Early Switching to Subcutaneous Anti-Hepatitis B Virus Immunoglobulins (HBIg) after Liver Transplantation: 12-Month Results of a Single-Center Study: 912

Purpose: We tested the efficacy, feasibility, and safety of early switching (≤30 days) from intravenous (i.v.) to subcutaneous (s.c.) anti-hepatitis B immunoglobulins (HBIg) after liver transplantation (LT). Methods: This is a pilot, single-arm, single-center, open-label study in 12 de novo LT recipients. Inclusion criteria called for: adult (≥18 years), hepatitis B virus surface antigen (HBsAg)-positive patients on nucleos(t) ide therapy before LT; undetectable HBV DNA; no hepatitis C virus (HCV) co-infection, and informed consent. Patients received 30,000 IU i.v. HBIg over 5 days immediately after surgery. If patients had 3 consecutive anti-HBs titers ≥150 IU/L they were converted to s.c. HBIg on the first outpatient visit within 30 days after LT. s.c. HBIg were administered as per label throughout the study period (i.e. 500/1000 IU per week if body weight < 75 kg/≥75 kg, respectively). Nucleos(t)ides were left unchanged. Primary endpoint at month (M) 12 post-LT was efficacy, as per anti-HBs titers ≥150 UI/L, negative HBV DNA and HBsAg. Key secondary endpoints were feasibility of self-administration and safety. Results: Twelve patients (M:F = 8:4; median age 56 years; median body weight 65 kilos) were enrolled between December 2010 and March 2011. All patients were converted to s.c. HBIg at a median of 25 days after LT and completed the 12-month schedule. Median (mean ±SD) anti-HBs titers (IU/L) at conversion, M2, M3, M4, M5, M6, and M12 post-LT were respectively: 608 (648±256.6); 371 (428.9±146.8); 345 (392.5±170.1); 300.3 (341.8±122.4); 346.7 (385.7±92.2), 270 (325.6±130.1), and 406 (358.8±159.9). Protective titers were reached throughout the study period with no viral breakthrough. Conclusion: Early (≤30 days) switching from i.v. to s.c. HBIg is feasible and allows for protective anti-HBs titers through M12 post-LT. Longer follow-up periods and larger series are advocated to confirm these preliminary results.