[Radiosensitization by hypoxic cell radiosensitizer--present status of radiosensitizer].
Because of the unsuccessful clinical trials of misonidazole (MISO), many efforts have been made to find a new hypoxic cell sensitizer which is more effective and/or less toxic than MISO. In Japan, RK-28 is already under going Phase II clinical evaluation and RP-170, KU-2285 and KIH-802 have been proven to be effective both in vitro and in vivo and are also waiting further clinical trials. But in U.S.A. and England, etanidazole (SR-2508) and pimonidazole (Ro 03-8799) are under going Phase III evaluation and clinical evaluation of SR-2508 will be key opened in early next year. Now, an appropriate goal for a new radiosensitizer would be more effective and/or less toxic than SR-2508 or clinically more useful than SR-2508. Clinical trials of SR-2508 have been performed using intravenous injection, however it may be difficult to give a sensitizer intravenously on a daily basis in accordance with requirements for standard fractionated radiotherapy in a clinical setting. In contrast, RP-170 and KU-2285 have the potential to produce considerable radiosensitization under both intravenous and oral administration.
Murayama
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C
Dept. of Radiation Oncology School of Med., Tokai Univ.
Mori
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T
D015687:Cell Hypoxia / Q000187:drug effects*; D017341:Etanidazole; D006801:Humans; D008920:Misonidazole / Q000031:analogs & derivatives / Q000494:pharmacology; D009593:Nitroimidazoles / Q000494:pharmacology; D009705:Nucleosides / Q000494:pharmacology; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*
D009593:Nitroimidazoles; D009705:Nucleosides; D011838:Radiation-Sensitizing Agents; C047778:1-(4'-hydroxy-2'-butenoxy)methyl-2-nitroimidazole; C060996:RP 170; D017341:Etanidazole; C033815:pimonidazole; D008920:Misonidazole