Weight gain in treatment-naive HIV-1 infected patients starting abacavir/lamivudine/dolutegravir or tenofovir alafenamide/emtricitabine/bictegravir

Weight Gain and Antiretroviral Therapy

Antiretroviral therapy (ART) agents as a determinant of body weight in ART-naïve and ART-experienced persons with human immunodeficiency virus (HIV) (PWH) has become a major focus area in research and clinical settings. Recent studies demonstrating weight-suppressing properties of efavirenz and tenofovir disoproxil fumarate led to re-evaluation of weight gain studies, and a reassessment of whether other agents are weight promoting versus weight neutral. In this review, the authors synthesize recent literature on factors related to obesity, clinical measurements of adiposity, weight gain in ART-naïve and ART-experienced PWH, metabolic consequences of ART and weight gain, and the clinical management of weight gain in PWH.

Improvement in insulin sensitivity after switching from an integrase inhibitor-based regimen to doravirine/tenofovir disoproxil fumarate/lamivudine in people with significant weight gain

OBJECTIVES

We performed an observational, retrospective, cohort study to assess changes in insulin sensitivity after a switch from dolutegravir/lamivudine (DOL/3TC) or bictegravir/emtricitabine/tenofovir alafenamide (BIC/F/TAF) to doravirine/tenofovir disoproxil fumarate/3TC (DOR/TDF/3TC) in virologically suppressed people living with HIV with recent significant weight gain.

METHODS

All non-diabetic patients with HIV treated with DOL/3TC or BIC/F/TAF for ≥12 months, with HIV RNA <20 copies/mL, and with a weight increase ≥3 kg in the last year, who underwent a switch to DOR/TDF/3TC were enrolled into the study. Serum levels of glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) index were evaluated every 6 months during a 12-month follow-up.

RESULTS

Overall, 81 patients were enrolled: 41 were treated with DOL/3TC and 40 with BIC/F/TAF. At baseline, median HOMA-IR index was 3.18 and insulin resistance (HOMA-IR index >2.5) was present in 49 subjects (60%). At 12 months after the switch to DOR/TDF/3TC, change in mean serum glucose concentration was not significant, but the reduction in median concentration of insulin was significant (-3.54 mcrUI/L [interquartile range -4.22 to -2.87]; p = 0.012), associated with a significant reduction in mean HOMA-IR index (-0.54 [interquartile range -0.91 to -0.18]; p = 0.021). A significant reduction in total and low-density lipoprotein cholesterol was also reported, whereas decreases in mean body weight and mean body mass index were not significant.

CONCLUSIONS

In our retrospective study in virologically suppressed people living with HIV treated with DOL/3TC or BIC/F/TAF and with recent weight gain, the switch to DOR/TDF/3TC led to a significant improvement in insulin sensitivity and plasma lipids, with a trend to decreased body weight.

Recent data on the role of antiretroviral therapy in weight gain and obesity in persons living with HIV

PURPOSE OF REVIEW

Antiretroviral therapy (ART) has long been implicated in fat alterations and weight variations leading to cardiometabolic consequences. Recent largely prescribed antiretrovirals (ARVs) from the integrase-strand-transfer-inhibitor (INSTI) class have been associated with excessive weight gain/obesity in a minority of persons with HIV (PWH). As well, in the nucleoside reverse transcriptase inhibitors (NRTI) class, tenofovir-alafenamide (TAF), often replacing tenofovir-disoproxil-fumarate (TDF), has been associated with weight gain, a worrying concern in the present worldwide obesogenic environment. The respective role of the different ARV, the risk factors and the mechanisms remain questionable.

RECENT FINDINGS

The INSTIs dolutegravir (DTG) and bictegravir (BIC) and TAF have a proper effect on weight gain, while efavirenz (EFV) and TDF inhibit it. These effects are reported in ART-naïve PWH, in addition to weight gain resulting from the return to health process, and in ART-controlled PWH. Also, INSTIs induce weight gain in adolescents and excessive weight gain during pregnancy. The effects of INSTIs and TAF are additive. Their trajectory differs. Most of the weight gain is observed during the initial 12-month period.The main risk factors are low CD4+ and high viral load (VL) in ART-naïve PWH, Black race or originating from some African countries and female gender. The role of age and BMI differs between studies. The reversibility of the effect of INSTI and TAF appears limited.Regarding the mechanisms, the INSTIs can directly alter adipose tissue in particular through inhibition of fat beiging, resulting in fat fibrosis and hypertrophy. Macrophage infiltration is decreased. The mechanisms explaining the opposite effects of TDF and TAF remain elusive.

SUMMARY

The specific impact of DTG, BIC and TAF on weight gain/obesity in PWH is confirmed in different populations independently of the weight limiting effect of EFV and TDF. ART-linked excessive weight gain is uncommon. African origin and female sex are risk factors that need to be considered. The mechanisms are better understood for INSTIs but unknown for TDF/TAF. The reversibility of weight gain/obesity when stopping INSTI or TAF remains limited.

Biktarvy for the treatment of HIV infection: Progress and prospects

Bictegravir (BIC), a second-generation integrase strand-transfer inhibitor (INSTI) with high resilience to INSTI-resistance mutations, is integrated as a key component of Biktarvy® - a fixed-dose once-daily triple-drug regimen of bictegravir (BIC), emtricitabine (FTC) plus tenofovir alafenamide (TAF). Based on the accumulated evidence from HIV clinical trials and real-world studies, the clinical effectiveness of BIC + FTC + TAF has been proven non-inferior to other fixed-dose once-daily combinations such as dolutegravir + FTC + TAF and dolutegravir + abacavir + lamivudine. Biktarvy also shows limited drug-drug interactions and a high barrier to drug resistance. According to recent HIV guidelines, BIC + FTC + TAF is recommended as initial and long-term therapy for the treatment of HIV infection. For the pre-exposure prophylaxis, tenofovir disoproxil fumarate (TDF) or tenofovir alafenamide (TAF) remains advisable, but BIC may be possibly added to TDF or TAF. In the development of a long-acting once-monthly regimen, the novel nano-formulation of BIC + FTC + TAF could be possibly developed in the future.

Metabolic implications and safety of dolutegravir use in pregnancy

Dolutegravir is recommended for all people living with HIV because of its efficacy, high barrier to resistance, favourable safety and tolerability profile, and affordability. Dolutegravir has the highest rates of viral suppression in pregnancy, therefore preventing perinatal HIV transmission. In view of these benefits, particularly for pregnant women, an important question is if dolutegravir is safe in pregnancy. Dolutegravir has been associated with metabolic complications, including weight gain and rare events of hyperglycaemia, that could affect maternal, fetal, and postnatal health. We review the current clinically and experimentally based literature on the implications of dolutegravir use for pregnant women and for developing embryos and fetuses. Possible effects on folate status, energy metabolism, adipogenesis, and oxidative stress are considered. In many instances, insufficient data are available, pointing to the need for additional research in this important area of HIV treatment.