Clinical and pharmacologic evaluation of two dosing schedules of indotecan (LMP400), a novel indenoisoquinoline, in patients with advanced solid tumors

Autor: Joseph E. Tomaszewski, Martin Gutierrez, Thomas D. Pfister, Ralph E. Parchment, Robert J. Kinders, Julianne L. Holleran, Yves Pommier, Julie L. Eiseman, Larry Rubinstein, James H. Doroshow, Joseph M. Covey, Jan H. Beumer, Shivaani Kummar, Jiuping Ji, Christophe E. Redon, Yiping Zhang, William H. Yutzy, Jerry M. Collins, Alice P. Chen, Deborah Allen, Lihua Wang, William M. Bonner
Rok vydání: 2016
Předmět:
Zdroj: Cancer Chemotherapy and Pharmacology. 78:73-81
ISSN: 1432-0843
0344-5704
DOI: 10.1007/s00280-016-2998-6
Popis: Indenoisoquinolines are non-camptothecin topoisomerase I (TopI) inhibitors that overcome the limitations of camptothecins: chemical instability and camptothecin resistance. Two dosing schedules of the novel indenoisoquinoline, indotecan (LMP400), were evaluated in patients with advanced solid tumors. The maximum tolerated dose (MTD), toxicities, and pharmacokinetics of two indotecan drug administration schedules (daily for 5 days or weekly) were investigated. Modulation of TopI and the phosphorylation of histone H2AX (γH2AX) were assayed in tumor biopsies; γH2AX levels were also evaluated in circulating tumor cells (CTCs) and hair follicles to assess DNA damage response. An MTD of 60 mg/m2/day was established for the daily regimen, compared to 90 mg/m2 for the weekly regimen. The TopI response to drug showed target engagement in a subset of tumor biopsies. Pharmacokinetics profiles demonstrated a prolonged terminal half-life and tissue accumulation compared to topotecan. Dose-dependent decreases in total CTCs were measured in seven patients. Formation of γH2AX-positive foci in CTCs (day 3) and hair follicles (4–6 h) was observed following treatment. We established the MTD of two dosing schedules for a novel TopI inhibitor, indotecan. Target engagement was demonstrated as Top1 downregulation and γH2AX response. No objective responses were observed on either schedule in this small patient cohort. The principal toxicity of both schedules was myelosuppression; no significant gastrointestinal problems were observed. Increased DNA damage response was observed in CTCs, hair follicles, and a subset of tumor biopsies.
Databáze: OpenAIRE
Externí odkaz: