The present invention provides methods for the identification of patients with an inflammatory or autoimmune disease that demonstrate an inadequate response to treatment with a multi-Fc therapeutic, and the determination of an optimal dose of a multi-Fc therapeutic for said patient based on the patient's circulating levels of inactivated C3b (iC3b) and/or additional complement components that may be employed as a surrogate for iC3b based on an analogous response to multi-Fc therapeutics. The present invention further provides for improvements in the use of such multi-Fc therapeutics in the treatment of autoimmune and inflammatory diseases
