Long-term immunogenicity and safety of the hepatitis B vaccine HepB-CpG (HEPLISAV-B) compared with HepB-Eng (Engerix-B) in adults with chronic kidney disease.

BACKGROUND: Hepatitis B virus (HBV) infection remains a significant global burden, especially for patients with chronic kidney disease (CKD) receiving hemodialysis. Three doses of HepB-CpG (HEPLISAV-B® vaccine) induced a superior immune response compared with 4 double doses of HepB-Eng (Engerix-B®) in a phase 3 trial (HBV-17) in adults with CKD. Here we report the long-term immunogenicity and safety of HepB-CpG and HepB-Eng in eligible participants of HBV-17 who enrolled in this optional 34-month follow-up trial (HBV-19). METHODS: HBV-19 is a multicenter, open-label, phase 3b trial of adults with CKD who previously received a complete series of HepB-CpG or HepB-Eng in the HBV-17 trial. Participants were assigned to seroprotection categories at enrollment on the basis of their antibody response to hepatitis B surface antigen (anti-HBs) in HBV-17. The objective was to evaluate the durability of seroprotection (defined as an anti-HBs concentration ≥ 10mIU/mL) induced by HepB-CpG and HepB-Eng. Participants whose anti-HBs concentration was below 10mIU/mL received additional HepB-CpG or HepB-Eng doses. RESULTS: 147 participants were enrolled; 66.7 % were men, median age was 65.0 years, and 83.7 % were white. The durability of seroprotection in participants with CKD was similar in those who received HepB-CpG and those who received HepB-Eng. Antibody concentrations ≥ 100mIU/mL persisted for longer in HepB-CpG than HepB-Eng recipients, among those with anti-HBs ≥ 100mIU/mL post vaccination. The geometric mean anti-HBs concentration in the HepB-CpG group was significantly higher than in the HepB-Eng group over time (P ≤ 0.0001). The safety profiles were similar between the vaccine groups. CONCLUSIONS: Due to the higher antibody levels induced by HepB-CpG in participants with CKD, seroprotection against HBV may be expected to persist longer than that induced by HepB-Eng. CLINICALTRIALS: gov: NCT01282762.

A randomized, double-blind, placebo-controlled, dose-ranging study using Genz-644470 and sevelamer carbonate in hyperphosphatemic chronic kidney disease patients on hemodialysis.

BACKGROUND: Genz-644470 is a new, nonabsorbed phosphate binding polymer. In an in vitro competitive phosphate binding assay, Genz-644470 bound significantly more phosphate per gram than sevelamer. As a consequence, this clinical study evaluated the ability of Genz-644470 to lower serum phosphorus in patients on hemodialysis and compared serum phosphorus lowering of Genz-644470 with sevelamer carbonate and placebo. Because three different fixed doses of Genz-644470 and sevelamer carbonate were used, phosphate-lowering dose-responses of each agent were also analyzed. METHODS: A randomized, double-blind, dose-ranging study was conducted. After a 2-week phosphate binder washout, 349 hyperphosphatemic (serum phosphorus >5.5 mg/dL) hemodialysis patients were randomized to one of seven fixed-dose groups: placebo, Genz-644470 2.4 g/day, Genz-644470 4.8 g/day, Genz-644470 7.2 g/day, sevelamer carbonate 2.4 g/day, sevelamer carbonate 4.8 g/day, or sevelamer carbonate 7.2 g/day. Indicated total daily doses were administered in fixed divided doses three times a day with meals for 3 weeks. The change in serum phosphorus during the treatment period and its dose-response patterns were assessed. RESULTS: Dose-dependent reductions in serum phosphorus were observed with both Genz-644470 and sevelamer carbonate. Serum phosphorus-lowering responses to fixed doses of sevelamer carbonate and Genz-644470 were enhanced in a roughly linear fashion with increasing doses over a threefold range after 3 weeks of treatment. Genz-644470 did not show any advantage in phosphorus lowering per gram of binder compared with sevelamer carbonate. Overall toler-ability was similar between active treatment groups. The tolerability of sevelamer carbonate was consistent with prior studies and with the established safety profile of sevelamer. CONCLUSION: Both Genz-644470 and sevelamer carbonate effectively lowered serum phosphate levels in a dose-dependent fashion in patients with chronic kidney disease on hemodialysis. However, Genz-644470 did not provide any advantage over sevelamer carbonate in phosphate lowering in vivo, as had been demonstrated in vitro.