Second-Line Switch to Dolutegravir for Treatment of HIV Infection

Background: Data to inform the switch from a ritonavir-boosted protease inhibitor (PI) to dolutegravir in patients living with human immunodeficiency virus (HIV) infection who do not have genotype information and who have viral suppression with second-line therapy containing a ritonavir-boosted PI have been limited.

Methods: In a prospective, multicenter, open-label trial conducted at four sites in Kenya, we randomly assigned, in a 1:1 ratio, previously treated patients without genotype information who had viral suppression while receiving treatment containing a ritonavir-boosted PI to either switch to dolutegravir or continue the current regimen. The primary end point was a plasma HIV type 1 RNA level of at least 50 copies per milliliter at week 48, assessed on the basis of the Food and Drug Administration snapshot algorithm. The noninferiority margin for the between-group difference in the percentage of participants who met the primary end point was 4 percentage points. Safety up to week 48 was assessed.

Results: A total of 795 participants were enrolled, with 398 assigned to switch to dolutegravir and 397 assigned to continue taking their ritonavir-boosted PI; 791 participants (397 in the dolutegravir group and 394 in the ritonavir-boosted PI group) were included in the intention-to-treat exposed population. At week 48, a total of 20 participants (5.0%) in the dolutegravir group and 20 (5.1%) in the ritonavir-boosted PI group met the primary end point (difference, -0.04 percentage points; 95% confidence interval, -3.1 to 3.0), a result that met the criterion for noninferiority. No mutations conferring resistance to dolutegravir or the ritonavir-boosted PI were detected at the time of treatment failure. The incidence of treatment-related grade 3 or 4 adverse events was similar in the dolutegravir group and the ritonavir-boosted PI group (5.7% and 6.9%, respectively).

Conclusions: In previously treated patients with viral suppression for whom there were no data regarding the presence of drug-resistance mutations, dolutegravir treatment was noninferior to a regimen containing a ritonavir-boosted PI when the patients were switched from a ritonavir-boosted PI-based regimen. (Funded by ViiV Healthcare; 2SD ClinicalTrials.gov number, NCT04229290.).