Valstar and Urocidin for EndoThese are two totally different drugs with two differentmechanism. Urocidin is an Immunotherapeutic and Valstar is a Chemotherapyagent.
Valrubicin is an anthracyclinethat affects a variety of inter-related biological functions, most of whichinvolve nucleic acid metabolism. It readily penetrates into cells, where itinhibits the incorporation of nucleosides into nucleic acids, causes extensivechromosomal damage, and arrests cell cycle in G2. Althoughvalrubicin does not bind strongly to DNA, a principal mechanism of its action,mediated by valrubicin metabolites, is interference with the normal DNAbreaking-resealing action of DNA topoisomerase II.
Urocidin has the same mechanism as BCG. Namely causing the body to produceantibodies and lymphocytes to eliminate or kill the tumor cells. It isalso more effective than BCG as shown by the 25% DFS in BCG refractorypopulation. (Thus I think, when it gets approved, it will very likely be usedalso for first-line off-label.)
Using Urocidin on the refractory population does not preclude the use ofValstar. There are patients that do not response to BCG and Urocidin and yetrespond to chemotherapy and vice versa.