Imatinib in advanced chordoma: A retrospective case series analysis

Introduction: Imatinib showed activity in 50 chordoma patients treated within a Phase II study. In that study, 70% of patients remained with stable disease (SD), median progression free survival (PFS) was 9 months and median overall survival (OS) was 34 months. We now report on a retrospective series of PDGFB/PDGFRB positive advanced chordoma patients treated with imatinib as a single agent within a compassionate-use programme at Istituto Nazionale Tumori, Milan, Italy (INT) between August 2002 and November 2010, when the programme was closed. Methods: 48 patients were consecutively treated with imatinib 800 mg/d. All patients had inoperable and progressive disease before starting imatinib. Demographics, treatment duration, toxicity and response rate by Response Evaluation Criteria in Solid Tumors (RECIST) were retrospectively recorded. Results: The median duration of therapy was 7 months (1-46.5). No patient is on therapy at present. 46 patients were evaluable for response. No partial responses were detected. Best response was: stable disease 34 (74%), progressive disease 12 (26%). At a median follow-up of 24.5 months (0.5-117), median PFS was 9.9 months (95% confidence interval (CI) 6.7-13). Eight patients (16.5%) remained on therapy >18 months and 10 patients (21%) remained progression-free >18 months. Median OS was 30 months (95% CI 20-40), with 24 (50%) patients dead at the time of the present analysis. Conclusions: We confirm the activity of imatinib in locally advanced and metastatic chordoma, in terms of >70% tumour growth arrest in previously progressive patients. Median duration of response lasted almost 10 months, with >20% of patients progression-free at 18+ months. (C) 2015 Elsevier Ltd. All rights reserved.