Drug complex for treatment of metastatic prostate cancer

A drug complex for delivery of a drug or other agent to a target cell, comprising a targeting carrier molecule which is selectively distributed to a specific cell type or tissue containing the specific cell type; a linker which is acted upon by a molecule which is present at an effective concentration in the environs of the specific cell type; and a drug or an agent to be delivered to the specific cell type. In particular, a drug complex for delivering a cytotoxic drug to prostate cancer cells, comprising a targeting carrier molecule which is selectively delivered to prostate tissue, bone or both; a peptide which is a substrate for prostate specific antigen; and a cytotoxic drug which is toxic to androgen independent prostate cancer cells.