The present invention relates to molecules, particularly polypeptides, more particularly immunoglobulins (e.g., antibodies), comprising a variant Fc region, wherein said variant Fc region comprises at least one
amino acid modification relative to a wild-type Fc region, which variant Fc region binds FcγRIIIA and / or FcγRIIA with a greater affinity, relative to a comparable molecule comprising the wild-type Fc region. The molecules of the invention are particularly useful in preventing, treating, or ameliorating one or more symptoms associated with a
disease, disorder, or infection. The molecules of the invention are particularly useful for the treatment or prevention of a
disease or disorder where an enhanced
efficacy of
effector cell function (e.g., ADCC) mediated by FcγR is desired, e.g.,
cancer, infectious
disease, and in enhancing the therapeutic
efficacy of therapeutic antibodies the effect of which is mediated by ADCC.