Chronic myeloid leukemia in blast crisis treated with imatinib 600 mg: outcome of the patients alive after a 6-year follow-up.
BACKGROUND
Imatinib mesylate is the first line treatment for chronic myeloid leukemia. In patients with advanced phase of the disease, the advent of imatinib significantly increased survival. However, few long-term data, based on large, prospective and controlled trials are available on the outcome of these patients.


METHODS
We conducted a phase II trial of imatinib 600 mg daily in patients with chronic myeloid leukemia in blast crisis. The return to chronic phase was defined as <15% blasts and <30% blasts plus promyelocytes in blood or bone marrow and <20% peripheral basophils. A complete hematologic response required the normalization of platelet and white cell differential counts and absence of extramedullary involvement. Cytogenetic response was assessed by the standard banding technique and rated as usual.


RESULTS
Ninety-two patients were enrolled (20 with lymphoid blast crisis and 72 with myeloid blast crisis). Forty-six patients (50%) returned to chronic phase, and 24 patients (26%) achieved also a complete hematologic response. Sixteen patients (17%) had a cytogenetic response (9 complete, 1 partial, and 6 minor or minimal). The complete cytogenetic response was subsequently lost by all but two patients between 2 and 12 months after first having achieved it: the median duration of complete cytogenetic response was 7 months. All responses were sustained for a minimum of 4 weeks. The median survival of all the patients was 7 months. After a median observation time of 66 months, seven (8%) patients are alive. Three of these patients are on imatinib treatment (1 in complete hematologic remission, 1 in partial cytogenetic response and 1 in complete cytogenetic remission). Three patients are in complete remission after allogeneic stem cell transplantation. One patient is alive in blast crisis, on therapy with a second-generation tyrosine kinase inhibitor.


CONCLUSIONS
Imatinib was effective and safe in the short-term treatment of chronic myeloid leukemia in blast crisis, but longer-term outcome was not significantly influenced (ClinicalTrials.gov identifier: NCT00514969).
Institute of Hematology and Medical Oncology L. and A. Seràgnoli, S. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
Francesca
F
Palandri
Fausto
F
Castagnetti
Nicoletta
N
Testoni
Simona
S
Luatti
Giulia
G
Marzocchi
Simona
S
Bassi
Massimo
M
Breccia
Giuliana
G
Alimena
Ester
E
Pungolino
Giovanna
G
Rege-Cambrin
Riccardo
R
Varaldo
Maurizio
M
Miglino
Giorgina
G
Specchia
Eliana
E
Zuffa
Felicetto
F
Ferrara
Monica
M
Bocchia
Giuseppe
G
Saglio
Fabrizio
F
Pane
Daniele
D
Alberti
Giovanni
G
Martinelli
Michele
M
Baccarani
Gianantonio
G
Rosti
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001549:Benzamides; D001752:Blast Crisis; D005260:Female; D005500:Follow-Up Studies; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D000068877:Imatinib Mesylate; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy* / Q000401:mortality / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000008:administration & dosage*; D011743:Pyrimidines / Q000008:administration & dosage*; D015996:Survival Rate; D013997:Time Factors; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D055815:Young Adult
D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate