Howard Colman, MD, PhD, FAAN, co-leader of the Neurologic Cancers Disease Center at the Huntsman Cancer Institute and Jon M. Huntsman Presidential Professor of Neuro-Oncology at the U, was the lead investigator on the STELLAR Phase III trial, supported by Orbus Therapeutics. The trial is an important step forward for treatment of patients with Grade 3 astrocytoma. “These tumors have historically been challenging to treat, with limited options for patients with recurrent tumors,” Dr. Colman said.
Under Dr. Colman’s leadership, the trial was conducted at 74 hospitals and clinics in 8 countries across North America and Europe and included 343 patients with recurrent isocitrate dehydrogenase (IDH)-mutant Grade 3 astrocytoma, IDH-mutant Grade 4 astrocytoma, or glioblastoma, based on changing disease definitions over the course of the study period. Dr. Colman and the other investigators evaluated the safety and efficacy of treating these patients with a combination of eflornithine—a compound that targets ornithine decarboxylase to inhibit tumor cell growth—and lomustine for standard oral chemotherapy.
During the trial, patients received either eflornithine every 8 hours and lomustine every six weeks or lomustine alone on the same schedule. There was no significant difference in the outcomes—either positive or negative—of those with glioblastoma or Grade 4 IDH mutant astrocytoma who received eflornithine and those who did not. However, patients with IDH mutant Grade 3 astrocytoma who received the combined treatment had significantly longer overall survival rates (34.9 months) than those who received lomustine alone (23.5 months).
Patients with IDH mutant Grade 3 astrocytoma who underwent the combination therapy not only had better overall survival rates, but their progression-free survival times (no recurrence for 15.8 months) were more than double those of patients who were taking lomustine alone (7.2 months). The improvements in progression-free and overall survival in the lower-grade tumors suggest that eflornithine is most effective in these tumors that are slow growing.
“It has been incredibly rewarding to collaborate on this important trial. We hope that the findings from this trial are a key step towards making eflornithine available as a new treatment option for our patients,” Dr. Colman said.