Background: Analytical data suggesting that immunoglobulin given intramuscularly (IGIM) may have reduced protection against hepatitis A virus (HAV) infection led to an update in the recommended IGIM dose (0.2 ml/kg).
Methods: This prospective, open-label, single-arm clinical study evaluated whether a single 0.2 ml/kg dose of IGIM provided protective levels of anti-HAV antibodies (≥ 10 mIU/ml for up to 60 days) in HAV-seronegative healthy adults.
Results: Of the 28 subjects enrolled and dosed, 26 (93%) completed the study. Mean uncorrected anti-HAV antibody titers peaked at 109 mIU/ml on day 5 and stayed above 10 mIU/ml through day 60 (N = 26). The mean uncorrected anti-HAV antibody titers had a median Tmax of 95.33 h, a mean Cmax of 118 mIU/ml, and a mean observed Thalf of 63.3 days; baseline-corrected titers had a median Tmax of 95.33 h, a mean Cmax of 114 mIU/ml, and a mean observed Thalf of 47.1 days (N = 27). All subjects (28/28) experienced at least 1 treatment-emergent adverse event (TEAE), with a total of 83 TEAEs reported; none was serious, and 96% (80/83) resolved without sequelae. Most (63%) events judged definitely and possibly related to study treatment involved localized pain due to intramuscular injections. There were no serious adverse events and no deaths or discontinuations due to TEAEs.
Conclusions: A single 0.2 ml/kg dose of IGIM provided protective anti-HAV levels for at least 60 days, with acceptable safety and tolerability profiles in healthy subjects. Uncorrected and baseline-corrected pharmacokinetic findings were similar and consistent with the corresponding sampling points in previous research.
Trial registration: ClinicalTrials.gov Identifier, NCT03351933.
Keywords: Efficacy; Hepatitis A virus; Infectious diseases; Intramuscular immunoglobulin; Pharmacokinetics; Safety; Tolerability.