DTS-201 sodium (CPI-0004Na) is a peptide prodrug of Doxorubicin. It contains a tetrapeptide segment that is hydrolyzed by endopeptidases in the tumor microenvironment to produce metabolites, which are then converted into active Doxorubicin upon cellular entry. DTS-201 has demonstrated antitumor efficacy in xenograft models of prostate, breast, and lung cancers.

DTS-201 sodium shows good tolerance in mice (40-100 mg/kg), rats (30-70 mg/kg), and dogs (4-8 mg/kg) when administered intravenously over 15 minutes. On days 1 and 22, a single intravenous injection of DTS-201 sodium is well tolerated in mice (50 mg/kg, MTD) and rats (40 mg/kg, MTD). Administered weekly for seven weeks at doses of 3.2, 12.8, and 25.6 mg/kg, DTS-201 sodium exhibits significantly less cardiac toxicity than Doxorubicin, maintaining an average total score of ≤0.3, regardless of the dose. In xenograft mice models NCI-H1299, PC-3, and MDA-MB-231, intravenous DTS-201 sodium (40-80 mg/kg) demonstrates a better therapeutic index compared to free Doxorubicin.