Ganglioside GM3-containing nanoparticles as immunomodulators

The present invention describes a pharmaceutical composition whose active ingredient includes conjugates of membrane vesicles of Neisseria meningitidis and the GM3 ganglioside in a conjugation ratio in excess of proteins, has particular characteristics of size, surface charge and a morphology associated with nano-particulate systems that give it advantageous properties as an immunomodulator, because it induces a convenient and significant reduction of myeloid-derived suppressor cells that has an impact on the response of lymphocytes and on the survival of patients with tumors. The invention further discloses the use of the pharmaceutical composition disclosed in the treatment of cancer, particularly those cancers where the myeloid-derived suppressor cells (MDSCs) are high; as well as a method of treatment with said composition in cancer patients and a method to select those who will receive said treatment.