Nilotinib Efficacy According to Baseline BCR-ABL Mutations in Patients with Imatinib-Resistant Chronic Myeloid Leukemia in Chronic Phase (CML-CP)

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3216-3216 ◽  
Author(s):  
Andreas Hochhaus ◽  
Dong-Wook Kim ◽  
Giovanni Martinelli ◽  
Timothy P. Hughes ◽  
Simona Soverini ◽  
...  
Keyword(s):  
Clonal Selection ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Response Rates ◽  
Cytogenetic Response ◽  
Kinase Domain ◽  
Molecular Response ◽  
Abl Kinase ◽  
Imatinib Resistant

Abstract Resistance or intolerance to imatinib in CML-CP occurs in ~20–30% of cases. The most frequent cause of resistance is clonal selection of cells harboring BCR-ABL kinase domain mutations. Nilotinib is a rationally designed, selective and potent BCR-ABL inhibitor with activity against most BCR-ABL mutants (not T315I) indicated for the treatment of Ph+ CML patients (pts) in chronic (CP) or accelerated phase (AP) resistant or intolerant to prior therapy including imatinib. This subanalysis of a phase II study of nilotinib in imatinib-resistant CML-CP pts assessed the occurrence of BCR-ABL mutations at baseline and during nilotinib treatment and their impact on treatment outcome after 12 months of nilotinib therapy. Of 321 CML-CP pts, 281 (88%) had baseline mutation data available, 114/281 (41%) had detectable BCR-ABL mutations prior to nilotinib therapy. The frequency of mutations at baseline was 55% among imatinib-resistant pts (n=192) and 10% among imatinib-intolerant pts (n=89). 23% of imatinib-resistant pts had mutations that were sensitive to nilotinib in vitro (IC50 ≤150 nM). These 12 different mutations (n=44) spread across the entire BCR-ABL kinase domain including P-loop, A-loop, and other regions. 14% of imatinib-resistant pts had 3 mutations that were less sensitive to nilotinib in vitro (IC50 >150 nM; Y253H, E255K/V, and F359C/V) and another 15% had a total of 16 mutations with unknown sensitivity to nilotinib. In imatinib-resistant pts lacking baseline mutations, after 12 months of therapy, major cytogenetic response (MCyR) was achieved in 60%, complete cytogenetic response (CCyR) in 40%, and major molecular response (MMR) in 28% of pts. In pts with detectable mutations, 51% achieved MCyR, 32% CCyR, and 20% MMR. Cytogenetic response rates in pts harboring mutations sensitive to nilotinib (MCyR 59%; CCyR 41%) or mutations with unknown sensitivity to nilotinib (MCyR 63%; CCyR 50%;) were comparable to those for pts without baseline mutations (MCyR 60%; CCyR 40%). Pts with mutations less sensitive to nilotinib in vitro had less favorable response after 12 months of therapy (23% MCyR). Pts with baseline mutations had a higher rate of disease progression during nilotinib treatment compared to pts without baseline mutations (46% vs. 26%). Different rates of progression were also observed with different mutations: 34% (15/44) of pts with mutations sensitive to nilotinib vs. 69% (18/26) with mutations less sensitive to nilotinib progressed. Mutations most frequently associated with progression were E255K/V (6/7) and F359C/V (9/11). Progression was defined as any of the following: investigator’s evaluation as progression, development of CML-AP or blast crisis, loss of CHR, loss of MCyR. During nilotinib therapy, 48/281 (17%) pts had newly detectable mutations, which were more frequent in pts with baseline mutations than in pts without baseline mutations (29% vs. 9%, respectively). The majority of pts without baseline mutations also did not have newly detectable mutation at the time of progression (n=14/18) suggesting that pts without baseline mutations are less likely to progress due to newly detectable mutations. In the 63 pts who progressed, 29% had no detectable mutation at progression, suggesting the involvement of alternative mechanisms of resistance in these pts. Overall, nilotinib treatment results in significant cytogenetic responses in pts with imatinib-resistant CML-CP with or without BCR-ABL mutations. The majority of imatinib-resistant pts with detectable BCR-ABL mutations at baseline also responded to nilotinib. Pts with BCR-ABL mutations sensitive and with unknown sensitivity to nilotinib in vitro achieved significant response rates with nilotinib therapy, comparable to those for pts without baseline mutations.

Acquired Mutations in the BCR-ABL Kinase Domain in Imatinib Resistant Patients. Multicentric Experience in Argentina and Uruguay.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4811-4811
Author(s):  
Patricia Gargallo ◽  
Beatriz Moiraghi ◽  
Eduardo Bullorsky ◽  
Rosa Santarelli ◽  
Maria Riva ◽  
...  
Keyword(s):  
Blast Crisis ◽  
Clonal Evolution ◽  
Point Mutations ◽  
Chronic Phase ◽  
Kinase Domain ◽  
Molecular Response ◽  
Multicentric Study ◽  
Abl Kinase ◽  
Imatinib Resistant ◽  
Kinase Domain Mutations

Abstract Imatinib induces complete cytogenetic response (CCyR) in 82% of patients with CML in chronic phase. There is a subset of patients who either failed to achieve or lose hematological/CCyR. Kinase domain mutations have emerged as a potential cause for treatment failure. Aims: In the current study we have investigated ABL kinase domain mutations, amplifications and quantification of BCR-ABL transcripts by Q-PCR in Imatinib resistant patients. Patients and Methods: A total of 84 patients (pts) with CML treated with Imatinib were studied and 82 were evaluable. Sixty-one (74%) were in chronic phase (CP), eleven (14%) were in accelerated phase (AP), and ten (12%) were in blast crisis (BC).We analyzed the DNA from blood samples. Mutations were screened by conformation sensitive gel electrophoresis (CSGE). The amplification products displaying an abnormal pattern were sequenced using automatic system. The amplification of BCR-ABL rearrangement was studied in interphase nuclei using Vysis extra-signaling probe. Real time quantitative PCR (RQ-PCR) of BCR-ABL transcripts was performed in a subset of 44 patients to assess molecular response, using Light Cycler (Roche®), Syber Green Method. Results: Eleven mutations from 82 evaluable patients were detected (13%). Seven were in p- loop: M244R (1), L247A (1), G250E (2), Q252H (1), E255K (2), and four in the Imatinib binding: T315I (3), H318L (1). Two patients had BCR-ABL amplifications with 4–6 signals in interphase nucleous and one of them showed extramedullary involvement in skin nodules. Five patients had clonal evolution with double Ph chromosome. Most of mutations were found in patients in late chronic phase (6/11: 54%). The detection occurred at a median of 49 months (range 12–154) after diagnosis. Eighty four percent of cases studied with RQ-PCR, had null molecular response (<1Log Reduction). Imatinib dose in patients with mutations had been escalated to 600–800 mg/day previously. Conclusion: This is the first multicentric study in spanish-speaking South America. T315I was the most frequent mutation detected in our study and was associated with poor outcome. We found 13% of resistant cases with point mutations, all of them located in the p-loop or imatinib binding.This is an ongoing study and further recruitment is needed to confirm these findings. Early detection of mutations can have prognostic implication and allow therapeutic intervention such as dose escalation, combination therapy or second generation tyrosine kinase inhibitors.

Patients with Chronic Myeloid Leukemia In Chronic Phase Carrying More Than One BCR-ABL Kinase Domain Mutation Exhibit Poorer Response Rates and Outcomes to Second-Line Dasatinib Compared to Those with No or Only One BCR-ABL Mutation

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2297-2297 ◽  
Author(s):  
Alfonso Quintás-Cardama ◽  
Hagop Kantarjian ◽  
Neil P. Shah ◽  
Charles A. Schiffer ◽  
Philipp le Coutre ◽  
...  
Keyword(s):  
Research Funding ◽  
Pcr Amplification ◽  
Chronic Phase ◽  
Response Rates ◽  
Cytogenetic Response ◽  
Kinase Domain ◽  
Recent Analysis ◽  
Imatinib Resistance ◽  
Abl Kinase ◽  
Imatinib Resistant

Abstract Abstract 2297 Background: BCR-ABL kinase domain mutations occur in 30%-90% of patients (pts) who develop resistance to imatinib. A recent analysis reported that 48% of pts with imatinib resistance or suboptimal response had a baseline mutation at the start of dasatinib therapy (Müller 2009). After 2 years of follow-up, dasatinib treatment of imatinib-resistant pts resulted in notable response rates (complete cytogenetic response [CCyR]: 43% vs 47%) and promising progression-free survival (PFS, 70% vs 80%) in pts with or without baseline mutations, respectively. However, some pts present with two or more co-existing mutations in one or more clones. The outcome of these pts after dasatinib therapy has not been described in detail. Methods: This is a retrospective analysis of pts with CML in chronic phase (CML-CP) receiving dasatinib who were imatinib resistant or intolerant and who had >1 BCR-ABL mutation at baseline. Pts with CML-CP from the phase 3 dose optimization trial (-034) and phase 2 START-C (-013) and START-R (-017; dasatinib only population) studies were evaluated. Since the frequency of >1 mutation was expected to be lower than the rates reported for the presence of any mutation, the inclusion of all 3 studies provided a larger population to determine pt responses and outcomes. A 2-year database was used for all 3 studies. Mutations were detected by conventional Sanger sequencing (sensitivity 10%-20%) after nested RT-PCR amplification of the BCR-ABL transcript. BCR-ABL polymorphisms were excluded from analysis. 1150 pts were included in the analysis: -034 (n=662), -013 (n=387), and -017 (n=101). Similar baseline characteristics among those analyzed included: median age (51-55 years), male (47%-53%), median duration of CML (54-64 months [mos]), prior imatinib therapy lasting >3 years (41%-53%) and prior response rates to imatinib (complete hematologic response [82%-92%], major cytogenetic response [MCyR, 28%-42%], and CCyR [15%-21%]). Only the rate of imatinib intolerance differed among the 3 trials: 26% for -034 and -013, whereas imatinib-intolerant pts were not eligible for the -017 study. Results: Of 1150 pts analyzed, baseline mutation data were available for 1043 dasatinib-treated pts (Table); 641 (61%) had no baseline mutation (202 intolerant) and 402 (39%) had a baseline mutation (18 intolerant). Of those with mutations, 70 (17%) had >1 mutation (4 intolerant) and 16 (4%) had >2 mutations. The TKI-resistant T315I mutation occurred in 21/402 (5%) and 5/70 (7%) of those with 1 or >1 mutation, respectively–with G250E also occurring in 2 of those 5 pts. The 24-mo response rates for pts with >1 mutation at baseline were lower than the rates in those who had only 1 mutation, or no mutations at baseline for MCyR (52.2% vs 56.4% vs 65%) and CCyR (36% vs 45% vs 56%). The 24-mo PFS rates on dasatinib for those with >1, 1, and no mutation were 57%, 73%, and 83%, respectively. While pts who achieved CCyR at 12 mos had excellent 2-year PFS, regardless of whether they had no, 1, or >1 mutation, pts who achieved partial cytogenetic response (PCyR) or less than PCyR at 12 mos had lower 2-year PFS if they carried >1 mutation compared to those with no or 1 mutation. The 2-year overall survival (OS) rates were 93.5% for those without a mutation and similar for those with 1 or >1 mutation (89%). Conclusion: Dasatinib shows considerable efficacy in pts with or without baseline BCR-ABL mutations. However, pts with baseline mutations tended to have lower rates of response and PFS compared with those without mutations at baseline. In addition, the presence of >1 mutation compared with the presence of only 1 mutation yielded the lowest rates of response and PFS. Disclosures: Quintás-Cardama: Bristol-Myers Squibb: Consultancy; Novartis: Consultancy. Kantarjian: Bristol-Myers Squibb: Research Funding; Pfizer: Research Funding; Ariad: Research Funding; Novartis: Consultancy, Research Funding. Shah: Bristol-Myers Squibb: Consultancy; Novartis: Consultancy; Ariad: Consultancy. Schiffer: Bristol-Myers Squibb: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy; Cellgenix: Consultancy. le Coutre: Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria. Saglio: Novartis: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria. Guilhot: Bristol-Myers Squibb: Consultancy; Novartis: Consultancy. Hochhaus: Bristol-Myers Squibb: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Bahceci: Bristol-Myers Squibb: Employment. Lambert: Bristol-Myers Squibb: Employment. Cortes: Bristol-Myers Squibb: Research Funding; Novartis: Research Funding; Pfizer: Research Funding.

Correlation of Clinical Response to Nilotinib with BCR-ABL Mutation Status in Advanced Phase Chronic Myelogenous Leukemia (CML-AP) Patients with Imatinib-Resistance or Intolerance.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1940-1940 ◽  
Author(s):  
Giuseppe Saglio ◽  
Dong-Wook Kim ◽  
Andreas Hochhaus ◽  
Simona Soverini ◽  
P. Erben ◽  
...  
Keyword(s):  
Disease Progression ◽  
Cytogenetic Response ◽  
Kinase Domain ◽  
Mutant Clone ◽  
Imatinib Resistance ◽  
Mutation Status ◽  
Abl Kinase ◽  
Imatinib Resistant ◽  
Kinase Domain Mutations

Abstract The 2nd-generation bcr-abl inhibitor nilotinib is more potent than imatinib (IC50 <30 nM) against unmutated bcr-abl and active against 32/33 imatinib-resistant BCR-ABL mutants in vitro. We investigated the in vivo activity of nilotinib stratified by the baseline BCR-ABL mutation status in 127 imatinib-resistant or -intolerant CML-AP patients (pts) enrolled in an open-label phase II trial of nilotinib. Eighty-five pts (85/127, 67%) were screened prior to nilotinib therapy for BCR-ABL kinase domain mutations by direct sequencing. Of the 85 pts, 75 (88%) were resistant to imatinib and 10 (12%) were intolerant using standard published criteria. Twenty-two different baseline mutations involving 19 amino acids were identified in 50 (59%) pts analyzed. Other 35 (41%) pts did not have a baseline mutation. The most frequent mutation types identified included M351T (8 pts), G250E (7 pts), Y253H (6 pts), M244V (5 pts), F359V (5 pts) and T315I (5 pts). Twenty-two percent of pts with baseline mutations (11/50) showed more than one mutation (9 with two, 1 with three, and 1 with four mutations). All baseline mutations occurred in imatinib-resistant pts but none in intolerant pts. After 12 months of therapy, confirmed (confirmed in two consecutive analyses 4 week apart) hematologic response (HR) was achieved in 48% (21/50), major cytogenetic response (MCR) in 20% (10/50), and complete cytogenetic response (CCR) in 16% (8/50) of imatinib-resistant pts with baseline mutation versus 44% (12/25), 40% (10/25), and 20% (2/25) of imatinib-resistant pts without baseline mutation, respectively. Responses appeared to be affected by the in vitro sensitivity of the mutant clone against nilotinib. Pts with less sensitive mutation (cellular IC50 of >200nM: Y253H, E255K, E255V, F359C) representing 13% (11/85) of all patients assessed for baseline mutation, showed 13% (1/11) HR and 13% (1/11) MCyR compared to 74% (17/28) and 18% (5/28) respectively in the mutant group with IC50 of ≤200 nM. The nilotinib resistant T315I mutation occurred in 5 pts. Only one of these 5 pts who had T315I and G250E dual mutation achieved HR conceivably reflecting the sensitivity of G250E or non-mutant clone to nilotinib. At the time of data analyses, 50% of pts with baseline mutation were free of disease progression versus 62% of pts without baseline mutation. Rate of progression was 64% (7/11) in the group with less sensitive mutations and 60% (3/5) in pts. with T315I. However, the mutants most frequently associated with progression were F359V and M244V both having 4/5 pts (80%) progressed. In summary, BCR-ABL kinase domain mutations were identified at baseline in 59% of all pts in this cohort and in 67% of pts with imatinib resistance. Responses were observed across a broad spectrum of mutant genotypes. The rate of responses and disease progression may be affected by the baseline mutation types, although a larger data set with longer follow up is needed to further establish the correlation.

Properties of CD34+ CML Cells That Predict Clinical Response to Tyrosine Kinase Inhibitors.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 324-324
Author(s):  
Xiaoyan Jiang ◽  
Donna Forrest ◽  
Franck Nicolini ◽  
Karen Lambie ◽  
Kyi Min Saw ◽  
...  
Keyword(s):  
Stem Cells ◽  
Tyrosine Kinase ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Kinase Domain ◽  
Abl Kinase ◽  
Cd34 Cells ◽  
Clinical Responses ◽  
Kinase Domain Mutations

Abstract Imatinib (IM) treatment causes remission in a majority of patients with chronic myeloid leukemia (CML) but relapses remain a problem. The frequent presence in relapsing cells of BCR-ABL kinase domain mutations suggests that their prior but undetected acquisition by rare CML stem cells may be a major contributor to IM treatment failures. We have recently demonstrated that enriched populations of CML stem cells (lin−CD34+CD38− cells) are relatively insensitive to IM and possess multiple unique features that would be expected to promote both innate and acquired mechanisms of resistance to BCR-ABL-targeted therapeutics. These include elevated BCR-ABL expression and tyrosine kinase activity, increased expression of ABCB1/MDR1 and ABCG2, decreased expression of OCT1, and a high degree of genetic instability, as demonstrated by a rapid accumulation of BCR-ABL mutations in vitro. To determine whether these parameters may be predictive of clinical responses to IM, immunomagnetically selected CD34+ stem/progenitor cells from 18 chronic phase CML patients’ samples obtained prior to IM therapy were evaluated and the results compared with subsequent clinical responses. Direct sequencing of transcripts cloned from extracts of freshly isolated CD34+ cells (10 clones/sample) detected a high frequency of pre-existing BCR-ABL kinase mutations in the CD34+ cells from 12 of 12 patients regardless of their subsequent IM responses (20–80%). Interestingly, a higher incidence of BCR-ABL kinase domain mutations was found in 5 IM-nonresponders (33–80% of transcripts showed ≥1 BCR-ABL kinase domain mutation) as compared to 5 IM-responders (values of 20-30%, P<0.02). A higher frequency of BCR-ABL kinase domain mutations was also detected in extracts of colonies generated from assays of cells harvested from 3-week suspension cultures initiated with the same starting CD34+ CML cells (21–68% vs 10–43%). A high incidence of BCR-ABL kinase domain mutations was also documented in freshly isolated or cultured CD34+ cells from 2 patients who developed sudden blast crisis (50–63% and 17–83%). Overall, 38 different mutations were identified from freshly isolated CD34+ CML cells and >50 additional mutations were identified in the progeny of CD34+ CML cells cultured ± IM. These included 15 point mutations frequently associated with clinical IM resistance (including G250, Q252, E255, T315, M351, F359 and H396) and >40 mutations not previously described. Furthermore, freshly isolated CD34+ cells from IM-nonresponders (including the 2 patients who developed blast crisis, n=10) showed a greater resistance to IM in vitro (∼2 fold, P< 0.001 with 5 μM and P<0.02 with 10 μM IM) as compared to CD34+ cells from IM-responders (n=8) in the presence of 5 and 10 μM IM, as determined by colony-forming cell (CFC) assays. Although more IM-resistant CFCs were obtained in the presence of IM from 3-week cultures initiated with CD34+ cells from the same IM-nonresponders than from IM responders, these latter differences were not significantly different (P= 0.28). These results suggest that the CD34+ leukemic cells from individual chronic phase CML patients harbor differences in their biologic properties that are predictive of how they will respond to IM therapy and that assessment of these differences may form the basis of rapid, practical and quantitative tests to assist in optimized patient management.

Dasatinib Efficacy in Patients with Chronic Myeloid Leukemia in Chronic Phase (CML-CP) and Pre-Existing BCR-ABL Mutations

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 449-449 ◽  
Author(s):  
Martin C Müller ◽  
Jorge Cortes ◽  
Dong-Wook Kim ◽  
Brian J. Druker ◽  
Philipp Erben ◽  
...  
Keyword(s):  
Amino Acids ◽  
Median Time ◽  
Chronic Phase ◽  
Response Rates ◽  
Cytogenetic Response ◽  
Molecular Response ◽  
Imatinib Treatment ◽  
Imatinib Resistant ◽  
Dasatinib Treatment

Abstract Dasatinib (SPRYCEL®) is an effective BCR-ABL inhibitor that is 325-fold more potent than imatinib and 16-fold more potent than nilotinib in vitro against unmutated BCR-ABL. Across a series of phase II and III trials, dasatinib has demonstrated durable efficacy in patients with CML following resistance, suboptimal response, or intolerance to imatinib. BCR-ABL mutations are an important cause of imatinib failure and suboptimal response. Here, the efficacy of dasatinib in patients with CML-CP who had baseline BCR-ABL mutations following imatinib treatment was analyzed using data from three trials (CA180-013, -017, and -034). Mutational assessment of the BCR-ABL kinase domain was performed using RT-PCR and direct sequencing of peripheral blood cell mRNA. Hematologic, cytogenetic, and molecular response rates were reported after ≥24 mos of follow-up. Duration of response, progression-free survival (PFS), and overall survival (OS; in 013/034) were calculated using Kaplan-Meier analysis, and rates were estimated at the 24-mo time point. Of 1,150 patients with CML-CP who received dasatinib, 1,043 had a baseline mutational assessment and were analyzed further. Of these, 402 patients (39%) had a BCR-ABL mutation, including 8% of 238 imatinib-intolerant and 48% of 805 imatinib-resistant patients. Excluding known polymorphisms, 64 different BCR-ABL mutations were detected affecting 49 amino acids, with G250 (n=61), M351 (n=54), M244 (n=46), F359 (n=42), H396 (n=37), Y253 (n=26), and E255 (n=25) most frequently affected. Dasatinib treatment in patients with or without a baseline BCR-ABL mutation, respectively, resulted in high rates of major cytogenetic response (MCyR; 56% vs 65%), complete cytogenetic response (CCyR; 44% vs 56%), major molecular response (MMR; 33% vs 45%); PFS (70% vs 83%), and OS (89% vs 94%) (Table). After 24 mos, CCyRs in patients with or without a BCR-ABL mutation had been maintained by 84% vs 85%, respectively, of those achieving this response. Among patients with mutations who received dasatinib 100 mg once daily, which has a more favorable clinical safety profile, efficacy and durability were similar (MCyR: 55%; CCyR: 41%; MMR: 36%; PFS: 73%; OS: 90%). In general, high response rates and durable responses were observed in patients with different mutation types, including highly imatinib-resistant mutations in amino acids L248, Y253, E255, F359, and H396. When responses were analyzed according to dasatinib cellular IC50 for individual BCR-ABL mutations, dasatinib efficacy was observed in 44 patients who had any of 5 imatinib-resistant mutations with a dasatinib cellular IC50 >3 nM (Q252H, E255K/V, V299L, and F317L, excluding T315I), including MCyR in 34%, CCyR in 25%, MMR in 18%, PFS in 48%, and OS in 81%. Among patients whose mutations had a dasatinib IC50 ≤3 nM (n=254) or unknown IC50 (n=83), responses and durability were comparable to patients with no BCR-ABL mutation. As expected, few patients with a T315I mutation (IC50 >200 nM; n=21) achieved a response. Among 70 patients with >1 mutation, a MCyR was achieved in 53% and a CCyR in 37%. Among patients with mutational analysis at last follow-up (n=162), 42 (26%) retained a BCR-ABL mutation (20 retained a mutation with IC50 >3 nM), 42 (26%) lost a mutation (5 lost a mutation with IC50 >3 nM), and 44 (27%) developed a new mutation (39 developed a mutation with IC50 >3 nM), with some patients counted in more than one category. Overall, this analysis demonstrates that dasatinib has broad efficacy against all BCR-ABL mutations except for T315l. For patients with BCR-ABL mutations, dasatinib treatment is associated with durable responses and favorable long-term outcomes. Table Analysis by dasatinib IC50 No BCR-ABL mutation BCR-ABL mutation BCR-ABL mutation treated with 100 mg QD >3 nM (excl. T315I) 3 nM* Unknown IC50** Some patients had >1 mutation. *Excluding patients with a concurrent mutation with dasatinib IC50 >3 nM. **Excluding patients with a concurrent mutation with known dasatinib IC50. Patients, n 641 402 49 44 254 83 Response rates (≥24 mos of follow-up), % CHR 93 90 90 82 94 96 MCyR 65 56 55 34 58 73 CCyR 56 44 41 25 47 54 MMR 45 33 36 18 34 43 Median time to MCyR, mos 2.8 2.9 2.8 5.7 2.9 2.8 Median time to CcyR, mos 3.0 5.3 3.0 5.7 5.4 3.4 24-mo PFS (95% CI), % 83 (79.8–86.5) 70 (65.3–75.2) 73 (60.1–86.3) 48 (31.2–64.7) 73 (66.6–78.9) 89 (82.3–96.3) 24-mo OS (95% CI), % 94 (91.4– 95.7) 89 (85.1– 92.1) 90 (81.2– 98.3) 81 (68.8– 93.8) 90 (85.8– 94.2) 96 (91.2–100)

Response and Outcomes to Nilotinib at 24 Months in Imatinib-Resistant Chronic Myeloid Leukemia Patients in Chronic Phase (CML-CP) and Accelerated Phase (CML-AP) with and without BCR-ABL Mutations.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1130-1130 ◽  
Author(s):  
Jerald P. Radich ◽  
Giovanni Martinelli ◽  
Andreas Hochhaus ◽  
Enrico Gottardi ◽  
Simona Soverini ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Median Time ◽  
Research Funding ◽  
Philadelphia Chromosome ◽  
Chronic Phase ◽  
Cytogenetic Response ◽  
Molecular Response ◽  
Advisory Committees ◽  
Imatinib Resistant

Abstract Abstract 1130 Poster Board I-152 Background Nilotinib is a selective and potent BCR-ABL inhibitor, with in vitro activity against most BCR-ABL mutants (excluding T315I) indicated for the treatment of patients with Philadelphia chromosome positive (Ph+) CML in CPor AP resistant or -intolerant to prior therapy, including imatinib. In a previous analysis of nilotinib in patients with BCR-ABL mutations, mutations occurring at three specific amino acid residues (E255K/V, Y253H, and F359C/V) were shown to be associated with less favorable response to nilotinib. The current analysis is based on mature data with a minimum follow-up of 24-months for all patients. Outcomes of patients at 24 months were analyzed by mutation type. Methods Imatinib-resistant CML-CP (n = 200) and CML-AP (n = 93) patients were subdivided into the following mutational subsets: no mutation, sensitive mutations (including mutations with unknown in vitro IC50). or E255K/V, Y253H, or F359C/V mutations at baseline. Patients with mutations of unknown in vitro sensitivity were classified as sensitive in this analysis based on a previous finding that patients with these mutations responded similarly to nilotinib as patients with sensitive mutation. Patients with baseline T315I mutations were excluded from this analysis. Patient groups were analyzed for kinetics and durability of cytogenetic and molecular response to nilotinib, as well as event-free survival (EFS), defined as loss of hematologic or cytogenetic response, progression to AP/BC, discontinuation due to disease progression, or death, and overall survival (OS). Results In CML-CP and -AP patients with no mutation, sensitive mutations, or E255K/V, Y253H, or F359C/V mutations, hematologic, cytogenetic and molecular responses are provided in the Table. Overall, patients with no mutations responded similarly to patients with sensitive mutations, whereas patients with E255K/V, Y253H, or F359C/V mutations had less favorable responses. This correlation was observed in both CML-CP and CML-AP patients, respectively. Median time to CCyR was 3.3 months (range, 1.0–26.7) for CML-CP patients with no mutations, and 5.6 months (range, 0.9–22.1) for patients with sensitive mutations. At 24 months, CCyR was maintained in 74% of CML-CP patients with no mutation and in 84% of patients with sensitive mutations. One patient with CML-CP and an E255K mutation achieved CCyR at 25 months and maintained until last assessment at 30 months. Median time to MMR was similar at 5.6 months (range, 0.9–25.8) for CML-CP patients with no mutations and 5.6 months (range, 2.7–22.1) for patients with sensitive mutations. No patient with a less sensitive mutation achieved MMR. Median EFS and 24-month estimated OS rate are provided in the Table. Conclusions Imatinib-resistant CML-CP and CML-AP patients treated with nilotinib therapy with BCR-ABL mutations (excluding E255K/V, Y253H, or F359C/V) achieved rapid and durable cytogenetic responses, and estimated EFS and OS at 24 months similar to that of patients with no mutations, respectively. Patients with E255K/V, Y253H, or F359C/V mutations had lower and less-durable responses and shorter EFS than patients with sensitive mutations. Alternative therapies may be considered for patients with these uncommon mutations (E255K/V, Y253H, and F359C/V). Disclosures Radich: Novartis: Consultancy, Honoraria, Research Funding. Hochhaus:Novartis: Research Funding. Branford:Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding. Shou:Novartis: Employment. Haque:Novartis: Employment. Woodman:Novartis: Employment. Kantarjian:Novartis: Research Funding. Hughes:Bristol-Myers Squibb: Advisor, Honoraria, Research Funding; Novartis: Advisor, Honoraria, Research Funding. Kim:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Wyeth: Research Funding. Saglio:Novartis: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau.

scholarly journals Impact of Baseline BCR-ABL Mutations on Response to Nilotinib in Patients With Chronic Myeloid Leukemia in Chronic Phase

2009 ◽  
Vol 27 (25) ◽  
pp. 4204-4210 ◽  
Author(s):  
Timothy Hughes ◽  
Giuseppe Saglio ◽  
Susan Branford ◽  
Simona Soverini ◽  
Dong-Wook Kim ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Phase Ii ◽  
Myeloid Leukemia ◽  
Chronic Phase ◽  
Cytogenetic Response ◽  
Molecular Response ◽  
Imatinib Resistance ◽  
Mutational Status ◽  
Imatinib Resistant

Purpose Nilotinib is a second-generation tyrosine kinase inhibitor indicated for the treatment of patients with chronic myeloid leukemia (CML) in chronic phase (CP; CML-CP) and accelerated phase (AP; CML-AP) who are resistant to or intolerant of prior imatinib therapy. In this subanalysis of a phase II study of nilotinib in patients with imatinib-resistant or imatinib-intolerant CML-CP, the occurrence and impact of baseline and newly detectable BCR-ABL mutations were assessed. Patients and Methods Baseline mutation data were assessed in 281 (88%) of 321 patients with CML-CP in the phase II nilotinib registration trial. Results Among imatinib-resistant patients, the frequency of mutations at baseline was 55%. After 12 months of therapy, major cytogenetic response (MCyR) was achieved in 60%, complete cytogenetic response (CCyR) in 40%, and major molecular response (MMR) in 29% of patients without baseline mutations versus 49% (P = .145), 32% (P = .285), and 22% (P = .366), respectively, of patients with mutations. Responses in patients who harbored mutations with high in vitro sensitivity to nilotinib (50% inhibitory concentration [IC50] ≤ 150 nM) or mutations with unknown nilotinib sensitivity were equivalent to those responses for patients without mutations (not significant). Patients with mutations that were less sensitive to nilotinib in vitro (IC50 > 150 nM; Y253H, E255V/K, F359V/C) had less favorable responses, as 13%, 43%, and 9% of patients with each of these mutations, respectively, achieved MCyR; none achieved CCyR. Conclusion For most patients with imatinib resistance and with mutations, nilotinib offers a substantial probability of response. However, mutational status at baseline may influence response. Less sensitive mutations that occurred at three residues defined in this study, as well as the T315I mutation, may be associated with less favorable responses to nilotinib.

Characteristics and Outcome of Patients (pts) with V299L BCR-ABL Kinase Domain (KD) Mutation After Therapy with Tyrosine Kinase Inhibitors (TKIs).

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3428-3428
Author(s):  
Elias Jabbour ◽  
Hagop M. Kantarjian ◽  
Dan Jones ◽  
Yin Cameron ◽  
Elizabeth Burton ◽  
...  
Keyword(s):  
Research Funding ◽  
Kinase Inhibitors ◽  
Chronic Phase ◽  
Cytogenetic Response ◽  
Experimental Models ◽  
Molecular Response ◽  
Primary Resistance ◽  
Secondary Resistance ◽  
Abl Kinase

Abstract Abstract 3428 Point mutations of the BCR-ABL KD are the most frequently identified mechanism of resistance in pts with CML who fail TKI. Experimental models of in vitro drug sensitivity have shown that specific mutations may develop after incubation with second generation TKIs, albeit at a decreased frequency compared with imatinib. Some of the mutations are novel and not previously described after imatinib failure; in some instances they did not confer resistance to imatinib. One of them, V299L was rarely encountered after imatinib therapy but was reported to emerge after dasatinib exposure in induced mutagenesis models causing resistance to dasatinib by impairing its binding. We assessed the incidence and pattern of development of V299L in pts with TKI-resistant CML at our institution, and the response following change of therapy. V299L mutation was detected in 15 pts with CML: 1 occurred among 186 pts assessed for mutations (0.05%) after imatinib failure (1% of all mutation detected), 9 among 69 of the 170 evaluable (i.e., had abl sequencing) pts (13%) who developed mutations on dasatinib, and 5 among 19 of the 72 evaluable pts (26%) who developed mutations on bosutinib (p<0.001); none of the 51 pts who developed mutations on nilotinib (among 125 tested) acquired V299L. Median age for pts with V299L was 56 years (range, 26–82 years). Eight pts were previously treated with interferon-alpha. One pt developed V299L after receiving imatinib for 26 months (mos). The median time to development of V299L was 14 mos (range, 1–30 mos) for those treated with dasatinib (7 received dasatinib after imatinib failure, 1 after imatinib and nilotinib failure; and 1 after failure of imatinib, INNO-406, and bosutinib), and 13 mos (range, 2–48 mos) for those treated with bosutinib (after imatinib failure in 1, and as 3rd TKI after imatinib and dasatinib failure). The best response to TKI immediately preceding V299L (1 imatinib, 9 dasatinib, 5 bosutinib) was complete hematologic response only in 6 (40%, 4 dasatinib, 2 bosutinib), minor cytogenetic response in 2 (13%; 1 imatinib, 1 dasatinib), complete cytogenetic response in 4 (27%; 3 dasatinib, 1 bosutinib); no response in 3 pts (20%; 1 dasatinib, 2 bosutinib). The median duration of response was 17 mos. V299L was associated with primary resistance in 4 pts, and secondary resistance in 9. Two pts on dasatinib therapy remained in CHR and minor cytogenetic response, respectively, 3 months after the mutation detection. At the time the mutation was detected, 5 pts were in chronic (CP), 7 in accelerated (AP), and 3 in blast phase (BP). 3 pts (1 CP, 1 AP, 1 BP) received nilotinib after V299L detection and 1 in CPresponded (major molecular response sustained for 40+ mos). One pt received INNO406 and did not respond. One pt in BP was refractory to allogeneic stem cell transplantation and acquired a T315I mutation. Two pts received homoharringtonine, did not respond, but had an eradication of the mutant clone. After a median follow-up of 23 mos (range, 3–48 mos), from the time V299L was detected, 8 died (4 CP and 4 BP). In conclusion, V299L occurs more frequently after dual Src/Bcr-Abl kinase inhibitors therapy, paralleling the findings of in vitro studies. TKIs showing in vitro activity against this mutation (e.g. nilotinib) may be good treatment options for pts with this mutation if treated in chronic phase, but more data is need to evaluate the long-term benefit of this approach. Disclosures: Jabbour: BMS: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau. Cortes:Novartis: Research Funding; BMS: Research Funding; Pfizer: Consultancy, Research Funding.

Higher-Dose Imatinib (600 mg/Day) with Selective Intensification in Newly Diagnosed CML Patients in Chronic Phase; Cytogenetic Response Rates at 12 Months Are Superior to IRIS.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1001-1001 ◽  
Author(s):  
Timothy Hughes ◽  
S. Branford ◽  
J. Reynolds ◽  
J. Seymour ◽  
K. Taylor ◽  
...  
Keyword(s):  
Blast Crisis ◽  
Chronic Phase ◽  
Dose Intensity ◽  
Response Rates ◽  
Cytogenetic Response ◽  
Rank Test ◽  
Molecular Response ◽  
Log Reduction ◽  
Historical Comparison ◽  
Log Rank Test

Abstract The IRIS trial demonstrated that imatinib at 400 mg/day was superior to alpha interferon as first line therapy for chronic phase CML. To assess the tolerability and efficacy of higher doses of imatinib in this setting we are conducting a Phase II trial (TIDEL) using imatinib 600 mg initially, increasing to 800 mg if specified response criteria are not met: complete hematologic response (CHR) at 3 Mo; major cytogenetic response (MCR) at 6 Mo; complete cytogenetic response (CCR) at 9 Mo, and &gt;4 log reduction in BCR-ABL at 12 Mo. Filgrastim was used in cases of neutropenia to maintain dose intensity. Of 103 patients enrolled, 8 came off study in the first 12 Mo (2 unrelated deaths, 3 blast crisis, 3 poor response). 80 patients are currently assessable at 12 Mo (median age 47 years, range 21–75). Protocol mandated dose increases to 800 mg for failure to achieve MCR or CCR targets were activated in 7 patients before 12 months. We made a historical comparison of the best response by 12 Mo to responses in the IRIS trial (95% confidence intervals). Response rates at 12 Mo MCR (0–35% Ph+) CCR (0% Ph+) MMR (≥3 log reduction in BCR-ABL) 400mg - imatinib arm of IRIS n=556 84.1% (81.0 – 87.2%) 69.3% (65.3 – 73.2%) 40% (NA) 600mg - imatinib in TIDEL trial n=80 94.2% (87.3 – 97.5%) 88.5% (80.3 – 93.5%) 47.4% (37.5 – 57.6%) P-value for z-test 0.0004 &lt;0.0001 NA Patients who had a mean daily dose (MDD) &lt;600 mg in the first 2 months (n=27) had a CCR rate at 12 months of 78%, significantly lower than the 12 month CCR rate of 93% in patients receiving a MDD of 600 mg (n=75)(P=0.0015, log-rank test). Within the subgroup of patients receiving a MDD &lt;600 mg in the first 2 Mo who subsequently received a MDD of 600 mg in months 2–6 the CCR rate at 12 Mo remained 73% (n=11) (P=0.004, log rank test). The probability of achieving MMR by 12 Mo was analysed according to the MDD of imatinib received in the first 6 Mo. Patients with a MDD of 600 mg had a probability of 58% (CI 45–71%) (n=62) of achieving MMR compared to 33% (CI 15–59%) in those with a MDD of 500 – 599 mg (n=17) and 32% in those with a MDD of &lt;500 mg (n=20). Given these marked differences even at a MDD of 500–599 mg we looked at the median Sokal score in each group to see if more poor risk patients were present in the groups receiving reduced dose. Median Sokal scores for the groups with MDD of 600mg, 500–599 mg and &lt;500 mg were no different − 0.94, 1.08; and 1.04 respectively. BCR-ABL mutations were detected in 7 patients within 12 Mo (2 had blast crisis, 1 lost CHR, 2 lost CCR and 2 maintain CCR on an increased imatinib dose). Mutation was the main cause of loss of response (5 of 8 patients). We conclude that cytogenetic response rates at 12 Mo are significantly superior to responses observed in the IRIS trial. Major molecular responses are frequent in the cohort able to tolerate a MDD of 600mg. The substantially lower rate of MMR in patients with a moderately reduced MDD was unexpected. These patients did not have less favourable CML biology based on Sokal scores. Although it is possible that other adverse prognostic factors were an influence in these patients, it suggests that dose intensity may be critically important to maximise molecular response.+

Correlation of Clinical Response to Dasatinib (BMS-354825) with BCR-ABL Mutation Status in Imatinib- Resistant Patients (pts) with Chronic Myeloid Leukemia (CML) Treated at MD Anderson Cancer Center (MDACC).

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1091-1091 ◽  
Author(s):  
Elias Jabbour ◽  
Jorge Cortes ◽  
Moshe Talpaz ◽  
Dan Jones ◽  
Susan O’Brien ◽  
...  
Keyword(s):  
Lymphoblastic Leukemia ◽  
Philadelphia Chromosome ◽  
Chronic Phase ◽  
Cytogenetic Response ◽  
Kinase Domain ◽  
Cancer Center ◽  
Abl Kinase ◽  
Hematologic Response ◽  
Imatinib Resistant ◽  
Wide Range

Abstract Resistance to imatinib in CML occurs most frequently through mutations of the BCR-ABL kinase domain. Dasatinib is an orally available, dual SRC/ABL kinase inhibitor with 300-fold greater potency than imatinib, and with preclinical activity against all but one (T315I) type imatinib-resistant Bcr-Abl mutants. Dasatinib is currently used to treat pts with CML in chronic phase (CP), accelerated phase (AP), or blast phase (BP) or with Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). We analyzed the response to dasatinib among pts with Bcr-Abl kinase mutations. Prior to therapy, peripheral blood samples were analyzed for mutation by DNA sequencing. 26 pts with 13 different imatinib-resistant point mutations in the Bcr-Abl kinase domain were treated (CP n=10, AP n=11, BP n=4, ALL n=1). The most common mutations were G250E/A (n=7, 27%), T315I (n=3, 12%), F317L (n=3, 12%), and E355G/A (n=3, 12%). 20 (77%) pts responded to therapy. Responses were: major molecular remission (MMR) in one pt (4%), complete cytogenetic response (CGCR) in 3 (12%), partial cytogenetic response (CGPR) in 5 (19%), complete hematologic response (CHR) in 6 (23%), partial hematologic response (PHR) in 3 (12%), and return to CP in 2 (8%). 6 pts did not respond: 3 of them were in AP (T315I, L364I, and G250E) and 3 in CP (2 T315I and F317L). Three pts (1 CP [F317L], 2 BP [M351T and E355G]) have lost their response (CGPR, CHR, and PHR) after a median of 3 months (range, 2–4 months) without developing any detectable new mutations. The median duration of response for the other 19 pts was 5+ months (range 1+–14+); 4 pts (1 CP [F486S], 3 AP [E255V and 2 G250E]) have a sustained response (1 MMR, 1 CGCR, and 2 CHR) beyond 6 months. Among 12 pts with P-loop mutations (2 in CP, 8 in AP, 2 in BP) 11 (92%) responded to therapy and their median survival since the start of therapy is 5+ months (range, 1+-11+ months). In 2 pts (CHR) subsequent analysis revealed persistence of mutations (E355G and E255V). In one pt G250E mutation occurred while patient was on treatment, but has remained in CHR. We conclude that clinical activity of dasatinib in imatinib-resistant CML is observed in pts with a wide range of imatinib-resistant Bcr-Abl kinase domain mutations. Pts harboring the T315I mutations are resistant to BMS-354825.

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