Switching to Second-Line Therapy Versus First-Line Antiretroviral

Fifty-five percent of patients who had low-level HIV-1 viraemia and switched to a second-line antiretroviral therapy (ART) achieved viral suppression.

The findings, presented during the International AIDS Society (IAS) AIDS 2020 Virtual Sessions this week, offered a glimpse of the benefit in switching to a second-line ART in this patient group.

The World Health Organization (WHO) has a guideline for virologic failure while using ART, which defines it as two consecutive viral loads (VL) '¥1000 copies/mL despite good adherence, then triggering an empiric switch to a next-line ART.

Investigators, led by Alain Amstutz, MD, Swiss Tropical and Public Health Institute, Basel, Switzerland, were seeking to assess if patients with sustained low-level HIV-1 viraemia on a first-line ART would benefit in a switch. The primary endpoint for the study was viral suppression (<50 copies/mL) at 9 months (36 weeks).

This multicenter, parallel-group, open-label, superiority, randomized, controlled trial enrolled patients on first-line ART containing non-nucleosidic reverse transcriptase inhibitors with two consecutive VLs '¥100 copies/mL, with the second VL between 100-999 copies/mL. The study was conducted at 8 clinics in Lesotho in Southern Africa.

The patient population consisted of 80 total participants who were eligible and randomly assigned to either the switch group (n=40) or control group (n=40).

The majority of the study’s participants were female (68%) with a median age of 42 years. Sixty-one percent of them were taking tenofovir disoproxil fumarate / lamivudine / efavirenz.

At nine months, 55% of study participants in the switch group versus 25% in the control group achieved viral suppression (adjusted difference 29%, 95% CI 8-50%, p=0·009). In addition, the switch group had significantly higher probability of viral suppression across different VL thresholds (<20, <100, <200, <400 copies/mL) but not for <1000 copies/mL.

In terms of safety, no adverse effects were witnessed.

“Switching to second-line ART among patients with low-level HIV-1 viraemia resulted in higher proportion of viral suppression,” the investigators concluded. “These results endorse lowering the threshold for virologic failure in future WHO guidelines.”