Overall survival and progression-free survival. Of the 454 patients, 109 (24%) died during imatinib treatment or during long-term follow-up after discontinuation of imatinib. The estimated 6-year overall survival (considering all deaths) was 76% (95% confidence interval, 71% to 80%). During study treatment, 157 patients (35%) either had values indicative of accelerated phase or blasts crisis or discontinued imatinib due to unsatisfactory therapeutic effect or death. The estimated 6-year PFS rate was 61% (95% confidence interval, 56% to 66%).