Characterization of the Genomic Landscape of BCR-ABL1 Kinase-Independent Mechanisms of Resistance to ABL1 Tyrosine Kinase Inhibitors in Chronic Myeloid Leukemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1119-1119 ◽  
Author(s):  
Christopher A. Eide ◽  
Daniel Bottomly ◽  
Samantha L. Savage ◽  
Libbey White ◽  
Beth Wilmot ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Board Of Directors ◽  
Research Funding ◽  
Kinase Inhibitors ◽  
Chronic Phase ◽  
Kinase Domain ◽  
Advisory Committees ◽  
Dana Farber Cancer Institute ◽  
Kinase Domain Mutation ◽  
Equity Ownership

Abstract Despite the well-established success of ABL1 tyrosine kinase inhibitors (TKIs) in the treatment of patients with chronic myeloid leukemia (CML), approximately 20% of patients treated with frontline imatinib develop resistance by 5 years on therapy. The majority (~60%) of such resistant cases are explained by acquired mutations within the BCR-ABL1 kinase domain that compromise inhibitor binding, and nearly all of these mutations are effectively targeted by one or more of the 2nd and 3rd generation ABL1 kinase inhibitors. In contrast, the remaining ~40% of imatinib-resistant cases harbor no explanatory BCR-ABL1 kinase domain mutation, presumably attributable to BCR-ABL1 kinase-independent mechanisms. We hypothesized that resistance in these patients results from acquired auxiliary molecular aberrations which persistently activate signaling pathways downstream despite inhibition of BCR-ABL1 kinase activity. To identify such mechanisms, we performed whole exome sequencing and RNA sequencing on a cohort of 135 CML patients comprising the following subgroups: newly diagnosed/TKI naïve (n=28), BCR-ABL1 kinase-dependent resistance (n=31), and BCR-ABL1 kinase-independent resistance (n=65), and TKI-induced remission (n=7). Resistant patients were required to have demonstrated clinical resistance to one or more ABL1 kinase inhibitors in the form of suboptimal response or loss of cytogenetic response; the subtype of resistance was defined based on the presence or not of an explanatory BCR-ABL1 kinase domain mutation at the time of resistance. The majority of samples collected were from patients with chronic phase CML (n=97), although smaller cohorts of accelerated phase CML, blast crisis CML, and Ph+ ALL were also profiled (n=20, 19, and 9, respectively). Among the 44,413 protein-altering and 902 splice site variants detected across the 120 WES samples, there were on average 908 missense, 146 truncation and 69 splice variants per sample. Genes with truncation and missense variants were compared between BCR-ABL1 kinase-independent and -dependent resistant chronic phase samples. A total of 44 genes were seen with a frequency difference of at least 10%, including PLEKHG5 and NKD2 (30% and 28% difference, respectively), which are involved in regulation of NF-kB and Wnt signaling. Consistent with previous reports, we also detected EZH2 and TET2 as exclusively mutated in the BCR-ABL1 kinase-independent resistance patients (6% and 3%, respectively). Further analyses stratifying variants among resistant patients according to specific ABL1 kinase inhibitor therapy failed and comparing, where available, serial samples from pre- and post-treatment for clonal expansion are underway. Additionally, sufficient material was available to perform ex vivo small-molecule inhibitor screening for 48 patient specimens, the resultant data of which was used to generate putative effective drug target profiles and integrated with exome sequencing variants to prioritize variants of functional relevance (HitWalker; Bottomly et al., Bioinformatics 2013). Among 23 patient samples exhibiting BCR-ABL1 kinase-independent resistance, the mutated genes most frequently ranked in the top 10 functional-prioritized variants were: ABL1 (which included non-kinase domain variants; 34.7%), MAP3K1, MUC4, FGF20 (each 17.4%), ARHGEF15, MEF2A, EPHA8, TYRO3, BMP2K, and IRS1 (each 13.0%). Notably, the top six candidates are members of the neutrophin (ABL1, MAP3K1, and IRS1), EPHA forward (EPHA8, ARHGEF15), and p38 MAPK signaling pathways (MAP3K1 and MEF2A). Taken together, these findings suggest that several of the same pathogenic molecular abnormalities seen in other myeloid malignancies are also present in CML patients with BCR-ABL1 kinase-independent resistance, including a subset which align to persistent re-activation of signaling pathways involved in CML disease pathogenesis and progression. As such, genetic and/or functional profiling of these patients in the clinic may translate to actionable candidates for combination therapy to maximize disease control and improve patient outcomes. Disclosures Agarwal: CTI BioPharma Corp: Research Funding. Radich:Novartis: Consultancy, Research Funding; BMS: Consultancy; Ariad: Consultancy. Deininger:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Research Funding; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Research Funding; CTI BioPharma Corp.: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Ariad: Consultancy, Membership on an entity's Board of Directors or advisory committees. Druker:Pfizer: Patents & Royalties; Dana-Farber Cancer Institute: Patents & Royalties: Millipore royalties via Dana-Farber Cancer Institute; Curis: Patents & Royalties; Array: Patents & Royalties; CTI: Consultancy, Equity Ownership; Pfizer: Patents & Royalties; Curis: Patents & Royalties; Array: Patents & Royalties; Dana-Farber Cancer Institute: Patents & Royalties: Millipore royalties via Dana-Farber Cancer Institute; Oncotide Pharmaceuticals: Research Funding; Novartis: Research Funding; BMS: Research Funding; ARIAD: Patents & Royalties: inventor royalties paid by Oregon Health & Science University for licenses, Research Funding; Roche: Consultancy; Gilead Sciences: Consultancy, Other: travel, accommodations, expenses; D3 Oncology Solutions: Consultancy; AstraZeneca: Consultancy; Ambit BioSciences: Consultancy; Agios: Honoraria; MolecularMD: Consultancy, Equity Ownership, Patents & Royalties; Lorus: Consultancy, Equity Ownership; Cylene: Consultancy, Equity Ownership.

Subset Analysis of Response to Treatment of Chronic Phase CML in a Phase 1 Study of Ponatinib in Refractory Hematologic Malignancies

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 602-602 ◽  
Author(s):  
Jorge E. Cortes ◽  
Hagop M. Kantarjian ◽  
Neil Shah ◽  
Dale Bixby ◽  
Michael J. Mauro ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Median Time ◽  
Research Funding ◽  
Phase 1 ◽  
Chronic Phase ◽  
Hematologic Malignancies ◽  
Employment Equity ◽  
Advisory Committees ◽  
Mutation Status ◽  
Equity Ownership

Abstract Abstract 602 Background: Ponatinib is a potent, oral, pan-BCR-ABL inhibitor active against the native enzyme and all tested resistant mutants, including the uniformly resistant T315I mutation. Initial findings of a phase 1 trial in patients (pts) with refractory hematologic malignancies have been reported. The effect of duration of treatment, prior treatment, and mutation status on response to treatment was examined in CML chronic phase (CP) pts who responded to ponatinib. Methods: An open-label, dose escalation, phase 1 trial of ponatinib in pts with hematologic malignancies is ongoing. The primary aim is to assess the safety; anti-leukemic activity is also being investigated. Pts resistant to prior treatments or who had no standard treatment available were enrolled to receive a single daily oral dose of ponatinib (2 mg to 60 mg). Subset analyses of factors impacting cytogenetic and molecular response endpoints (MCyR and MMR) were performed for pts with CP-CML. Data are presented through April 15, 2011. Results: In total, 81 pts (54% male) received ponatinib. Overall, 43 pts had CP with 34 ongoing at analysis. MCyR was observed as best response in 31/43 (72%), 27 (63%) CCyR. The median time to MCyR was 12 (3 to 104) wks. Response rates were assessed by duration of treatment (1 pt in CCyR at entry was excluded; 6 pts in PCyR had to achieve CCyR). At the 3 month assessment, 22/42 (52%) CP pts achieved MCyR; at 6 months, 24/42 (57%); at 12 months, 29/42 (69%) had MCyR. The impact of prior treatment on response and time to response was assessed. 42 pts (98%) had >2 prior TKIs and 28 (65%) ≥3 prior TKIs, including investigational agents. Of approved TKIs, all pts were previously treated with imatinib, 19 dasatinib or nilotinib after imatinib, and 21 both dasatinib and nilotinib after imatinib. MCyR rate decreased with number of prior TKIs (2 prior TKIs 13/14 [93%], ≥3 prior TKIs 17/28 [61%]) and number of approved TKIs (imatinib followed by dasatinib or nilotinib 17/19 [90%], or by both dasatinib and nilotinib 12/21 [57%]). Time to response was prolonged in pts more heavily treated with prior TKIs. Median time to MCyR increased with the number of prior TKIs and approved TKIs (2 TKIs 12 wks, ≥3 TKIs 32 wks). The effect of mutation status on response and time to response was also evaluated. At entry, 12 pts had the T315I mutation, 15 had other BCR-ABL kinase domain mutations, 12 had no mutations detected, 4 did not allow sequencing. MCyR response rate for CP pts with T315I was 11/12 (92%); for other mutations, 10/15 (67%); and no mutation, 7/12 (58%). Similarly, mutation status had an impact on time to response: median time to MCyR was 12 wks for those with T315I or other mutations and 32 wks in resistant pts with no mutation. All CP patients were evaluable for MMR. At analysis, MMR was 17/43 (40%). MMR rate was inversely related to number of prior TKIs (2 TKIs 10/14 [71%], ≥3 TKIs 6/28 [21%]), approved TKIs (imatinib followed by dasatinib or nilotinib 12/19 [63%], or by both dasatinib and nilotinib 4/21 [19%]), and was higher for T315I pts (7/12, 58%) and those with other mutations (7/15, 47%) compared with no mutation (2/12, 17%). Median time to MMR for CP pts was 97 wks; median time to MMR was shorter for pts who were less heavily treated (2 prior TKIs 24 wks) and those with T315I or other mutations (63 wks). Conclusion: In this subset analysis of the phase 1 data, ponatinib had substantial activity in all subgroups analyzed. Time on treatment, less prior therapy and kinase domain mutations were associated with higher response rates and early responses in CP pts. Cytogenetic responses improved over the first 12 months of treatment and were higher in less heavily treated pts. Disclosures: Cortes: Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Ariad: Consultancy, Research Funding. Kantarjian:Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; BMS: Consultancy, Research Funding; ARIAD: Research Funding. Shah:Ariad: Consultancy, Research Funding. Bixby:Novartis: Speakers Bureau; BMS: Speakers Bureau; GSK: Speakers Bureau. Mauro:ARIAD: Research Funding. Flinn:ARIAD: Research Funding. Hu:ARIAD: Employment. Clackson:ARIAD: Employment, Equity Ownership. Rivera:ARIAD: Employment, Equity Ownership. Turner:ARIAD: Employment, Equity Ownership. Haluska:ARIAD: Employment, Equity Ownership. Druker:MolecularMD: OHSU and Dr. Druker have a financial interest in MolecularMD. Technology used in this research has been licensed to MolecularMD. This potential conflict of interest has been reviewed and managed by the OHSU Conflict of Interest in Research Committee and t. Deininger:BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Ariad: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Genzyme: Research Funding. Talpaz:ARIAD: Research Funding.

Inhibition of USP10 Induces Degradation of Oncogenic FLT3: A Novel Approach to Therapy of Leukemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 524-524
Author(s):  
Sara Buhrlage ◽  
Ellen Weisberg ◽  
Nathan Schauer ◽  
Jing Yang ◽  
Ilaria Lamberto ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Research Funding ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Leukemia Cell ◽  
Initial Assessment ◽  
Large Trial ◽  
Newly Diagnosed ◽  
Advisory Committees ◽  
Equity Ownership

Abstract Acute myeloid leukemia (AML) is the most common type of acute leukemia in adults. Overall, the survival with current chemotherapy is only 20-40%, declining steadily with advancing age. Approximately 30% of AML patients have mutations that constitutively activate the FLT3 gene. The most common FLT3 mutation results in tandem duplications within the juxtamembrane domain, observed in 20-25% of AML patients (internal tandem duplication, ITD), associated with markedly decreased survival. FLT3 kinase domain inhibitors, including SU11248, SU5416, CEP-701 and PKC412 (midostaurin), have been shown to induce partial, and usually brief, remissions in clinical trials of relapsed AML patients when administered as single agents. In a large trial in newly diagnosed patients, however, midostaurin was shown to increase survival when combined with standard chemotherapy.[1] This study supports the notion that inhibition of FLT3 may be important, at least in patients with mutations in the FLT3 gene. Since drug resistance develops in some patients with newly diagnosed AML and virtually all patients with advanced disease, additional strategies to target FLT3 would be of value. We discovered that the deubiquitinating enzyme (DUB) ubiquitin specific protease 10 (USP10) removes a degradative ubiquitin tag from mutant FLT3 thereby contributing to high levels of the oncogenic protein in AML (Fig 1a). Screening of our preclinical DUB inhibitor library for ability to selectively kill growth factor-independent FLT3-ITD-positive Ba/F3 cells over IL-3-dependent parental Ba/F3 cells identified HBX19818, a reported USP7 inhibitor, as the top hit. The effects are not unique to the Ba/F3 system: when profiled against a panel of 7 leukemia cell lines, HBX19818 conferred a substantial growth suppressive effect only to those expressing the FLT3-ITD oncoprotein (Fig 1b). As an initial assessment of the mechanism of HBX19818 we confirmed that it does promote ubiquitin-mediated degradation of FLT3-ITD (Fig 1c) and that the effect is selective as HBX19818 does not impact protein levels of wt FLT3. HBX19818 is published as an irreversible USP7 inhibitor,[2] however DUBome selectivity profiling data we generated identifies USP10 as the most potently inhibited DUB of the compound (USP10 IC50 = 14 µM). We went on to validate USP10 as the DUB that stabilizes FLT3-ITD using a combination of small molecule and genetic experiments. Notably, HBX19818 binds and inhibits USP10 in cells (data not shown), small hairpin knockdown of USP10 phenocopies the antiproliferative and FLT3 degradation effects of HBX19818 (Figure 1d and data not shown), and a direct interaction between USP10 and FLT3-ITD is observed in co-immunoprecipitation experiments (Fig 1e). Additionally, SAR studies reveal correlation among USP10 IC50, FLT3-ITD degradation and anti-proliferative effects for the HBX19818 chemical series, and we identified a second chemotype that phenocopies its effects. In support of the translational potential of USP10 inhibition for FLT3 mutant AML, we observed that both USP10 inhibitor series synergize with FLT3 kinase inhibitors, suppress growth of mutant FLT3-expressing primary AML cells and primagraft AML cells and, importantly, display the ability to overcome the FLT3 inhibitor-resistant mutant FLT3-ITD-F691L among other FLT3 kinase inhibitor-resistant mutants (Fig. 1f and data not shown). Overall, our data strongly support degradation of mutant FLT3 as an alternative approach to therapeutically target FLT3. This approach, which focuses on targeting USP10, could prove more efficacious than kinase inhibitors by simultaneously blocking both enzymatic and scaffolding functions of FLT3, and blocking compensatory increases in FLT3 protein or resistant point mutations associated with some kinase inhibitors. Importantly, this is the first demonstration of stabilization of an AML mutant driver protein by a DUB enzyme and introduces a novel therapy for FLT3 mutant-positive AML. References: 1. Stone, R.M., ASH, 2015. 2. Reverdy, C., et al., Chem Biol, 2012. 19, 467-77. Figure 1. Figure 1. Disclosures Weisberg: novartis: Research Funding. Weinstock:Novartis: Consultancy, Research Funding. Stone:Celator: Consultancy; Pfizer: Consultancy; Xenetic Biosciences: Consultancy; Novartis: Consultancy; Seattle Genetics: Consultancy; Roche: Consultancy; Amgen: Consultancy; ONO: Consultancy; Xenetic Biosciences: Consultancy; Sunesis Pharmaceuticals: Consultancy; Juno Therapeutics: Consultancy; Sunesis Pharmaceuticals: Consultancy; Karyopharm: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy; Agios: Consultancy; Jansen: Consultancy. Gray:Gatekeeper: Equity Ownership; Petra: Consultancy, Equity Ownership; C4: Consultancy, Equity Ownership; Syros: Consultancy, Equity Ownership. Griffin:Janssen: Research Funding; Novartis: Consultancy, Research Funding.

scholarly journals T-Cell Suppression By Src/ABL Kinase Inhibitors When Combined with Blinatumomab in Ph+ Acute Lymphoblastic Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2694-2694 ◽  
Author(s):  
Jessica Leonard ◽  
Yoko Kosaka ◽  
Pavani Malla ◽  
Brandon Hayes-Lattin ◽  
Adam J. Lamble ◽  
...  
Keyword(s):  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Kinase Inhibitors ◽  
Cell Function ◽  
Lymphoblastic Leukemia ◽  
Advisory Committees ◽  
Abl Kinase ◽  
Equity Ownership ◽  
Abl Kinase Inhibitors

Abstract Introduction: Targeted ABL kinase inhibitors (TKIs) have shown great activity in Ph+ Acute Lymphoblastic Leukemia (Ph+ ALL), however relapsed disease remains an unmet need. The bispecific antibody blinatumomab was recently approved as a single agent for use in patients with Ph+ ALL and there is much interest in combining this with targeted therapies. Second generation ABL kinase inhibitors inhibit both Src and LYN in addition to ABL. This is of particular interest in Ph+ ALL as LYN is important for leukemogenesis. T cell receptor (TCR) signaling is also dependent upon Src family kinase activity, and Src inhibitors may impact the efficacy of immunotherapies reliant on native T cell function. We sought to investigate the in vitro effects of ABL specific vs dual Src/ABL kinases on blinatumomab efficacy in both healthy donor as well as primary patient samples. Methods: We isolated peripheral blood mononuclear cells (PBMC) via Ficoll-Hypaque gradient from five healthy donors as well as from two patients with de novo and one patient with relapsed Ph+ ALL who harbored a T315I mutation. PBMC were labeled with CellTrace Violet and cultured for 5 days with no stimulation, blinatumomab, or blinatumomab in combination with imatinib, dasatinib, ponatinib or nilotinib at varying concentrations. Immunophenotyping was performed using multi-parameter flow cytometry for the following cell surface markers: CD45, CD3, CD4, CD8, CD56, and CD19. Blinatumomab efficacy was assessed by comparing the numbers of CD19+ / CD3- cells in untreated samples to those that had been treated with blinatumomab in the presence or absence of TKIs. Cell division of T cells was measured by CellTrace Violet dilution. Cytokine production was assessed via LEGENDplex Human Th Cytokine Panel. Levels of total Src, phospho-Src, total LCK and phospho-LCK were assessed via immunoblot. Results: After 5 days of exposure, blinatumomab led to T-cell proliferation in both healthy donor and patient PBMCs. Proliferation was observed in both CD8+ and CD4+ T cell subsets, although the effect was more pronounced in CD8+ cells. T cell proliferation, however, was completely suppressed by either dasatinib or ponatinib at nanomolar concentrations. This effect was far less pronounced with the ABL kinase inhibitors imatinib and nilotinib. Treatment of PBMCs with blinatumomab led to increased production of the cytokines IFN-g, IL-17-a and IL-22 in patient samples and healthy donors, while levels of IL-6 were increased in the patient samples only and levels of IL-10 in healthy subjects only. Cytokine production was absent in samples treated with blinatumomab and either dasatinib or ponatinib, while levels of IFN-g, IL-17a and IL-22 were minimally affected when blinatumomab was combined with imatinib. Immunoblots confirmed that dasatinib and ponatinib but not imatinib nor nilotinib inhibited phosphorylation of total Src as well as of LCK, likely explaining the inhibitory effects of these agents. In patient samples, blinatumomab alone and the TKIs alone greatly reduced the number of CD19+ cells. However, when dasatinib and blinatumomab were combined in the sample with a T315I mutation, there was little reduction in the percentage of CD19+ cells and no amplification of CD3+ cells, suggesting that dasatinib was able to inhibit the cytotoxic effects of blinatumomab with no effect to the leukemic cells. Discussion: Our results suggest that the combination of dual Src/ABL inhibitors with blinatumomab may abrogate the effects of blinatumomab by directly inhibiting T cell function. This is likely via inhibition of LCK, a known member of the TCR signaling pathway. Although small case series have reported responses in patients treated with blinatumomab and TKIs, it is possible that the majority of the response is from the TKI rather than blinatumomab. Only a randomized trial of a TKI +/- blinatumomab would be able to discern whether there is benefit of adding a dual Src/ABL TKI to bispecific antibody therapy. While our data are limited by sample numbers and by the fact that responses in living subjects may differ according to many other complex interactions in the in vivo immune microenvironment, the potential immunomodulatory effects of targeted therapies should be taken into consideration before they are combined with immunotherapies. Disclosures Leonard: Amgen: Research Funding. Druker:McGraw Hill: Patents & Royalties; Fred Hutchinson Cancer Research Center: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; ARIAD: Research Funding; Monojul: Consultancy; Millipore: Patents & Royalties; Novartis Pharmaceuticals: Research Funding; Oregon Health & Science University: Patents & Royalties; Leukemia & Lymphoma Society: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Meyers Squibb: Research Funding; ALLCRON: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Cepheid: Consultancy, Membership on an entity's Board of Directors or advisory committees; Beta Cat: Membership on an entity's Board of Directors or advisory committees; MolecularMD: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Patient True Talk: Consultancy; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees; Third Coast Therapeutics: Membership on an entity's Board of Directors or advisory committees; GRAIL: Consultancy, Membership on an entity's Board of Directors or advisory committees; Aileron Therapeutics: Consultancy; Henry Stewart Talks: Patents & Royalties; Aptose Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Tyner:Constellation: Research Funding; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees; Janssen: Research Funding; Gilead: Research Funding; Aptose: Research Funding; Incyte: Research Funding; Genentech: Research Funding; Array: Research Funding; Takeda: Research Funding; AstraZeneca: Research Funding. Lind:Celgene: Research Funding; Janssen Pharmaceutical R&D: Research Funding; Amgen: Research Funding; Fluidigm: Honoraria; Monojul: Research Funding.

scholarly journals Comparative Efficacy Among 3rd Line Post-Imatinib Chronic Phase-Chronic Myeloid Leukemia (CP-CML) Patients after Failure of Dasatinib or Nilotinib Tyrosine Kinase Inhibitors

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4551-4551 ◽  
Author(s):  
Jeffrey H. Lipton ◽  
Dhvani Shah ◽  
Vanita Tongbram ◽  
Manpreet K Sidhu ◽  
Hui Huang ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Kinase Inhibitors ◽  
Cytogenetic Response ◽  
Comparative Efficacy ◽  
Employment Equity ◽  
Advisory Committees ◽  
Equity Ownership

Abstract INTRODUCTION Patients with chronic myeloid leukemia (CP-CML) failing 1st line imatinib are most commonly treated with the second-generation (2G) tyrosine kinase inhibitors (TKIs) dasatinib and nilotinib. However, for patients who experience resistance or intolerance (R/I) to 2G-TKIs in 2nd line, there currently is no consensus on the optimal therapy sequence for 3rd line treatment. The comparative efficacy of using ponatinib in the 3rd line after 2G TKI failure was examined in a previous study (Lipton et al., ASH 2013). This study assesses the comparative efficacy of ponatinib versus sequential treatment of alternate 2G TKIs in 3rdline setting in two separate patient populations, post-imatinib and dasatinib patients and post-imatinib and nilotinib patients. METHODS A systematic review was conducted in MEDLINE, EMBASE and the Cochrane Libraries (2002-2014), as well as 3 conferences (ASH (2008-2014), ASCO (2008-2014), and EHA (2008-2013)). Studies evaluating any TKI were included if they enrolled 10 or more post-imatinib adult patients with CP-CML who were also R/I to dasatinib or nilotinib. All study designs were considered and no restriction was applied with respect to therapy dose, due to incomplete reporting of doses in the available studies. Analyses was run on two groups of patients, those failing imatinib and dasatinib (Group Ima/Das) and those failing imatinib and nilotinib (Group Ima/Nil). Bayesian methods were used to synthesize major cytogenetic response (MCyR) and complete cytogenetic response (CCyR) from individual studies and estimate the overall response probability with 95% credible interval (CrI) for each treatment. Bayesian analysis also was used to estimate the likelihood that each treatment offers the highest probability of CCyR/MCyR based on available evidence. RESULTS Six studies evaluating bosutinib, nilotinib and ponatinib for Group Ima/Das (n= 419) and five studies evaluating bosutinib, dasatinib and ponatinib for Group Ima/Nil (n=83) were included in the analysis. All studies reported CCyR in both groups. Five studies evaluating bosutinib, nilotinib and ponatinib reported MCyR in Group Ima/Das and three studies evaluating bosutinib and ponatinib reported MCyR in Group Ima/Nil. Synthesized treatment-specific probabilities and 95% CrI for CCyR are presented in Figure 1. Synthesized treatment-specific probabilities of CCyR for Group Ima/Das were 27% for nilotinib, 20% for bosutinib and 54% (95% CrI 43%% to 66%) for ponatinib. Treatment-specific probabilities of MCyR for Group Ima/Das were 41% for nilotinib, 28% for bosutinib and 66% (95% CrI 55%% to 77%) for ponatinib. The probability of ponatinib providing superior response to all other included treatments for group Ima/Das was estimated to be >99% for both CCyR and MCyR. Synthesized treatment-specific probabilities of CCyR for Group Ima/Nil were 25% for dasatinib, 26% for bosutinib and 67% (95% CrI 51%% to 81%) for ponatinib. Treatment-specific probabilities of MCyR for Group Ima/Nil were 33% for bosutinib and 75% (95% CrI 60%% to 87%) for ponatinib. The probability of ponatinib providing superior response to all other included treatments for group Ima/Nil was estimated to be >99% for both CCyR and MCyR. CONCLUSIONS The post imatinib and dasatinib group included more studies with larger sample sizes compared with the post imatinib and nilotinib group. Overall, response rates appear higher for TKIs in the post imatinib and nilotinib group compared with the post imatinib and dasatinib group. For both groups, patients on ponatinib had higher CCyR and MCyR rates compared with the sequential 2G TKIs included in this analysis. Based on available data, ponatinib appears to provide a higher probability of treatment response for patients failing imatinib and dasatinib/ nilotinib compared with sequential 2G TKI therapy commonly used in this indication. Figure 1 Figure 1. Disclosures Lipton: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol Myers: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Ariad: Equity Ownership, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Shah:Ariad Pharmaceuticals: Research Funding. Tongbram:Ariad Pharmaceuticals: Research Funding. Sidhu:Ariad Pharmaceuticals Inc.: Research Funding. Huang:ARIAD Pharmaceuticals, Inc.: Employment, Equity Ownership. McGarry:ARIAD Pharmaceutical, Inc.: Employment, Equity Ownership. Lustgarten:ARIAD Pharmaceuticals Inc: Employment, Equity Ownership. Hawkins:Ariad Pharmaceuticals Inc.: Research Funding.

scholarly journals Myeloid-Lineage Enhancers Drive Oncogene Synergy and Represent a Novel Therapeutic Target in CSF3R-CEBPA Mutant AML

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 543-543
Author(s):  
Theodore Braun ◽  
Cody Coblentz ◽  
Sarah A Carratt ◽  
Mariam Okhovat ◽  
Amy Foley ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Board Of Directors ◽  
Median Survival ◽  
Stock Options ◽  
Research Funding ◽  
Wild Type ◽  
Advisory Committees ◽  
Dana Farber Cancer Institute ◽  
Equity Ownership ◽  
Cebpa Mutations

Acute Myeloid Leukemia (AML) results from the stepwise accumulation of mutations from distinct functional classes, ultimately culminating in malignant transformation. Based on their oncogenic activity, mutations can be classified into three distinct groups. Class I mutations activate signaling pathways, produce uncontrolled proliferation, and in isolation produce a myeloproliferative phenotype. Class II mutations result from point mutations or chromosomal translocation events in lineage determining transcription factors, producing differentiation arrest and myelodysplasia in isolation. A classic example of oncogene synergy between distinct mutational classes can be found in the co-occurrence of mutations in the transcription factor CCAAT-enhancer binding protein alpha (CEBPA) with mutations in colony stimulating factor receptor 3 (CSF3R). Mutations in CEBPA occur in approximately 10% of AML where they block differentiation and convey favorable risk. In contrast, CSF3R mutations lead to constitutive receptor activation and uncontrolled neutrophil proliferation. In the absence of co-occurring Class II mutations, membrane proximal CSF3R mutations produce the myeloproliferative neoplasm chronic neutrophilic leukemia (CNL). Interestingly, patients with CEBPA mutant AML that also harbor an oncogenic CSF3R mutation have worse prognosis than those with wild type CSF3R. However, the mechanism underlying this oncogene synergy remains unknown. To model the co-occurrence of these mutations, we expressed CSF3RT618I (The most common membrane proximal CSF3R mutation) in fetal liver hematopoietic stem cells harboring compound heterozygous CEBPA mutations in the endogenous allele (CEBPAK/L). Mice transplanted with mutant CEBPA alone developed a long latency AML with a median survival of 60 weeks. In contrast, mice transplanted with mutant CSF3RT618I/CEBPAK/L cells developed a much more rapid AML with a median survival of 13 weeks. These results were corroborated in an orthogonal model in which mutant CSF3R and a C-terminal mutant CEBPA were retrovirally expressed prior to bone marrow transplant. To dissect the underlying mechanism, we performed a comprehensive transcriptomic and epigenetic analysis on cells expressing each mutation in isolation as well as the combination. This analysis revealed that mutant CSF3R activates a distinct set of enhancers that regulate genes associated with differentiation and drive neutrophil differentiation. Co-expression of mutant CEBPA blocks the activation differentiation-associated enhancers but is permissive to those associated with proliferation. Differentiation but not proliferation-associated enhancers are bound by wild type CEBPA. Thus, the dominant negative impact of mutant CEBPA at these enhancers explains its differential impact on differentiative and proliferative transcriptional programs. Enhancer activation precedes promoter activation and CEBPA mutations are thought to represent early events in AML initiation. The epigenetic mechanism underlying the observed oncogene synergy argues that CEBPA mutations must occur prior to CSF3R to impact differentiation. We therefore developed a retroviral vector system enabling temporal control of Cre-mediated oncogene expression. Using this system, we found that only when mutant CEBPA is expressed prior to mutant CEBPA is differentiation arrest observed. Furthermore, AML develops in vivo only when mutant CEBPA is expressed prior to mutant CSF3R. To develop novel therapeutic strategies for this subclass of AML with adverse prognosis, we performed medium throughput drug screening on CSF3R/CEBPA mutant AML cells and identified sensitivity to inhibitors of JAK/STAT signaling as well as Lysine Demethylase 1 (LSD1). In other subtypes of AML, LSD1 inhibitors activate enhancers associated with differentiation. We confirmed that LSD1 inhibition promotes neutrophilic differentiation in CSF3R/CEBPA and through epigenetic and transcription profiling establish that this occurs via the reactivation of differentiation-associated enhancers. We further found that the combination of ruxolitinib (JAK/STAT inhibitor) and GSK2879552 produce a complete hematologic response and double median survival in mice harboring CSF3R/CEBPA mutant AML. Thus, the combination of JAK/STAT and LSD1 inhibitors represents and exciting therapeutic strategy for CSF3R/CEBPA mutant AML. Disclosures Druker: Celgene: Consultancy; Gilead Sciences: Other: former member of Scientific Advisory Board; ICON: Other: Scientific Founder of Molecular MD, which was acquired by ICON in Feb. 2019; Monojul: Other: former consultant; Novartis: Other: PI or co-investigator on clinical trial(s) funded via contract with OHSU., Patents & Royalties: Patent 6958335, Treatment of Gastrointestinal Stromal Tumors, exclusively licensed to Novartis, Research Funding; Bristol-Myers Squibb: Other: PI or co-investigator on clinical trial(s) funded via contract with OHSU., Research Funding; Pfizer: Other: PI or co-investigator on clinical trial(s) funded via contract with OHSU., Research Funding; Beat AML LLC: Other: Service on joint steering committee; The RUNX1 Research Program: Membership on an entity's Board of Directors or advisory committees; Patient True Talk: Consultancy; GRAIL: Equity Ownership, Other: former member of Scientific Advisory Board; Cepheid: Consultancy, Honoraria; Burroughs Wellcome Fund: Membership on an entity's Board of Directors or advisory committees; Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Beta Cat: Membership on an entity's Board of Directors or advisory committees, Other: Stock options; Aptose Biosciences: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Amgen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; ALLCRON: Membership on an entity's Board of Directors or advisory committees; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees, Other: Stock options; OHSU (licensing fees): Patents & Royalties: #2573, Constructs and cell lines harboring various mutations in TNK2 and PTPN11, licensing fees ; Merck & Co: Patents & Royalties: Dana-Farber Cancer Institute license #2063, Monoclonal antiphosphotyrosine antibody 4G10, exclusive commercial license to Merck & Co; Dana-Farber Cancer Institute (antibody royalty): Patents & Royalties: #2524, antibody royalty; CureOne: Membership on an entity's Board of Directors or advisory committees; Pfizer: Research Funding; Aileron Therapeutics: #2573, Constructs and cell lines harboring various mutations in TNK2 and PTPN11, licensing fees , Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Patents & Royalties, Research Funding.

Nilotinib Shows Safety and Efficacy in Older Patients (≥ 65 years) with Newly Diagnosed Chronic Myeloid Leukemia in Chronic Phase Comparable with That in Younger Patients with Chronic Myeloid Leukemia in Chronic Phase: Results From ENESTnd,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3768-3768 ◽  
Author(s):  
Richard A. Larson ◽  
Udomsak Bunworasate ◽  
Anna G. Turkina ◽  
Stuart L. Goldberg ◽  
Pedro Dorlhiac-Llacer ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Chronic Phase ◽  
Newly Diagnosed ◽  
Employment Equity ◽  
Advisory Committees ◽  
Equity Ownership ◽  
Grade 3

Abstract Abstract 3768 Background: Data from the phase 3, randomized multicenter ENESTnd trial have demonstrated the superiority of nilotinib over imatinib after 24 months (mo) of follow-up, with significantly higher rates of complete cytogenetic response (CCyR) and major molecular response (MMR), and significantly lower rates of progression to accelerated phase/blast crisis (AP/BC). The current subanalysis evaluated the efficacy and safety of nilotinib 300 mg twice daily (Nil300) and nilotinib 400 mg twice daily (Nil400) in older (≥ 65 years [yrs] at study entry) patients (pts) with newly diagnosed chronic myeloid leukemia (CML) in chronic phase (CP) with a minimum follow-up of 24 mo. Methods: In ENESTnd, 846 pts stratified by Sokal risk score were randomized 1:1:1 to Nil300 (n = 282), Nil400 (n = 281), or imatinib 400 mg once daily (n = 283). Pts with impaired cardiac function or ECOG performance status > 2 were excluded. Rates of CCyR and MMR by 24 mo, progression to AP/BC on treatment, and safety were evaluated according to age group (< 65 vs ≥ 65 yrs) in the 2 nilotinib arms. Safety data are reported for any pt who received ≥ 1 dose of nilotinib (n = 279, Nil300; n = 277, Nil400). Results: 36 pts (13%) and 28 pts (10%) were ≥ 65 yrs old in the Nil300 and Nil400 arms, respectively. Of the pts aged ≥ 65 yrs, 51/64 (80%) had an ECOG performance status of 0 at baseline and 60/64 (94%) had intermediate or high Sokal risk scores. Of the older pts, 8 (22%) on Nil300 and 6 (21%) on Nil400 had type 2 diabetes at baseline. CCyR rates by 24 mo were 83% and 68% among older pts treated with Nil300 and Nil400, respectively, and 87% for pts aged < 65 yrs in each nilotinib arm. By 24 mo, MMR was achieved by 72% and 61% of older pts on Nil300 and Nil400, respectively; in pts aged < 65 yrs, the respective rates were 71% and 67%. All 5 pts who progressed to AP/BC on treatment (2 on Nil300 and 3 on Nil400) were aged < 65 yrs. The frequency of grade 3/4 hematologic adverse events (AEs) was low in older pts; no pts had grade 3/4 neutropenia and only 1 older pt reported grade 3/4 thrombocytopenia in each nilotinib arm (Table). Transient, asymptomatic lipase elevations were reported in 11% and 16% of older pts treated with Nil300 and Nil400, and 7% of younger pts in each arm. Hyperglycemia occurred in 23% and 16% of older pts on Nil300 and Nil400, respectively, and 4% of younger pts in each arm; regardless of age, no pt discontinued study due to hyperglycemia. Among the 12 older pts with grade 3/4 hyperglycemia (8 on Nil300; 4 on Nil400), 9 pts had type 2 diabetes at baseline. There were no QTcF increases of > 60 msec from baseline in older pts and 3 in nilotinib-treated pts < 65 yrs old (1 on Nil300; 2 on Nil400). QTcF prolongation of > 500 msec did not occur in any pt treated with nilotinib on study. Periodic echocardiograms were done, and there were no decreases of > 15% in left ventricular ejection fraction from baseline in any pt treated with nilotinib on study. There were 4 cases of ischemic heart disease reported in older pts (1/35 [3%] on Nil300; 3/25 [12%] on Nil400) and 7 cases in pts < 65 yrs of age (4/244 [2%] on Nil300; 3/252 [1%] on Nil400). No sudden deaths occurred on study. Discontinuation occurred in approximately 25% of older and younger pts with Nil300, of which, 6% and 9%, respectively, were due to AEs/lab abnormalities. Discontinuation from study with Nil400 was 46% in older pts and 19% in younger pts; of which, 36% and 10% were due to AEs/lab abnormalities. Conclusions: Older pts treated with nilotinib demonstrated high rates of cytogenetic and molecular responses and low rates of progression. Nilotinib was generally well tolerated by older pts. In older pts, Nil300 had numerically higher rates of CCyR and MMR and was generally better tolerated (as evidenced by fewer AEs and discontinuations) vs Nil400. These data support the use of Nil300 in older pts with newly diagnosed CML-CP. Disclosures: Larson: Novartis Pharmaceuticals: Consultancy, Honoraria, Research Funding. Bunworasate:Novartis Pharmaceutical: Research Funding. Turkina:Novartis: Consultancy, Honoraria; BMS: Honoraria. Goldberg:Bristol Myers Squibb: Honoraria, Research Funding, Speakers Bureau; Novartis Pharmaceutical: Honoraria, Research Funding, Speakers Bureau; Ariad: Research Funding. Dorlhiac-Llacer:Bristol Myers Squibb: Research Funding; Novartis: Research Funding. Kantarjian:Novartis: Consultancy; Novartis: Research Funding; Pfizer: Research Funding; BMS: Research Funding. Saglio:Bristol-Myers Squibb: Consultancy, Speakers Bureau; Novartis Pharmaceutical: Consultancy, Speakers Bureau; Pfizer: Consultancy. Hochhaus:Ariad: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Novartis Pharmaceutical: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria, Research Funding. Hoenekopp:Novartis Pharmaceutical: Employment, Equity Ownership. Blakesley:Novartis Pharmaceutical: Employment. Yu:Novartis: Employment, Equity Ownership. Gallagher:Novartis: Employment, Equity Ownership. Clark:Bristol Myers Squibb: Honoraria, Research Funding; Novartis Pharmaceutical: Honoraria, Research Funding, Speakers Bureau. Hughes: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; Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Identification of Effective Targeted Drug Combinations Using Functional Ex Vivo Screening of Primary Patient Specimens

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 865-865 ◽  
Author(s):  
Stephen E Kurtz ◽  
Elie Traer ◽  
Jakki Martinez ◽  
Andrew Park ◽  
Jake Wagner ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Research Funding ◽  
Kinase Inhibitors ◽  
Ex Vivo ◽  
Single Agent ◽  
Hematologic Malignancies ◽  
Drug Combinations ◽  
Advisory Committees ◽  
Heat Map ◽  
Equity Ownership

Abstract Introduction: The intratumoral heterogeneity of Acute Myeloid Leukemia (AML) and other hematologic malignancies presents a challenge in developing effective single-agent targeted treatments. Furthermore, the emergence of genetically heterogeneous subclones leading to relapse suggests that effective therapies associated with discrete genotypes may require drug combinations, each of which modulates distinct pathways. In addition, microenvironmental rescue signals as well as tumor-intrinsic feedback pathways in AML and other hematologic malignancy subsets will necessitate combinatorial therapy approaches. Towards the goal of identifying new therapeutic combinations for AML and other hematologic malignancies, we assessed the sensitivity of primary patient samples to various drug combinations using an ex vivo functional platform. Methods: We have previously screened over 1000 primary patient specimens against a panel of single-agent small-molecule inhibitors. Using these historical drug sensitivity data, we ranked drugs by their IC50, and used these rankings to assemble an initial panel (1) of 44 drug combinations consisting primarily of kinase inhibitors with non-overlapping pathways. Primary patient samples (n = 74) with various hematologic malignancies were assessed for sensitivities to these combinations by culturing cells in the presence of fixed molar concentrations of the drugs over a dose series. Sensitivity was assessed by a viability assay on day 3 using a tetrazolium reagent. IC50 values for samples sensitive to a combination were sorted according to disease type and compared to those for each single agent to derive an index of effectiveness. Based on data from panel 1, we generated a second panel (2) consisting of 44 drug combinations, including new combinations of kinase inhibitors as well as combinations of drugs from different classes, such as bromodomain inhibitors, BH3 mimetics, proteasome inhibitors, IDH1/2 inhibitors coupled with kinase inhibitors. Primary patient samples (n = 78) were assessed for sensitivities to these combinations. Results: The performance of drug combinations across AML, ALL, CLL, CML or other MDS/MPN specimens are displayed in a heat map (Figure 1) representing the sensitivities of each drug combination relative to either of the single agents comprising that combination (the combination IC50 divided by the lowest single agent IC50 is our combination ratio). For each combination, we then compared the combination ratio of each individual specimen to the median combination ratio across all specimens tested, and cases with a combination ratio value less than 20% of the median were considered hypersensitive to that combination. We calculated the percentage of cases that were sensitive to each combination within the diagnostic subsets of AML, ALL, CLL, CML, and MDS/MPN and subsets with the most frequent sensitivity to a drug combination are indicated on the heat map (<20%, dark red; 20-50%, dark pink; 50-80%, light pink; and >80%, white). Combinations of two kinase inhibitors that included the p38MAPK inhibitor, doramapimod, were generally more effective on AML and CLL samples than other diagnostic subsets (panel 1). For CLL sample, combinations including midostaurin and either alisertib, ruxolitinib or sorafenib were particularly effective. Among combinations on panel 2, doramapimod coupled with an apoptosis inducer (ABT-199) exhibited broad efficacy on AML samples. In addition, combinations with the bromodomain inhibitor, JQ1, or the BH3 mimetic, ABT-199, were more broadly effective across diagnostic subsets than many of the kinase-kinase pairs tested. To validate the apparent synergies observed with patient samples, we tested selected combinations on AML-derived cell lines and observed synergies, which were supported with combination indices derived by the Chou-Talalay method. Conclusions: These data suggest that specific drug combinations formed either with two kinase inhibitors or with two compounds from different drug classes are effective in a patient-specific manner with enrichment for certain drug pairs within specific diagnostic subsets. While a secondary evaluation is necessary to validate the initial observation of sensitivity, linking this methodology with genetic attributes for patient samples will identify effective combinations of targeted agents and add therapeutic options for AML treatment. Figure 1. Figure 1. Disclosures Pandya: Microsoft: Employment, Equity Ownership. Bolosky:Microsoft: Employment, Equity Ownership. Druker:Oregon Health & Science University: Patents & Royalties; Henry Stewart Talks: Patents & Royalties; CTI Biosciences: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals: Research Funding; Aptose Therapeutics, Inc (formerly Lorus): Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; McGraw Hill: Patents & Royalties; Leukemia & Lymphoma Society: Membership on an entity's Board of Directors or advisory committees, Research Funding; MolecularMD: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Roche TCRC, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Research Funding; Millipore: Patents & Royalties; AstraZeneca: Consultancy; Oncotide Pharmaceuticals: Research Funding; Cylene Pharmaceuticals: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Fred Hutchinson Cancer Research Center: Research Funding; ARIAD: Research Funding; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sage Bionetworks: Research Funding. Tyner:Incyte: Research Funding; Janssen Pharmaceuticals: Research Funding; Constellation Pharmaceuticals: Research Funding; Array Biopharma: Research Funding; Aptose Biosciences: Research Funding.

Treatment-Free Remission in Patients with Chronic Myeloid Leukemia in Chronic Phase According to Reasons for Switching from Imatinib to Nilotinib: Subgroup Analysis from ENESTop

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 792-792 ◽  
Author(s):  
Timothy P. Hughes ◽  
Carla Maria Boquimpani ◽  
Naoto Takahashi ◽  
Noam Benyamini ◽  
Nelma Cristina D Clementino ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Chronic Phase ◽  
Molecular Response ◽  
Employment Equity ◽  
Advisory Committees ◽  
Loss Of Response ◽  
Equity Ownership ◽  
Treatment Free Remission

Abstract Background: ENESTop, an ongoing, single-arm, phase 2 study (ClinicalTrials.gov, NCT01698905), is the first trial specifically evaluating treatment-free remission (TFR; ie, stopping tyrosine kinase inhibitor [TKI] treatment without a loss of response) in patients with chronic myeloid leukemia in chronic phase (CML-CP) who achieved a sustained deep molecular response after switching from imatinib (IM) to nilotinib (NIL). Of 126 patients in ENESTop who were eligible to stop NIL, 57.9% (95% CI, 48.8%-66.7%) maintained TFR at 48 weeks. Here we present results from a subgroup analysis based on reasons for switching from IM to NIL, categorized as intolerance, resistance, and physician preference. Methods:Eligible patients were adults with CML-CP who received ≥ 3 years of total TKI therapy (> 4 weeks of IM, followed by ≥ 2 years of NIL) and achieved a sustained MR4.5 (BCR-ABL1 ≤ 0.0032% on the International Scale [BCR-ABL1IS]) on NIL therapy; patients with a documented MR4.5 at the time of switch from IM to NIL were not eligible. Enrolled patients continued NIL treatment in a 1-year consolidation phase, and those without confirmed loss of MR4.5 (ie, consecutive BCR-ABL1IS > 0.0032%) were eligible to stop NIL in the TFR phase. Patients with loss of major molecular response (MMR; ie, BCR-ABL1IS > 0.1%) or confirmed loss of MR4 (ie, consecutive BCR-ABL1IS > 0.01%) during the TFR phase reinitiated NIL treatment. The primary endpoint was the proportion of patients who maintained TFR (ie, no loss of MMR, confirmed loss of MR4, or treatment reinitiation) at 48 weeks after stopping NIL. In this post hoc analysis, rates of TFR at 48 weeks after stopping NIL and a Kaplan-Meier (KM) analysis of treatment-free survival (TFS; defined as the time from the start of TFR to the earliest occurrence of any of the following: loss of MMR, confirmed loss of MR4, reinitiation of NIL due to any cause, progression to accelerated phase/blast crisis, death due to any cause) were evaluated in subgroups of patients who switched from IM to NIL due to intolerance, resistance, or physician preference. These categories were determined by grouping the reasons for switching from IM to NIL, as reported by the investigators, based on relatedness to safety (intolerance), loss of response/treatment failure (resistance), and the physician's clinical judgment (physician preference); individual reasons included within each category are presented in the Figure. Results:A total of 125 patients who entered the TFR phase were included in this analysis; 1 patient who was found to have had atypical transcripts was excluded. Among these 125 patients, the reasons for switching to NIL were categorized as intolerance in 51 patients (40.8%), resistance in 30 patients (24.0%), and physician preference in 44 patients (35.2%). The proportion of patients who maintained TFR at 48 weeks after stopping NIL was generally similar across the 3 subgroups: 30 of 51 (58.8%; 95% CI, 44.2%-72.4%) in the intolerance subgroup, 16 of 30 (53.3%; 95% CI, 34.3%-71.7%) in the resistance subgroup, and 27 of 44 (61.4%; 95% CI, 45.5%-75.6%) in the physician preference subgroup. KM analysis of TFS showed that in all 3 subgroups, the majority of TFS events occurred within the first 24 weeks after stopping NIL (Figure). There were no notable differences in the kinetics of TFS events among subgroups. The KM-estimated median duration of TFS was not reached by the data cutoff date in all 3 subgroups. Conclusion: Primary analysis from ENESTop showed that among patients with CML-CP who achieved a sustained MR4.5after switching from IM to NIL, 57.9% of those who stopped NIL maintained TFR at 48 weeks. In the present analysis, TFR was maintained at 48 weeks after stopping NIL by > 50% of patients in the intolerance, resistance, and physician preference subgroups, with generally similar results across subgroups. These findings suggest that the rate of successful TFR following second-line NIL does not differ based on the reasons for switching from IM to NIL. Figure. Figure. Disclosures Hughes: Ariad: 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; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Australasian Leukaemia and Lymphoma Group (ALLG): Other: Chair of the CML/MPN Disease Group. Boquimpani:Novartis: Research Funding, Speakers Bureau; BMS: Speakers Bureau. Takahashi:Novartis: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; BMS: Honoraria. Shuvaev:Pfizer: Honoraria; BMS: Honoraria; Novartis pharma: Honoraria. Ailawadhi:Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy. Lipton:Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Ariad: Consultancy, Research Funding. Turkina:Pfizer: Honoraria; Novartis Pharma: Honoraria; BMS: Honoraria. Moiraghi:BMS: Speakers Bureau; NOVARTIS: Speakers Bureau. Nicolini:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria; Ariad pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees. Sacha:BMS: Consultancy, Honoraria, Speakers Bureau; Incyte: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Adamed: Consultancy, Honoraria. Kim:Pfizer: 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, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; ILYANG: Consultancy, Honoraria, Research Funding. Fellague-Chebra:Novartis: Employment. Acharya:Novartis Healthcare Pvt. Ltd.: Employment. Krunic:Novartis: Employment, Equity Ownership. Jin:Novartis: Employment, Equity Ownership. Mahon:BMS: Honoraria; PFIZER: Honoraria; NOVARTIS PHARMA: Honoraria, Research Funding; ARIAD: Honoraria.

scholarly journals Second Treatment Free Remission after Combination Therapy with Ruxolitinib Plus Tyrosine Kinase Inhibitors in Chronic Phase Chronic Myeloid Leukemia (CML)

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2555-2555
Author(s):  
Kendra Sweet ◽  
Ehab L. Atallah ◽  
Jerry P. Radich ◽  
Mei-Jie Zhang ◽  
Eva Sahakian ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Kinase Inhibitors ◽  
Chronic Phase ◽  
Molecular Response ◽  
Advisory Committees ◽  
Treatment Free Remission ◽  
One Year

Abstract Background: Discontinuation of tyrosine kinase inhibitors (TKIs) is feasible in a subset of CML patients who have maintained a deep molecular response for at least two years. Numerous discontinuation trials have been performed and consistently show approximately 50% of patients relapse after stopping TKIs. A recent study examining rates of treatment free remission (TFR) after a second attempt at stopping TKIs found, with a median follow up time of 38.3 months, 64.3% of patients had a molecular relapse (defined as a loss of major molecular response (MMR)). At 12, 24 and 36 months, TFR rates were 48%, 42% and 35%, respectively. These data suggest some patients with a history of molecular relapse upon TKI cessation could successfully stop treatment on a subsequent attempt, yet the majority will relapse a second time. 'Complete eradication' of CML remains elusive in most patients likely as a result of minimal residual disease (MRD), which is the result of BCR-ABL independent drug resistance. More specifically, CML cells that reside in sanctuary sites such as the bone marrow adhere to fibronectin and demonstrate cell adhesion mediated drug resistance (CAM-DR). The bone marrow microenvironment contains many cytokines and growth factors capable of inducing STAT3-Y705 phosphorylation via the JAK-STAT pathway leading to protection against TKI-induced cell death. Inhibiting JAK2 and TYK2 leads to complete inhibition of pSTAT3-Y705, thereby implicating the role of activation of JAK2 and TYK2 in STAT3-Y705 phosphorylation and resistance towards BCR-ABL TKI-induced cell death. A phase I clinical trial combined ruxolitinib, which inhibits JAK2 and TYK2, plus nilotinib in chronic phase (CP) CML patients and found that ruxolitinib 15mg PO BID was safe and well tolerated with 4/10 patients achieving undetectable BCR-ABL1 transcripts by PCR. Study Design and Methods: This single arm phase II study (NCT03610971) will enroll 41 subjects from the H Jean Khoury Cure CML Consortium. Eligible subjects must have a confirmed diagnosis of CP-CML and have previously attempted to discontinue TKI therapy per NCCN guidelines and had molecular recurrence, defined as loss of MMR, and were restarted on TKI. This trial combines ruxolitinib 15mg BID plus BCR-ABL TKI (imatinib, dasatinib, nilotinib or bosutinib) for 12 28-day cycles in the combination treatment phase (CTP). RQ-PCR to measure BCR-ABL transcripts will be checked at screening and every three months during the CTP. In the event that a subject experiences intolerance to a TKI, has confirmed loss of MMR, or loss of MR4.5 (&gt;0.0032% IS) on two central PCR results, or discontinues ruxolitinib, the subject will be removed from CTP and enter into long term follow-up (LTFU). CTP phase will be followed by further RQ-PCR screening for the concurrent TFR phase. At this time ruxolitinib will be discontinued and any subject who has met the criteria for the TFR phase will be enrolled. During the TFR phase, subjects will discontinue their TKI and be monitored off treatment with RQ-PCR checked monthly for the first year, every six weeks for year two, and every 12 weeks during year three. Upon molecular recurrence, defined as loss of MMR, TKIs will be restarted. The primary endpoint is the 12-month TFR rate subsequent to completion of 12 cycles of combination therapy; however, subjects will remain in the TFR phase for three years. Therefore, the total duration of the trial will be approximately five years (one year on CTP + three years in the TFR phase + one-year LTFU). Study statistical design was calculated to yield a one-sided type I error rate of 0.025 and power of 65% when the true one-year relapse rate is 35%. This study will additionally assess patient-reported outcomes in conjunction with RQ-PCR testing. PROMIS and other measures will be self-administered through REDCap. Correlative studies will include comparing changes in pSTAT3 in K562 and KU812 cell lines using plasma from CML patients being treated with TKIs plus ruxolitinib, using the plasma inhibitory assay technique. Changes in pSTAT3 and pSTAT5 will be correlated with clinical response and rate of TFR. Additional correlatives include multiparameter flow-based assessment of the T-cell compartment (activity/polarization) as well as natural killer cell fractions in CML patients at various time points (TKIs alone, TKIs plus ruxolitinib and during TFR). Thus far, 14 patients have been enrolled. Disclosures Sweet: Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; AROG: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Bristol Meyers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees. Atallah: Amgen: Consultancy; BMS: Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Abbvie: Consultancy, Speakers Bureau. Radich: Amgen: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees. Thompson: Novartis/ Bristol-Myers Squibb: Research Funding. Mauro: Pfizer: Consultancy; Takeda: Consultancy; Bristol Myers Squibb: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Sun Pharma / SPARC: Research Funding. Pinilla Ibarz: AbbVie, Janssen, AstraZeneca, Novartis, TG Therapeutics, Takeda: Consultancy, Other: Advisory; Sellas: Other: ), patents/royalties/other intellectual property; MEI, Sunesis: Research Funding; AbbVie, Janssen, AstraZeneca, Takeda: Speakers Bureau. OffLabel Disclosure: Ruxolitinib is being used off-label in chronic myeloid leukemia

scholarly journals Stroma-Derived Factors Significantly Impact the Drug Response Profiles of Patient-Derived Primary AML Cells: Implications for Drug Sensitivity Testing

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3505-3505
Author(s):  
Riikka Karjalainen ◽  
Tea Pemovska ◽  
Muntasir Mamun Majumder ◽  
David Tamborero ◽  
Bhagwan Yadav ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Conditioned Medium ◽  
Research Funding ◽  
Drug Testing ◽  
Stromal Cell ◽  
Kinase Inhibitors ◽  
Ex Vivo ◽  
Tumor Stroma ◽  
Advisory Committees ◽  
Equity Ownership

Abstract Background: Bone marrow (BM) microenvironment plays an important role in development of drug resistance in acute myeloid leukemia (AML) by supporting survival of therapy resistant leukemic cells that eventually may lead to disease relapse. Consideration of tumor stroma factors is therefore critically important when assessing the efficacy of drugs in the ex vivo drug testing of primary AML cells. To study the effects of tumor stroma factors on the response of AML patient cells ex vivo to a panel of cancer drugs, we evaluated the effects of stroma-derived conditioned medium (CM) on the sensitivity of genomically defined primary AML cells. Methods: Primary AML cells were isolated by Ficoll gradient separation from BM aspirates or peripheral blood of AML patients (n=13). For drug testing, 303 small molecule inhibitors were plated on 384-well plates in 5 different concentrations over a 10,000-fold concentration range. The stromal-cell conditioned medium (CM) was made by culturing human bone marrow (BM) stromal cell line HS-5 (American Type Culture Collection) in RPMI 1640 medium for 3 days. AML cells were added to the plates in either CM diluted with RPMI 1640 medium (25% CM) or in mononuclear cell medium (MCM, Promocell), which was used as the standard medium comparison. Cell viability was measured after 72 h and dose response curves generated for each drug. Drug sensitivity scores (DSS) were calculated as described previously (Yadav et al, 2014). Phosphorylation profiles of 43 proteins were analyzed with a human phospho-kinase array (R&D Systems). In addition, somatic mutations were identified by exome sequencing using DNA from the leukemia cells and matched skin biopsies, while expressed fusion genes were identified by transcriptome sequencing. Results: AML samples with activating mutations to kinases such as FLT3 or PDGFRB exhibited more sensitive ex vivo drug response profiles, particularly to broad-spectrum kinase inhibitors, compared to samples driven by other types of mutations. When the same AML samples were compared between the two conditions, CM or MCM, the drug sensitivities were different for many classes of drugs (Table 1). In CM, samples typically lost sensitivity to many of the tested drugs, such as topoisomerase II inhibitors, BCL2 inhibitors and several other classes of tyrosine kinase inhibitors (TKIs). The loss of TKI sensitivity in CM was particularly striking in the FLT3 and PDGFRB mutated cases. Cluster analysis of overall drug responses for AML samples tested in MCM resulted in a tight group of most TKIs, reflecting their overlapping target profiles. However, when the analysis was applied to responses from the same cells tested in CM, the TKI grouping was more dispersed. Thus, these results indicate that tyrosine kinase signaling is stringently regulated in standard medium, whereas CM helps to support cell survival resulting in lower responses to a range of TKIs. To test this hypothesis, phosphorylation of 43 different kinases was measured with AML samples incubated in either CM or MCM. CM induced phosphorylation of multiple proteins including p38α, HSP27, Src, Lyn, Hck and STAT6 proving the activation of other signaling pathways. Conclusions: Our dataindicate that stromal cell conditioned medium may have prominent effects on ex vivo drug responses of AML cells. BM factors likely provide survival cues that make primary patient-derived AML cells resistant to several targeted agents, such as topoisomerases and TKIs. This underscores the need to develop drug testing methods that take into account tumor-microenvironment interactions. Disclosures Gjertsen: BerGenBio AS: Membership on an entity's Board of Directors or advisory committees; Boehringer Ingelheim : Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Kinn Therapeutics AS: Equity Ownership. Porkka:Bristol-Myers Squibb: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Kallioniemi:Medisapiens: Consultancy, Membership on an entity's Board of Directors or advisory committees. Wennerberg:Pfizer: Research Funding. Heckman:Celgene: Research Funding.

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