Studies examine switch to TAF-based regimens in patients with renal impairment
ART regimens composed of elvitegravir, cobicistat, emtricitabine and tenofovir alafenamide may be a safe and effective option for adults with HIV who also have renal impairment, or are at risk for renal impairment, according to data from two studies presented at ASM Microbe 2016.
Both studies examined the efficacy of a single-tablet regimen of elvitegravir, cobicistat, emtricitabine and tenofovir alafenamide (TAF; E/C/F/TAF) as a switch from existing therapy.
Switch to TAF-based regimen benefits patients at risk for chronic kidney disease
The first trial randomly assigned 784 patients to switch from a TDF-based regimen to E/C/F/TAF; 394 continued with a TDF-based regimen. The percentage of patients at high risk for chronic kidney disease was balanced between arms (34% in the E/C/F/TAF arm vs. 36% in the TDF arm). The researchers defined high risk as having 2 or more risk factors at baseline, which included female sex, age ≥ 50 years, black race, any NSAID use, CD4 < 200 cells/uL, dyslipidemia, hypertension, diabetes and clinical or subclinical renal adverse events. Participants were considered low risk if they had ≤ 1 risk factor.
Statistically significant declines from baseline in quantitative proteinuria were observed in patients prescribed E/C/F/TAF compared with an increase from baseline among patients assigned TDF regimens across all risk groups. Discontinuation due to renal adverse events and incident eGFRCG < 60 mL/minute were low for both treatment arms and risk groups, according to the study results. High rates of virologic suppression were sustained in both groups at week 48 (E/C/F/TAF, 97% vs TDF, 94%).
Patients with HIV at high risk for chronic kidney disease who switched to E/C/F/TAF “had more favorable renal outcomes,” the researchers wrote. “These data provide further support for the switch from a TDF- to [a] TAF-based regimen.”
E/C/F/TAF may fill ‘unmet need’ for women with impaired renal function
Women with HIV and renal disease “urgently need” efficacious ART regimens with improved tolerability, according to the researchers involved in the second study. This trial assessed the safety and efficacy of switching to a once-daily, single-tablet regimen of E/C/F/TAF among 242 adults with stable renal impairment (eGFRCG, 30 to 69 mL/minute).
About one quarter of participants (21%) in the study were women. At baseline, women had lower bone mineral density at the hip (0.84 vs. 0.92 g/cm2) and spine (0.962 vs. 1.10 g/cm2) than men (P < .001 for both); 59% of women and 51% of men had osteopenia or osteoporosis.
At week 96, women had achieved greater percentage increases in spine bone mineral density (3.6% vs. 1.6%; P = .09) and similar increases in hip bone mineral density (2.1% vs. 1.8%; P = .96); 19% of women showed improvements in osteopenia/osteoporosis compared with 10% of men. Most participants (90% of women and 88% of men) achieved a viral load of < 50 copies/mL.
Women with HIV and renal impairment who switched to E/C/F/TAF “had excellent virologic suppression and improvement in BMD after two years,” the researchers wrote. “E/C/F/TAF may fulfill an unmet need as a potent and safe regimen for women with impaired renal function.”
TAF-based regimen is safe, efficacious for patients with diabetes, renal impairment
In addition, David K. Stein, MD, of Albert Einstein College of Medicine and Jacobi Medical Center, both in the Bronx, NY, presented data showing that a fixed-dose combination tablet of E/C/F/TAF demonstrated “encouraging” results in a post-hoc analysis of patients with HIV and renal impairment, some of whom had diabetes.
The investigation looked specifically at markers of renal function, including proteinuria, and found that these markers declined in patients with and without diabetes. This may indicate that E/C/F/TAF is “a safer alternative” for patients with HIV, diabetes and renal impairment, according to Stein.
To see more about the presentation by Stein, click here. – by Julia Ernst, MS
Huhn G, et al. Switching from TDF to TAF in patients with high risk for CKD. Presented at: ASM Microbe; June 16-20, 2016; Boston.
McDonald C, et al. Efficacy and safety of tenofovir alafenamide in HIV-infected women with renal impairment: 96 week results. Presented at: ASM Microbe; June 16-20, 2016; Boston.
Disclosure: Huhn reports serving as a consultant for Gilead Sciences and ViiV Healthcare, as a research contractor for Bristol-Myers Squibb, Gilead Sciences, Janssen Pharmaceuticals and ViiV Healthcare, and as a scientific advisor for Gilead Sciences and ViiV Healthcare. McDonald reports serving as a research contractor for Bristol-Myers Squibb, Gilead Sciences, Janssen Pharmaceuticals, Merck and ViiV Healthcare and serving on a speakers bureau for Bristol-Myers Squibb, Gilead Sciences and ViiV Healthcare. Please see the full studies for a list of all other researchers’ relevant financial disclosures.