Safety, pharmacokinetics, and functional activity of human anti-Pseudomonas aeruginosa monoclonal antibodies in septic and nonseptic patients.

A mixture of five IgM human monoclonal antibodies (MAbs) against lipopolysaccharide antigens of Pseudomonas aeruginosa, plus a human IgG1 MAb against exotoxin A, were studied in 12 noninfected patients and 8 patients with P. aeruginosa bacteremia or pneumonia (or both). The preparation was well tolerated over a dose range of 0.3-1.2 ml/kg (0.75-3.0 mg/kg IgM protein). After a single infusion of 1.2 ml/kg (3.0 mg/kg IgM protein), serum antibody titers were boosted into therapeutic range, with serum half-lives ranging from 34 to 99 h. Also, opsonophagocytic activity in serum rose more than 1 log10 for all but one antibody. In no patient was an immunologic response against the MAb preparation detected.