, and the preliminary analysis has provided insights into how to improve long-term ARV management in children and adolescents.
“The results of the drug resistance monitoring study highlight the young age and short duration of first-line treatment and the time to second-line failure,” says Dr. Scott Purdon, director of Government Affairs and Access at ViiV Healthcare. “This demonstrates a clear need to improve access to more efficacious and tolerable HIV medicines, to address physician resistance training needs, and to support the community to understand the importance of adherence.”
By the end of the follow-up period, 15% of the participants had an elevated HIV viral load that indicated failure to their second-line treatment, within a median time from treatment initiation of just 2.5 years. In many Asian settings, children and adolescents who have developed resistance to first-line therapy have access to few second- and third-line treatment options, which makes maximizing the longevity of the available treatments critical to the patients’ ability to control HIV infection into adulthood.
“Many Asian countries have resource constraints that limit the antiretroviral drugs that are available,” says the study’s principal investigator Wasana Prasitsuebsai, M.D., M.P.H., from HIV-NAT/Thai Red Cross AIDS Research Centre, Bangkok. “So it is very important to understand exactly how the second-line treatments we are using in our children and adolescents are working and how long they are going to help them.”
Successful HIV treatment requires access to effective medicines and patients to be able to adhere to taking them. The TASER-P researchers found that the most commonly used strategies to boost and measure young people’s adherence, including verbal reports and pill counts, were less reliable than testing hair samples for long-term ARV levels.
The study also found that among the participants with elevated HIV levels, most of those given a regimen with a boosted protease inhibitor were able to re-suppress their virus. These drugs have a higher intrinsic barrier to resistance than other ARVs, making them more “forgiving” when a patient misses a few doses. “We need better treatment options for adolescents that do not result in failure after missing a few doses,” says Annette Sohn, M.D., director of TREAT Asia and amfAR vice president. “Innovative approaches like long-lasting antiretrovirals must be prioritized for perinatally infected adolescents who have already had to deal with a lifetime of treatment.”
Using a grant from AIDS Life, TREAT Asia will continue to follow approximately 60 children who have developed resistance to second-line treatment for another two years in order to better understand which third-line ARVs will be most needed in the region.