IDDF2021-ABS-0079 Switching from tenofovir disoproxil fumarate (TDF) and/or other oral antivirals (OAVS) to tenofovir alafenamide (TAF) in virally suppressed chronic hepatitis B (CHB) patients with hepatic impairment: final 2-year efficacy and safety results from a phase 2

Background We have previously shown that in hepatically impaired CHB patients, switching to TAF from TDF and/or other OAVs maintains high rates of viral suppression with stable bone and renal safety parameters through 48 weeks. Here we present our final 2-year (Week 96) results. Methods In this Phase 2 study (NCT03180619), virally suppressed CHB patients (HBV DNA Results Of 31 patients enrolled, mean age was 55 y (29% ≥60 y), 68% male, 81% Asian, and 90% HBeAg-negative; median (Q1, Q3) CTP and MELD scores were 6 (5, 8) and 10 (7.5, 14.2), respectively, median eGFRCG98.5 mL/min; 19% had osteoporosis on spine DXA. Twenty-five (81%) patients completed 96 weeks of TAF treatment (6 discontinued early: 2-withdrew consent, 1-adverse event [AE; Grade 2 creatinine increase], 1-investigator decision, and 2-death [respiratory failure and aspiration pneumonia - both not treatment-related]). Week 96 efficacy/safety results are summarized in the Table. 96% of patients on TAF treatment had HBV DNA Conclusions At 2 years, CHB patients with hepatic impairment who were switched to TAF maintained high rates of viral suppression and normal ALT values while bone and renal parameters remained stable.