Definition

An orally bioavailable flavored formulation composed of the hydrochloride salt form of irinotecan, a semisynthetic derivative of camptothecin, with potential antineoplastic activity. Upon oral administration of oral irinotecan HCl formulation VAL-413, irinotecan is converted to the biologically active metabolite 7-ethyl-10-hydroxy-camptothecin (SN-38) by a carboxylesterase-converting enzyme. In turn, SN-38 inhibits topoisomerase I activity by stabilizing the cleavable complex of topoisomerase I and DNA, resulting in DNA breaks. This results in an inhibition of DNA replication and an induction of apoptosis in cancer cells. VAL-413 may improve tolerability of oral irinotecan and improve compliance.