Comparison of Renal Outcomes in Chronic HBV Infection Treated With TDF vs Entecavir

Tenofovir disoproxil fumarate (TDF) use was not a predictor of renal impairment in patients infected with chronic hepatitis B virus (HBV) with normal baseline renal function, according to a study published in Clinical Gastroenterology and Hepatology. For patients with baseline renal impairment, a decline in renal function was noted was among patients given TDF compared to patients given entecavir.

This retrospective cohort study sought to determine whether medications used to treat chronic HBV infection caused renal impairment by comparing the estimated glomerular filtration rate (eGFR) of patients treated with TDF vs patients treated with entecavir.

The study included 410 patients, including participants with chronic HBV infection who were treated with TDF (n=239) or entecavir (n=171) from 2000 to 2016. Patients included in the study did not have prior exposure to adefovir or any anti-HBV medications associated with renal impairment, nor did patients report co-infection with hepatitis C, hepatitis D, or HIV. Researchers calculated renal outcomes using serum creatinine levels of patients who were on treatment for at least 12 months and with at least 2 follow-up creatinine measurements. For this study, researchers defined moderate renal impairment as eGFR <60 mL/minute/1.73 m2 and mild renal impairment as 60 ≤ eGFR<90 mL/minute/1.73 m2.

Propensity score matching was performed between the 2 treatment groups for age, gender, baseline eGFR ≥60, follow-up duration, and for the presence of cirrhosis, hypertension, or diabetes. After adjusting for cirrhosis, hypertension, and diabetes, researchers calculated the mean eGFR rate for both matched and unmatched cohorts (including overall cohort, cohort with eGFR <60, and cohort of patients older than 60). They then used Cox regression models to identify associations between patient characteristics and the development of renal impairment.

A subgroup of patients defined by baseline moderate renal impairment (eGFR <60) included 32 patients treated with entecavir and 26 patients treated with TDF. In the unmatched overall cohort and in the cohort with eGFR <60, patients treated with TDF revealed significantly lower adjusted mean eGFR (P <.001) than patients treated with entecavir. However, in the matched cohort with eGFR ≥60, the adjusted mean eGFR was similar for both treatments. In the Cox regression analysis, TDF was not shown to be a significant predictor for renal impairment compared with entecavir; age, cirrhosis, and hypertension, however, were significantly associated with the development of moderate renal impairment.

Limitations of the study included the non-randomized design; propensity score matching may have been insufficient to adjust for all renal risk factors among treatment groups. Longer-term data is needed, as chronic HBV often requires life-long treatment. Finally, analyses were not adjusted for any drug use with potential renal toxicity, including NSAIDs and antibiotics.

TDF was not associated with worsening renal function when used to treat patients with chronic HBV infection and without baseline renal impairment. However, patients with moderate baseline renal impairment experienced a significant decline in renal function when treated with TDF vs entecavir.

Multiple authors declare affiliations with the pharmaceutical industry. Please refer to reference for a complete list of authors’ disclosures.

Reference

Trinh S, Le AK, Chang ET, et al. Changes in renal function in patients with chronic HBV infection treated with tenofovir disoproxil fumarate vs entecavir [published online August 18, 2018]. Clin Gastroenterol Hepatol. doi: 10.1016/j.cgh.2018.08.037