Of the 47 patients who discontinued treatment prior to Year 5, 10 had HBV DNA ≥300 copies/mL at the last on-treatment measurement. Genotypic testing of isolates from these 10 patients found no evidence of entecavir resistance. The safety profile for this cohort during treatment with open-label entecavir (study ETV-901) is summarized in Table 2. During ETV-901, no patient in this cohort discontinued entecavir due to an adverse event (Table 2). Adverse events occurring in ≥10% of patients are shown in Table 3. The most common serious adverse events were increased
ALT and liver abscess, both occurring in two (1%) patients. One patient, who stopped study medication 172 weeks after initially starting on entecavir, experienced an ALT flare that was associated with a ≥2-log increase in HBV DNA. This patient
was subsequently lost RXDX-106 nmr to follow-up at Week 176. The safety profile for the entecavir long-term cohort during study ETV-901 was consistent with the safety profile reported for all entecavir-treated patients through 2 years in study ETV-022.19 Within study ETV-901, there was no observed difference between the cumulative safety profile of the entecavir long-term cohort (n = 146) and that of the larger patient population treated in the rollover study (ETV-901). Through 5 years of entecavir treatment FK506 and posttreatment follow-up, one patient (of 146) in the entecavir long-term cohort developed HCC (described below). For the entecavir long-term cohort, five deaths were reported during study ETV-901, including off-treatment follow-up. No death was attributed to study medication. The investigator-assigned causes of death were liver failure (1), find more motor vehicle accident (3), and unknown (1). The patient
who died from liver failure was diagnosed with HCC at Week 51 of study ETV-022, and completed 2 years of dosing in that study. The patient subsequently enrolled in study ETV-901, was treated for 40 weeks and died during Week 136 (total entecavir treatment time) of liver failure secondary to progression of HCC. This analysis provides data on long-term treatment with entecavir in nucleoside-naïve, HBeAg-positive patients with CHB, and demonstrates that long-term entecavir therapy in this population achieved and maintained HBV DNA suppression. At Year 5, 94% of patients in the entecavir long-term cohort had HBV DNA <300 copies/mL. The importance of maintaining prolonged HBV DNA suppression to avoid or minimize the long-term complications of CHB has been recognized in several long-term studies of disease progression and outcome.3, 4, 24 Patients with persistently elevated viral load are at the greatest risk of developing liver disease progression and adverse outcomes.3, 4 It has also been shown that even patients with low-level HBV DNA viremia (below 104 to 105 copies/mL) are at risk of fibrosis, cirrhosis, and HCC.