A method for increasing the therapeutic efficacy of a human immunoglobulin G class 1 (IgG1) antibody, includes: mutating the human CH1γ1 domain from the antibody, to restore the pairing between CH1 and CL domains that is typical of the other IgG subclasses, or by substituting the human CH1γ1 domain by the CH1 domain from a human IgG2 (CH1γ2), IgG3 (CH1γ3) or IgG4 (CH1γ4); the antibody obtained by such method, includes a) a light chain including the following amino acid sequences: i) the Light Chain Variable Region (LCVR) specific from an antigen; and ii) a human kappa (κ)Constant (CL) domain; and b) a heavy chain including the following amino acid sequences: i) the Heavy Chain Variable Region (HCVR) specific from the antigen; ii) the CH2 and CH3 domains from a human IgG1; and iii) the CH1 domain from a human IgG1, mutated to restore pairing between CHI and CL domains.