Single-Tablet Regimens Produce Better HIV Virologic Response Than Multiple-Tablet Regimens

Since the introduction of antiretroviral therapy (ART) for the treatment of HIV, treatment has evolved from complex multiple-tablet regimens to single once-daily pills. According to a new study, these single-tablet regimens may provide better virologic response and control than multiple-tablet regimens for people living with HIV.

At both 6 and 12 months, people living with HIV taking a single-tablet regimen had significantly higher rates of undetectable viral load compared with those taking a multiple-tablet regimen.

“Understanding the impact of single-tablet regimens is especially important today, as we stand on the verge of multiple effective agents being available as generic formulations with the potential to decrease the cost of ARV therapy, and affect significant cost-savings nationally,” wrote the researchers. “These cost-savings may result in a ‘desimplification’ of treatment as patients on currently branded single-tablet regimens may be asked to change to a less costly multiple-pill alternative.”

To assess the differences in outcomes between single-tablet and multiple-tablet regimens, the researchers followed 218 patients enrolled in the Infectious Disease Practice at the New Jersey Medical School in Newark, New Jersey, between 2007 and 2013. Of these patient, 103 (47%) received a single-tablet regimen and 115 (53%) received a multiple-tablet regimen. Patients taking a single-tablet regimen were less likely to be female (25% vs 44%) and less likely to be black (54% vs 70%). Patients taking a multiple-tablet regimen had higher rates of substance abuse history (53% vs 39%).

At baseline, median HIV viral load was comparable.

At 6 months, 77% of patients taking a single-tablet regimen had an undetectable viral load compared with 66% of patients taking a multiple-tablet regimen. Patients taking a single-tablet regimen also had a significantly greater CD4 increase.

At 12 months, both groups improved, with 82% of patients taking a single-tablet and 66% of patients taking a multiple-tablet regimen having an undetectable viral load. CD4 count increases were similar among the 2 groups.

Looking within subpopulations, the researchers observed that both men and women in the single-tablet regimen group had higher rates of virologic suppression compared with their counterparts in the multiple-tablet regimen group. However, at 6 months, statistical significance was only seen among men.

The relative risk of virologic failure at 6 months was 1.6 for patients taking a multiple-tablet regimen compared with patients taking a single-tablet regimen. At 12 months, the relative risk was 2.2. According to the researchers, substance abuse, mental illness, gender, and age at enrollment were not significant variables.

“Our study was not able to directly measure adherence to therapy, but we suspect the increase in adherence associated with a lower pill burden may have helped drive the outcomes here, specifically virologic suppression,” wrote the researchers.

Reference

Kapadia S, Grant R, German S, et al. HIV virologic response better with single-tablet once daily regimens compared to multiple-tablet daily regimens [published online December 4, 2018]. SAGE Open Med. doi: 10.1177/2050312118816919.