Development of a mouse-feline chimeric antibody against feline tumor necrosis factor-alpha

DOKI, Tomoyoshi; TAKANO, Tomomi; HOHDATSU, Tsutomu

Purified mouse mAb 2-4 and chimeric mAb 2-4 were administered to cats. Five administrations of the mAb did not cause any anaphylactic reaction in either group. Umehashi et al. reported the relationship between repeated administration of mouse mAb and mouse-feline chimeric mAb and the induction of anaphylactic reactions, in which several administrations of 10 mg/kg mouse mAb or chimeric mAb did not cause any anaphylactic reaction in cats, whereas 50 mg/kg mouse mAb did [22] . Based on this finding, the antibody dose and dosing frequency adopted in our study were within the range shown not to induce anaphylactic reaction. Because a human-mouse chimeric mAb, infliximab, is repeatedly administered to humans at doses of 3 or 5 mg/kg, and mouse mAb 2-4 exhibited a therapeutic effect at 3 mg/ kg in FIP cats, the doses used in the present study were set based on these findings [8, 10, 11] . Experiments to confirm whether or not an anaphylactic reaction is induced by highdose repeated administration are warranted.