Miguel A. Villalona-calero, MD

Irinotecan and mitomycin (Mutamycin) possess significant single-agent activity against several tumor types, and mitomycin activates topoisomerase I, the cellular target of irinotecan. We conducted a phase I dose-escalation study of irinotecan and mitomycin in 37 evaluable patients with solid tumors. Antitumor responses included 2 complete responses, 5 partial responses, 10 minor responses, and a CA 19-9 tumor marker response.

Most of the clinical experience with irinotecan (CPT-11 [Camptosar]) has been with either a weekly or an every-3-week schedule. Recent phase I trials have explored new routes and schedules of administration. One approach

A better understanding of the biology and biochemistry of the cancer cell has led to the development of various promising new antineoplastic compounds that are now undergoing phase I, II, and III clinical testing. These drugs include topoisomerase I inhibitors, such as camptothecin and its analogs 9-aminocamptothecin, irinotecan, and topotecan; the paclitaxel analog docetaxel; gemcitabine, an antimetabolite structurally related to cytarabine; and fluorouracil prodrugs and other thymidylate synthase (TS) inhibitors.