CTNI-18. RESULTS FROM A PHASE 1 STUDY OF SONODYNAMIC THERAPY WITH WHOLE HEMISPHERIC LOW INTENSITY NON-ABLATIVE ULTRASOUND IN PATIENTS WITH RECURRENT HIGH GRADE GLIOMA

Abstract We report the first use of a novel device that delivers non-ablative low intensity diffuse ultrasound (LIDU) across the entire hemisphere in combination with the oral sonosensitizing agent 5-ALA for the treatment of recurrent high grade glioma. LIDU in combination with 5-ALA focally targets tumor cells with sonodynamic therapy (SDT), causing selective tumor cell death across the entire hemisphere via 1) direct tumor targeting and 2) stimulation of immunogenic cell death. In this 3x3 clinical trial designed for safety (n=12, NCT05362409), two patients were enrolled after multiple recurrences and seven patients had multifocal or multicentric disease. Treatments were delivered monthly for a minimum of four sessions. A treatment duration of 120 minutes was established after dose escalation and expansion. SDT delivered via a novel device and in conjunction with 5-ALA was well tolerated, with no duration-limiting toxicities or serious related adverse events. Compared to historical data, we observed a significant increase in overall survival (mOS of 14.0+ months, with 7 of 12 patients still alive at the time of this submission and final median OS not yet achieved). A Phase 2b randomized, multicenter, double-blind, placebo-controlled study has been planned to commence in 2025 to assess the safety and efficacy of LIDU with sonosensitization in patients with newly diagnosed GBM.