A phase II trial of oral gimatecan for recurrent glioblastoma

Jethro Hu, Patrick Y. Wen, Lauren E. Abrey, Camilo E. Fadul, Jan Drappatz, Nadia Salem, Jeffrey G. Supko, Fred Hochberg

Gimatecan is a lipophilic oral camptothecin analogue with preclinical activity in glioma models. We conducted a multicenter phase II trial to evaluate the efficacy of gimatecan in adults with recurrent glioblastoma. Eligibility criteria included ≤1 prior treatment for recurrent disease, age ≥18, Eastern Cooperative Oncology Group performance status 0-1, and normal organ function. Patients taking enzyme-inducing anti-seizure medications were excluded. Gimatecan 1.22 mg/m(2) was given orally once daily for 5 consecutive days during each 28-day cycle. The primary endpoint was progression-free survival at 6 months. A Simon 2-stage optimal design was used in which 19 patients were evaluated in the 1st stage, with an additional 36 patients accrued if >4 patients in stage 1 achieved PFS at 6 months. 29 patients were enrolled in the study, with median age of 58 years (range, 25-77 years); 58.6 % female. All patients received prior surgery, radiation therapy, and at least one chemotherapy regimen. The daily dose was reduced to 1.0 mg/m(2) after four of the first 10 patients experienced grade 4 hematologic toxicity. Treatment-related grade 3/4 toxicities included thrombocytopenia (17.2 %), leukopenia (17.2 %) and neutropenia (10.3 %). None of the 19 patients treated at 1.0 mg/m(2)/day experienced grade 4 hematologic toxicity. One patient had a partial radiographic response by modified Macdonald criteria. Only 3 patients (12 %) were progression-free at 6 months. Median time to progression was 12.0 weeks (7.0, 17.0).Treatment with gimatecan 1.0 mg/m(2)/day for 5 days, repeated every 28-days showed minimal efficacy.