No evidence of an effect of the M184I/V on the doravirine/lamivudine/tenofovir switch efficacy in people living with HIV.

Objectives: The effect of the M184I/V mutation on the rate of virological failure (VF) in people living with HIV (PLWHIV) with plasma HIV RNA viral load (VL) <50 copies/mL switching to a triple-therapy regimen of doravirine+lamivudine+ tenofovir or abacavir has not been evaluated.

Design: A retrospective national study of antiretroviral-experienced PLWHIV who were switched to a doravirine plus lamivudine and abacavir or tenofovir regimen in the context of maintenance (VL<50 copies/mL) was conducted. Virological failure (VF) was characterized by either two consecutive plasma viral loads (VL) ≥ 50 copies/mL or a single VL ≥ 200 copies/mL. Viral blip (VB) was defined as an isolated VL 50_200 copies/mL at any time up to month 6 after switching to the doravirine-containing regimen.

Results: Among the 338 PLWHIV, doravirine was mainly associated with tenofovir+lamivudine (311/338, 92.0%). Of these, 45 had a M184I/V mutation before switching. VF at M6 was 14.0% and 17.8% in the absence and presence of M184I/V, respectively, with an adjusted odds ratio (aOR) of 2.409, 95%CI 0.574-10.113, p=0.21. The risk of VF at M6 was associated with the level of zenith plasma HIV VL, with an aOR of 1.646, 95% CI 1.163-2.328, p = 0.0049, per additional log10 unit. The proportion of VB at M6 was 2.4% and 6.7% in PLWHIV in the absence and presence of M184I/V, respectively, with an aOR of 0.818, 95%CI 0.187-3.587, p = 0.7897.

Conclusions: Among PLWHIV with antiretroviral experience, there was no evidence that switching to doravirine + lamivudine plus tenofovir affected short-term treatment response in individuals harboring HIV M184I/V mutations.