FIELD : biotechnology.SUBSTANCE : invention relates to biotechnology, specifically to recombinant fused proteins, and can be used in medicine. Fusion protein based on a heavy chain of human ferritin, which contains at N-end of protein at least one sequence of splitting matrix metalloproteinase (MMP) and unstructured polypeptide, consisting essentially of proline, serine and alanine (PAS), acting as masking polymer. Nanoparticle consisting of several monomers of said fused protein is also obtained. Nanoparticle or fused protein is a part of the anticancer pharmaceutical composition together with doxorubicin.EFFECT : invention increases stability of the protein-drug complex.13 cl, 13 dwg, 11 ex