9556 Background: Erlotinib hydrochloride (OSI-774), a selective inhibitor of the EGFR tyrosine kinase, may be active in childhood brain tumors, particularly in combination with irradiation. Methods: Multicenter, non-randomized phase I study with separate dose findings for erlotinib as single agent in children with refractory or relapsing brain tumors (group 1), and combined to irradiation in newly diagnosed brain stem glioma (group 2). Erlotinib was administered orally daily at 75, 100, 125 or 150 mg/m2. Dose escalation was performed in a classical 3+3 methodology for group 1 and according to the continuous reassessment method for group 2; dose-limiting toxicity (DLT) was evaluated at 3 and 6 weeks, respectively. Results: In total, 31 patients have been entered to date, 30 received treatment, 17 in group 1 (3 relapsing brain stem glioma, 4 ependymoma, 4 oligodendroglioma, 6 other) and 13 in group 2 with a median age of 9 and 6 years (range 4–16 and 2–12), respectively. Median treatment duration was 1.5 and >5 months, respectively. In group 1, 3 patients each were treated at 75 mg/m2 and 100 mg/m2, 7 at 125 mg/m2, 4 at 150 mg/m2. One patient with a glioneuronal tumor treated at 125 mg/m2 experienced G5 intra-tumoral hemorrhage at day 4 which was considered as DLT; at 150 mg/m2, 1 patient with an oligodendroglioma experienced G3 asthenia at day 18 and G3 intratumoral hemorrhage at day 29, and 1 patient with an ependymoma experienced G5 intra-tumoral hemorrhage at day 49. In group 2, 1/6 patients treated with erlotinib 75 mg/m2 and irradiation experienced seizures and died, no DLT occurred in 6 patients at 100 mg/m2. Non-hematological toxicities included G1-G2 erythema, folliculitis, dry skin, trichomegaly, G1 transaminitis, bilirubinemia, G1–3 asthenia, G1–5 intra-tumoral hemorrhage. Minor tumor response was observed in an oligodendroglioma. Pharmacokinetic and biological evaluations are ongoing. Conclusions: Erlotinib was well tolerated in children with cutaneous symptoms being the most frequent treatment toxicity. However, neurological toxicity and intra-tumoral hemorrhage was notable in these children with brain tumors. Inclusion at 125 mg/m2 is ongoing to confirm the MTD. No significant financial relationships to disclose.
Childhood Brain Stem Glioma