Clinical trial of safety and efficacy of INH-A21 for the prevention of nosocomial staphylococcal bloodstream infection in premature infants. Multicenter study to assess safety and efficacy of INH-A21, a donor-selected human staphylococcal immunoglobulin, for prevention of nosocomial infections in very low birth weight infants. A blinded, randomized, multicenter study of an intravenous Staphylococcus aureus immune globulin.
To determine if INH-A21, an intravenous immune globulin (IGIV) derived from donors with high titers of antibody to surface adhesins of Staphylococcus epidermidis and S. aureus prevents late-onset sepsis (LOS) in very low birth weight (VLBW) infants.
                In this double-blind, placebo-controlled study, infants with birth weights 500 to 1250 g were randomized to receive up to four doses of INH-A21 (Veronate) or placebo. The primary objective was to determine the safety and efficacy of INH-A21 versus placebo for prevention of S. aureus LOS in VLBW infants.
                A total of 1983 infants from 95 neonatal intensive care units were randomized, and received at least one dose of study drug. S. aureus LOS developed in 50 of 989 (5%) and 60 of 994 (6%) infants who received placebo or INH-A21, respectively (P = .34). No differences were found in the frequencies of LOS caused by coagulase-negative staphylococci (CoNS), Candida spp, or overall mortality. No adverse events were statistically significantly associated with INH-A21 infusions compared with placebo.
                INH-A21 failed to reduce the incidence of staphylococcal LOS or candidemia in premature infants. Prophylactic administration of intravenous immunoglobulin has been inconsistent in reducing the risk of sepsis in very low birth weight (VLBW) infants presumably because of varying titers of organism specific IgG antibodies. INH-A21 is an intravenous immunoglobulin from donors with high titers of antistaphylococcal antibodies. This dose-ranging study explored safety and preliminary activity of INH-A21 for prevention of staphylococcal sepsis in VLBW infants.
                This was a multicenter, double blind, group-sequential study. Infants with birth weights 500-1250 g were randomized to receive up to 4 doses of placebo, 250 mg/kg, 500 mg/kg or 750 mg/kg INH-A21. Safety and frequencies of sepsis were compared across treatment groups.
                All treatment groups had similar mean gestational age, birth weight, Apgar score and maternal use of antibiotics. Randomizations to 250 mg/kg (N = 94) and 500 mg/kg (N = 96) doses were terminated after interim analyses demonstrated a low probability of finding a difference when compared with placebo. Infants randomized to the INH-A21 750 mg/kg group (N = 157) had fewer episodes of Staphylococcus aureus sepsis [relative risk (RR), 0.37; 95% confidence interval (CI), 0.12-1.12; P = 0.14], candidemia (RR 0.34; 95% CI 0.09-1.22; P = 0.09) and mortality (RR 0.64; 95% CI 0.25-1.61; P = 0.27) when compared with the placebo-treated cohort (N = 158). No dose-related trends were observed for adverse events or morbidities associated with prematurity.
                INH-A21 750 mg/kg demonstrated potential to reduce sepsis caused by S. aureus, candidemia and mortality in VLBW infants. Although statistical significance was not reached, based on the magnitude of the estimated differences, the efficacy and safety of INH-A21 750 mg/kg should be evaluated in an adequately powered, well-controlled study. 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.
                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.
                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 < or =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 <2 and <5 mcg/ml for types 5 and 8 in both weight groups. Three episodes of S. aureus bacteremia occurred in each arm.
                Infusion of Altastaph in VLBW neonates resulted in high levels of specific S. aureus types 5 and 8 CPS IgG. The administration of this anti-staphylococcal hyperimmune globulin was well tolerated in this population.
Antistaphylococcal immunoglobulins (INH A-21 and Altastaph) are not recommended for prevention of staphylococcal infections in preterm or VLBW neonates. Further research to investigate the efficacy of other products such as Pagibaximab is needed.