Role of ABL Gene Mutations in Chronic Myeloid Leukemia Patients Resistant to Imatinib and Results of Treatment Shift to Second-Generation Tyrosine Kinase Inhibitors

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4442-4442
Author(s):  
Silvia Marce ◽  
Lurdes Zamora ◽  
Marta Cabezon ◽  
Blanca Xicoy ◽  
Concha Boqué ◽  
...  

Abstract Abstract 4442 Introduction: Chronic myeloid leukemia (CML) is a model of disease in the development of targeted therapies. Tyrosine kinase inhibitors (TKIs) have transformed the approach to management of CML and have dramatically improved patients' outcome. Clinical response is obtained in the majority of patients. However, a significant proportion of patients do not achieve the optimal desirable outcome or are completely resistant to this treatment. ABL kinase domain mutations have been extensively implicated in the pathogenesis of TKI resistance. Treatment with second-generation TKIs has produced high rates of hematologic and cytogenetic response in mutated ABL patients. The aim of this study was analyzed the presence of ABL mutations in imatinib resistant patients and determine the importance of changing to second-generation TKIs treatment as soon as failure or suboptimal response is recognized. Patients and methods: From 420 CML patients diagnosed in 6 centers between 2004 and 2010, we have amplified and sequenced the ABL1 domain from BCR-ABL1 amplicon of 45 imatinib resistant patients (23 patients with suboptimal response, 14 with treatment failure, 4 who lost the molecular response and 4 patients who progressed to blast phase). The obtained sequences were compared with the published ABL1 sequence, GenBank U07563, using BLAST 2 software. Results: We have detected mutations in 15 of 45 patients (33%), some of them with more than one mutation (Table 1). Seven of these patients were treated with second-generation TKIs as a single treatment. Three of them achieve a major molecular response (MMR), one patient is in complete cytogenetic response (CCyR) and the other two patients are in major (MCyR) and partial (PCyR) cytogenetic response. Another patient received nilotinib followed by hematological stem cell transplantation (HSCT) and is in MMR. Two patients were submitted to a HSCT and achieve MMR. Only one patient treated with nilotinib as second option has not reach a cytogenetic response one year after detection of the mutation. Two of the patients with the T315I mutation were treated with IFN and nilotinib achieving PCyR and MCyR, respectively, and are still alive. The other T315I patient, and two patients in blast-crisis (BC) disease with the F317L mutation who received dasatinib prior to the study of ABL mutations, died before a change of treatment could have been performed. Conclusions: Disclosures: No relevant conflicts of interest to declare.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4282-4282
Author(s):  
Fabio P S Santos ◽  
Jorge Cortes ◽  
Charles Koller ◽  
Elias Jabbour

Abstract Abstract 4282 Mutations of BCR-ABL1 have been observed in 50% of patients with chronic myeloid leukemia (CML) who develop resistance to imatinib. The gate-keeper mutation T315I is one of the mutations with universal resistance to imatinib and to the second-generation tyrosine kinase inhibitors (TKI) that are approved for the treatment of patients with imatinib failure. The use of new kinase inhibitors with in vitro activity against T315I mutation as well as other agents with different mechanisms of actions is being evaluated in clinical trials. We report the case of a 57-year old man that was diagnosed with CML in 2003. Patient received initial therapy with standard-dose imatinib that was subsequently increased to 800 mg daily. He did achieve a complete cytogenetic response (CCyR) 9 months post dose escalation. He was followed by RT-PCR for BCR-ABL1.. In May, 2007, the patient BCR-ABL1/ABL1 ratio increased to 16.38 but the patient remained in CCyR. BCR-ABL1 sequencing revealed the T315I mutation in 100% of cells (Figure 1). One month later the patient lost CCyR (5% Philadelphia-positive [Ph+] cells) and the BCR-ABL1/ABL1 ratio was 5.08. The patient was started on the T315I specific inhibitor KW-2449 (100 mg orally twice daily for 14 days, every 3 weeks). Patient had a progressive decline in percentage of cells with the T315I mutation (Figure 1). However, at the same time he had an increase in percentage of Ph+ cells. In September, 2007, three months after starting therapy with KW-2449, patient had no cytogenetic response (80% Ph+ cells, PCR for BCR-ABL1 ratio > 100) and the T315I mutation was undetectable. At that time, a new ABL1 sequencing revealed the F359I mutation (no quantification was done). Patient was maintained on KW-2449 for the next 6 months, without significant improvement in cytogenetic response nor BCR-ABL1 ratio, but the clone with the T315I mutation did not reappear. In February, 2008, the patient lost hematologic response and presented with an elevated white blood cell count of 22×109/L. The F359I mutation was still present. Therapy with KW-2449 was stopped and the patient started dasatinib 100 mg/day and Interferon-a 3,000,000 units. Three months later, the patient acheived CCyR with a BCR-ABL1/ABL1 ratio of 0.05. At the last evaluation, 16 months after the start of dasatinib and interferon combination, the patient was maintaining CCyR and major molecular response. In conclusion, this case illustrates the benefit of the use of combination therapy, mainly TKI and agent with different mechanism of action either sequentially (TKI followed by KW-2449) or concomitantly (TKI + interferon) in eradicating resistant disease with T315I clone. Figure 1 Serial Monitoring of Ph+ Cells, T315I Cells and BCR-ABL1/ABL1 Ratio Figure 1. Serial Monitoring of Ph+ Cells, T315I Cells and BCR-ABL1/ABL1 Ratio Disclosures: Cortes: Novartis: Research Funding. Jabbour:Novartis: Speakers Bureau; Bristol Myers Squibb : Speakers Bureau.


Blood ◽  
2009 ◽  
Vol 113 (21) ◽  
pp. 5058-5063 ◽  
Author(s):  
Carmen Fava ◽  
Hagop M. Kantarjian ◽  
Elias Jabbour ◽  
Susan O'Brien ◽  
Nitin Jain ◽  
...  

Abstract Second-generation tyrosine kinase inhibitors are effective in Philadelphia chromosome–positive (Ph+) acute lymphoblastic leukemia (ALL) and chronic myeloid leukemia (CML). Occasionally, patients with Ph+ ALL, or accelerated phase (AP) or blast phase (BP) CML achieve a major cytogenetic response (MCyR) but not a complete hematologic response (CHR). We analyzed 126 patients with CML in AP or BP, or with Ph+ ALL treated with dasatinib or nilotinib after imatinib failure. Twenty patients received sequential treatment with both dasatinib and nilotinib for a total of 146 instances. CHR and MCyR rates were 54% and 37%, respectively in AP, 17% and 39% in BP, and 33% and 50% in Ph+ ALL. Failure to achieve a CHR at the time of achievement of a MCyR was associated with an inferior outcome, similar to that of patients without a MCyR (2-year survival rate, 37% and 35%, respectively). In contrast, patients with MCyR and concomitant CHR had a 77% 2-year survival rate. Twelve of 29 patients with MCyR without concomitant CHR later achieved a CHR; the 2-year survival rate for these patients was 55% compared with 22% for those who never achieved a CHR. These results suggest that achievement of a MCyR without concomitant CHR is associated with poor outcome.


Blood ◽  
2011 ◽  
Vol 118 (17) ◽  
pp. 4541-4546 ◽  
Author(s):  
Elias Jabbour ◽  
Hagop Kantarjian ◽  
Susan O'Brien ◽  
Jenny Shan ◽  
Alfonso Quintas-Cardama ◽  
...  

Abstract We analyzed the association between achievement of early complete cytogenetic response (CCyR) and event-free survival (EFS) and overall survival (OS) in patients with newly diagnosed chronic myeloid leukemia in chronic phase treated with imatinib 400 mg (n = 73), or imatinib 800 mg daily (n = 208), or second- generation tyrosine kinase inhibitors (n = 154). The overall CCyR rates were 87%, 91%, and 96%, respectively (P = .06); and major molecular response (MMR) rates were 77%, 87%, and 89%, respectively (P = .05). Their 3-year EFS rates were 85%, 92%, and 97% (P = .01), and OS rates were 93%, 97%, and 100% (P = .18), respectively. By landmark analysis, patients with 3-, 6-, and 12-month CCyR had significantly better outcome: 3-year EFS rates of 98%, 97%, and 98% and OS rates of 99%, 99%, and 99%, respectively, compared with 83%, 72%, and 67% and 95%, 90%, and 94%, in patients who did not achieve a CCyR. Among patients achieving CCyR at 12 months, the depth of molecular response was not associated with differences in OS or EFS. In conclusion, second tyrosine kinase inhibitors induced higher rates of CCyR and MMR than imatinib. The achievement of early CCyR remains a major determinant of chronic myeloid leukemia outcome regardless of whether MMR is achieved or not.


Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1643
Author(s):  
Prahathishree Mohanavelu ◽  
Mira Mutnick ◽  
Nidhi Mehra ◽  
Brandon White ◽  
Sparsh Kudrimoti ◽  
...  

Tyrosine kinase inhibitors (TKIs) are the frontline therapy for BCR-ABL (Ph+) chronic myeloid leukemia (CML). A systematic meta-analysis of 43 peer-reviewed studies with 10,769 CML patients compared the incidence of gastrointestinal adverse events (GI AEs) in a large heterogeneous CML population as a function of TKI type. Incidence and severity of nausea, vomiting, and diarrhea were assessed for imatinib, dasatinib, bosutinib, and nilotinib. Examination of combined TKI average GI AE incidence found diarrhea most prevalent (22.5%), followed by nausea (20.6%), and vomiting (12.9%). Other TKI GI AEs included constipation (9.2%), abdominal pain (7.6%), gastrointestinal hemorrhage (3.5%), and pancreatitis (2.2%). Mean GI AE incidence was significantly different between TKIs (p < 0.001): bosutinib (52.9%), imatinib (24.2%), dasatinib (20.4%), and nilotinib (9.1%). Diarrhea was the most prevalent GI AE with bosutinib (79.2%) and dasatinib (28.1%), whereas nausea was most prevalent with imatinib (33.0%) and nilotinib (13.2%). Incidence of grade 3 or 4 severe GI AEs was ≤3% except severe diarrhea with bosutinib (9.5%). Unsupervised clustering revealed treatment efficacy measured by the complete cytogenetic response, major molecular response, and overall survival is driven most by disease severity, not TKI type. For patients with chronic phase CML without resistance, optimal TKI selection should consider TKI AE profile, comorbidities, and lifestyle.


2017 ◽  
Vol 59 (3) ◽  
pp. 766-769 ◽  
Author(s):  
Emilie Cayssials ◽  
Florence Tartarin ◽  
Joëlle Guilhot ◽  
Nathalie Sorel ◽  
Jean Claude Chomel ◽  
...  

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