Current event-free survival after sequential tyrosine kinase inhibitor therapy for chronic myeloid leukemia.
BACKGROUND
Imatinib is an effective tyrosine kinase inhibitor (TKI) for patients with chronic myeloid leukemia (CML) in chronic phase (CP). Although some patients may fail on therapy with imatinib, effective salvage therapy is available with second-generation TKIs. Current measurement of efficacy for each therapy is judged by its individual impact on overall survival and event-free survival (EFS).


METHODS
In total, 586 patients with CML in CP who received imatinib were included in this analysis in 2 cohorts: imatinib as front-line therapy (n = 281) or after failure on interferon-α (IFN-α) (n = 305). By accounting for successful salvage treatment (ie, regain of complete cytogenetic response), the current EFS (CEFS) rate was calculated to obtain a more accurate impression of the outcome of patients with CML who received treatment with sequential TKIs.


RESULTS
For patients who received imatinib after failing on IFN-α, the 7-year EFS rate was 61%, whereas the CEFS rate was 69%. The 7-year EFS rate for patients who received imatinib as initial therapy was 81% compared with a 7-year CEFS rate of 88%.


CONCLUSIONS
CEFS provided a more accurate representation of the outcome of patients with CML in CP. These patients may frequently be treated successfully with subsequent TKIs after experiencing failure on the first TKI.
Al-Kali
Aref
A
Department of Leukemia, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Kantarjian
Hagop
H
Shan
Jianqin
J
Bassett
Roland
R
Quintás-Cardama
Alfonso
A
Borthakur
Gautam
G
Jabbour
Elias
E
Verstovsek
Srdan
S
O'Brien
Susan
S
Cortes
Jorge
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001549:Benzamides; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D000068877:Imatinib Mesylate; D016898:Interferon-alpha / Q000627:therapeutic use; D015466:Leukemia, Myeloid, Chronic-Phase / Q000188:drug therapy* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000627:therapeutic use*; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011743:Pyrimidines / Q000627:therapeutic use*; D019233:Retreatment; D016879:Salvage Therapy
D001549:Benzamides; D016898:Interferon-alpha; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D000068877:Imatinib Mesylate