Methods of therapy for B-cell malignancies are provided. The methods comprise administering a therapeutically effective amount of an antagonist anti-CD40 antibody or antigen-binding fragment thereof to a patient in need thereof. The antagonist anti-CD40 antibody or antigen-binding fragment thereof is free of significant agonist activity when the antibody binds a CD40 antigen on a normal human B cell, exhibits antagonist activity when the antibody binds a CD40 antigen on a malignant human B cell, and can exhibit antagonist activity when the antibody binds a CD40 antigen on a normal human B cell. Antagonist activity of the anti-CD40 antibody or antigen-binding fragment thereof beneficially inhibits proliferation and/or differentiation of malignant human B cells.