The hydrochloride salt of the semi-synthetic camptothecin analogue belotecan with potential antitumor activity. Belotecan binds to and inhibits the activity of topoisomerase I, stabilizing the cleavable complex of topoisomerase I-DNA, which inhibits the religation of single-stranded DNA breaks generated by topoisomerase I; lethal double-stranded DNA breaks occur when the topoisomerase I-DNA complex is encountered by the DNA replication machinery, DNA replication is disrupted, and the tumor cell undergoes apoptosis. Topoisomerase I is an enzyme that mediates reversible single-strand breaks in DNA during DNA replication. or A rare type of kidney cancer that grows and spreads quickly. It begins in the duct of Bellini in the kidney. Also called BDC.