CTNI-16. FEASIBILITY PILOT STUDY OF OKN-007 IN COMBINATION WITH ADJUVANT TEMOZOLOMIDE CHEMORADIOTHERAPY IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA

Abstract BACKGROUND Temozolomide (TMZ) is the standard of care chemotherapy agent for glioblastoma. Unfortunately, intrinsic or acquired resistance eventually renders TMZ ineffective. The novel anti-cancer agent OKN-007 plus TMZ increased survival in glioma-bearing mice compared to TMZ alone. Furthermore, OKN-007 increased TMZ sensitivity in both TMZ-sensitive and TMZ-resistant cell lines. Therefore, we initiated a clinical trial (NCT03587038) of OKN-007 in combination with TMZ and radiation therapy (RT). Here we report the safety and tolerability findings of this trial in-progress. METHODS Adults with newly-diagnosed and resected GBM are eligible. OKN-007 is administered by IV at 60 mg/kg. There are three treatment phases: Concomitant, Pre-Maintenance, and Maintenance. In the Concomitant Phase, patients receive OKN-007 three times per week (Cohort 1) or five times per week (Cohort 2); all patients receive TMZ at 75 mg/m2 daily and RT at 60 Gy over 30 fractions. In the 28-day Pre-Maintenance Phase, all patients receive OKN-007 thrice weekly. In the Maintenance Phase (MP), comprising up to eighteen 28-day cycles, TMZ is dosed at 150–200 mg/m2 on days 1–5 of each cycle for six cycles. OKN-007 is administered thrice weekly for six cycles, then twice weekly for three cycles, then once weekly for nine cycles. An expansion cohort of up to 25 patients will use the highest tolerated dosing protocol. RESULTS To date, five patients have been enrolled. Three patients in Cohort 1 and one in Cohort 2 advanced to the MP, and no dose-limiting toxicities (DLTs) occurred. One patient in Cohort 2 was removed due to a DLT (grade 3 neutropenic fever). CONCLUSIONS The treatment plan in Cohort 1 appears safe and well-tolerated. Recruitment for Cohort 2 is ongoing and will be expanded to further evaluate safety. Once the outcome of Cohort 2 is known, the regimen for the expansion cohort will be determined.