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.

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.

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.

Second-line bosutinib (BOS) for patients (pts) with chronic phase (CP) chronic myeloid leukemia (CML): Final 10-year results of a phase 1/2 study.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 7009-7009
Author(s):  
Carlo Gambacorti-Passerini ◽  
Tim H. Brümmendorf ◽  
Dong-Wook Kim ◽  
Yeow Tee Goh ◽  
Irina S Dyagil ◽  
...  
Keyword(s):  
Phase 1 ◽  
Philadelphia Chromosome ◽  
Chronic Phase ◽  
Dose Intensity ◽  
Cytogenetic Response ◽  
Molecular Response ◽  
Second Line ◽  
Prior Therapy ◽  
Kaplan Meier ◽  
Imatinib Resistant

7009 Background: BOS is approved for Philadelphia chromosome (Ph)+ CML resistant/intolerant to prior therapy and newly diagnosed Ph+ CP CML. In a phase 1/2 study, second-line BOS showed durable efficacy and manageable toxicity in pts with imatinib-resistant (IM-R) or -intolerant (IM-I) Ph+ CP CML. Methods: This final efficacy and safety analysis of the phase 1/2 study and extension study was based on ≥10 y of follow-up (FU). Ph+ CP CML pts who received BOS starting at 500 mg/d after prior treatment (Tx) with imatinib only were included. Results: 19% of pts were on BOS at y 10, and 13% were still on BOS at study completion after ≥10 y; 19% completed ≥10 y of FU. Median duration of Tx and FU were 26 and 54 mo, respectively. Median (range) dose intensity was 436 (87–599) mg/d. The most common primary reasons for permanent Tx discontinuation were lack of efficacy (unsatisfactory response or disease progression; 27%) and adverse events (AEs; 26%). In pts with a valid baseline assessment, cumulative complete cytogenetic response (CCyR), major molecular response (MMR) and MR4 rates (95% CI), respectively, were 50% (43–56), 42% (35–49) and 37% (30–44) (IM-R: 48% [41–56], 46% [37–55] and 39% [31–48]; IM-I: 53% [41–64], 36% [25–48] and 33% [22–45]). Responses were durable, with estimated probabilities of maintaining CCyR, MMR and MR4 > 50% after ≥10 y (Table). At 10 y, cumulative incidence of on-Tx progression/death was 24% and Kaplan-Meier (K-M) overall survival 72% (Table); 55 deaths (IM-R: n = 41; IM-I: n = 14) occurred on study, none BOS-related. Any grade Tx-emergent AEs (TEAEs) in ≥40% of pts were diarrhea (86%), nausea (46%) and thrombocytopenia (42%). Pleural effusion, cardiac and vascular TEAEs occurred in 13%, 12% and 11% of pts, respectively. 28% of pts had AEs leading to permanent Tx discontinuation; most common (≥2% of pts) were thrombocytopenia (6%), neutropenia (2%) and alanine aminotransferase increased (2%). Conclusions: These 10-y data are consistent with prior results of durable efficacy and manageable toxicity with second-line BOS and support long-term BOS use in CP CML pts after imatinib failure. Clinical trial information: NCT00261846 and NCT01903733. [Table: see text]

Early treatment decisions with interferon-alfa therapy in early chronic-phase chronic myelogenous leukemia.

1998 ◽  
Vol 16 (3) ◽  
pp. 882-889 ◽  
Author(s):  
S Sacchi ◽  
H M Kantarjian ◽  
T L Smith ◽  
S O'Brien ◽  
S Pierce ◽  
...  
Keyword(s):  
Chronic Myelogenous Leukemia ◽  
Univariate Analysis ◽  
Group Analysis ◽  
Philadelphia Chromosome ◽  
Chronic Phase ◽  
Cytogenetic Response ◽  
Interferon Alfa ◽  
Myelogenous Leukemia ◽  
Costal Margin ◽  
Hematologic Response

PURPOSE To determine, in patients with Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML) on interferon alfa (IFNalpha), whether combining pretreatment characteristics and early response profiles would distinguish patients with differential benefits that would allow better decisions on subsequent therapy. PATIENTS AND METHODS A total of 274 patients treated from 1982 through 1990 with IFNalpha regimens were analyzed. A second group of 137 patients treated with IFNalpha and low-dose cytarabine (ara-C) between 1990 and 1994 was later used to confirm the guidelines derived from the original study group analysis. Patients' pretreatment factors and response to IFNalpha therapy at 3, 6, and 12 months were analyzed in relation to subsequent achievement of major cytogenetic response. After univariate analysis of prognostic factors, a multivariate analysis selected, at 6 months, independent pretreatment factors that added to the response status in predicting subsequent outcome. The results were then applied at the 3- and 12-month periods and confirmed in the subsequent population. RESULTS Response to IFNalpha therapy at 3, 6, and 12 months was a significant predictor of later major cytogenetic response. The presence of splenomegaly > or = 5 cm below the costal margin (BCM) or thrombocytosis > or = 700 x 10(9)/L pretreatment added significant independent prediction to response. At 6 months, patients with a partial hematologic response (PHR) or resistant disease had a less than 10% chance of achieving a later major cytogenetic response, as were those in complete hematologic response (CHR) and who had pretreatment splenomegaly and thrombocytosis. Applying the model at 3 months showed that only patients with < or = PHR and pretreatment splenomegaly or thrombocytosis at 3 months had such a low major cytogenetic response rate. Finally, at 12 months, patients with CHR still had a 15% to 25% chance of having a major cytogenetic response later if they did not have pretreatment splenomegaly and thrombocytosis. CONCLUSION This analysis allows better selection of patients with Ph-positive CML on IFNalpha therapy for continuation of IFNalpha versus changing therapy early in the course of CML. For treatment programs that choose to change patients to other investigational therapies (eg, intensive chemotherapy and/or autologous stem-cell transplantation [SCT]), baseline outcome expectations are provided for patients continued on IFNalpha therapy, against which the results of new approaches can be compared.

Dasatinib (SPRYCEL®) in Patients (pts) with Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia Who Are Imatinib-Resistant (im-r) or -Intolerant (im-i): Updated Results from the CA180-015 ‘START-L’ Study.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 286-286 ◽  
Author(s):  
Herve Dombret ◽  
O.G. Ottmann ◽  
G. Rosti ◽  
B. Simonsson ◽  
R.A. Larson ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Median Duration ◽  
Lymphoblastic Leukemia ◽  
Philadelphia Chromosome ◽  
Cytogenetic Response ◽  
Molecular Response ◽  
Cell Transplant ◽  
Hematologic Response ◽  
Grade 3 ◽  
Philadelphia Chromosome Positive

Abstract Dasatinib (SPRYCEL®, formerly BMS-354825) is a novel, oral, multi-targeted kinase inhibitor of BCR-ABL and SRC. Relapsing pts with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) who have been previously treated with chemotherapy including im have a very poor prognosis. START-L is an open label, multi-center, global phase-II study, which treated 46 im-r or im-i pts with Ph(+) ALL from January through June 2005. Dasatinib was given orally, 70 mg twice daily (BID) with escalation to 100 mg BID for poor response or reductions to 50 mg and 40 mg BID for toxicity. Response was assessed on weekly blood counts and monthly bone marrow exams, including cytogenetics. Mutation analysis was conducted at baseline and at end of study. Quantitative PCR was carried out pretreatment and at the time of complete cytogenetic response (CCyR). At the time of this update, all 46 pts had a minimum of 9 months (mo) of follow-up. Of these, 44 (96%) were im-r; due to the small number of im-i pts, data for all pts are presented. 59% of patients were male and median age was 48 years. The median time from initial Ph(+) ALL diagnosis to first dose was 18 mo. All patients had been pretreated with im including 46% with 600 mg per day or more, and 52% whose duration of im treatment was more than 12 mo. 37% of the pts had received a stem cell transplant. At baseline, 67% of pts had WBC <2000/mm3, 74% had platelets <100 × 103/mm3, and 24% had extramedullary disease outside of the spleen. In the 40 pts with baseline mutation data, im-resistant BCR-ABL mutations were observed in 78%, one with T315I. The median duration of therapy was 3.0 mo (range 0.03–16.5) for all pts and was 13.0 mo (9.2–16.5) for pts still on study. The overall complete hematologic response rate was 35%. The major cytogenetic response was 57%, including 54% CCyR. The major hematologic response (MHR) in the 31 pts with baseline mutations was 45%. The median duration of MHR was 11 mo and the median progression-free survival was 3.7 mo (95% CI 1.6–6.1). Grades 3 and 4 thrombocytopenia occurred in 13% and 67%, respectively and grades 3 and 4 neutropenia occurred in 27% and 52% of pts, respectively. Most frequent non-hematologic toxicities included diarrhea in 30% (grade 3–4, 7%), nausea in 22% (no grade 3–4), pyrexia in 22% (grade 3–4, 2%), and pleural effusion in 22% (grade 3–4, 7%) of pts. Dose was reduced in 30% and interrupted in 43% of pts, primarily due to non-hematologic toxicities. Dasatinib has important efficacy in this Ph(+) ALL pt population. Updated efficacy (including molecular response), safety, and mutational analysis data will be presented at the meeting.

ShRNA Targeting p190BCR-ABL Successfully Eliminates Ph-ALL Cells with or without ABL Kinase Domain Mutation.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1838-1838
Author(s):  
Muneyoshi Futami ◽  
Toshiyuki Hatano ◽  
Yasushi Soda ◽  
Seiichiro Kobayashi ◽  
Makoto Miyagishi ◽  
...  
Keyword(s):  
Lentiviral Vector ◽  
High Titer ◽  
Therapeutic Option ◽  
Lymphoblastic Leukemia ◽  
Philadelphia Chromosome ◽  
Kinase Domain ◽  
Leukemia Cells ◽  
Specific Cell ◽  
Dependent Manner ◽  
Abl Kinase

Abstract In the majority of Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (Ph-ALL) cases, the resulting BCR-ABL gene generates 190 kD active tyrosine kinase (p190) which is responsible for leukemogenesis and can be a molecular target for therapy. Although a series of ABL kinase inhibitors including imatinib, nilotinib and dasatinib reveal potent activities against Ph-ALL, acquired resistance caused by point mutations in the kinase domain such as T315I still remains to be overcome. That is why a novel strategy is desired in the treatment of Ph-ALL. We previously reported that lentiviral delivery of maxizyme targeting p190 specifically induced apoptosis of Ph-ALL cells (Blood 104:356, 2004). Since RNA interference proved to be a more powerful tool in selective gene silencing, we applied this technology to test whether specific and efficient killing of Ph-ALL cells could be achieved by down-regulation of p190. We designed a series of 21-mer and 27-mer small hairpin RNA (shRNA) targeting p190 mRNA and constructed plasmid vectors expressing these shRNA, which were screened by transfection of 293T/p190 cells to determine optimal target sites. As a result, three candidate sequences were identified; junctional 27-mer, junctional 21-mer and ABL 21-mer. Then, we inserted each of the shRNA expression cassettes into the lentiviral vector (HIV-U6/shRNA) and prepared high titer virus stock for infection of leukemia cells. shBCR-ABL/21, but not shBCR-ABL/27, induced significant and specific cell death of p190+ Ph-ALL cells in a time-dependent manner. shABL was more potent than shBCR-ABL/21 and also active against p210+ CML cells as well as 293 cells, but did not substantially affect Ph-negative leukemia cells. Both shABL and shBCR-ABL/21 completely inhibited growth of Ba/F3 cells harboring either wild-type or mutant p190 which renders those resistant to imatinib. Furthermore, both shRNA at low multiplicity of infection additively cooperated with imatinib in growth inhibition of Ba/F3-p190 cells. These data suggest that shRNA targeting p190 may become a therapeutic option in Ph-ALL by improvement of its delivery system like liposome. Growth of BA/F3-p190BCR-ABL Cells transduced with shRNA Targeting p190BCR-ABL Growth of BA/F3-p190BCR-ABL Cells transduced with shRNA Targeting p190BCR-ABL

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 &lt;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 &gt;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.

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.

To Study Resistant Mechanisms and Reversal In An Imatinib Resistant Ph+ Positive Acute Lymphoblastic Leukemia Cell Line

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2135-2135
Author(s):  
Hongyun Xing ◽  
Yuping Gong ◽  
Ting Liu
Keyword(s):  
Cell Signaling ◽  
Cell Line ◽  
Lymphoblastic Leukemia ◽  
Kinase Domain ◽  
Rt Pcr ◽  
Imatinib Resistance ◽  
Abl Kinase ◽  
Imatinib Resistant ◽  
Cell Signaling Pathways

Abstract Abstract 2135 Objective To establish an imatinib resistant Bcr-Abl positive acute lymphoblastic leukemia (ALL) cell line in vitro and to study imatibin resistance in Ph+ ALL. The reversal of the imatinib resistance by rapamycin, the second generation tyrosine kinase inhibitor and proteasome inhibitor was studied. Methods Ph(+) ALL SUP-B15 cell line was cultured in gradually increasing concentrations of imatinib to generate the imatinib resistant cell line at 6 μM imatinib. The cytotoxic effect of imatinib and other drugs was analyzed by MTT assay. RT-PCR, flow cytometry, Western blot analyses of proteins, DNA sequence analysis of ABL kinase domain were used to clarify the possible mechanisms of the imatinib resistance in the SUP-B15/RI cell line. Results We established the imatinib resistant Ph+ ALL cell line. The fusion bcr-abl gene was 6.1 times as high as that of the parental sensitive cell, and the mdr1 gene also increased 1.7 times in SUP-B15/RI cell line by the RT-PCR detection. However, the expression of hoct1 Abcl–2 and topoIIα gene were no difference between two cell lines by the RT-PCR detection. A K362S point mutation in the Abl kinase domain of SUP-B15/RI was found. The detection of cell signaling pathway of PI3K/AKT/mTOR, RAS/RAF, NF-κBA JNK and STAT showed the expression of PTEN and 4EBP-1 was down-regulated, AKT, mTOR and P70S6K was up-regulated and the expression of other cell signaling pathways in SUP-B15/RI was similar to its parental sensitive cell line. Dasatinib, nilotinib, and bortezomib could inhibit proliferation of SUP-B15/RI cells at nM concentration. SUP-B15/RI cell line also showed partial resistance to dasatinib and nilotinib, but not bortezomib. The combination of imatinib with rapamycin had synergistic effect to the resistance cell line. Conclusion In vitro, we establish imatinib resistant Ph + ALL cell line. Overexpression of bcr-abl and mdr1 gene, K362S point mutation in ABL kinase domain and up-regulation of the cell signaling pathways of PI3K/AKT/mTOR, RAS/RAF in SUP-B15/RI cell line were involved in the resistance mechanisms. The SUP-B15/RI cell line was also resistant to the second generation tyrosine kinaeses dasatinib and nilotinib,not bortezomib in vitro. However, the combination of imatinib with rapamycin can partially overcome the resistance. Blockade of the ubiquitin-proteasome could be a promising pathway to overcome resistance to imatinib. Disclosures: No relevant conflicts of interest to declare.

CBL, CBLB, TET2, ASXL1, and IDH1/2 Mutations as Well as Additional Chromosomal Aberrations Constitute Molecular Events Contributing to Malignant Progression In Advanced Philadelphia Chromosome-Positive Disorders.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3396-3396
Author(s):  
Hideki Makishima ◽  
Anna Jankowska ◽  
Michael A McDevitt ◽  
Simon Dujardin ◽  
Heather Cazzolli ◽  
...  
Keyword(s):  
Clinical Features ◽  
Copy Number ◽  
Chromosomal Abnormalities ◽  
Philadelphia Chromosome ◽  
Chronic Phase ◽  
Kinase Domain ◽  
Chromosome 8 ◽  
Molecular Events ◽  
Advanced Phase ◽  
Imatinib Resistant

Abstract Abstract 3396 Chronic myeloid leukemia (CML) is characterized by the BCR/ABL fusion gene. However, secondary molecular events leading to accelerated (AP) or blast phase (BP) have not been sufficiently clarified. We hypothesized that, in analogy to other MDS/MPN or MPN, TET2, ASXL1, CBL and IDH family mutations may also occur in CML and contribute as secondary events leading to progression to AP or BP. Similarly, higher resolution of cytogenetic testing by single nucleotide polymorphism array (SNP-A)-based karyotyping may reveal additional chromosomal abnormalities associated with stepwise progression. This study is focused on the combined analysis of chromosomal lesions and mutations associated with AP, BP and Philadelphia chromosome (Ph) positive acute lymphoblastic leukemia (ALL) and the association of these defects with clinical features. We screened TET2, ASXL1, CBL and IDH for mutations in AP (N=14) and BP (N=26) and Ph+ ALL (N=9). Chronic phase (CP) (N=14) and Ph negative ALL (N=9) served as controls. We identified 3 CBL family (9%), 7 TET2 (21%), 2 ASXL1 (6%) and 2 IDH family (6%) mutations in patients with AP and myeloid BP. Subsequently, we also detected a TET2 mutation in a case of Ph+ ALL. None of these mutations were found in patients with CP or Ph negative ALL. We also performed SNP-A-based karyotyping and only included lesions which did not overlap with copy number variations (CNVs) or germ line regions of homozygosity present in any of the controls. 23 gains, 21 losses and 4 regions of somatic UPD lesions were identified. By SNP-A, additional copy number abnormalities, including microdeletions were found in 67% and 50% of patients with AP and BP, respectively. Recurrent lesions were detected on chromosome 1, 8, 9, 17 and 22. Microdeletions on chromosome 17 and 21 involved tumor associated genes NF1 and RUNX1. Deletions flanking the ABL1 and BCR genes were observed in 3 cases with der(22)t(9;22) or der(9)t(9;22) by metaphase cytogenetics. Gains including 1q25.3q41, chromosome 8 and 17q24.3 were found in 3 cases. Regions of UPD included UPD5q, 8q, 11p and 17q but no UPD involving 11q (CBL) and 4q (TET2) regions were found confirming heterozygous nature of the corresponding mutations. Newly detected molecular lesions associated with AP and BP may change the biology and thereby clinical features of affected cases. Overall survival of patients with mutations did not differ from those without mutations. Of note is that BCR/ABL1 kinase domain mutations were detected in 9/10 patients with imatinib resistance. In these 9 cases, 3 TET2 and 2 CBLB mutations were detected (but no mutations in the other genes). In an imatinib-resistant patient without BCR/ABL1 kinase domain mutation, CBL mutation was present. In the patients with TET2 mutations, additional chromosomal lesions were found by SNP-A, significantly more frequently when compared with WT cases (P=0.017). Of the 9 TET2 variants in 8 cases, 7 (78%) were missense substitutions, 1 (11%) was frame shift and 1 (11%) produced a stop codon and were located within the N-terminus as well as in a conserved DSBH 2OG-Fe(II)-dependent dioxygenase domain. The presence of nonsense and frameshift mutations suggests that mutated lesions result in inactivation, consistent with putative tumor suppressor functions, while heterozygous mutations indicate that the wild type allele is not completely protective. Since no TET2 mutations were identified in chronic phase CML, these mutations might represent an additional pathogenic event and contribute to progression. In 3 cases we observed a combination of 2 mutations. Coincidence of CBLB and TET2 mutations in 2 cases suggests that these might cooperate in the evolution of advanced phase of CML. We also found a combination of IDH1 and ASXL1 mutations in a patient with BP, suggesting that both mutations contribute to clonal advantage. In conclusion, while CBL family, ASXL1 and IDH family mutations as well a additional unbalanced chromosomal abnormalities not seen by metaphase cytogenetics can occur in myeloid type advanced phase CML, TET2 mutations were identified in Ph+ ALL, as well as myeloid BP and AP. These mutations likely represent secondary lesions which contribute to either disease progression or more aggressive features and commonly occur in association with imatinib-resistant BCR/ABL mutations. Disclosures: No relevant conflicts of interest to declare.

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