Abstract: A method is provided for determining the efficacy of GPC3-targeting drug therapy for cancer in a patient before the start of GPC3-targeting drug therapy or for determining the continuation of GPC3-targeting drug therapy for a patient treated with GPC3-targeting therapy. The method includes determining the number of an immunocyte or an expression level of a molecule expressed on the immunocyte in a biological sample isolated from the patient before the start of GPC3-targeting drug therapy and/or the patient treated with the GPC3-targeting drug therapy, wherein when the number of the immunocyte or the expression level of the molecule expressed on the immunocyte is a predetermined value, the efficacy of the GPC3-targeting drug therapy is determined or the continuation of the GPC3-targeting drug therapy is determined. GPC3-targeting drugs and drug preparations for use according to the disclosed methods are also provided.

Abstract: The disclosure provides methods for measuring M-proteins in a biological sample obtained from a subject, comprising applying purified immunoglobulins to a liquid chromatography (LC) mass spectrometry (MS). In some aspects, the immunoglobulins are purified using an immunocapture (IC). In certain aspects, the subject has a plasma cell disorder, e.g., multiple myeloma.

Abstract: A method is provided for determining the efficacy of GPC3-targeting drug therapy for cancer in a patient before the start of GPC3-targeting drug therapy or for determining the continuation of GPC3-targeting drug therapy for a patient treated with GPC3-targeting therapy. The method includes determining the number of an immunocyte or an expression level of a molecule expressed on the immunocyte in a biological sample isolated from the patient before the start of GPC3-targeting drug therapy and/or the patient treated with the GPC3-targeting drug therapy, wherein when the number of the immunocyte or the expression level of the molecule expressed on the immunocyte is a predetermined value, the efficacy of the GPC3-targeting drug therapy is determined or the continuation of the GPC3-targeting drug therapy is determined. GPC3-targeting drugs and drug preparations for use according to the disclosed methods are also provided.