A blinded, randomized, multicenter study of an intravenous Staphylococcus aureus immune globulin

Objectives: Very low birth weight (VLBW) infants are vulnerable to nosocomial infections and subsequent morbidity; including infections caused by Staphylococcus aureus: 85% of nosocomial S. aureus infections are caused by capsular polysaccharide (CPS) types 5 and 8. Altastaph™ is a polyclonal investigational human immunoglobulin G (IgG) with high levels of opsonizing S. aureus CPS types 5 and 8 IgG. Methods: A Phase 2 clinical trial to assess the safety and kinetics of Altastaph in VLBW infants. Neonates in this multicenter study were randomized to receive two identical 20?ml/kg i.v. infusions of either 0.45% NaCl placebo or 1000?mg Altastaph/kg. Each infant was followed for 28 days after the second infusion or until discharge. Serum S. aureus CPS types 5 and 8 IgG levels were measured preinfusion and at various times after each infusion. Results: Of 206 neonates, 158 received both infusions. Adverse events were similar in the two treatment groups. Six subjects (3% in each group) discontinued owing to an adverse event. Geometric mean anti-type 5 IgG levels were 402 and 642?mcg/ml 1 day following infusion of the first (day 0) and Second (day 14) doses, respectively, in neonates ⩽1000?g and slightly higher in neonates 1001 to 1500?g. Trough levels before second infusion were 188?mcg/ml. Type 8 IgG levels were similar. Geometric mean IgG levels among placebo recipients were consistently