Long-term outcome of patients with chronic myeloid leukemia treated with second-generation tyrosine kinase inhibitors after imatinib failure is predicted by the in vitro sensitivity of BCR-ABL kinase domain mutations.
Secondary imatinib resistance in chronic myeloid leukemia (CML) is associated in approximately 50% of cases with mutations in the BCR-ABL kinase domain, necessitating switch to one of several new tyrosine kinase inhibitors (TKIs) that act differentially on mutated BCR-ABL. We assess here whether scoring mutation based on in vitro inhibitory concentration of each TKI-mutation pair can predict long-term clinical outcome. Among 169 patients with CML after imatinib failure, mutations were detected before TKI switch in 41 (48%) treated with dasatinib and 45 (52%) treated with nilotinib. Inhibitory concentration values for each TKI-mutation pair were stratified into high (n = 42), intermediate (n = 25), low (T315I, n = 9), or unknown sensitivity (n = 10). Hematologic and cytogenetic response rates were similar for patients with or without mutations. For patients in chronic phase, hematologic and cytogenetic responses correlated with mutation score; tumors with low and intermediate scores had lower response rates than those with highly sensitive mutations, and worse event-free and overall survival. These correlations with overall survival were not seen for advanced phases. Mutation scoring can predict outcome in CML-chronic phase with imatinib failure treated with second-generation TKIs and can help in therapy selection. More complex prognostic models will be required for advanced stages of disease.
Jabbour
Elias
E
Department of Leukemia, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
Jones
Daniel
D
Kantarjian
Hagop M
HM
O'Brien
Susan
S
Tam
Constantine
C
Koller
Charles
C
Burger
Jan A
JA
Borthakur
Gautam
G
Wierda
William G
WG
Cortes
Jorge
J
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001549:Benzamides; D000069439:Dasatinib; D018572:Disease-Free Survival; D019008:Drug Resistance, Neoplasm / Q000187:drug effects / Q000235:genetics*; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000037:antagonists & inhibitors* / Q000235:genetics*; D006779:Hospitals, Public; D006801:Humans; D000068877:Imatinib Mesylate; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy / Q000201:enzymology / Q000235:genetics / Q000401:mortality; D008017:Life Expectancy; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010879:Piperazines / Q000008:administration & dosage*; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage*; D017434:Protein Structure, Tertiary / Q000235:genetics; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics*; D011743:Pyrimidines / Q000008:administration & dosage*; D012189:Retrospective Studies; D013030:Spain; D015996:Survival Rate; D013844:Thiazoles / Q000008:administration & dosage*
D001549:Benzamides; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D013844:Thiazoles; D000068877:Imatinib Mesylate; D011505:Protein-Tyrosine Kinases; D016044:Fusion Proteins, bcr-abl; C498826:nilotinib; D000069439:Dasatinib