Treatment of children with newly diagnosed brain stem gliomas with intravenous recombinant β-interferon and hyperfractionated radiation therapy: A childrens cancer group phase I/II study

BACKGROUND. Prognosis for the majority of children with brain stem gliomas is dismal. In previous studies, recombinant beta-interferon (rβIF) has been shown to be effective for children with recurrent brain stem gliomas and may also act synergistically with radiotherapy (RT). METHODS. Thirty two children with diffuse intrinsic brain stem gliomas were treated with (rβIF) and 7200 centigray (cGy) of hyperfractionated RT (100 cGy twice-daily fractions) to determine the toxicity of treatment and the tolerance of the brain stem to this regimen, as well as to assess survival. Patients were treated with rβIF 3 times per week during RT and then for 8 weeks following RT. Initially, a dose escalation trial was performed. RESULTS. Interferon was initially begun at 12.5 x 10⁶ IU/m² and escalated up to 400 x 10⁶ IU/m². The safe starting dose was determined to be 100 x 10⁶ IU/m². Due to unacceptable toxicity, the maintenance dose was reduced to 200 x 10⁶ IU/ m². Therapy was relatively well tolerated, although 13 of the patients required dose modifications due to hepatic or hematologic toxicity. Four of the patients had to discontinue treatment due to this toxicity. One patient died while receiving maintenance IF of encephalopathy, seizures, and brain stein dysfunction; believed possibly due to the rβIF. Thirty of the 32 patients bare developed progressive disease. The median time to progression from study entry was five months and the median time to death was 9 months. CONCLUSIONS. We conclude that rβ1F plus hyperfractionated therapy can be tolerated by children with newly diagnosed brain stem gliomas, although there is occasional dose-limiting hepatic, blood, and central nervous system toxicity. This therapy did not result in a higher rate of disease control.