Clinical development of new formulations of cytotoxics in solid tumors.

To discuss the clinical development of new formulations of old cytotoxic agents and highlight the value of adopting this strategy. Several drugs are currently in clinical development with high potential in improving clinical outcomes compared with their older counterparts. We emphasize on the results of four of these agents, each belonging to a known group of cytotoxics namely amrubicin, EndoTAG-1, pralatrexate and NKTR-102. Each has shown promising results that have the potential in addressing some limitations that have been observed with the 'earlier generation' agents. Improvement in drug development strategies and the appreciation of the mechanisms of action and resistance of the cytotoxic agents currently available in the clinic open the door for developing agents that have the potential of improving clinical outcomes with better safety profiles. It is important to adopt innovative clinical trials designs integrating molecular markers in early clinical development in order to identify the subgroups of patients who would derive the maximal benefit of these novel agents.