Tyrosine Kinase Inhibitors Nilotinib Research Articles

Chronic Myeloid Leukemia: Part II—Cost of Care Among Patients in Advanced Phases or Later Lines of Therapy in Chronic Phase in the United States from a Commercial Perspective

Background: Tyrosine kinase inhibitors (TKIs) are the standard-of-care treatment for chronic myeloid leukemia in chronic phase (CML-CP). Despite advances in therapy, there remains a proportion of patients with CML-CP that are refractory/intolerant to TKIs, and these patients cycle through multiple lines of therapy. Moreover, even with TKIs, some patients progress to accelerated phase/blast crisis (AP/BC), which is associated with particularly poor clinical outcomes. Objectives: To describe real-world treatment patterns, healthcare resource utilization (HRU), and costs of patients with CML-CP reaching later lines of therapy or progressing to AP/BC in the United States. Methods: Adult CML patients from administrative claims data (January 1, 2000–June 30, 2019) were classified by health state: on third-line (CML-CP On Treatment), on fourth or later lines (CML-CP Post-Discontinuation), or progressed to AP/BC (CML-AP/BC). Outcomes were assessed by health state. Results: There were 296 (4620 patient-months), 83 (1644 patient-months), and 949 (25 593 patient-months) patients classified in the CML-CP On Treatment, CML-CP Post-Discontinuation, and CML-AP/BC cohorts, respectively. Second-generation TKIs (nilotinib, dasatinib, and bosutinib) were most commonly used in the CML-CP On Treatment (69.1% of patient-months) and CML-CP Post-Discontinuation cohorts (59.1% of patient-months). Three-month outpatient incidence rates (IRs) were 7.6, 8.3, and 7.0 visits in the CML-CP On Treatment, CML-CP Post-Discontinuation, and CML-AP/BC cohort, respectively, with mean costs of $597 per service. Three-month inpatient IRs were 0.6, 0.7, and 1.4 days in the CML-CP On Treatment, CML-CP Post-Discontinuation, and CML-AP/BC cohort, respectively, with mean costs of $5892 per day. Mean hematopoietic stem cell transplantation cost was $352 333; mean 3-month terminal care cost was $107 013. Discussion: Cost of CML care is substantial among patients with CML reaching third-line, fourth or later lines, or progressing to AP/BC, suggesting that the disease is associated with a significant economic and clinical burden. From third-line to fourth or later lines, HRU was observed to increase, and the incidence of inpatient days was particularly high for those who progressed to AP/BC. Conclusion: In this study, patients with CML cycling through TKIs in later lines of therapy or progressing to AP/BC experienced substantial HRU and costs, suggesting unmet treatment needs.

Chronic Myeloid Leukemia: Part II-Cost of Care Among Patients in Advanced Phases or Later Lines of Therapy in Chronic Phase in the United States from a Commercial Perspective.

Background: Tyrosine kinase inhibitors (TKIs) are the standard-of-care treatment for chronic myeloid leukemia in chronic phase (CML-CP). Despite advances in therapy, there remains a proportion of patients with CML-CP that are refractory/intolerant to TKIs, and these patients cycle through multiple lines of therapy. Moreover, even with TKIs, some patients progress to accelerated phase/blast crisis (AP/BC), which is associated with particularly poor clinical outcomes.Objectives: To describe real-world treatment patterns, healthcare resource utilization (HRU), and costs of patients with CML-CP reaching later lines of therapy or progressing to AP/BC in the United States.Methods: Adult CML patients from administrative claims data (January 1, 2000–June 30, 2019) were classified by health state: on third-line (CML-CP On Treatment), on fourth or later lines (CML-CP Post-Discontinuation), or progressed to AP/BC (CML-AP/BC). Outcomes were assessed by health state.Results: There were 296 (4620 patient-months), 83 (1644 patient-months), and 949 (25 593 patient-months) patients classified in the CML-CP On Treatment, CML-CP Post-Discontinuation, and CML-AP/BC cohorts, respectively. Second-generation TKIs (nilotinib, dasatinib, and bosutinib) were most commonly used in the CML-CP On Treatment (69.1% of patient-months) and CML-CP Post-Discontinuation cohorts (59.1% of patient-months). Three-month outpatient incidence rates (IRs) were 7.6, 8.3, and 7.0 visits in the CML-CP On Treatment, CML-CP Post-Discontinuation, and CML-AP/BC cohort, respectively, with mean costs of $597 per service. Three-month inpatient IRs were 0.6, 0.7, and 1.4 days in the CML-CP On Treatment, CML-CP Post-Discontinuation, and CML-AP/BC cohort, respectively, with mean costs of $5892 per day. Mean hematopoietic stem cell transplantation cost was $352 333; mean 3-month terminal care cost was $107 013.Discussion: Cost of CML care is substantial among patients with CML reaching third-line, fourth or later lines, or progressing to AP/BC, suggesting that the disease is associated with a significant economic and clinical burden. From third-line to fourth or later lines, HRU was observed to increase, and the incidence of inpatient days was particularly high for those who progressed to AP/BC.Conclusion: In this study, patients with CML cycling through TKIs in later lines of therapy or progressing to AP/BC experienced substantial HRU and costs, suggesting unmet treatment needs.

Pharmacokinetics, Bioequivalence, and Safety Studies of a Generic Selective Tyrosine Kinase Inhibitor Nilotinib Capsule Versus a Branded Product in Healthy Chinese Volunteers.

Nilotinib, a second-generation tyrosine kinase inhibitor (TKI), has been approved in the United States and Europe as a treatment for patients with newly diagnosed chronic myeloid leukemia (CML)-chronic phase (CP) and patients with CML-CP or chronic myeloid leukemia-accelerated phase (CML-AP) who are resistant or intolerant to imatinib (a first-generation TKI). This study compared the bioequivalence and safety of the test nilotinib capsule and reference nilotinib capsule (Tasigna, Novartis) in healthy Chinese volunteers under fasting conditions for marketing authorization in China. The results of the study are reported for the first time. This was a single-dose, randomized, open-label, two-period, and cross-over study. Thirty healthy volunteers were randomly assigned to receive a single dose of a 200-mg test or reference capsule under fasting conditions in each period with a 10-day washout. Plasma samples were analyzed with liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were calculated with WinNonlin software. The geometric mean ratio and the corresponding 90% confidence intervals of Cmax , AUC0-t , and AUC0-∞ for nilotinib between the two fixed-dose combination formulations were within the bioequivalence acceptance range of 80%-125%, therefore the generic and branded formulations were bioequivalent in healthy Chinese volunteers.

The tyrosine kinase inhibitor nilotinib targets the discoidin domain receptor DDR2 in calcific aortic valve stenosis.

Background and PurposeTyrosine kinase inhibitors (TKI) used to treat chronic myeloid leukaemia (CML) have been associated with cardiovascular side effects, including reports of calcific aortic valve stenosis. The aim of this study was to establish the effects of first and second generation TKIs in aortic valve stenosis and to determine the associated molecular mechanisms.Experimental ApproachHyperlipidemic APOE*3Leiden.CETP transgenic mice were treated with nilotinib, imatinib or vehicle. Human valvular interstitial cells (VICs) were isolated and studied in vitro. Gene expression analysis was perfromed in aortic valves from 64 patients undergoing aortic valve replacement surgery.Key ResultsNilotinib increased murine aortic valve thickness. Nilotinib, but not imatinib, promoted calcification and osteogenic activation and decreased autophagy in human VICs. Differential tyrosine kinase expression was detected between healthy and calcified valve tissue. Transcriptomic target identification revealed that the discoidin domain receptor DDR2, which is preferentially inhibited by nilotinib, was predominantly expressed in human aortic valves but markedly downregulated in calcified valve tissue. Nilotinib and selective DDR2 targeting in VICs induced a similar osteogenic activation, which was blunted by increasing the DDR2 ligand, collagen.Conclusions and ImplicationsThese findings suggest that inhibition of DDR2 by nilotinib promoted aortic valve thickening and VIC calcification, with possible translational implications for cardiovascular surveillance and possible personalized medicine in CML patients.

Genome‑wide expression and methylation analyses reveal aberrant cell adhesion signaling in tyrosine kinase inhibitor‑resistant CML cells

Although chronic myeloid leukemia (CML) can be effectively treated using BCR-ABL1 kinase inhibitors, resistance due to kinase alterations or to BCR-ABL1 independent mechanisms remain a therapeutic challenge. For the latter, the underlying mechanisms are widely discussed; for instance, gene expression changes, epigenetic factors and alternative signaling pathway activation. In the present study, in vitro-CML cell models of resistance against the tyrosine kinase inhibitors (TKIs) imatinib (0.5 and 2 µM) and nilotinib (0.1 µM) with biological replicates were generated to identify novel mechanisms of resistance. Subsequently, genome-wide mRNA expression and DNA methylation were analyzed. While mRNA expression patterns differed largely between biological replicates, there was an overlap of 71 genes differentially expressed between cells resistant against imatinib or nilotinib. Moreover, all TKI resistant cell lines demonstrated a slight hypermethylation compared with native cells. In a combined analysis of 151 genes differentially expressed in the biological replicates of imatinib resistance, cell adhesion signaling, in particular the cellular matrix protein fibronectin 1 (FN1), was significantly dysregulated. This gene was also downregulated in nilotinib resistance. Further analyses showed significant FN1-downregulation in imatinib resistance on mRNA (P<0.001) and protein level (P<0.001). SiRNA-mediated FN1-knockdown in native cells reduced cell adhesion (P=0.02), decreased imatinib susceptibility visible by higher Ki-67 expression (1.5-fold, P=0.04) and increased cell number (1.5-fold, P=0.03). Vice versa, recovery of FN1-expression in imatinib resistant cells was sufficient to partially restore the response to imatinib. Overall, these results suggested a role of cell adhesion signaling and fibronectin 1 in TKI resistant CML and a potential target for novel strategies in treatment of resistant CML.

Abstract 3533: Effects of tyrosine kinase inhibitors imatinib, dasatinib, and nilotinib on cancer-associated fibroblast phenotypes in colorectal cancer

Abstract Background: Cancer-associated fibroblasts (CAFs) are major regulators of the immune microenvironment and therapeutic response in colorectal cancer (CRC). Neutralizing their role in modulating the immune landscape could be the key to enhancing immunotherapy success. Imatinib, dasatinib, and nilotinib are tyrosine kinase inhibitors with several kinase targets. Methods: Tissue microarrays spanning 153 patients were stained for αSMA, TAGLN, PDPN, ICAM1, and CD8. CD8 stains were quantified as number of tumor infiltrating lymphocytes per high powered field (TILs/HPF) in the epithelial compartment. All other stains were quantified by intensity on a 0-3+ scale. Scores for αSMA and TAGLN were combined into a myCAF score, and PDPN and ICAM1 into an iCAF score. myCAF gene expression signatures derived from a re-analysis of scRNA-seq data previously done by our lab were entered into the LINCS database to discover potential drugs to reverse the phenotype. Primary cancer associated fibroblasts were derived from patient tumor samples, then treated with clinically relevant concentrations of imatinib, dasatinib, or nilotinib for 96 hours. RNA was isolated and RT-qPCR was performed to quantify the myCAF genes ACTA2, COL11A1, and TAGLN, and the iCAF genes ICAM1, PDPN, IL1R1, CXCL1 and CXCL2. TGFB1 expression was also measured. Expression was normalized to untreated cells and GAPDH expression levels. Results: Cancers with high expression of myCAF markers but low expression of iCAF markers had the most CD8+ TILs (average 10.2; median 1.5; range 0-73), while cancers with low myCAF scores and high iCAF scores had the least (average 1.5; median 0; range 0-19; p &amp;lt; 0.01). Reversing the myCAF signature relative to iCAFs in the LINCs database revealed nilotinib as a top hit. Treatment with imatinib did not significantly alter the expression of myCAF genes (control vs. max dose: p = 0.06 for ACTA2, COL11A1 p =0.2, TAGLN p = 1), while treatment with dasatinib significantly increased these genes (ACTA2 1.4x higher, p &amp;lt; 0.001; COL11A1 2.6x higher, p &amp;lt; 0.01; TAGLN 1.5x higher, p &amp;lt; 0.001). Only treatment with nilotinib significantly decreased myCAF genes (ACTA2 2.2x lower, p &amp;lt;0.001; COL11A1 1.3x lower, p =0.05; TAGLN 1.9x lower, p &amp;lt; 0.01). All three drugs decreased iCAF gene CXCL1, and all but dasatinib decreased CXCL2. All three drugs significantly decreased TGFB1, a potential functional marker for altering myCAF phenotype (dasatinib 1.1x lower, p = 0.1; imatinib 1.6x lower, p &amp;lt; 0.001; nilotinib 1.5x lower, p &amp;lt; 0.05). Conclusions: myCAFs may be major actors in immune exclusion in the microenvironment, and the reversal of the myCAF phenotype may be a target for treatment with immunotherapy. Nilotinib, but not imatinib or dasatinib, is effective at decreasing expression of myCAF genes. Further research is warranted into the mechanisms of this drug on altering expression and whether these trends continue in vivo. Citation Format: Katherine Anne Johnson, Anna L. Lippert, Sean G. Kraus, Grace E. McGrath, Philip B. Emmerich, Cheri A. Pasch, Linda Clipson, Kristina A. Matkowskyj, Wei Zhang, Dustin A. Deming. Effects of tyrosine kinase inhibitors imatinib, dasatinib, and nilotinib on cancer-associated fibroblast phenotypes in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3533.

Downregulation of hERG channel expression by tyrosine kinase inhibitors nilotinib and vandetanib predominantly contributes to arrhythmogenesis

Cardiotoxicity by tyrosine kinase inhibitors remains an important concern. Nilotinib and vandetanib clinically carry high proarrhythmic risk and the exact mechanism underlying arrhythmogenesis is not fully understood. In this study, we investigated the effects of nilotinib and vandetanib on the abundance of human ether-á-go-go-related gene (hERG) K+ channel and assessed the potential role of acute hERG blockage versus chronic effects in arrhythmogenesis. We found that both nilotinib and vandetanib prolonged the field potential duration reflecting the repolarisation process and induced cellrythmias of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in a time-and concentration-dependent manner after, after chronic exposure. Patch-clamp recordings revealed significant reductions of hERG current densities by nilotinib or vandetanib after chronic incubation with hERG-HEK293 cells in addition to the acute inhibition. Western blot analysis showed that nilotinib and vandetanib decreased mature hERG protein (155-kDa) expression, in a greater extent than that of the immature form (135-kDa). A serum and glucocorticoid kinase 1 (SGK1) activator, C4-ceramide, prevented the nilotinib-and vandetanib-induced hERG protein downregulation and thus the incidence of cellrrhythmias. Taken together, our data demonstrated that the downregulation of hERG channel abundance on the cellular membrane predominantly contributed to the proarrhythmic effect of nilotinib and vandetanib.

Development of a Sensitive and High-Throughput Assay for Simultaneous Quantification of 5 Tyrosine Kinase Inhibitors and 2 Active Metabolites in Human Plasma Using Ultra-high Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry.

Breakpoint cluster region-Abelson (BCR-ABL) tyrosine kinase inhibitors (TKIs) demonstrate improved therapeutic efficacy in chronic myeloid leukemia (CML). However, drug-drug interactions, nonadherence, and host-related factors may influence plasma concentrations. Therefore, therapeutic drug monitoring may be necessary for patients presenting inadequate treatment responses or adverse events. Herein, the authors aimed to develop a more sensitive and high-throughput method than those previously reported to simultaneously quantify 5 TKIs (imatinib, nilotinib, dasatinib, bosutinib, and ponatinib) and 2 active metabolites (N-desmethyl imatinib and N-desmethyl ponatinib) using ultra-performance liquid chromatography coupled with tandem mass spectrometry. Plasma samples were prepared according to a solid-phase extraction protocol using an Oasis MCX µElution plate. The assay fulfilled the requirements of the US Food and Drug Administration for assay validation, with a lower limit of quantification of 0.2 ng/mL for dasatinib, 0.3 ng/mL for N-desmethyl ponatinib, 0.5 ng/mL for N-desmethyl imatinib, bosutinib, and ponatinib, and 2.5 ng/mL for imatinib and nilotinib. Within-batch and batch-to-batch precision at the lower limit of quantification and quality control levels were within 14.3% and 10.9%, respectively. Within-batch and batch-to-batch accuracies ranged from 15.5% to 13.0% and 5.70% to 7.03%, respectively. A positive electrospray ionization mode was used with a run time of 6.0 minutes. The assay applicability was verified by the successful measurement of 78 clinical samples from patients undergoing CML therapy. The method allows assessment of trough concentrations of TKIs and active metabolites in patients with CML, and hence can be used to assess blood samples in routine clinical settings.

The new generation tyrosine kinase inhibitor improves the survival of chronic myeloid leukemia patients after allogeneic stem cell transplantation.

The introduction of tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML) treatment has dramatically improved the prognosis of CML patients and reduced the number of patients receiving allogeneic stem cell transplantation (allo-SCT). However, the impact of the newest-generation TKIs on the overall survival (OS) after allo-SCT has not been well described. To investigate the beneficial effects of TKIs on the prognosis after allo-SCT, we conducted a retrospective observational study using the Transplant Registry Unified Management Program database in Japan. We analyzed 1188 patients (male/female: 738/450; median age: 44years; range: 16-75) who underwent their first allo-SCT between January 2001 and December 2018. We divided the patients into two groups according to the TKI treatment used before allo-SCT: group 1 was treated with the first generation TKI imatinib; group 2 was treated with the second generation TKIs nilotinib, dasatinib, or bosutinib and/or the third generation TKI ponatinib. We compared the post allo-SCT OS between the two groups. The 3-year OS rates (95%CI) of groups 1 and 2 were 59.3% (54.8%-63.5%) and 65.8% (61.6%-69.6%), respectively (p=0.017). Multivariate analysis confirmed that group 2 had superior OS after allo-SCT compared to group 1 (p=0.002). Other factors associated with superior prognosis were age ≤65, performance status (PS) 0/1, a 6/6 HLA-matched donor and chronic-phase (CP) disease status at allo-SCT. A subgroup analysis showed poor prognoses for patients who could not obtain a molecular response before allo-SCT and patients with positive T315I mutation in the BCR/ABL gene. In group 2, early allo-SCT was correlated with superior OS in patients with a blast-crisis disease status at allo-SCT (p=0.001). The cumulative incidence of non-relapse mortality rate significantly decreased in group 2 (p=0.0005). The post allo-SCT OS was improved both by pre- and post-management of allo-SCT and by the introduction of newer TKIs.

Combining nilotinib and PD-L1 blockade reverses CD4+ T-cell dysfunction and prevents relapse in acute B-cell leukemia

AbstractPatients with acute lymphoblastic leukemia have experienced significantly improved outcomes due to the advent of chimeric antigen receptor (CAR) T cells and bispecific T-cell engagers, although a proportion of patients still relapse despite these advances. T-cell exhaustion has been recently suggested to be an important driver of relapse in these patients. Indeed, phenotypic exhaustion of CD4+ T cells is predictive of relapse and poor overall survival in B-cell acute lymphoblastic leukemia (B-ALL). Thus, therapies that counter T-cell exhaustion, such as immune checkpoint blockade, may improve leukemia immunosurveillance and prevent relapse. Here, we used a murine model of Ph+ B-ALL as well as human bone marrow biopsy samples to assess the fundamental nature of CD4+ T-cell exhaustion and the preclinical therapeutic potential for combining anti–PD-L1 based checkpoint blockade with tyrosine kinase inhibitors targeting the BCR-ABL oncoprotein. Single-cell RNA-sequence analysis revealed that B-ALL induces a unique subset of CD4+ T cells with both cytotoxic and helper functions. Combination treatment with the tyrosine kinase inhibitor nilotinib and anti–PD-L1 dramatically improves long-term survival of leukemic mice. Depletion of CD4+ T cells prior to therapy completely abrogates the survival benefit, implicating CD4+ T cells as key drivers of the protective anti-leukemia immune response. Indeed, treatment with anti–PD-L1 leads to clonal expansion of leukemia-specific CD4+ T cells with the aforementioned helper/cytotoxic phenotype as well as reduced expression of exhaustion markers. These findings support efforts to use PD1/PD-L1 checkpoint blockade in clinical trials and highlight the importance of CD4+ T-cell dysfunction in limiting the endogenous anti-leukemia response.

The Prognostic Implication of Adult Comorbidity Evaluation 27 Score in CML Patients on Tyrosine-Kinase Inhibitors

The Prognostic Implication of Adult Comorbidity Evaluation 27 Score in CML Patients on Tyrosine-Kinase Inhibitors

Analysis of Early Events during the First Year of Tyrosine Kinase Inhibitor Therapy in Patients with Chronic Phase - Chronic Myeloid Leukemia: A “Campus CML” Study

Background Tyrosine kinase inhibitors (TKIs) revolutionized treatment of chronic myeloid leukemia (CML). However, the first months of therapy are crucial, as optimal response is defined as the achievement of molecular milestones at 3, 6 and 12 months (mo.) and as many toxicities, also causing a TKI switch, are more frequent in the 1st year.Methods To evaluate achievement of early molecular response (MR) and incidence of events leading to a TKI change during the 1st year of therapy, we retrospectively studied 1650 CP-CML patients diagnosed from 2012 and 2019 at 31 Hematology Centres and treated with frontline imatinib (IM) or second-generation (2G) TKIs dasatinib or nilotinib. Optimal MR at 3, 6 and 12 mo. were assessed according to 2020 ELN recommendations.Results Frontline TKI was IM in 926 (56.1%) and 2G-TKIs in 724 (43.9%) cases: the main clinical features at diagnosis of the entire cohort and according to frontline treatment is reported in the Table 1. Commonest comorbidities were arterial hypertension (38.7%), previous neoplasm (13.6%), diabetes (11.3%), peripheral vascular diseases (7.8%), COPD (7.5%) and ischemic heart disease (6.8%). IM-treated patients were older (p<0.001), with higher ELTS score (int/high 47.6% vs 35.6%, p<0.001) and more comorbidities (p<0.005 for all diseases).Optimal MR was achieved at 3 mo. by 1186/1430 (82.9%), at 6 mo. by 1025/1352 (75.8%) and at 12 mo. by 826/1264 patients (65.3%), respectively.Total number of patients discontinuing TKI in the 1st year was 321/1650 (19.4%), being higher with IM (237/926, 25.5%) than 2G-TKIs (84/724, 11.6%) (p<0.001). Main causes were primary resistance (8.7%, 12.3% IM vs 4.2% 2G-TKIs, p<0.001), extra-hematologic toxicity (6.4%, 8.2% IM vs 4.2% 2G-TKIs, p>0.001), hematologic toxicity (1.7%, 2.0% IM vs 1.4% 2G-TKIs, p=0.25) and progression (1.0%, 1.2% IM vs 0.8% 2G-TKIs, p=0.56). Cumulative incidence of discontinuation at 3, 6 and 12 mo. were 5.6%, 10.7% and 19.3%, respectively; values for IM and 2G-TKIs at the three timepoints were 8.1%, 15.0%, 25.5% and 2.5%, 5.3%, 11.5% (p<0.001) (Fig. 1).Conclusions This real-world study on over 1600 CML patients shows that almost 20% discontinue frontline TKI during the 1st year, mostly for primary resistance or toxicity. Discontinuation rates are higher with IM compared to 2G-TKIs, mostly at 3 mo. and are probably due to a lower attainment of early MR. The impact of older age, higher risks and heavier burden of comorbidities in IM patients should be considered and need deeper investigation. [Display omitted] DisclosuresElena: GILEAD: Membership on an entity's Board of Directors or advisory committees; NOVARTIS: Membership on an entity's Board of Directors or advisory committees; PFIZER: Membership on an entity's Board of Directors or advisory committees; CELGENE: Other: funding for meeting participation. Sportoletti: AstraZeneca: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria. Stagno: InCyte: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria, Other: Support for attending meetings and/or travel; Novartis: Consultancy, Honoraria, Other: Support for attending meetings and/or travel, Research Funding. Iurlo: Pfizer: Speakers Bureau; Incyte: Speakers Bureau; Novartis: Speakers Bureau; Bristol Myers Squibb: Speakers Bureau. Bonifacio: Novartis: Honoraria; Pfizer: Honoraria; Amgen: Honoraria; Bristol Myers Squibb: Honoraria. Breccia: Pfizer: Honoraria; Incyte: Honoraria; Abbvie: Honoraria; Bristol Myers Squibb/Celgene: Honoraria; Novartis: Honoraria. Latagliata: Novartis: Honoraria; Pfizer: Honoraria; BMS Cellgene: Honoraria.

Custom High Throughput Drug Sensitivity Assay Reveals Therapeutic Options for Chronic Myeloid Leukemia Patients Resistant to or Intolerant of Tyrosine Kinase Inhibitors

Introduction. Tyrosine kinase inhibitors (TKIs) have revolutionized chronic phase (CP) chronic myeloid leukemia (CML) care with many patients achieving major and deeper molecular responses. However, for those who are resistant to or do not tolerate the approved TKIs, there are few alternatives. We therefore developed a custom high throughput drug screen comprised of both FDA approved and investigational agents.Methods. Fifty-six samples (50 individual patients) have undergone testing in the drug sensitivity assay, for which a large fraction exhibited resistance to approved agents. The Quellos High Throughput Core Laboratory's Cancer Drug Sensitivity has been CLIA approved for leukemia since 2015. Blood and bone marrow samples were obtained from CML patients with written informed consent. Mononuclear cells were isolated by density depletion. The myeloid population was obtained by lineage depletion of non-myeloid cells using magnetic beads and antibodies to erythroid lineage (CD235a), T (CD3) and B (CD19) lymphocytes, and NK (CD56) cells. Flow cytometry confirmed successful enrichment of the myeloid cell population. Cells were plated on extracellular matrix coated 384 well plates to test under conditions of adhesion mediated chemotherapy resistance. Initially, the assay was comprised of 32 drugs (11 patients) selected based on published activity in CML and resistant CML. The assay was then expanded to 64 drugs. Compounds are added (ranging from 5 pM to 100 μM) to patient samples using the CyBio CyBi-Well Vario and incubated at 37°C, 5% CO2 for 72 hours, then viability is assessed by CellTiterGlo. IC50s and AUCs are calculated for each drug using XLFit (IDBS) and a standard 4 parameter logistical model. Transcriptome analysis is planned for these samples.Results. Clinical characteristics are shown in Table 1. Mean and median BCR-ABL1 transcripts were 69% and 70% in diagnosis samples and 63% and 55% in resistant samples, respectively (P=0.607). ABL mutations were present in 5 patients (M244V, T315I, F359I). Additional myeloid mutations were present in 5 of 6 evaluable advanced phase samples, 4 of 17 evaluable diagnostic samples, and 3 of 10 evaluable resistant samples and included ASXL1, DNMT3A, IDH1, JAK2V617F, NRAS, RUNX1, and TET2. Figure 1 illustrates the breadth of sensitivity to agents in the assay. Figure 2 is a heat map of area under the curve (AUCs) illustrating the unique drug sensitivity patterns for all patients, with unsupervised clustering.For new diagnosis patients, the TKIs imatinib, dasatinib, nilotinib, bosutinib, and ponatinib ranked in the top 8 drugs. For primary resistant patients, the IC50 values for imatinib, nilotinib, bosutinib, and ponatinib were higher than the new diagnosis patients. For example, for ponatinib, the mean IC50 was 402.6 ± 354.7 X 10 E-9 M for primary resistant samples vs. 1.65 ± 0.45 X 10 E-9 M for diagnosis group, p=0.015 (Welch t test), or about 250-fold higher (less sensitive). In accelerated and blast phase samples drugs with IC50 values lower than 0.1 µM, a range that could correlate with in vivo drug response, were identified for all patients (range, 3-20 drugs per patient). Top candidates included proteasome and kinase inhibitors. In 2 patients harboring NRAS mutations, IC50 for trametinib was less than 0.1 µM as compared to patients without NRAS mutations, where the IC50s were higher. Clinical outcomes are available for nearly all patients. Although the study was not designed to select next-line TKI therapy in resistant patients, drug profiling was informative in many cases. Data for 7 resistant patients are shown in Table 2. For example, CML-012 had the lowest IC50 value (indicating most sensitive) for dasatinib, 4.1 X 10E-8 M and responded to dasatinib after failing imatinib (IC50 8.4 X 10E-7M). CML-003 did not respond to bosutinib (IC50 1.2 X 10E-6M) and did respond to dasatinib (IC50 1.2 X 10E-7M). CML-056 did not respond to nilotinib (IC50 1.4 X 10E-6M), dasatinib (IC50 6.9 X 10E-4M), or ponatinib (IC50 1.0 X 10E-6M). Notably, in all resistant patient samples we identified drugs with IC50 values lower than 0.1 µM. These therapeutics can be prioritized for further evaluation, either alone or in combination with TKIs, in resistant CML patients.Conclusion. In vitro drug sensitivity testing provides data for potential agents for patients with resistance or intolerance to FDA approved TKIs, or those that have entered accelerated phase or blast phase. [Display omitted] DisclosuresOehler: Blueprint Medicines: Consultancy; Takeda: Consultancy; Pfizer: Research Funding; OncLive: Honoraria; BMS: Consultancy. Becker: Abbie: Research Funding; SecuraBio: Research Funding; Cardiff Oncology: Research Funding; Pfizer: Research Funding; BMS: Research Funding; CVS Caremark: Consultancy; Glycomimetics: Research Funding. OffLabel Disclosure:We developed a custom high throughput drug screen comprised of both FDA approved and investigational agents

Trial in Progress: A Multicenter, Open Label, Randomized, Phase III Study of Asciminib (80 mg Once Daily) Vs Investigator-Selected TKI in Newly Diagnosed Adult Patients with Chronic Myeloid Leukemia in Chronic Phase

Trial in Progress: A Multicenter, Open Label, Randomized, Phase III Study of Asciminib (80 mg Once Daily) Vs Investigator-Selected TKI in Newly Diagnosed Adult Patients with Chronic Myeloid Leukemia in Chronic Phase

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

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

Trial in Progress: A Multicenter, Open-Label, Phase Ib/II Study to Determine the Dose and Safety of Asciminib in Pediatric Patients with Philadelphia Chromosome-Positive Chronic Myeloid Leukemia in Chronic Phase Treated with ≥1 Prior Tyrosine Kinase Inhibitor

BACKGROUND: Tyrosine kinase inhibitors (TKIs) are the standard of care for adult and pediatric patients (pts) with chronic myeloid leukemia in chronic phase (CML-CP). In adults, 5 TKIs are approved: imatinib, dasatinib, nilotinib, bosutinib and ponatinib. In the pediatric population, however, only imatinib, dasatinib and nilotinib are approved. Pediatric pts have similar cytogenetic and molecular response rates to first-line (1L) imatinib and 1L second-generation TKIs nilotinib and dasatinib as adults. While the safety profiles for TKIs are similar in adult and pediatric pts, growth retardation has been reported specifically in the pediatric population. Therefore, safer and more efficacious options are needed for pediatric pts. Asciminib is an investigational drug that inhibits BCR-ABL1 by specifically targeting the ABL myristoyl pocket (STAMP inhibitor). Asciminib has shown promising efficacy and safety in adults with CML-CP in phase I-III trials, given without food for 1 hour prior and 2 hours after taking asciminib (fasted). In the phase I asciminib monotherapy trial in heavily pretreated adult pts, 48% and 28% without and with T315I mutations, respectively, achieved or maintained major molecular response (MMR) by 12 months. In the phase III ASCEMBL trial for adults with CML-CP who are resistant to or intolerant of ≥2 TKIs, 25.5% of pts on asciminib vs 13.2% of pts on bosutinib achieved MMR at 24 weeks. Here we present the phase Ib/II trial evaluating asciminib monotherapy in pediatric pts.OBJECTIVE: The primary objectives of this study are to characterize the pharmacokinetic (PK) profile of asciminib in pediatric pts and identify a pediatric formulation dose (taken with food) leading to an asciminib exposure comparable to that of 40 mg twice daily (BID) in adult pts (fasted).DESIGN: This is a multicenter, open-label, phase Ib/II study (NCT04925479, Figure 1). Eligible pts have Philadelphia chromosome-positive CML-CP resistant to or intolerant of ≥1 prior TKI, do not bear T315I mutations and are aged ≥1 to <18 years. Adolescent pts aged ≥14 to <18 years and weighing ≥40 kg will be enrolled in the exploratory adult formulation group, receiving 40 mg asciminib BID in the fasted state until the pediatric formulation is available. There is no prespecified sample size for this group.In part 1 (dose-determining cohort), 4 to 6 pts aged ≥1 to <18 years will receive the pediatric formulation (body weight-adjusted dose of asciminib minitablets taken with food) to obtain ≥4 participants evaluable for PK data. This evaluation will determine whether median exposure in pediatric pts is comparable to that of asciminib 40 mg BID in adult pts (fasted). Dose adjustments will be made if the minimum exposure is less than that of 20 mg BID in adults or higher than double the maximum exposure in adults at 40 mg BID. During the first 28 days after treatment initiation, safety will be assessed based on predefined dose-limiting toxicities.In part 2 (expansion cohort), the body weight-adjusted dosing determined in part 1 will be used, and the total pts enrolled on pediatric formulation will be increased to 30, including those from part 1 (15 pts aged 1 to <12 years and 15 pts aged 12 to <18 years). Pts receiving the adult formulation will have the opportunity to switch to the pediatric formulation in part 2 but will not be counted toward the 30 pts enrolled in part 2. A second interim PK and safety analysis will be conducted after all pts in part 2 have completed 28 days of treatment (Figure 2).The total duration of the study treatment period is 5 years. The primary analysis (primary PK endpoints, safety, and pharmacodynamics) will be assessed after all pts have been on study for 52 weeks or discontinued earlier. A final analysis will be completed after all pts have been on study for 5 years or discontinued earlier. Pts who discontinue the study early will be followed up for survival until the study is complete.MAIN OUTCOMES MEASURES: The primary endpoints include PK parameters. Secondary endpoints include treatment-associated AEs, hematologic and molecular responses, and acceptability and palatability of asciminib (Table 1).CONCLUSIONS: Data from this study will be used to support a strategy of full extrapolation from adult data to use in the pediatric setting.This study is sponsored by Novartis. [Display omitted] DisclosuresHijiya: Novartis: Consultancy; Stemline Therapeutics: Consultancy. Kapoor: Novartis: Current Employment, Current equity holder in publicly-traded company. Descamps: Novartis: Current Employment. Bayar: Novartis: Current Employment. Ramscar: Novartis: Current Employment.

Ultra-deep sequencing mutation analysis of the BCR/ABL1 kinase domain in newly diagnosed chronic myeloid leukemia patients

Ultra-deep sequencing detects low-frequency genetic mutations with high sensitivity. We used this approach to prospectively examine mutations in the BCR/ABL1 tyrosine kinase from patients with newly diagnosed, chronic-phase chronic myeloid leukemia (CML) treated with the tyrosine kinase inhibitor nilotinib. Between May 2013 and November 2014, 50 patients from 18 institutions were enrolled in the study. We screened 103 somatic mutations and found that mutations in the P-loop domain were the most frequent (173/454 mutations in the P-loop) and noted the presence of the V299 L mutation (dasatinib-resistant/nilotinib-sensitive) in 98 % of patients (49/50). No patients had Y253H, E255 V, or F359 V/C/I mutations, which would recommend dasatinib rather than nilotinib treatment. The S417Y mutation was associated with lower achievement of a major molecular response (MMR) at 6 months, and the V371A mutation was associated with reduced MMR and MR4.5 durations (MMR for 2 years: 100 % for no mutation vs. 75 % for mutation, P=0.039; MR4.5 for 15 months: 94.1 % vs. 25 %, P=0.002). Patients with known nilotinib-resistant mutations had lower rates of MR4.5 achievement. In conclusion, ultra-deep sequencing is a sensitive method for genetic-based treatment decisions. Based on the results of these mutational analyses, nilotinib treatment is a promising option for Korean patients with CML.

Which Tyrosine Kinase Inhibitors Should Be Selected as the First-Line Treatment for Chronic Myelogenous Leukemia in Chronic Phase?

Simple SummaryThis review discusses the optimal selection of BCR-ABL1 tyrosine kinase inhibitors (TKIs) as the first-line treatment for newly diagnosed chronic myelogenous leukemia in chronic phase (CML-CP). With the advent of TKIs, the treatment goals for CML-CP patients have changed from “simply survival” to “survival with adequate quality of life”, hence the number of CML-CP patients aiming to achieve treatment-free remission has increased, irrespective of age or comorbidities. Therefore, optimal selection of TKIs for maximizing the number of patients to achieve treatment-free remission is an important factor for consideration in future studies. To this end, we must understand the advantages and disadvantages of each TKI in terms of treatment response, disease risk at diagnosis, comorbidities, and medical expenses, and use of effective 2GTKIs based on patient background. This review provides insights into “shared decision-making” in individual cases, including the elderly population.With the use of tyrosine kinase inhibitors (TKIs), chronic myelogenous leukemia in chronic phase (CML-CP) has been transformed into a non-fatal chronic disease. Hence, “treatment-free remission (TFR)” has become a possible treatment goal of patients with CML-CP. Currently, four types of TKIs (imatinib, nilotinib, dasatinib, and bosutinib) are used as the first-line treatment for newly diagnosed CML-CP. However, the second-generation TKI (2GTKI), the treatment response of which is faster and deeper than that of imatinib, is not always recommended as the first-line treatment for CML-CP. Factors involved in TKI selection in the first-line treatment of CML-CP include not only patients’ medical background, but also patients’ choice regarding the desired treatment goal (survival or TFR?). Therefore, it is important that clinicians select an appropriate TKI to successfully achieve the desired treatment goal for each patient, while minimizing the development of adverse events. This review compares the pros and cons of using imatinib and 2GTKI for TKI selection as the first-line treatment for CML-CP, mainly considering treatment outcomes, medical history (i.e., desire for pregnancy, aging factor, and comorbidity), and cost. The optimal use of 2GTKIs is also discussed.

Treatment Responses in Patients with Chronic Myeloid Leukemia on Tyrosine Kinase Inhibitors (TKI) Therapy

Background: Chronic myeloid leukemia (CML) is a cancer of white blood cells results by the BCR-ABL translocation. Part of BCR gene from chromosome 22 is fused with ABL gene on chromosome 9. Aim: To observe percentage of patients achieving Cytogenetics response (CR), and Deep molecular response (DMR) in CML patients taking TKI (Imatinib and Nilotinib). Study Design: Retrospective Cohort study. Methodology: This study was conducted in 2018-2019 in about 198 CML patients to evaluate TKI therapy response and observation was based upon their Quantitative PCR test which gave percentage of BCR-ABL gene translocation in IU. Patients which were diagnosed with CML in 2016 and was regular in their treatment for about 2 years were included in the study. No intervention was given as in vivo study. Statistical analysis: Data analyzed by SPSS 25.0v. Results: Results showed that out of 198 CML patients, started on 1st line TKI (imatinib) 95 males (48%) and 103 females (52%) showed cytogenetic response at start of therapy and after 2 years of therapy 157 (79.3%) patient showed DMR. Conclusion: This study concluded that regular 2-year treatment of chronic CML patients with TKIs produced significant response in patients. Keywords: BCR-ABL Translocation, Cytogenetic Response, Major Molecular Response, Complete Molecular Response and Deep Molecular Response.

Combination of tyrosine kinase inhibitors and the MCL1 inhibitor S63845 exerts synergistic antitumorigenic effects on CML cells

Tyrosine kinase inhibitor (TKI) treatment has dramatically improved the survival of chronic myeloid leukemia (CML) patients, but measurable residual disease typically persists. To more effectively eradicate leukemia cells, simultaneous targeting of BCR-ABL1 and additional CML-related survival proteins has been proposed. Notably, several highly specific myeloid cell leukemia 1 (MCL1) inhibitors have recently entered clinical trials for various hematologic malignancies, although not for CML, reflecting the insensitivity of CML cell lines to single MCL1 inhibition. Here, we show that combining TKI (imatinib, nilotinib, dasatinib, or asciminib) treatment with the small-molecule MCL1 inhibitor S63845 exerted strong synergistic antiviability and proapoptotic effects on CML lines and CD34+ stem/progenitor cells isolated from untreated CML patients in chronic phase. Using wild-type BCR-ABL1-harboring CML lines and their T315I-mutated sublines (generated by CRISPR/Cas9-mediated homologous recombination), we prove that the synergistic proapoptotic effect of the drug combination depended on TKI-mediated BCR-ABL1 inhibition, but not on TKI-related off-target mechanisms. Moreover, we demonstrate that colony formation of CML but not normal hematopoietic stem/progenitor cells became markedly reduced upon combination treatment compared to imatinib monotherapy. Our results suggest that dual targeting of MCL1 and BCR-ABL1 activity may efficiently eradicate residual CML cells without affecting normal hematopoietic stem/progenitors.