Immunofluorescence imaging as a tool for studying the pharmacokinetics of a human monoclonal single chain fragment antibody

We have used immunofluorescence imaging to study binding of a monoclonal antibody fragment to subcutaneously implanted human melanoma cells in nude mice. The data acquired using this nontraditional approach was then analyzed using standard pharmacokinetic methods to produce estimates of k_e (0.06 h^-1), t₁2/ (16 h), mean residency time (23.4 h) and percent exposure of the antibody to the tumor (40%). To our knowledge this is the first time standard pharmacokinetic analyzes have been conducted on immunofluorescence imaging data. The combination of this novel imaging technique and standard pharmacokinetic analytical methods should prove to be a useful tool for comparing the properties of antibody fragments in animal models.