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.

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.

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.

Molecular Predictors for the Response to Nilotinib Treatment After Acquired Imatinib Failure In Ph+ Chronic Myeloid Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2283-2283
Author(s):  
Mridul Agrawal ◽  
Philipp Erben ◽  
Benjamin Hanfstein ◽  
Armin Leitner ◽  
John Reynolds ◽  
...  
Keyword(s):  
Gene Expression ◽  
Research Funding ◽  
Chronic Phase ◽  
Cytogenetic Response ◽  
Kinase Domain ◽  
Mdr1 Gene ◽  
Mutation Status ◽  
Line Therapy ◽  
Imatinib Resistant ◽  
Mdr1 Gene Expression

Abstract Abstract 2283 Introduction: A switch to the 2nd generation tyrosine kinase inhibitor nilotinib has been proven to be effective in case of resistance or intolerance to imatinib for the majority of patients with Ph+ chronic myeloid leukemia (CML) in chronic phase (CP). Besides mutations in the BCR-ABL kinase domain and various BCR-ABL-independent mechanisms, e.g. clonal evolution and activation of pathways bypassing BCR-ABL, efficacy of imatinib and nilotinib are dependent on intracellular drug levels, which are influenced by the activity of the efflux transporter protein multidrug resistance 1 (MDR1). Cell culture data suggest overexpression of MDR1 as a cause of resistance to nilotinib (Mahon et al., Cancer Res 2008). Moreover, Dulucq et al. (Blood 2008) report the association of MDR1 single nucleotide polymorphisms (SNPs) with the chance to achieve major molecular response (MMR) on first-line imatinib therapy. Aim: In order to allow risk stratification, we sought to elucidate molecular markers, e.g. MDR1 gene expression, BCR-ABL transcript burden, BCR-ABL mutation status and common SNPs in the MDR1 gene regarding their potency to predict therapy-related endpoints, such as MMR, complete cytogenetic response (CCyR), and progression-free survival (PFS) during second line therapy with nilotinib in imatinib-resistant CML-CP patients. Patients and Methods: A cohort of 83 imatinib-resistant patients in chronic phase CML treated with nilotinib was investigated within the AMN107A2101 phase I/II trial. Baseline BCR-ABL mutations were detected by D-HPLC and direct sequencing. MDR1 and BCR-ABL mRNA expression levels were determined by qRT-PCR using LightCycler™ technology, normalized against beta-glucuronidase (GUS) expression. BCR-ABL levels were standardized according to the international scale (IS). MDR1 SNPs (1236C>T, 2677G>T) were investigated using conventional sequencing. Log-rank tests were performed to compare the time to MMR (BCR-ABL IS ≤0.1%), CCyR, and PFS. Results: By 12 or 24 months, patients with MDR1/GUS ratios ≥2 achieved MMR in an estimated rate of 34%, CCyR was attained in rates of 53% and 58%, and PFS rates were 88% and 75%, whereas those with initial MDR1/GUS ratios <2 showed MMR in 13% (p=0.026), CCyR in 25% and 35% (p=0.028), and PFS in 71% and 50% (p=0.027), respectively (Table). Further, combining BCR-ABL load and MDR1 expression prior to nilotinib produced a significant association with subsequent molecular and cytogenetic response and PFS. By 12 or 24 months, patients presenting with BCR-ABL IS <13% and MDR1/GUS ≥2 showed MMR in 56%, CCyR in 75% and 81% and longer PFS in 93% and 85% compared to those with BCR-ABL IS ≥13% and MDR1/GUS <2 achieving MMR rates of 5% (p<0.001), CCyR rates of 26% and 38% (p=0.002) and PFS rates of 72% and 41%, respectively (p=0.013). Also, BCR-ABL kinase domain mutation status prior to the onset of nilotinib was significantly associated with PFS under nilotinib therapy: Patients without any mutation showed PFS rates of 90% and 71% at 12 or 24 months, respectively; whereas those harboring less sensitive or resistant mutations (Hughes et al., JCO 2009) attained only 26% PFS (p=0.028). Except for patients harboring less sensitive or resistant mutations there was no significant difference between unmutated and mutated patients. 31 of 39 patients revealed SNPs at the 1236 position and 33 of the 39 showed SNPs at the 2677 position. Nilotinib efficacy was not affected by MDR1 SNPs. Neither an association with the molecular outcome nor MDR1 gene expression under nilotinib therapy was found. Conclusions: The rates of MMR, CCyR, and PFS on nilotinib 2nd line therapy are significantly associated with baseline levels of MDR1 gene expression and tumor burden of imatinib-resistant CML-CP patients. Further, baseline BCR-ABL mutations predict the probability of PFS rates but do not seem to do so for MMR and CCyR. These findings might deliver new molecular tools for the clinical risk stratification for treatment with nilotinib in case of resistance under imatinib front line therapy and suggest the need for prospective validation. Disclosures: Reynolds: Novartis Oncology: Employment, Equity Ownership. Woodman: Novartis Oncology: Employment. Robin: Novartis Oncology: Employment. Hofmann: Novartis Oncology: Honoraria, Research Funding. Hochhaus: Novartis Oncology: Honoraria, Research Funding. Müller: Novartis Oncology: Honoraria, Research Funding.

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.

Several Bcr-Abl kinase domain mutants associated with imatinib mesylate resistance remain sensitive to imatinib

Blood ◽  
2003 ◽  
Vol 101 (11) ◽  
pp. 4611-4614 ◽  
Author(s):  
Amie S. Corbin ◽  
Paul La Rosée ◽  
Eric P. Stoffregen ◽  
Brian J. Druker ◽  
Michael W. Deininger
Keyword(s):  
Imatinib Mesylate ◽  
Kinase Inhibitor ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Kinase Domain ◽  
Myelogenous Leukemia ◽  
Imatinib Resistance ◽  
Abl Kinase ◽  
Cellular Assays ◽  
Kinase Domain Mutations

Abstract Imatinib mesylate is a selective Bcr-Abl kinase inhibitor, effective in the treatment of chronic myelogenous leukemia. Most patients in chronic phase maintain durable responses; however, many in blast crisis fail to respond, or relapse quickly. Kinase domain mutations are the most commonly identified mechanism associated with relapse. Many of these mutations decrease the sensitivity of the Abl kinase to imatinib, thus accounting for resistance to imatinib. The role of other mutations in the emergence of resistance has not been established. Using biochemical and cellular assays, we analyzed the sensitivity of several mutants (Met244Val, Phe311Leu, Phe317Leu, Glu355Gly, Phe359Val, Val379Ile, Leu387Met, and His396Pro/Arg) to imatinib mesylate to better understand their role in mediating resistance.While some Abl mutations lead to imatinib resistance, many others are significantly, and some fully, inhibited. This study highlights the need for biochemical and biologic characterization, before a resistant phenotype can be ascribed to a mutant.

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 &gt;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 &gt;200 nM; n=21) achieved a response. Among 70 patients with &gt;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 &gt;3 nM), 42 (26%) lost a mutation (5 lost a mutation with IC50 &gt;3 nM), and 44 (27%) developed a new mutation (39 developed a mutation with IC50 &gt;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 &gt;3 nM (excl. T315I) 3 nM* Unknown IC50** Some patients had &gt;1 mutation. *Excluding patients with a concurrent mutation with dasatinib IC50 &gt;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.

Efficacy and Safety of Nilotinib in Elderly Patients with Imatinib-Resistant or -;Intolerant Chronic Myeloid Leukemia (CML) in Chronic Phase (CP): A Sub-Analysis of the ENACT (Expanding Nilotinib Access in Clinical Trials) Study.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3286-3286 ◽  
Author(s):  
Philipp D. le Coutre ◽  
Anna Turkina ◽  
Dong-Wook Kim ◽  
Bernadeta Ceglarek ◽  
Giuliana Alimena ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Research Funding ◽  
Kinase Inhibitor ◽  
Chronic Phase ◽  
Study Drug ◽  
Cytogenetic Response ◽  
Efficacy And Safety ◽  
Advisory Committees ◽  
Imatinib Resistant ◽  
Grade 3

Abstract Abstract 3286 Poster Board III-1 Introduction: Nilotinib, a potent and highly selective BCR-ABL kinase inhibitor, is approved for the treatment of patients (pts) with Philadelphia chromosome-positive chronic myelogeneous leukemia (Ph+ CML) in chronic phase (CML-CP) and accelerated phase (CML-AP) who are resistant or intolerant to prior therapy including imatinib. The ENACT study is a Phase IIIb, open-label, multicenter study that evaluated the efficacy and safety of nilotinib in adult pts with imatinib-resistant or intolerant CML in a clinical practice setting outside of a registration program. It is the largest single source of efficacy and safety information of any available tyrosine kinase inhibitor (TKI) in CML, particularly among the elderly. Methods: The present is a sub-analysis of the ENACT study on the efficacy and safety of 400 mg twice daily nilotinib in elderly (aged =60 years) pts initiating treatment in CML-CP who were resistant and/or intolerant to imatinib. Results: Of the 1,422 CML-CP pts enrolled in the ENACT study between January 2006 and October 2008, 452 (32%) were elderly (=60 years) at study initiation and 165 (37%) of these pts were =70 years [10 (2%) were =80 years]. Countries that enrolled =20 elderly pts include France, Italy, USA, Germany, UK, Spain, Canada, and Brazil. At study initiation, elderly pts had longer median durations of CML (<60: 51.1 months; =60: 69.3; =70: 66.6) and higher proportions with CML duration >5 years (<60: 43%; =60: 56%; =70: 52%). Besides imatinib, prior CML treatments received by elderly pts included dasatinib (=60: 20%; =70: 19%), cytarabine (=60: 23%; =70: 19%), busulfan (=60: 10%; =70: 7%), and interferons (=60: 50%; =70: 42%). Elderly pts were previously treated with imatinib for longer median durations (<60: 27.4 months; =60: 32.7; =70: 29.9), with higher proportions treated for >5 years (<60: 12%; =60: 19%; =70: 18%). The proportion of imatinib-intolerant to resistant elderly pts was about 1:1, which was higher than the proportion among <60 pts at about 0.6:1, such that relatively few elderly pts had prior highest imatinib dose >800 mg (<60: 34%; =60: 26%; =70: 21%). While response rates to prior imatinib were similar, among pts who required therapy after failing imatinib, elderly pts had lower cytogenetic response rates (<60: 22%; =60: 17%; =70: 19%) to prior dasatinib. During ENACT, less than 50% of elderly pts experienced nilotinib dose interruptions (=60: 46%; =70: 41%) and reductions (=60: 7%; =70: 6%) lasting >5 days, which was consistent with the overall ENACT dataset. The median duration of dose interruptions and reductions was 15 (=70: also 15) and 41 (=70: 32) days, respectively. The main reason for dose interruptions and reductions was adverse events (AEs). The median duration of nilotinib exposure was 227 days (=70: 219) and the median dose intensity was 749 mg/day (=70: 775). Efficacy was similar among elderly pts, with 39% (=70: 35%) of pts achieving complete hematologic response (CHR), 41% (=70: 39%) achieving major cytogenetic response (MCyR) and 31% (=70: 33%) achieving complete cytogenetic response (CCyR). MCyR rate was also similar among elderly hematologic responders (=60: 64%; =70: 65%). Among elderly pts requiring nilotinib therapy after both imatinib and dasatinib, and therefore have more resistant CML, CHR rate was 39% (=70: 32%), MCyR rate was 28% (=70: 29%) and CCyR rate was 20% (=70: 16%). Safety was likewise similar among elderly pts, with grade 3/4 study drug-related AEs occurring in 56% of pts (=70: 53%). The most frequent of these AEs were thrombocytopenia (=60: 24%; =70: 21%) and neutropenia (=60: 14%; =70: 11%). The most common method of managing these AEs was brief dose interruptions and/or reductions [thrombocytopenia (=60:86/108 pts; =70: 30/35), neutropenia (=60: 42/62 pts; =70: 9/18)]. Among elderly pts with prior dasatinib, 53% (=70: 58%) experienced grade 3/4 study drug-related AEs, while 7 out of 8 pts with pleural effusion on dasatinib no longer had it on nilotinib. Conclusions: In ENACT, pts aged =60 years at study initiation appear to have longer durations of CML, be more heavily pre-treated and more intolerant to imatinib than the younger cohort. Nonetheless, nilotinib induced comparable clinical responses in CML-CP pts regardless of age. Importantly, the safety profile of nilotinib is maintained in elderly pts. Disclosures: le Coutre: Novartis: Honoraria, Research Funding; BMS: Honoraria. Turkina:Novartis Pharmaceuticals: Honoraria. Kim:Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Wyeth: Research Funding. Ceglarek:Novartis Pharmaceuticals: Honoraria. Shen:Novartis Pharmaceuticals: Honoraria. Smith:Novartis Pharmaceuticals: Honoraria. Rizzieri:Novartis Pharma: Honoraria, Research Funding, Speakers Bureau. Szczudlo:Novartis: Employment. Berton:Novartis Pharmaceuticals: Employment. Wang:Novartis Pharmaceuticals: Employment. Wang:Novartis Pharmaceuticals: Research Funding. Nicolini:Novartis Pharma: Consultancy, Honoraria, Research Funding, Speakers Bureau; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding, Speakers Bureau; Chemgenex: Honoraria, 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.

Nilotinib in Imatinib-Resistant or -Intolerant Patients (pts) with Chronic Myeloid Leukemia in Chronic Phase (CML-CP): 48-Month Follow-up Results of a Phase 2 Study,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3770-3770 ◽  
Author(s):  
Philipp D. le Coutre ◽  
Francis J. Giles ◽  
Javier Pinilla-Ibarz ◽  
Richard A. Larson ◽  
Norbert Gattermann ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Research Funding ◽  
Lung Neoplasm ◽  
Chronic Phase ◽  
Dose Intensity ◽  
Advisory Committees ◽  
Imatinib Resistance ◽  
Imatinib Resistant ◽  
Significant Difference

Abstract Abstract 3770 Background: Nilotinib is a selective and potent BCR-ABL TKI approved for the treatment of pts with newly diagnosed Ph+ CML-CP, and for pts with CML-CP or CML-AP resistant to or intolerant of imatinib. Here, we present the 48-mo follow-up data from the 2101 trial for pts with imatinib resistance or intolerance. Methods: Pts were treated with nilotinib 400 mg twice daily (BID). Key endpoints included PFS (defined as progression to AP/BC or discontinuation due to disease progression as assessed by investigator or death from any cause) and OS (includes deaths during treatment or follow-up after discontinuation). Results: 321 pts were enrolled (70% imatinib resistant; 30% imatinib intolerant with resistance). At baseline (BL), 36% of pts were in CHR. At the time of data cutoff, 224/321 pts (70%) discontinued nilotinib therapy (Table), and 31% of all pts had at least 48 mo of treatment. The median nilotinib dose intensity was 789 mg/day (range, 151–1110) and 62% of pts received ≥ 400 mg BID nilotinib as their last dose available. Pts with BL CHR had a significantly higher PFS rate at 48 mo vs pts without BL CHR (71% vs 49%, respectively; P =.001). Only 11 (3%) pts progressed to advanced disease (AP/BC) during study. Estimated 48-mo OS rate was 78% (95% CI 74%-83%). Among resistant pts, those without BL mutations (n = 92) had a significantly higher OS rate at 48 mo vs pts with sensitive mutations at BL (n = 78) (84% vs 74%, respectively, P =.029); however, there was no significant difference in OS among pts with sensitive and insensitive mutations (Y253H, E255K/V or F359C/V, n = 27) at BL (74% vs 71%, respectively, P =.804). No new safety signals were observed, and few additional AEs were reported since 24 mo follow-up (Table). Biochemical lab abnormalities were generally mild, transient, and easily managed; grade 3/4 lipase elevation (19%), hypophosphatemia (18%), and hyperglycemia (13%) were most common. Reports of any-grade pleural effusions remained low (1%), and no new cases were reported with longer follow-up. No new cases of QTcF >500 ms and 3 new cases of QTcF increases > 60 ms from BL were reported. Nine pts died during treatment or within 28 days of discontinuation: 8 deaths were previously reported and occurred in the first 24 mo of follow-up; 1 additional death due to lung neoplasm occurred between 24 and 48 mo (35 mo). Conclusions: With longer follow up, nilotinib continues to be effective and well tolerated in pts with Ph+ CML-CP resistant to or intolerant of imatinib therapy. Nilotinib prevented progression to AP/BC in the majority of pts on treatment and was associated with high OS rates. No cumulative toxicity was observed. Data demonstrating the higher rate of PFS in pts who entered the study with a BL CHR suggest that switching pts to nilotinib prior to hematologic failure on imatinib, and according to current treatment guidelines, may maximize the efficacy of nilotinib therapy. Disclosures: le Coutre: Novartis: Honoraria, Research Funding, Speakers Bureau; BMS: Honoraria. Giles:Novartis: Consultancy, Honoraria, Research Funding. Pinilla-Ibarz:Novartis: Research Funding, Speakers Bureau. Larson:Novartis: Consultancy, Honoraria, Research Funding. Gattermann:Novartis: Honoraria, Research Funding. Ottmann:Novartis: Consultancy; BMS: Consultancy, Research Funding. Hochhaus:Novartis: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Ariad: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria, Research Funding. Radich:BMS: Consultancy; Novartis: Consultancy, Research Funding. Saglio:Novartis: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau; Pfizer: Consultancy. Hughes: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; Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees. Martinelli:Novartis: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Pfizer: Consultancy. Kim:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding. Branford:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Honoraria, Research Funding; Ariad: Research Funding. Müller:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Shou:Novartis: Employment. Novick:Novartis: Employment, Equity Ownership. Fan:Novartis: Employment. Cortes:Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Ariad: Consultancy, Research Funding. Baccarani:Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau. Kantarjian:Novartis: Consultancy, Research Funding; BMS: Research Funding; Pfizer: Research Funding.

Sign in / Sign up

Export Citation Format

Share Document