title: Therapeutic efficacy of the topoisomerase I inhibitor 7-ethyl-10-(4-[1-piperidino]-1-piperidino)-carbonyloxy-camptothecin against pediatric and adult central nervous system tumor xenografts.
abstract: Therapy of patients with malignant central nervous system tumors is frequently unsuccessful, reflecting limitations of current surgical, radiotherapeutic, and pharmacotherapeutic treatments. The camptothecin derivative irinotecan (CPT-11) has been shown to possess antitumor activity in phase II trials for patients with carcinoma of the lung, cervix, ovary, colon, or rectum and for patients with non-Hodgkin's lymphoma. The current study was designed to test the efficacy of the drug against a panel of human tumor xenografts derived from adult and pediatric central nervous system malignancies. Tumors included childhood high-grade gliomas (D-212 MG, D-456 MG), adult high-grade gliomas (D-54 MG, D-245 MG), medulloblastomas (D341 Med, D487 Med), ependymomas (D528 EP, D612 EP), and a rhabdomyosarcoma (TE-671), as well as sublines with demonstrated resistance to busulfan (D-456 MG (BR)), cyclophosphamide (TE-671 CR), procarbazine (D-245 MG (PR)) or melphalan (TE-671 MR), growing subcutaneously and intracranially in athymic nude mice. In replicate experiments, CPT-11 was given at a dosage of 40 mg/kg per dose via intraperitoneal injection in 10% dimethylsulfoxide on days 1-5 and 8-12, which is the dosage lethal to 10% of treated animals. CPT-11 produced statistically significant (P < 0.001) growth delays in all subcutaneous xenografts tested, including those resistant to busulfan, cyclophosphamide, procarbazine, and melphalan, with growth delays ranging from 21.3 days in D487 Med to 90+ days in several tumor lines. Further, tumor regression was evident in every treated animal bearing a subcutaneous tumor, with some xenografts yielding complete tumor regression. Statistically significant (P < 0.001) increases in survival were demonstrated in the two intracranial xenografts-D341 EP (73.0% increase) and D-456 MG (114.2% increase)-treated with CPT-11. These studies demonstrate that, of over 40 drugs evaluated in this laboratory, CPT-11 is the most active against central nervous system xenografts and should be advanced to clinical trial as soon as possible.
authors.affiliation: Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: C B
authors.initials: CB
authors.lastname: Hare
authors.forename: G B
authors.initials: GB
authors.lastname: Elion
authors.forename: P J
authors.initials: PJ
authors.lastname: Houghton
authors.forename: J A
authors.initials: JA
authors.lastname: Houghton
authors.forename: S
authors.initials: S
authors.lastname: Keir
authors.forename: S L
authors.initials: SL
authors.lastname: Marcelli
authors.forename: D D
authors.initials: DD
authors.lastname: Bigner
authors.forename: H S
authors.initials: HS
authors.lastname: Friedman
mesh_terms: D000328:Adult; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000188:drug therapy*; D002166:Camptothecin / Q000031:analogs & derivatives* / Q000627:therapeutic use; D002648:Child; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D000077146:Irinotecan; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D059004:Topoisomerase I Inhibitors; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D059004:Topoisomerase I Inhibitors; D000077146:Irinotecan; D002166:Camptothecin