Rajen Mody1, Lili Zhao2, Gregory Anthony Yanik1, Valerie Opipari1,3. 1. Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan. 2. Department of Biostatistics, University of Michigan, Ann Arbor, Michigan. 3. A. Alfred Taubman Research Institute, University of Michigan, Ann Arbor, Michigan.
Abstract
PURPOSE: Prognosis for relapsed/refractory high-risk neuroblastoma (HR-NBL) remains poor. Bortezomib, a proteasome inhibitor, has shown preclinical activity against NBL as a single agent and in combination with cytotoxic chemotherapy including irinotecan. PATIENTS AND METHODS: Eighteen HR-NBL patients with primary refractory (n = 8) or relapsed (n = 10) disease were enrolled in a Phase I study using modified Time To Event Continual Reassessment Method. Bortezomib (1.2 mg/m2 /day) was administered on days 1, 4, 8, and 11 intravenously (IV) and irinotecan was given IV on days 1-5 (35, 40, or 45 mg/m2 /day, on dose levels [DL] 1-3, respectively). The maximum tolerated dose (MTD), dose-limiting toxicity (DLT), and response rate were examined. RESULTS: Eighteen NBL patients were evaluable for toxicity; 17 were evaluable for response assessment. A total of 142 courses were delivered (mean 8.2, median 2, range 1-48), with two patients receiving more than 40 courses of therapy. Two DLTs were reported, including a grade 4 thrombocytopenia (DL2) and a grade 3 irritability (DL3). MTD was estimated as DL3. Two of 17 (12%) evaluable patients showed objective responses (ORs) lasting more than 40 courses, including 1 partial remission and 1 complete remission. Four patients (23%) had prolonged stable disease (SD) lasting six or more courses, with a total of 35% study patients demonstrating clinical benefit in the form of prolonged OR or SD. CONCLUSION: The combination of bortezomib and irinotecan was well tolerated by patients with relapsed/refractory NBL with favorable toxicity profile. It also showed modest but promising clinical activity and merits further testing in Phase II studies.
PURPOSE: Prognosis for relapsed/refractory high-risk neuroblastoma (HR-NBL) remains poor. Bortezomib, a proteasome inhibitor, has shown preclinical activity against NBL as a single agent and in combination with cytotoxic chemotherapy including irinotecan. PATIENTS AND METHODS: Eighteen HR-NBLpatients with primary refractory (n = 8) or relapsed (n = 10) disease were enrolled in a Phase I study using modified Time To Event Continual Reassessment Method. Bortezomib (1.2 mg/m2 /day) was administered on days 1, 4, 8, and 11 intravenously (IV) and irinotecan was given IV on days 1-5 (35, 40, or 45 mg/m2 /day, on dose levels [DL] 1-3, respectively). The maximum tolerated dose (MTD), dose-limiting toxicity (DLT), and response rate were examined. RESULTS: Eighteen NBL patients were evaluable for toxicity; 17 were evaluable for response assessment. A total of 142 courses were delivered (mean 8.2, median 2, range 1-48), with two patients receiving more than 40 courses of therapy. Two DLTs were reported, including a grade 4 thrombocytopenia (DL2) and a grade 3 irritability (DL3). MTD was estimated as DL3. Two of 17 (12%) evaluable patients showed objective responses (ORs) lasting more than 40 courses, including 1 partial remission and 1 complete remission. Four patients (23%) had prolonged stable disease (SD) lasting six or more courses, with a total of 35% study patients demonstrating clinical benefit in the form of prolonged OR or SD. CONCLUSION: The combination of bortezomib and irinotecan was well tolerated by patients with relapsed/refractory NBL with favorable toxicity profile. It also showed modest but promising clinical activity and merits further testing in Phase II studies.