Distinct Characteristics of e13a2 versus e14a2 BCR-ABL Chronic Myeloid Leukemia under Upfront Treatment with Imatinib – an Analysis of the German CML Study IV,

Abstract Abstract 3773 Introduction: The vast majority of chronic myeloid leukemia (CML) patients express a BCR-ABL fusion gene mRNA encoding a 210 kDa tyrosine kinase which is constitutively activated and hence the mainspring of leukemic transformation. Two typical mRNA variants exist that differ in the presence or absence of the 75 basepair BCR exon 14: the e13a2 (lacking exon 14, also known as “b2a2”) and the e14a2 BCR-ABL transcript (“b3a2”). The significance of the additional 25 amino acid residues of the e14a2 BCR-ABL oncoprotein was extensively studied in the pre-imatinib era. However, the influence of the BCR-ABL transcript variant on the individual disease phenotype and outcome remained controversial and is still undefined in the imatinib era. Patients and methods: A total of 1,104 patients (median age 52 years, range 16–85, 40% female) expressing typical BCR-ABL transcript types (e13a2, n=447; e14a2, n=491; e13a2 and e14a2, n=166) were included in the randomized German CML study IV and treated with an imatinib based therapy consisting of imatinib 400 mg, imatinib 800 mg and combinations of standard dose imatinib with interferon alpha and low-dose cytarabine. The type of BCR-ABL transcript was defined by multiplex PCR. BCR-ABL expression was determined by quantitative RT-PCR and standardized according to the international scale (IS). Cytogenetic response was determined by conventional metaphase analyses. Response landmarks were defined according to European LeukemiaNet criteria, MR4 was defined as BCR-ABL IS ≤ 0.01% Results: No differences regarding age, sex and Euro risk were observed. A significant difference was observed comparing white blood cells (90,400/μl vs. 69,100/μl, p<0.001) and platelets (293,000/μl vs. 424,000/μl, p<0.001) at diagnosis (median, e13a2 vs. e14a2, respectively) indicating a distinct phenotype. No significant difference was observed regarding spleen size, basophils, eosinophils, blasts or adverse events under imatinib. Molecular response as determined by a transcript independent quantitative PCR assay was superior in e14a2 patients as compared to e13a2 patients (median time to major molecular response, MMR 1.5 years vs. 1.2 years, p<0.001; median time to MR4 4.2 years vs. 2.5 years, p<0.001). No difference was observed with regard to the achievement of a complete cytogenetic remission (CCyR). The superior molecular response rate of e14a2 patients did not translate into differences in progression free survival (PFS) or overall survival (OS). Conclusion: Distinct initial blood counts suggest a different phenotype of e13a2 and e14a2 driven CML. MMR and MR4 are achieved earlier by e14a2 patients whereas no difference was observed with regard to PFS and OS. Disclosures: Schnittger: Münchner Leukämie Labor: Equity Ownership. Haferlach:Münchner Leukämie Labor: Equity Ownership. German CML Study Group:Deutsche Krebshilfe: Research Funding; Novartis: Research Funding; BMBF: Research Funding; EU: Research Funding; Roche: Research Funding; Essex: Research Funding.

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The Comparison of Dasatinib 70 Mg/Day to 100 Mg/Day in Newly Diagnosed Patients with Chronic Myeloid Leukemia in Chronic Phase (CML-CP): A Multicenter, Prospective, Randomized Controlled Study

Blood ◽

10.1182/blood-2021-148349 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 3615-3615

Author(s):

Dan Yu ◽

Zhuangzhi Yang ◽

Hui Cheng ◽

Rui Jiang ◽

Jingming Guo ◽

...

Keyword(s):

Chronic Myeloid Leukemia ◽

Myeloid Leukemia ◽

Standard Dose ◽

Chronic Phase ◽

Controlled Study ◽

Molecular Response ◽

Newly Diagnosed ◽

Efficacy And Safety ◽

Best Response ◽

Significant Difference

Abstract Background: The purpose of this study is to compare efficacy and safety of patients with newly diagnosed chronic myeloid leukemia in chronic phase (CML-CP) treated with frontline dasatinib 70 mg/day with those who received standard-dose dasatinib 100 mg/day. Method: From July 2019 to July 2021, 81 patients with newly diagnosed CML-CP were enrolled across 11 centers. All of the patients were randomly treated with dasatinib 70 mg/day (N=43) or standard-dose dasatinib 100 mg/day (N=38). Results: Among 81 enrolled patients, 16 patients were off study at different times for different reasons.All patients achieved hematological remission after 3 months of treatment, and the best response rates were 84.00% (21/25) and 88.89% (24/27) for 70mg/d and 100mg/d groups (P>0.05).At 6 months, the best response, complete cytogenetic response (CCyR) and major molecular response (MMR) rate were 94.44% vs 92.86% (P > 0.05), 94.44% vs 92.86% (P > 0.05) and 55.56% vs 71.43% (P > 0.05), respectively.At 9 months, the rates of CCyR and MMR were 90.91% vs 88.89% (P > 0.05) and 66.67% vs 72.73% (P > 0.05);CCyR and MMR by 12 months, respectively, were 90.91% vs 100.00% (P > 0.05), 81.82% vs 80.00% (P > 0.05).The adverse events (AEs) of the two groups were mild, and there was no significant difference (P > 0.05).The most common grade ≥3 hematological AEs in 70 mg/d group were leukopenia (1/43), neutropenia (1/43) and anemia (2/43), and In 100mg/d group were leukopenia (4/38), neutropenia (6/38), anemia (3/38) and thrombocytopenia (3/38). Conclusions: Our study suggests that patients with newly diagnosed CML-CP treated with dasatinib 70 mg/day or 100 mg/day, there is no significant difference in efficacy and safety. Decreasing the dose of dasatinib can ensure the efficacy of patients, while reducing the economic burden of patients and increasing patient compliance. Disclosures No relevant conflicts of interest to declare.

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BCL2L11 (BIM) Deletion Polymorphism Is Associated with Molecular Relapse after ABL Tyrosine Kinase Inhibitor Discontinuation in Patients with Chronic Myeloid Leukemia with Complete Molecular Response

Blood ◽

10.1182/blood.v124.21.1797.1797 ◽

2014 ◽

Vol 124 (21) ◽

pp. 1797-1797 ◽

Cited By ~ 2

Author(s):

Seiichiro Katagiri ◽

Tetsuzo Tauchi ◽

Yuu Saito ◽

Tamiko Sugro ◽

Michiyo Asano ◽

...

Keyword(s):

Chronic Myeloid Leukemia ◽

Tyrosine Kinase ◽

Myeloid Leukemia ◽

Research Funding ◽

Molecular Response ◽

Deletion Polymorphism ◽

Significant Difference ◽

Treatment Free Remission ◽

Tki Discontinuation ◽

Complete Molecular Response

Abstract Background: The inhibition of BCR-ABL1 kinase with tyrosine kinase inhibitors (TKIs) has markedly improved the prognosis of chronic myeloid leukemia (CML). Recently, it has been recognized that some CML patients with a complete molecular response (CMR) are able to maintain treatment-free remission (TFR) after discontinuation of TKIs. However, no predictive prognostic factors for successful discontinuation of the treatment have yet been identified. We set out to further clarify the role of predictive biomarkers in molecular relapse and non-relapse after ABL TKI discontinuation. Materials and methods: Patients in sustained CMR (MR 4.5) undergoing TKI therapy were eligible for inclusion in the study. Molecular relapse was defined as loss of major molecular response (MMR) of at least one point. Genomic DNA was obtained from whole blood using a DNA Extractor WB Kit (Wako, Osaka, Japan), and was subjected to polymerase chain reaction (PCR) amplification using primers designed to detect a deletion site (2903 bp) in intron two of the BCL2L11 gene (forward: 5′-AATACCACAGAGGCCCACAG-3′; reverse: 5′-GCCTGAAGGTGCTGAGAAAG-3′) and JumpStart RedAccuTaq LA DNA polymerase (Sigma Aldrich, St. Louis, MO, USA). Results: 32 CML patients (17 men, 15 women, median age 58.4 years) were included in this study (Sokal category; low 24, intermediate 7, high 1). Six patients were treated with IFNα before TKI treatment, and 3 were treated with IFNα after stopping TKI. Median duration from TKI initiation to discontinuation was 79.3 months (range; 22 to 138 months); median duration of CMR before TKI discontinuation was 47.3 months (range; 5 to 97 months). Seven patients showed loss of MMR; 6 relapsed within 6 months and one showed late relapse at 25 months after discontinuation. The cumulative incidence of MMR loss was estimated as 18.8% at 12 months and at 24 months. Fluctuation of BCR-ABL transcript levels below the MMR threshold (> two consecutive positive values) was observed in 6.25% of patients at 24 months after ABL TKI discontinuation. Treatment-free remission was estimated as 81.2% at 12 months and at 24 months. The median period of restoration of second CMR was 6.0 months in re-treated patients. No patient died during the follow-up period. TKI-free remission was estimated as 78.1% at 30 months. There was only a significant difference in BCL2L11 (BIM) deletion polymorphism between the patients who maintained and those who lost MMR (p = 0.0253). No significant difference was observed in prior IFNα therapy, time to complete cytogenetic response (CCyR), time to MMR, and time to CMR between relapsing and non-relapsing patients. Conclusion: Our study shows a specific association between BCL2L11 (BIM) deletion polymorphism and clinical outcome after ABL TKI discontinuation in patients with long-lasting molecular undetectable residual disease. BCL2L11 (BIM) deletion polymorphism may predict relapse after ABL TKI discontinuation, which may have an impact on future ABL TKI discontinuation trials. These results further illustrate the importance of single nucleotide polymorphisms in successful long-term treatment of CML. Disclosures Ohyashiki: Bristol-Myers Squibb KK : Research Funding, Speakers Bureau; Novartis KK: Research Funding, Speakers Bureau.

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An Ongoing Phase 3 Study of Bosutinib (SKI-606) Versus Imatinib In Patients with Newly Diagnosed Chronic Phase Chronic Myeloid Leukemia

Blood ◽

10.1182/blood.v116.21.208.208 ◽

2010 ◽

Vol 116 (21) ◽

pp. 208-208 ◽

Cited By ~ 16

Author(s):

Carlo Gambacorti-Passerini ◽

Dong-Wook Kim ◽

Hagop M. Kantarjian ◽

Tim H. Brummendorf ◽

Irina Dyagil ◽

...

Keyword(s):

Adverse Events ◽

Median Time ◽

Myeloid Leukemia ◽

Research Funding ◽

Chronic Phase ◽

Molecular Response ◽

Employment Equity ◽

Phase 3 ◽

Advisory Committees ◽

Equity Ownership

Abstract Abstract 208 Bosutinib is an orally bioavailable dual Src/Abl tyrosine kinase inhibitor (TKI), with minimal inhibitory activity against PDGFR or c-kit. In a phase 2 study, bosutinib demonstrated activity in patients with Philadelphia chromosome–positive (Ph+) chronic phase (CP) chronic myeloid leukemia (CML) in the second- and third-line treatment settings (Cortes JE, et al. ASCO 2010, Abstract #6502; Khoury JH, et al. ASCO 2010, Abstract #6514), as well as in patients with advanced Ph+ leukemias (Gambacorti-Passerini C, et al. ASCO 2010, Abstract #6509) following resistance or intolerance to imatinib and other TKIs. The current randomized, open-label, phase 3 study compared the activity and safety of bosutinib with that of imatinib in newly diagnosed patients with CP CML. The study enrolled adults aged 318 years with cytogenetic diagnosis of Ph+ CP CML within 6 months, adequate hepatic and renal function, and an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. Patients were randomized to daily oral treatment with 500 mg bosutinib or 400 mg imatinib. Adverse events were graded using the National Cancer Institute Common Terminology Criteria, version 3.0. The primary efficacy endpoint was the rate of complete cytogenetic response (CCyR) at 1 year; the rates of hematologic response, molecular response, and progression and transformation to accelerated or blast phase were also evaluated. The study randomized 502 patients: 56.6% male, median age of 48 years (range, 18–91 years), and median time since diagnosis of 0.7 months (range, -0.3-7.9 months; the range minimum is negative due to CML diagnosis during the study screening period, and the range maximum is >6 months because of 1 patient considered a major protocol violator). The median duration of treatment was 11.1 months (range, 0.03–24.8 months). At Week 48 (approximately 11 months), 71.5% and 74.8% of patients (both treatment arms combined) were in CCyR and complete hematologic response (CHR), respectively. During the study, 81.4% of patients achieved a CCyR at or before Week 48, with a median time to CCyR of 24 weeks; 82.6% of patients achieved a CHR, with a median time to CHR of 8 weeks; and 40.6% of patients achieved a major molecular response (MMR), with a median time to MMR of 49 to 61 weeks for the 2 treatment arms. For the combined treatment arms, common treatment-emergent adverse events included diarrhea (43.7%), nausea (32.3%), vomiting (22.0%), rash (16.8%), pyrexia (11.6%), and fatigue (11.0%). The only grade 33 treatment-emergent adverse event observed in 32% of patients was diarrhea (5.2%), which was usually limited to the first weeks of treatment. Grade 33 hematologic laboratory abnormalities included neutropenia (14.2%), thrombocytopenia (12.4%), and anemia (5.8%). Other grade 33 laboratory abnormalities (35% of patients) included alanine aminotransferase elevation (11.6%), phosphatemia (7.6%), and aspartate aminotransferase elevation (6.4%). Overall, 22.2% patients discontinued therapy; adverse events led to discontinuation or death in 12.8% of patients, and 4.2% of patients discontinued due to disease progression. The high combined percentage of patients achieving MMR, CCyR, and CHR and the relatively low incidence of generally manageable grade 33 events observed suggest good efficacy and an overall favorable safety profile. Data for individual treatment arms will be unblinded by the end of August 2010, and will be presented at the meeting. Disclosures: Gambacorti-Passerini: Pfizer Inc: Research Funding. Kim:BMS, Novartis, Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Kantarjian:Novartis: Consultancy, Research Funding; BMS, Pfizer: Research Funding. Brummendorf:Pfizer Inc: Membership on an entity's Board of Directors or advisory committees. Griskevicius:Pfizer Inc: Research Funding. Goh:Novartis and Janssen Ciliag: Research Funding. Wang:Pfizer Inc: Employment, Equity Ownership. Gogat:Pfizer Inc: Employment, Equity Ownership. Cortes:Pfizer Inc: Consultancy, Research Funding.

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Efficacy of Ponatinib after Multiple Lines of Therapy for Chronic Myeloid Leukemia

Blood ◽

10.1182/blood-2018-99-119914 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 3013-3013

Author(s):

Mahesh Swaminathan ◽

Hagop M. Kantarjian ◽

Koji Sasaki ◽

Farhad Ravandi ◽

Gautam Borthakur ◽

...

Keyword(s):

Chronic Myeloid Leukemia ◽

Median Time ◽

Myeloid Leukemia ◽

Research Funding ◽

Chronic Phase ◽

Cytogenetic Response ◽

Molecular Response ◽

Genetics Research ◽

Line Therapy ◽

Line Of Therapy

Abstract Background: Ponatinib, a third-generation pan-tyrosine kinase inhibitor (TKI), was found to be effective in heavily pretreated patients (pts) with chronic myeloid leukemia (CML). With the availability of multiple TKI, these agents are used in different sequences, and there is limited information on the value of various TKI in different lines of therapy. Since ponatinib has been effective in 3rd and subsequent lines of therapy, we performed an analysis of a cohort of pts with CML who received ponatinib as a different line of treatment. Method: A total of 80 pts with chronic phase of CML and received ponatinib from 2009 to 2018 were analyzed. Only pts who received ponatinib as a second or subsequent line of therapy of CML were included. Major cytogenetic response (MCyR), complete cytogenetic response (CCyR), major molecular response (MMR), molecular response (MR) 4, and MR 4.5 were assessed. Event-free (EFS), transformation-free (TFS), failure-free (FFS) and overall survival (OS) were also analyzed. Results: Nine pts (11%) received ponatinib as a 2nd line therapy (prior TKI imatinib in 6, dasatinib in 1, and nilotinib in 2 pts); 21 (26%) as a 3rd line, 26 (33%) as a 4th line, and 24 (30%) as a 5th and above line. The median age was over 50 years (Y) in all the groups except for pts who received ponatinib as a 3rd line [38 Y (23-76)]. Among pts who received ponatinib as 2nd line, 9 (100%) achieved CCyR and MR 4.5; the median time to achieve CCyR and MR 4.5 was 3 and 6.8 months (mo), respectively (Table 1). In pts treated in 3rd line CCyR and MR 4.5 were 67% and 57%, respectively and the median time to response was 4.8 and 19.3 mo, respectively. Of the 26 pts treated in 4th line, 13 (50%) achieved CCyR (median time to CCyR 3 mo) and 7 (27%) achieved MR 4.5 (median time 11.6 mo). In 5th line and above 14 (58%) achieved CCyR (median time 6.4 mo) and 8 (33%) achieved MR 4.5 (median time 12.3 mo) (Figure 1). After a median follow-up of 59.8 months (range, 4.7 to 114.3) for all pts, the median OS was not reached in pts treated in 2nd to 4th line and 81.4 mo in ≥5th line. The median FFS was not reached in 2nd line, and was 45.6, 20.2, and 17.8 mo in 3rd, 4th, and ≥5th line, respectively. The median EFS and TFS was not reached in any line of treatment. The TFS was significantly better in pts who received ponatinib as a 2nd-4th line therapy as compared to ≥5th [p=0.0026, HR-55.97 (4.076-768.7)] (Figure 2). Conclusion: Our results suggest that CCyR and MR 4.5 were higher when ponatinib was used in up to 4th line of therapy for resistant CML, and it was particularly effective in 2nd or 3rd line where high rates of MR4.5 can be achieved. These results underscore the efficacy of ponatinib in these settings. Disclosures Sasaki: Otsuka Pharmaceutical: Honoraria. Ravandi:Jazz: Honoraria; Macrogenix: Honoraria, Research Funding; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; Abbvie: Research Funding; Jazz: Honoraria; Xencor: Research Funding; Astellas Pharmaceuticals: Consultancy, Honoraria; Orsenix: Honoraria; Sunesis: Honoraria; Abbvie: Research Funding; Amgen: Honoraria, Research Funding, Speakers Bureau; Astellas Pharmaceuticals: Consultancy, Honoraria; Sunesis: Honoraria; Orsenix: Honoraria; Macrogenix: Honoraria, Research Funding; Xencor: Research Funding; Amgen: Honoraria, Research Funding, Speakers Bureau. Kadia:Takeda: Consultancy; Jazz: Consultancy, Research Funding; Celgene: Research Funding; Novartis: Consultancy; Celgene: Research Funding; Takeda: Consultancy; Abbvie: Consultancy; Novartis: Consultancy; Jazz: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; BMS: Research Funding; Pfizer: Consultancy, Research Funding; Abbvie: Consultancy; BMS: Research Funding; Amgen: Consultancy, Research Funding; Amgen: Consultancy, Research Funding. DiNardo:Agios: Consultancy; Bayer: Honoraria; Medimmune: Honoraria; Karyopharm: Honoraria; Celgene: Honoraria; Abbvie: Honoraria. Konopleva:Stemline Therapeutics: Research Funding; abbvie: Research Funding; cellectis: Research Funding; Immunogen: Research Funding. Pemmaraju:stemline: Consultancy, Honoraria, Research Funding; cellectis: Research Funding; novartis: Research Funding; samus: Research Funding; plexxikon: Research Funding; daiichi sankyo: Research Funding; celgene: Consultancy, Honoraria; Affymetrix: Research Funding; SagerStrong Foundation: Research Funding; abbvie: Research Funding. Daver:ARIAD: Research Funding; BMS: Research Funding; Novartis: Research Funding; Incyte: Consultancy; Incyte: Research Funding; Karyopharm: Research Funding; Kiromic: Research Funding; Pfizer: Research Funding; Daiichi-Sankyo: Research Funding; Sunesis: Research Funding; Alexion: Consultancy; ImmunoGen: Consultancy; Karyopharm: Consultancy; Otsuka: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; Sunesis: Consultancy. Wierda:Genentech: Research Funding; AbbVie, Inc: Research Funding. Jabbour:novartis: Research Funding. Cortes:novartis: Research Funding.

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Chronic myeloid leukemia: successful therapy with nilotinib in a young patient with high Sokal risk and in sub-optimal response with imatinib

Clinical Management Issues ◽

10.7175/cmi.v4i6s.1098 ◽

2015 ◽

Vol 4 (6S) ◽

pp. 13-16

Author(s):

Fausto Palmieri

Keyword(s):

Chronic Myeloid Leukemia ◽

Young Patient ◽

Myeloid Leukemia ◽

Second Generation ◽

Kinase Inhibitor ◽

Standard Dose ◽

Chronic Phase ◽

Molecular Response ◽

Optimal Response ◽

Increased Risk

Here we describe a case of a young patient with chronic myeloid leukemia, at high-risk according to the Sokal index, who started imatinib at standard dose and obtained a sub-optimal response at 12 months. This condition was not automatically an indication to change therapy, but considering the patient as suboptimal, we decided to switch to a second-generation tyrosine kinase inhibitor (TKI), nilotinib 800 mg/die, obtaining soon a complete cytogenetic response (CCYR), thereafter a major molecular response (MMolR). Delayed achievement of cytogenetic and molecular is associated with increased risk of progression among patients with chronic myeloid leukemia in early chronic phase receiving imatinib therapy. Therefore we can hypothesise that this kind of patient could be elegible for an early switch to second-generation TKI.

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Dasatinib Is Well-Tolerated and Efficacious in Imatinib-Intolerant Patients with Chronic-Phase Chronic Myeloid Leukemia (CP-CML).

Blood ◽

10.1182/blood.v114.22.1128.1128 ◽

2009 ◽

Vol 114 (22) ◽

pp. 1128-1128 ◽

Cited By ~ 2

Author(s):

Hanna Jean Khoury ◽

Michael J. Mauro ◽

Yousif Matloub ◽

Tai-Tsang Chen ◽

Erkut Bahceci ◽

...

Keyword(s):

Chronic Myeloid Leukemia ◽

Median Duration ◽

Myeloid Leukemia ◽

Research Funding ◽

Kinase Inhibitor ◽

Chronic Phase ◽

Phase Iii ◽

Hematologic Toxicity ◽

Molecular Response

Abstract Abstract 1128 Poster Board I-150 Imatinib (IM), a tyrosine kinase inhibitor (TKI), has been the mainstay of treatment for chronic phase chronic myeloid leukemia (CP-CML). However, IM resistance and intolerance are of considerable clinical relevance. Dasatinib (DAS), a second-line TKI, is effective in the IM-intolerant patient population. The purpose of this study was to determine baseline factors that can affect DAS response and evaluate long term efficacy in this population. Intolerance to IM was defined as ≥ Grade 3 non-hematologic toxicity and/or Grade 4 hematologic toxicity lasting > 7 days. A total of 271 Ph+ CP-CML IM-intolerant patients who received DAS were pooled from two randomized trials (Phase II-trial, CA 180013 and Phase III trial, CA 180034). DAS doses were 50 mg BID (n=43), 70 mg BID (n=141), 100 mg QD (n=43) or 140 mg QD (n=44). At baseline, the median duration of disease for the IM-intolerant patients was 24 months (range: 0.9-182.5) and the median duration of IM therapy was 9 months (range: 0.03-69.06). Of these patients, 46 (17%) had hematologic toxicity and 228 (84.1%) had non-hematologic toxicity to IM. Seventy-nine (29%) patients had prior complete cytogenetic response (CCyR) on IM and 171 (63%) patients did not. The data for prior CyR to IM was not reported for 21 (7.7%) patients. Of the 79 patients who had achieved CCyR on IM, 30 patients had maintained CCyR and 49 patients had lost this response prior to start of DAS. Of the 171 patients who did not achieve CCyR on IM, 62 (36.3%) had been on IM for 3 12 months and 109 (63.7%) for < 12 months. At 2-year follow up of the 271 patients treated with DAS, 121 (44.6%) discontinued DAS (7.4% due to hematologic toxicity and 14% due to non-hematologic toxicity). Of the patients who were intolerant of IM due to hematologic toxicity (n=46), 10 (21.7%) discontinued DAS due to hematologic toxicity, and 3 (6.5%) due to other toxicities. Of the patients with non-hematologic IM-intolerance (n=228), 10 (4.4%) discontinued DAS due to hematologic toxicity, and 35 (15.4%) due to other toxicities. The median average daily dose of DAS was 99 mg/day in the population who achieved CCyR on DAS and 71.5 mg/day in the population who did not achieve CCyR on DAS. The probability of achieving CCyR on DAS was 43.5% in patients with hematologic IM-intolerance versus 78.9% with non-hematologic IM-intolerance. The CCyR, major molecular response (MMR), progression-free survival (PFS) and overall survival (OS) at 2-year follow up for the groups classified by their CCyR status at start of DAS or IM-intolerance status are summarized in Table 1. Conclusions DAS was well-tolerated and associated with high rates of CyR in IM-intolerant patients. Patients with a prior CCyR to IM and those who switched due to non-hematologic imatinib-intolerance had the highest rates of CCyR and MMR on DAS, while patients without CCyR after more than 12 months of IM therapy or IM-intolerance due to hematologic toxicity had the lowest rates of CCyR and MMR. Disclosures Khoury: BMS: Honoraria; Wyeth: Honoraria; Novartis Pharmaceuticals: Honoraria; Chemgenex: Honoraria; Genzyme: Honoraria. Mauro:Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding. Matloub:Bristol-Myers Squibb: Employment. Chen:Bristol-Myers Squibb: Employment. Bahceci:Bristol-Myers Squibb: Employment. Deininger:Novartis: Consultancy; Bristol-Myers Squibb: Consultancy; Calistoga: Research Funding; Genzyme: Research Funding.

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Results of Imatinib Dose Escalation After 36 Months of Follow-up in Chronic Myeloid Leukemia Patients with Failure or Sub-Optimal Response According to 2006 EuropeanLeukemia Net (ELN) Criteria.

Blood ◽

10.1182/blood.v114.22.3302.3302 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3302-3302

Author(s):

Massimo Breccia ◽

Fabio Stagno ◽

Roberto Latagliata ◽

Paolo Vigneri ◽

Laura Cannella ◽

...

Keyword(s):

Chronic Myeloid Leukemia ◽

Dose Escalation ◽

Myeloid Leukemia ◽

Conflicts Of Interest ◽

Standard Dose ◽

Acquired Resistance ◽

Chronic Phase ◽

Cytogenetic Response ◽

Molecular Response

Abstract Abstract 3302 Poster Board III-190 Introduction Imatinib mesylate (IM) given at a daily dose of 400 mg currently represents the gold standard of care for patients with chronic myeloid leukemia (CML) in chronic phase (CP). European LeukemiaNet (ELN) guidelines propose IM dose escalation to rescue those CML patients with either suboptimal response or drug resistance. We report on the long-term efficacy of IM dose escalation in 74 patients with CP-CML after suboptimal response or failure to IM conventional dose. Patients and methods Median age was 50 years (range 19-85), there were 52 males and 22 females. Thirteen patients were classified as hematologic failure (10 primary and 3 secondary), 57 patients as cytogenetic resistance (24 primary and 33 acquired). Three patients escalated the dose for cytogenetic suboptimal response and one patient for molecular suboptimal response at 18 months. Fifty-four received IM dose escalation from 400 to 600 mg and 20 patients from 400 to 800 mg. Results Overall, after a median follow-up of 36 months, 68/74 (91.8%) patients maintained or achieved a complete haematologic response (CHR); this was maintained in all patients who escalated the dose for cytogenetic failure or suboptimal response. A major cytogenetic response (MCyR) was achieved in 41 patients (72%) who escalated the dose for cytogenetic failure and in 6/13 (46%) patients who escalated imatinib for hematologic failure (p=0.002). Overall, complete cytogenetic responses (CCR) were achieved in 27 (37%) out of 74 CML patients: of the 13 hematologic failure patients, only 5 achieved CCyR: all patients had prior acquired resistance to imatinib. Of the 57 cytogenetic failure, 22 reached CCR: this response was obtained in 27% of the primary cytogenetic resistant, and in 50% of the acquired cytogenetic resistant patients (p=0.02). Three patients who escalated the dose for cytogenetic suboptimal response obtained CCR and complete molecular response (CMR), whereas one patient who escalated the dose for molecular suboptimal response at 18 months did not obtain CMR. Median time to cytogenetic response was 3.5 months. Cytogenetic responses occurred in 37/50 patients who escalated the dose to 600 mg and in 10/20 patients who escalated to 800 mg daily (p=0.234). CMR was obtained in 10 patients: in 7 patients who escalated the dose for cytogenetic failure and in 3 patients who escalated imatinib for suboptimal cytogenetic response. Estimated 2 year-progression free survival (PFS) and overall survival (OS) is 87% and 85% respectively. Sixteen patients (21.6%) experienced toxicities and had temporarily IM interruption. Conclusions Imatinib dose escalation can induce sustained responses in a subset of patients with cytogenetic resistance and a prior suboptimal cytogenetic response to standard-dose imatinib, whereas it appears less effective in haematologic failure patients or in molecular sub-optimal responders. The availability of second generation TKI should be taken into account in these letter categories of patients. Disclosures No relevant conflicts of interest to declare.

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Long Term Adherence to Imatinib Therapy Is the Critical Factor for Achieving Molecular Responses in Chronic Myeloid Leukemia Patients.

Blood ◽

10.1182/blood.v114.22.3290.3290 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3290-3290 ◽

Cited By ~ 6

Author(s):

Alex Bazeos ◽

Jamshid Khorashad ◽

François-Xavier Mahon ◽

Lina L Eliasson ◽

Dragana Milojkovic ◽

...

Keyword(s):

Chronic Myeloid Leukemia ◽

Myeloid Leukemia ◽

Research Funding ◽

Independent Predictor ◽

Chronic Phase ◽

Imatinib Therapy ◽

Adherence Rate ◽

Molecular Response ◽

Molecular Responses ◽

Adherence To Therapy

Abstract Abstract 3290 Poster Board III-1 There is a great variability in the degree of molecular responses achieved by chronic myeloid leukemia (CML) patients treated with imatinib. These different levels of molecular response could reflect different degrees of adherence to therapy. We measured the adherence to imatinib therapy in 87 consecutive CML chronic phase patients who had received imatinib 400 mg day as first line therapy for a median of 59.7 months before enrolment (range 25–104) and therefore all them were in complete cytogenetic response. Adherence levels were monitored during a 3-month period using microelectronic monitoring devices (MEMS) and were related to levels of molecular response. MEMS consist of an electronic device fitted in the cap of a normal looking medication bottle that automatically records each time the bottle is opened. MEMS are considered as the ‘gold standard' for measuring adherence. We also measured the imatinib plasma level, the presence of TKD mutations and the following prognostic factors measured at diagnosis: hOCT1 transcripts level, polymorphism 1236C>T in ABCB1, Sokal risk group, hemoglobin, leukocytes , BCR-ABL1 transcript type and BCR1-ABL1 ratio and demographic data. The study protocol was approved by the Research Ethics Committee and patients gave written informed consent to participate. The median adherence rate was 97.6% (range 22.6–103.8%). In 23 (26.4%) patients adherence was ≤90% (median 76%) and in 12 (13.8%) ≤80% (median 63%). We found a strong association between adherence rate (≤90% or >90%) and the 6-year probability of major molecular response (MMR) (28.4% vs 94.5%, p<0.0001) and complete molecular response (CMR) (0% vs 43.8%, p=0.002) (Fig 1). Multivariate analysis identified adherence (RR=11.7, p=0.001) and expression of the molecular transporter hOCT1, (RR=1.79, p=0.038) as the only independent predictors for MMR. Adherence was the sole independent predictor for CMR. No molecular responses were observed when the adherence was ≤20% (p=0.0001). In patients whose imatinib dose had been increased (n=32) the adherence was poor (median 86.4%). Adherence was the only independent predictor for failure to achieve a 3-log transcript reduction (RR=17.66, p=0.006) in this subgroup of patients. Patients with CML vary greatly in their response, as demonstrated originally by Sokal et al. in 1984, and the same variation is seen in patients treated with imatinib in the modern era. The basis for this variation is unknown but it has been attributed to the intrinsic biological heterogeneity of the leukemia. In contrast we show here that adherence to therapy is the major factor determining the degree of response that a CML patient treated with imatinib will achieve. Disclosures: Mahon: Novartis: Consultancy, Research Funding. Apperley:Novartis: Consultancy, Honoraria. Rezvani:Novartis: Consultancy, Honoraria, Research Funding. Marin:Novartis: Consultancy, Research Funding.

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Specific Drug Transporter Genotypes Are Significantly Associated with Increased Rates of Major and Complete Molecular Responses In Newly Diagnosed Chronic Myeloid Leukemia Patients Treated with Imatinib – A TOPS Correlative Substudy

Blood ◽

10.1182/blood.v116.21.670.670 ◽

2010 ◽

Vol 116 (21) ◽

pp. 670-670

Author(s):

Simona Soverini ◽

Sabrina Angelini ◽

Eleonora Turrini ◽

Matt Burnett ◽

Gloria Ravegnini ◽

...

Keyword(s):

Chronic Myeloid Leukemia ◽

Cumulative Incidence ◽

Myeloid Leukemia ◽

Research Funding ◽

Phase Iii ◽

Molecular Response ◽

Newly Diagnosed ◽

First Line ◽

Favorable Alleles ◽

Summary Measures

Abstract Abstract 670 The availability of multiple options for chronic myeloid leukemia (CML) treatment is not paralleled by the availability of biological predictors of outcome allowing to identify patients (pts) who are more likely to benefit from dasatinib or nilotinib rather than imatinib (IM). Pharmacogenetics has proven a potential source of biomarkers given the known influence of polymorphisms in key genes encoding drug transporters and metabolizing enzymes on drug delivery – hence effectiveness. In CML, only two studies had so far explored this field, but both were conducted in heterogeneous populations including pts at different stages of disease, not all receiving IM first-line. We thus aimed to investigate a panel of 20 single nucleotide polymorphisms (SNPs) in ABCB1, ABCG2, SLC22A1, OATP1A2, OCTN1, CYP3A4 and CYP3A5 genes that can be hypothesized to influence IM transport and metabolism in 189 newly diagnosed CML pts enrolled in the TOPS phase III trial (Cortes et al, J Clin Oncol 2010). Pts selection was exclusively based on availability of written informed consent and sufficient amount of archived material. Median age was 46 years; male to female ratio was 103 to 86; 156 (83%) pts were Caucasian and 23 (12%) were Asian; low, intermediate and high Sokal risk pts were 84 (44.4%), 65 (34.4%) and 40 (21.2%), respectively. Baseline demographic/clinical features did not differ significantly from those of the overall population. Treatment outcomes (complete cytogenetic response [CCyR]; major molecular response [MMR] and complete molecular response [CMR]) were compared according to i) each candidate genotype ii) summary measures based on combinations of SNPs in the same gene and iii) summary measures based on combinations of SNPs in functionally related genes (uptake; efflux). CC genotype in OCTN1 had a favorable impact on the achievement of MMR at 12 months (MMR@12m; P = 0.03). With respect to the summary measures, combination of SNPs in the SLC22A1 gene was significantly correlated with MMR@12m (P = 0.03). When considering summary measures of uptake and efflux, the former was found to be associated with both MMR@12m and CMR@12m (P = 0.003 and P = 0.01, respectively). A separate analysis limited to Caucasian pts (n=156) yielded similar results (Table 1). In addition, the analysis in the Caucasian subgroup evidenced a significant association between the CC genotype in ABCB1 rs60023214 and MMR@12m (P = 0.005) (Table 1). Cumulative incidence plots based on the Kaplan-Meier method were also analyzed in the overall population and in Caucasians, with comparable results. Representative plots are shown in Figure 1. There was evidence for difference among MMR cumulative incidence curves for 2 single SNPs and 2 score measures. Presence of the major allele in OCTN1 (CC) and of the minor allele in CYP3A4 rs2740574 (GG) were associated with increased MMR rate (P = 0.028 and P = 0.042, respectively, in the overall population and P = 0.027 and P = 0.038, respectively, in Caucasians). Similarly, an increase in the number of favorable alleles in the SLC22A1 gene was associated with increased MMR rate (P = 0.030 and P = 0.043 in the overall population and in Caucasians, respectively). In addition, the combination of favorable alleles in the genes involved in IM uptake was associated with increased rates of both MMR and CMR (P = 0.004 and P = 0.015, respectively, in the overall population and P = 0.005 and P = 0.009, respectively, in Caucasians). Our results suggest that SNP genotyping might be helpful in selecting pts who are more likely to benefit from first-line use of more potent inhibitors. Further assessment of the SNPs here identified in larger series of pts is warranted. Supported by Novartis Oncology, Clinical Development, TOPS Correlative Studies Network Disclosures: Hughes: Novartis: Honoraria, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Research Funding; Ariad: Honoraria. White:Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Research Funding. Saglio:Novartis: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria. Rosti:Novartis: Consultancy, Honoraria; BMS: Consultancy, Honoraria. Hatfield:Novartis: Employment. Martinelli:Novartis: Consultancy, Honoraria; BMS: Honoraria; Pfizer: Consultancy.

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Rapid Reduction of Chronic Myeloid Leukemia Stem Cells After Treatment with Second-Generation BCR-ABL Kinase Inhibitors, Dasatinib and Nilotinib

Blood ◽

10.1182/blood.v116.21.4457.4457 ◽

2010 ◽

Vol 116 (21) ◽

pp. 4457-4457

Author(s):

Yosuke Minami ◽

Akihiro Abe ◽

Yuka Nomura ◽

Miho Minami ◽

Yachiyo Kuwatsuka ◽

...

Keyword(s):

Stem Cells ◽

Chronic Myeloid Leukemia ◽

Myeloid Leukemia ◽

Research Funding ◽

Second Generation ◽

Kinase Inhibitors ◽

Newly Diagnosed ◽

Rapid Reduction ◽

Population Total ◽

Significant Difference

Abstract Abstract 4457 Chronic myeloid leukemia (CML) is effectively treated with imatinib (IM), however, several mathematical models and ex vivo-examinations suggested that IM-therapy does not eradicate BCR-ABL-positive hematopoietic stem cells (HSC). We prospectively (0, 3, 6 and 12 months after IM-therapy) investigated 16 newly diagnosed and 22 long-term followed CML-chronic phase (CP) cases using methods previously reported (Jamieson et al., N Engl J Med, 2004. and Abe et al., Int J Hematol, 2008) (Figure 1) with FACSAria™ and quantitative RT-PCR of BCR-ABL among each sorted population; total mononuclear cells, HSC/Thy-1+, HSC/Thy-1–, common myeloid progenitors (CMP), granulocyte macrophage progenitors (GMP) and megakaryocyte erythroid progenitors (MEP). In optimal responders to IM-therapy, BCR-ABL transcripts in the HSC populations (HSC/Thy-1+ and HSC/Thy-1–) tended to be more retentive than other populations while gradual reduction was observed during the first 12 months in all populations. And discrepancy of minimum residual diseases (MRD) between the HSC populations and other populations was larger in patients after longer IM-therapy. In evaluating properties of CML stem cells and other markers, we observed irrelevant distribution of side population (SP) and expressions of ABC transporters (ABCB1 and ABCG2) in comparison with CD34/38 expression. We also prospectively investigated BCR-ABL transcripts in each population of 23 IM-resistant or -intolerant CML-CP cases and one newly diagnosed CML-accelerated phase (AP) case during treatment with second-generation tyrosine kinase inhibitors (2nd TKIs), dasatinib or nilotinib. Treatment with each inhibitor induced more rapid reduction of BCR-ABL transcripts even in the HSC population (CD34+CD38–) during the first 6 months and there was no significant difference of MRD among each population in optimal responders to 2nd TKIs-therapy. In the stromal co-culturing system using primary cells and leukemic NOD/SCID/IL2rgnull (NOG) mice xenotransplanted with Ph+ leukemia cells, retention of quiescent slow-cycling (Hoechst 33342low/Pyronin Ylow) CD34+ population after IM-treatment were observed and cell death mechanisms after treatment with 2nd TKIs are also under investigation. These results imply that therapy with 2nd TKIs could be a promising approach for quick and efficient reduction of the CML stem cells and cure of disease. Figure 1 Figure 1. Disclosures: Naoe: Kyowa-Kirin: Research Funding; Novartis: Research Funding; Bristol-Myers Squibb: Research Funding.

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