HIV Resuppression Outcomes Not Improved with Resistance Testing

Adding genotypic resistance testing (GRT) to routine care did not improve HIV virologic outcomes for patients for whom first-line ART failed, the study authors wrote.

Rates of HIV resuppression were not improved using GRT compared to standard care in sub-Saharan Africa after first-line virologic failure, according to a paper published in Annals of Internal Medicine.

Investigators from Mass General conducted an unblinded, randomized controlled trial among 840 people with HIV in sub-Saharan Africa for whom first-line therapy failed in order to estimate the effectiveness of GRT for improving virologic suppression rates among this population.

“These so-called ‘resistance tests’ are commonly used worldwide, but have not been tested in Africa due to concerns about cost and logistics,” corresponding study author Mark Siedner, MD, told Contagion.

The investigators included adults receiving first-line antiretroviral therapy in their study who had a recent HIV RNA viral load of 1000 copies/mL or higher between December 2016 and December 2019. About half of those enrolled were women (51 percent), the study authors said, with a median age of 37 years. The median duration of ART use was 3.2 years, the study authors noted The goal was for the patients to achieve an HIV RNA viral load below 200 copies/mL at 9 months post-enrollment.

The study was conducted in partnership with scientists from Uganda and South Africa, and the patients enrolled were divided equally between countries, the authors said. Most of the patients (72 percent) were receiving tenofovir, emtricitabine, and efavirenz at enrollment, the study authors observed.

The patients were randomly assigned to receive standard of care which meant adherence counseling sessions and repeated viral load testing, or immediate GRT, the study authors explained.

After 9 months, there was no difference among the standard care group or the GRT group in terms of virologic suppression, the investigators found. Siedner called it relatively low, at 60 percent. This was similar among subgroups categorized by CD4 T-cell count at enrollment, self-reported adherence at enrollment, and country. Additionally, it was true once the investigators excluded participants with blood drawn at an out-of-window outcome visit that occurred during the era of COVID-19.

For their secondary outcomes, the study authors wrote that they found no difference between the standard of care or GRT groups in the odds of virologic suppression less than the limit of assay detection, in the odds of achieving viral suppression at 9 months of a first-line regimen, in the odds of 9-month retention in care, or in the odds of 9-month survival.

“Investigators concluded that patients with treatment failure require additional support to help them overcome the many barriers to successful treatment – and that a single blood test was no magic bullet,” Dr. Siedner continued. “In other words, patients failing HIV treatment in sub-Saharan Africa likely face many challenges to care—and simple changes in regimens or additional diagnostic tests are not the full solution. We still need to novel and innovative methods to better support these patients but within the clinic and in the community.”

The study authors concluded by writing that interventions that can improve virologic outcomes for this group of people at high risk continue to be elusive, but also a priority to meet worldwide goals to control HIV.