CLINICAL NEWS
SAEs deemed related to imatinib occurred in 9.3 percent ( n = 51 / 551 ) of patients , the most frequent of which was abdominal pain ( 0.7 %; n = 4 ). Cardiac SAEs of any cause were reported in 39 patients ( 7.1 %) and SAEs of a second neoplasm were reported in 62 patients ( 11.3 %). “ No new safety signals were observed since the 5-year analysis ,” the authors noted .
At 10 years , 47 percent of patients ( n = 260 ) were alive and still receiving treatment , while 17.4 percent were alive and not receiving treatment . “ Approximately half of the patients in the imatinib group discontinued the trial early , which suggests that the high rate of OS in the imatinib group must be attributed to the use of commercially available imatinib or effective secondline therapies in these patients ,” the authors wrote . At the end of the trial , 89 patients ( 16.1 %) in the imatinib group died ; 37 of those deaths were related to CML in patients who had not undergone hematopoietic cell transplantation ( HCT ). In the interferon alfa plus cytarabine group , 105 patients ( 19 %) died ; 48 of those deaths were related to CML in those who had not undergone HCT .
Progression to accelerated phase or blast crisis during the study was less frequent in imatinib-treated patients ( 6.9 % vs . 12.8 %), and the estimated freedom from progression at 10 years was 92.1 percent for the imatinib group ( p values not reported ). Rates of event-free survival at 10 years were also higher in the imatinib group ( 79.6 % [ 95 % CI 75.9-83.2 ] vs . 56.6 % [ 95 % CI 51.5-61.6 ]).
Survival rates were especially high in those who had a major molecular response at 12 or 18 months and those with low Sokal scores ( based on age , spleen size , peripheral blood platelet count , and blast count ). Patients with high Sokal scores had an estimated 10-year OS rate of 68.6 percent , compared with 80.3 percent for intermediate scores and 89.9 percent for low scores .
The study results are limited by the large number of patients with unknown survival status ( approximately 20 % in the imatinib group ) or no molecular or cytogenetic assessments ( approximately 50 % in the imatinib group ). Long-term safety information was limited . The trial also was not able to compare the safety and efficacy of imatinib with newer-generation tyrosine kinase inhibitors ( TKIs ) that became available during the follow-up period .
“ Nonetheless , these results highlight the safety and efficacy of imatinib therapy , with a clear
improvement over the outcomes that were expected in patients who received a diagnosis of CML before the introduction of TKI therapy , when interferon alfa and HCT were the standard therapies ,” Dr . Hochhaus and co-authors wrote .
REFERENCE
Hochhaus A , Larson RA , Guilhot F , et al . Long-term outcomes of imatinib treatment for chronic myeloid leukemia . N Engl J Med . 2017 ; 376:917-27 .
“ [ Imatinib showed ] a clear improvement over the outcomes that were expected in patients who received a diagnosis of CML before the introduction of TKI therapy .”
— ANDREAS HOCHHAUS , MD
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