Effectiveness of second-generation integrase strand-transfer inhibitor-based regimens for antiretroviral-experienced people with HIV who had viral rebound

BACKGROUND

Antiretroviral regimens containing a second-generation integrase strand-transfer inhibitor (INSTI) plus 2 nucleos(t)ide reverse-transcriptase inhibitors (NRTIs) are the recommended therapy for people with HIV (PWH) who are antiretroviral-naïve or on stable antiretroviral therapy (ART) with viral suppression. Real-world data on the virologic effectiveness of co-formulated bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) among PWH with virologic failure while receiving other ART remain sparse.

METHODS

We retrospectively reviewed the medical records of PWH who had viral rebound with plasma HIV RNA >1000 copies/mL and were switched to either dolutegravir combined with 2 NRTIs or BIC/FTC/TAF. The primary end point was re-achieving viral suppression within the first 48 weeks of switch. The association between NRTI-related resistance-associated mutations (RAMs) and virologic effectiveness was examined.

RESULTS

Seventy-nine PWH with viral rebound while receiving other antiretroviral regimens were included. Within the first 48 weeks of switch, the overall probability of re-achieving viral suppression was 79.7% (82.5% [33/40] and 76.9% [30/39] for BIC/FTC/TAF and dolutegravir-based regimens, respectively, p = 0.78). PWH with a higher CD4 lymphocyte count (adjusted odds ratio, per 100-cell/mm3 increase, 1.41; 95% confidence interval, 1.02-1.95) were more likely to re-achieve viral suppression. Among PWH switching to BIC/FTC/TAF who had pre-existing RAMs to NRTIs before switch, 14 of 15 (93.3%) successfully achieved viral suppression.

CONCLUSIONS

Switching to BIC/FTC/TAF and dolutegravir-based regimens could re-achieve viral suppression in four-fifth of the PWH who experienced viral rebound during treatment with other antiretroviral regimens. Pre-existing NRTI-related RAMs did not have adverse impact on the effectiveness of dolutegravir combined with 2 NRTIs or BIC/FTC/TAF.

Switching to coformulated bictegravir, emtricitabine, and tenofovir alafenamide maintained viral suppression in adults with historical virological failures and K65N/R mutation

OBJECTIVES

Real-world experience with coformulated bictegravir, emtricitabine, and tenofovir alafenamide (BIC/FTC/TAF) is sparse as a switch regimen among people living with HIV (PLWH) having achieved viral suppression after previous virologic failures with the emergence of K65N/R.

METHODS

In this retrospective study, PLWH aged ≥20 years who had previous virologic failures with emergent K65N/R were included for switching to BIC/FTC/TAF after having achieved plasma HIV RNA load (PVL) <200 copies/ml for ≥3 months. PLWH were excluded if integrase inhibitor resistance-associated mutations were detected. The primary end point was losing virologic control (PVL >50 copies/ml) at week 48 using a modified US Food and Drug Administration snapshot algorithm.

RESULTS

A total of 72 PLWH with K65N/R who switched to BIC/FTC/TAF were identified. A total of 42 (59.7%) had concurrent M184V/I, and 9 (12.5%) had ≥1 thymidine analog mutations. The median duration of viral suppression was 4.7 years (interquartile range 2.3-5.8), and 97.2% (n = 70) had PVL <50 copies/ml before switching. After a median observation of 98.6 weeks (interquartile range 77.9-120.3), 94.4% (n = 68) continued BIC/FTC/TAF. At week 48, the rate of losing virologic control was 2.8% (2/72). M184V/I was not associated with viral rebound.

CONCLUSION

Despite the emergence of K65N/R +/- M184V/I after virologic failures, BIC/FTC/TAF could be an option for simplification after viral suppression.

Incidence and impact of low-level viremia among people living with HIV who received protease inhibitor- or dolutegravir-based antiretroviral therapy

OBJECTIVES

The impact of very low-level viremia (VLLV) and low-level viremia (LLV) are rarely investigated among people living with HIV (PLWH) receiving dolutegravir- vs protease inhibitor (PI)-based antiretroviral therapy (ART).

METHODS

Virally suppressed PLWH receiving long-term PI-containing ART were included in this study. The incidences of developing VLLV (plasma HIV RNA load (PVL) 20-49 copies/ml), LLV (PVL 50-999 copies/ml), and virological failure (any PVL ≥ 1000 copies/ml) were compared between those switched to dolutegravir-based ART and those remaining on PI-containing ART.

RESULTS

A total of 183 PLWH were switched to dolutegravir-based regimens and 309 remained on PI-containing regimens. The incidences of VLLV and LLV were 26.5 and 13.2 per 100 person-years of follow-up in the dolutegravir group, respectively, and 17.1 and 7.0 per 100 person-years of follow-up in the PI group; there were no statistically significant differences after adjusting for confounders. The rate of virological failure was 1.3 per 100 person-years of follow-up in the dolutegravir group and 1.9 per 100 person-years of follow-up in the PI group (p = 0.32). Neither VLLV nor LLV was related to subsequent virological failure.

CONCLUSIONS

Among virally suppressed PLWH, the risk of developing VLLV or LLV were similar between those switched to dolutegravir-based therapy and those who continued PI-based therapy. VLLV and LLV were not associated with subsequent virological failure.

Effectiveness of switching from protease inhibitors to dolutegravir in combination with nucleoside reverse transcriptase inhibitors as maintenance antiretroviral therapy among HIV-positive patients

Prolonged exposure to regimens containing protease inhibitors (PIs) as second-line therapy for human immunodeficiency virus (HIV) infection may have a negative impact on metabolic profiles and increase the risk of cardiovascular diseases. Real-world experience with dolutegravir (DTG)-based regimens as alternatives to PI-based regimens is limited in antiretroviral-experienced patients with previous failure or intolerance to first-line therapy. The current study included HIV-positive patients receiving PI-containing regimens with viral suppression for ≥6 months. Virological response and lipid profiles were compared between patients who were subsequently switched to DTG-based therapy plus nucleoside reverse transcriptase inhibitors (NRTIs) and those remaining on their PI-containing regimen at Week 48. In total, 189 patients were switched to DTG-based regimens and 313 remained on PI-containing regimens during the observation period. Patients in the DTG group were younger (mean age 40.0 years vs. 44.6 years) and were more likely to have a previous history of virological failure (44.4% vs. 19.5%) than those in the PI group. At Week 48, 1.1% of the DTG group and 3.8% of the PI group had virological non-response (HIV-RNA load >50 copies/mL) (difference, -2.7%, 95% CI -5.5% to 0.5%). The presence of M184V/I mutation and other NRTI resistance-associated mutations (RAMs) did not increase the risk of virological failure in either group. Patients switched to DTG-based therapy had statistically significant improvement of lipid profiles. Among virally suppressed HIV-positive patients, a switch to DTG-based therapy was non-inferior to continuation of PI-based therapy in virological effectiveness at Week 48, even in the presence of NRTI RAMs.