Phase I study of vandetanib, imatinib mesylate, and hydroxyurea for recurrent malignant glioma.

e13007 Background: Malignant glioma (MG), an incurable primary CNS tumor, is characterized by frequent aberrant activation of EGFR, VEGFR, and PDGFR. This study will determine the MTD and DLT of vandetanib (V), a once-daily, oral selective inhibitor of VEGFR and EGFR when combined with imatinib mesylate (IM), an inhibitor of multiple tyrosine kinases including PDGFR and hydroxyurea (H). METHODS: Adult recurrent MG patients with ≤ 3 prior recurrences, KPS ≥ 60% and adequate organ function were stratified based on concurrent enzyme-inducing anticonvulsant use (EIAC). Both strata were independently escalated using a "3+3" design. H is administered at 500 mg BID while IM is administered at 500 mg BID for patients on EIAC and 400 mg QD for those not on EIAC. V is increased by 100 mg in successive cohorts beginning at 100 mg and 200 mg for patients not on and on EIAC, respectively. Evaluations were after every other 28-day cycle. Pharmacokinetics of V and IM were obtained on days 1 and 28 of cycle 1. RESULTS: Twenty-six patients (grade 4 MG, n = 20; grade 3 MG, n = 6) have enrolled. Only 1 DLT (reversible grade 4 transaminase elevation; dose level 1) occurred among 22 non-EIAC patients and enrollment to this stratum is planned to continue at dose level 4. The MTD of V for patients on EIAC is 200 mg/day due to 2 of 3 patients developing grade 3 thrombocytopenia at the 300 mg/day dose level. Evidence of therapeutic benefit to date includes 1 partial response and 15 patients (58%) with stable disease for at least 4 weeks, including 4 patients for ≥4 months. CONCLUSIONS: Combination of V, IM, and H is well-tolerated in recurrent MG patients. Further accrual is ongoing and an update of outcome, toxicity, and pharmacokinetic analyses will be presented. No significant financial relationships to disclose.

Duke Scholars

Author John P. Kirkpatrick Radiation Oncology

Author Katherine Barnett Peters Neurosurgery, Neuro-Oncology

Author Henry Seth Friedman Neurosurgery, Neuro-Oncology