Drug
Metab Dispos. 2005 Jul;33(7):1056-61. Epub 2005 Apr 20.
Monoclonal nicotine-specific antibodies reduce nicotine
distribution to brain in rats: dose- and affinity-response relationships.
Keyler DE, Roiko SA, Benlhabib E, LeSge MG, St Peter JV, Stewart S,
Fuller S, Le CT, Petnel PR
Minneapolis Medical Research Foundation, Minnesota, USA.
Vaccination against nicotine is being studied as a potential treatment for
nicotine dependence. Some of the limitations of vaccination, such as
variability in antibody titer and affinity, might be overcome by instead
using passive immunization with nicotine-specific monoclonal antibodies. The
effects of antibodies on nicotine distribution to brain were studied using
nicotine-specific monoclonal antibodies (NICmAbs) with K(d) values ranging
from 60 to 250 nM and a high-affinity polyclonal rabbit antiserum (K(d) =
1.6 nM). Pretreatment with NICmAbs substantially increased the binding of
nicotine in serum after a single nicotine dose, reduced the unbound nicotine
concentration in serum, and reduced the distribution of nicotine to brain.
Efficacy was directly related to antibody affinity for nicotine. Efficacy of
the highest affinity NICmAb, NICmAb311, was dose-related, with the highest
dose reducing nicotine distribution to brain by 78%. NICmAb311 decreased
nicotine clearance by 90% and prolonged the terminal half-life of nicotine
by 120%. At equivalent doses, NICmAb311 was less effective than the higher
affinity rabbit antiserum but comparable efficacy could be achieved by
increasing the NICmAb311 dose. These data suggest that passive immunization
with nicotine-specific monoclonal antibodies substantially alters nicotine
pharmacokinetics in a manner similar to that previously reported for
vaccination against nicotine. Antibody efficacy is a function of both dose
and affinity for nicotine.