Safety evaluation of monophosphoryl lipid A (MPL): an immunostimulatory adjuvant.
Animal models have shown the potential use of monophosphoryl lipid A (MPL), a detoxified bacterial lipopolysaccharide, as a vaccine adjuvant. Immunostimulatory activity with diverse effects on the cellular elements of the immune system has been demonstrated and a range of vaccines incorporating MPL, including allergy vaccines, are currently under clinical evaluation. A series of preclinical safety investigations was performed to support clinical use of MPL as used in allergy vaccines and comprised cardiovascular/respiratory assessment in dog (up to 100 microg/kg/day); repeat-dose toxicity in rat, rabbit, and dog (up to 2500 and 1200 microg/kg/day in the rat and dog, respectively); reproduction toxicity in rat and rabbit (up to 100 microg/kg/day); and genotoxicity studies. Overall, repeat-dose toxicity studies in the rat and dog showed expected immunostimulatory effects and/or signs of toxicity associated with overstimulation of the immune system (notably increased spleen weight and white blood cell values). Studies in the rabbit with weekly doses of MPL produced no effects. MPL was shown to have no adverse effects on cardiovascular/respiratory function, reproduction, and genotoxicity.
Baldrick
Paul
P
Covance Laboratories Ltd. Otley Road, Harrogate, North Yorkshire, HG3 1PY, England, United Kingdom.
Richardson
Derek
D
Elliott
Gary
G
Wheeler
Alan W
AW
D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000633:toxicity*; D000818:Animals; D016466:CHO Cells / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects; D002869:Chromosome Aberrations / Q000139:chemically induced; D006224:Cricetinae; D003412:Cricetulus; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D005260:Female; D007114:Immunization; D007275:Injections, Intravenous; D008050:Lipid A / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000633:toxicity*; D008297:Male; D009152:Mutagenicity Tests; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D012098:Reproduction / Q000187:drug effects; D012129:Respiratory Function Tests; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics
D000276:Adjuvants, Immunologic; D008050:Lipid A; C048436:monophosphoryl lipid A