The present invention is related to pharmaceutical compositions based on vaccines and monoclonal antibodies that neutralize the Interleukin-2, which are useful in the treatment of tumors. Particularly the present invention is related to therapeutic formulations able to increase the immunogenicity of the IL-2 conjugated to the carrier protein P64k from the Neisseria Meningitidis in Montanide ISA 51 adjuvant for the induction of IL-2 neutralizing autoantibodies and the effective methods for the treatment of tumors, including breast cancer and melanoma. Furthermore, the present invention is related to therapeutic combination of the IL-2 based vaccine with other cancer vaccines based on specific tumor antigens or tumor growth factors, as well as chemotherapeutics agents or radiotherapy of standard use for cancer treatment.
