Radiation/chemotherapy sensitizer to be used for intratumoral local injection and for controlled release of hydrogen peroxide with hydrogel as carrier

Abstract

The present invention provides a radiation sensitizer or anti-cancer chemotherapy sensitizer that prevents the decomposition of hydrogen peroxide for a longer period of time, and that maintains its effect. The radiation sensitizer or anti-cancer chemotherapy sensitizer according to the present invention is characterized by using hydrogen peroxide together with a hydrogel containing a crosslinked gelatin gel.

1 - 11 . (canceled) 
     
     
         12 . A sensitizer for enhancing a therapeutic effect of radiation or an anti-cancer agent on a tumor, the sensitizer comprising a combination of:
 (a) hydrogen peroxide and   (b) a hydrogel comprising a crosslinked gelatin gel prepared from an acidic gelatin, and the sensitizer being locally administered to a tumor area.   
     
     
         13 . The sensitizer according to  claim 12 , wherein the acidic gelatin has an isoelectric point of 4.5 to 5.5. 
     
     
         14 . The sensitizer according to  claim 12 , wherein the tumor is resistant to treatment using radiation or an anti-cancer agent. 
     
     
         15 . The sensitizer according to  claim 12 , wherein a first administration of the sensitizer is performed during a period from 3 days before a first irradiation with radiation or a first administration of the anti-cancer agent until the start of the irradiation or the administration of the anti-cancer agent. 
     
     
         16 . The sensitizer according to  claim 15 , wherein a second administration of the sensitizer is performed 5 to 14 days after the first administration of the sensitizer. 
     
     
         17 . The sensitizer according to  claim 12 , wherein the crosslinked gelatin gel has a water content of 92 to 99.7%. 
     
     
         18 . The sensitizer according to  claim 12 , which, in the form of a final formulation, is administered in an amount of 0.1 to 10 mg, on a dry weight basis of the crosslinked gelatin gel, per 200 mm 3  of the tumor volume. 
     
     
         19 . The sensitizer according to  claim 12 , which, in the form of the final formulation, contains hydrogen peroxide in an amount of 0.01 to 3.5 wt. %. 
     
     
         20 . A method for treating a tumor, comprising the steps of:
 locally administering to a tumor area a sensitizer comprising a combination of (a) hydrogen peroxide and (b) a hydrogel comprising a crosslinked gelatin gel prepared from an acidic gelatin; and   (2) irradiating the tumor area with radiation or administering an anti-cancer agent to a patient suffering from the tumor.   
     
     
         21 . A composition for treating a tumor using radiation or an anti-cancer agent, the composition comprising a combination of (a) hydrogen peroxide and (b) a hydrogel comprising a crosslinked gelatin gel prepared from an acidic gelatin, and the composition being locally administered to a tumor area. 
     
     
         22 . Use of a composition for local administration to a tumor area in the manufacture of a sensitizer for enhancing a therapeutic effect of radiation or an anti-cancer agent on a tumor, the composition comprising a combination of the following components (a) and (b):
 (a) hydrogen peroxide; and   (b) a hydrogel comprising a crosslinked gelatin gel prepared from an acidic gelatin.