AT-53 * PHASE I/II STUDY OF DIANHYDROGALACTITOL IN PATIENTS WITH RECURRENT MALIGNANT GLIOBLASTOMA MULTIFORME (GBM)

Abstract

Median survival for patients with recurrent GBM is <6 months. Front-line systemic therapy is temozolomide but resistance due to O6-methylguanine-DNA-methyltransferase (MGMT) activity is implicated in poor outcomes. Dianhydrogalactitol (VAL-083) is a structurally unique bi-functional DNA alkylating agent that accumulates in brain tumor tissue. In in vitro studies, VAL-083 demonstrated activity in pediatric and adult GBM cell lines, as well as GBM cancer stem cells. Notably, VAL-083 overcomes resistance to MGMT in vitro. Previous clinical studies suggest that VAL-083 has anti-tumor activity against a range of tumors, including GBM. In light of extensive safety data from clinical trials and promising efficacy in CNS tumors, we initiated a new clinical study to establish the maximum tolerated dose (MTD) and identify a dose and dosing regimen for future efficacy trials in GBM. Early in the development of VAL-083, a cumulative IV dose of 125 mg/m2 delivered in a 35 day cycle in combination with radiation was shown superior to radiation alone in brain cancer (Eagan, et al. 1979). In the present study, the cumulative dose in a 33 day cycle ranges from 9 mg/m2 (cohort 1) to 240 mg/m2 (cohort 7). Six dose cohorts have completed the trial with no drug-related serious adverse events: MTD was not yet reached. Enrollment for cohort 7 (33 day cumulative dose: 240 mg/m2) has been initiated and higher doses may be explored; the results will determine the design of the safety and efficacy registration trial. METHODS: Open-label, single-arm Phase I/II dose-escalation study in patients with histologically-confirmed initial diagnosis of malignant GBM. The study utilizes a 3 + 3 dose-escalation design. Patients receive VAL-083 IV on days 1, 2, and 3 of a 21 day cycle. GBM patients previously been treated with surgery and/or radiation, if appropriate, must have failed both bevacizumab and temozolomide, unless contraindicated. ClinicalTrials.gov Identifier {type:clinical-trial,attrs:{text:NCT01478178,term_id:NCT01478178}}NCT01478178.