The FLT3 F691L Gatekeeper Mutation Promotes Clinical Resistance to Gilteritinib + Venetoclax (GILT + VEN) in AML

Abstract Background: FMS-like tyrosine kinase (FLT3) is one the most frequently mutated genes in AML and is associated with poor prognosis. FLT3 internal tandem duplication (ITD) and tyrosine kinase domain (TKD) mutations occur in up to 30% and 5-10% of AML, respectively. Several small molecule FLT3 inhibitors (FLT3i) have been developed but their use as single agents is limited due to the development of drug resistance. Our lab developed a two-step model of early and late resistance to FLT3i that recapitulates resistance in AML patients (Traer et al. Cancer Res. 2016; Joshi et al. Cancer Cell 2021). Early resistance, also known as AML persistence, is the stage when residual AML cells are dependent upon the marrow microenvironment for survival and patients are clinically responding. Late resistance to GILT was characterized by expansion of intrinsic mutations, with NRAS mutations being the most frequent mutation, in addition to a few gatekeeper FLT3 mutations. Current therapies are looking at combinations to overcome GILT resistance, including chemotherapy, hypomethylating agents (HMAs), and venetoclax (VEN) +/- HMAs. GILT+VEN, in particular, has shown good initial activity in relapsed/refractory FLT3 AML patients (Daver et al. ASH 2020), however the mechanism of resistance to this combination is unknown. Results: Early resistance cell cultures to GILT+VEN were created by exposing MOLM14 cells to GILT 25nM + VEN 25nM alone or supplemented with microenvironmental ligands FGF2 or FLT3 ligand (FL; N=3/group). Media, drugs, and ligands were replenished twice weekly. After 25 weeks, only the cultures exposed to ligand resumed growth (N=1 for FGF2 and N=3 for FL). Ligands were then removed from these early resistant cultures to induce late resistance. There was an initial drop in cell viability but cells resumed growth after only 3.5 weeks (Fig. 1). In contrast, the time to develop early and late resistance to GILT monotherapy was 8 and 15 weeks, respectively. Immunoblot analysis of GILT + VEN early and late resistant cultures demonstrated restoration of FLT3 signaling, as well as phosphorylation of downstream AKT/MAPK pathways. These results also contrasted to late GILT monotherapy resistant cultures, which had downstream AKT/MAPK activation via outgrowth of NRAS mutations. Since FLT3 appeared to be functionally active, we sequenced FLT3 and found that all early and late GILT + VEN resistance cultures had gatekeeper FLT3 F691L mutations. F691L accounted for only in a minority of resistance cultures to GILT monotherapy. To test if FLT3 signaling was important for resistance, we exposed parental cells to higher concentrations of gilteritinib, which have been shown to partly overcome F691L, as well as the FLT3i FF-10101, which binds FLT3 at a different site and is not affected by the F691L mutation. Both of these approaches restored sensitivity to FLT3i in vitro. As expected, the F691L mutation provided broad resistance to most FLT3i (Fig. 2). To validate this mechanism of resistance in patients, we identified a relapsed FLT3-ITD patient who was treated with GILT monotherapy for 5 months, followed by GILT + HMA for 4 cycles, and then GILT + VEN for resistant proliferative disease. After an initial response to GILT + VEN, the leukemia cells began to increase again in the peripheral blood. A repeat genetic test was ordered and the patient was found to have developed a FLT3 F691L mutation at a high variant allele frequency (Fig. 3). Conclusion: We have developed a robust cell line model of early and late resistance to FLT3i that mimics the timing and expansion of resistance mutations in the clinic. Our model of early and late resistance to GILT combinations can prospectively predict mechanisms of resistance. Although uncommon as a mechanism of resistance to GILT monotherapy, our model and early patient data predicts that F691L mutations are more important for GILT + VEN resistance. Figure 1 Figure 1. Disclosures Tyner: Seattle Genetics: Research Funding; Astrazeneca: Research Funding; Array: Research Funding; Janssen: Research Funding; Takeda: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Petra: Research Funding; Constellation: Research Funding; Genentech: Research Funding; Agios: Research Funding; Schrodinger: Research Funding. Traer: ImmunoGen: Membership on an entity's Board of Directors or advisory committees; Schrodinger: Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees; Servier/Agios: Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte: Research Funding; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees.

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The Genomic Landscape of Childhood and Adult Acute Erythroid Leukemia

Blood ◽

10.1182/blood.v128.22.39.39 ◽

2016 ◽

Vol 128 (22) ◽

pp. 39-39 ◽

Cited By ~ 2

Author(s):

Ilaria Iacobucci ◽

Ji Wen ◽

Manja Meggendorfer ◽

Catherine Carmichael ◽

John K Choi ◽

...

Keyword(s):

Dna Methylation ◽

Tyrosine Kinase ◽

Board Of Directors ◽

Transcription Regulation ◽

Research Funding ◽

Complex Karyotype ◽

Advisory Committees ◽

Nih3t3 Cells ◽

Genomic Landscape

Abstract Introduction: The genetic basis of several acute myeloid leukemia (AML) subtypes remains poorly characterized, such as that of acute erythroid leukemia (AEL, AML M6) which is currently subclassified by morphology alone, and is associated with poor outcome. Here we sought to perform a definitive genomic analysis of AEL and translate these findings into faithful experimental models and novel therapeutic approaches. Methods: We studied 151 AEL cases (19.2% pediatric, 4.6% young adult, 21.9% adult and 54.3% older adult). Diagnosis of AEL was centrally confirmed and subclassified according to WHO 2008 and revised 2016 criteria. Whole exome and/or genome sequencing, RNA-sequencing and SNP array analysis were performed on all cases and in 2 AEL cell lines (TF-1 and Hel). Genomic data were compared to those from non-M6 childhood and adult AML from TARGET (n=192) and TCGA (n=197) studies. The functional effects of fusion transcripts and mutated genes were examined in IL-3 dependent Ba/F3 cells, NIH3T3 cells for focus formation assays and/or mouse lineage negative hematopoietic stem cells (lin- HSC) for colony forming and transplantation assays. Avatars of human AEL were established in immunocompromised NSGS and MISTRG mice for preclinical studies. Results: a) Genomic landscape of AEL. We identified 2,250 non-synonymous clonal and subclonal somatic mutations in 1,723 genes with a mean of 16.4 per case (range 2-88) and with missense and frameshift mutations accounting for 47.1% and 22.5% of all mutations, respectively. 78 genes were recurrently mutated in at least 3 cases. In frame fusions were detected in 31% of childhood and 27.5% of adult cases, and were more frequent in cases with complex karyotype. 124 potential driver genes were identified by statistical analysis or known pathogenic role in cancer, 9 of which were recurrent novel targets of mutation, most commonly involving chromatin modification (60.3%), cell cycle/tumor suppression (TP53, 33.8%), DNA methylation (28.5%), transcription regulation (26.5%), splicing (15.9%), NPM1 (11.9%), Ras (11.3%), JAK-STAT signaling (9.9%), the cohesin complex (8.6%), ALK/NTRK1 (4.6%) and PI3K signaling (3.3%). Overall, 33% of cases harbored a mutation in signaling genes amenable to inhibition by tyrosine kinase/Ras inhibitors. Mutations in TP53 and DNA methylation genes were significantly more frequent in adults while mutations in transcription regulators and Ras pathway were more frequent in children. Splicing mutations correlated with MDS phenotype and PI3K alterations with therapy-related AEL. Based on the co-occurrence and exclusivity of mutations 7 main distinct AEL genetic subtypes were defined: 1) pediatric AEL with NUP98-rearrangements (3.3% of all cases); 2) adult complex karyotype AEL with TP53 mutations (33.8%); 3) AEL with MLL-rearrangements (12.6%); 4) NPM1-mutated AEL (11.9%); 5) DNA-methylation/splicing mutated AEL (17.8%); 6) splicing/Ras/transcription regulation mutated AEL (21.2%) and 7) Other (8.6%) (Fig.1A). Mutations of chromatin modifiers occurred independently of karyotype, age and subtype (Fig.1B). NUP98-fusions and mutations in PTPN11, UBTF and GATA1 were more frequent in pediatric AEL compared to non-M6 AML. Among adults, mutations in TP53 and MLL were more frequent in AEL while FLT3, NPM1, DNMT3A and IDH1 were more in frequent in non-M6 subtypes. A complex karyotype, therapy-related AEL, TP53 mutations and NUP98-rearrangements were associated with poor outcome. b) Functional AEL modeling and therapeutic translations. Expression of NUP98-JARID1A in lin- HSC resulted in sustained self-renewal and development of an aggressive transplantable leukemia. At least three classes of signaling pathway mutations are targetable in AEL. ALK mutations in the extracellular MAM domain transformed Ba/F3 cells which were sensitive to crizotinib in vitro. Mutations in the tyrosine kinase domain of NTRK1 transformed NIH3T3 cells and were sensitive to entrectinib in vitro. Targeting of JAK-STAT, mTOR and PI3K pathways were examined in xenografts and sensitivity to JAK2 inhibitor ruxolitinib was confirmed in vivo. Conclusions: We provided the first comprehensive landscape of genomic alterations in AEL and defined distinct genomic groups with unique patterns of mutation occurrence compared to non-M6 AML. Finally, we showed that several pathogenic pathways are amenable to inhibition by approved targeted compounds. Disclosures Meggendorfer: MLL Munich Leukemia Laboratory: Employment. Wei:Novartis: Honoraria, Research Funding. Loh:Abbvie: Research Funding; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Mullighan:Amgen: Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees; Loxo Oncology: Research Funding.

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ATP Dependent Efflux Transporters ABCB1 and ABCG2 Are Unlikely to Impact the Efficacy, or Mediate Resistance to the Tyrosine Kinase Inhibitor, Ponatinib

Blood ◽

10.1182/blood.v118.21.2745.2745 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2745-2745 ◽

Cited By ~ 1

Author(s):

Deborah L. White ◽

Liu Lu ◽

Timothy P. Clackson ◽

Verity A Saunders ◽

Timothy P Hughes

Keyword(s):

Tyrosine Kinase ◽

Board Of Directors ◽

Cell Lines ◽

Research Funding ◽

Kinase Inhibitor ◽

K562 Cells ◽

Temperature Dependent ◽

Advisory Committees ◽

Significant Difference

Abstract Abstract 2745 Ponatinib is a potent pan-BCR-ABL tyrosine kinase inhibitor (TKI) currently in a pivotal phase 2 clinical trial. Ponatinib (PON) was specifically designed to target both native and all mutant forms of BCR-ABL, including T315I. The phase I study of oral ponatinib in patients with refractory CML/ALL or other hematologic malignancies recently reported that 66% and 53% of patients with CP-CML achieved MCyR and CCyR respectively (Cortes et al., ASH 2011 abstract #210). While extensive modelling experiments in BaF3 cells have been performed characterising in vitro response to ponatinib, little is known about the interactions of this drug and drug transporters that impact the response of other tyrosine kinase inhibitors (TKIs). To explore this we have examined both the degree of in vitro kinase inhibition mediated by ponatinib in BCR-ABL+ cell lines, and the intracellular uptake and retention (IUR) of ponatinib achieved. The IC50 was determined by assessing the reduction in %p-Crkl in response to increasing concentrations of ponatinib in vitro. The IUR assay was performed as previously using [14-C]-ponatinib. To determine the role of ABCB1 and ABCG2, both previously implicated in the transport of other TKIs, IC50 analysis was performed on K562 cells, and variants; ABCB1 overexpressing K562-DOX and ABCG2 overexpressing K562-ABCG2. As shown in Table 1, in contrast to the results previously observed with imatinib (IM), nilotinib (NIL) and dasatinib (DAS) there was no significant difference in the IC50ponatinib between these three cell lines, suggesting neither ABCB1 nor ABCG2 play a major role in ponatinib transport. Furthermore, the addition of either the ABCB1 and ABCG2 inhibitor pantoprazole, or the multidrug resistance (MDR) inhibitor cyclosporin did not result in a significant change in the IC50ponatinib in any of the cell lines tested. In contrast the addition of either pantoprazole or cyclosporin resulted in a significant reduction in IC50IM, IC50NIL. and IC50DAS of K562-DOX cells, supporting the notion that these TKIs interact with ABCB1.Table 1:The IC50 of ponatinib (compared to IM, NIL and DAS) in K562 cells and the over-expressing variants DOX and ABCG2 in the presence of the ABC inhibitors pantoprazole and cyclosporin. n=5. *p<0.05IC50% reduction in IC50+ pantoprazole+ cyclosporinPON (nM)IM (μM)NIL (nM)DAS (nM)PONIMNILDASPONIMNILDASK5627.793751111544*NA−107NA2DOX7.919*598*100*1018*63*1655*88*ABCG26.4730025*6NA To further examine the effect of ABC transporters on ponatinib efflux we have determined the IUR of [14-C]-ponatinib in K562, DOX and ABCG2 cell lines. We demonstrate no significant difference in the IUR between these cell lines at 37°C (n=6) (K562 vs DOX p=0.6; K562 vs ABCG2 p=0.37 and DOX vs ABCG2 p=0.667 at 2uM respectively). Temperature dependent IUR experiments reveal a significant reduction in the ponatinib IUR at 4°C compared to 37°C in K562 cells (n=6) (p=0.008), DOX cells (p=0.004) and ABCG2 cells (p=0.002) supporting the likely involvement of an ATP/temperature dependent, and yet to be determined, component of ponatinib influx. There was no significant difference in the IUR between these cell lines at 4°C (p=0.824, p=0.7 and p=0.803 respectively). Importantly, these data are consistent with the IC50ponatinib findings. If ATP dependent efflux pumps (ABCB1 and ABCG2) were actively transporting ponatinib, a significant decrease in IUR in DOX and ABCG2 at 37°C compared to K562 cells would be expected, but is not observed here. Analysis of ponatinib IUR in the prototypic ABCB1 over-expressing CEM-VBL100 cells, and their parental, ABCB1 null counterparts (CCRF-CEM) further confirmed these findings. The IUR in VBL100 cells was significantly higher than that observed in CEM's (p<0.001; n=5), providing further evidence that ponatinib was not being exported from the cell actively via ABCB1. These data suggest that the transport of ponatinib is, at least in part, temperature-dependent indicating a yet to be determined ATP transporter may be involved in the transport of ponatinib into leukaemic cells. Importantly, this data suggests that ponatinib is unlikely to be susceptible to resistance via the major ATP efflux transporters (ABCB1 or ABCG2) that have been previously demonstrated to significantly impact the transport of, and mediate resistance to other clinically available TKIs. Disclosures: White: BMS: Honoraria, Research Funding; Novartis Pharmaceuticals: Honoraria, Research Funding. Clackson:ARIAD: Employment. Hughes:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; ARIAD: Honoraria, Membership on an entity's Board of Directors or advisory committees.

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Inhibition Of Lyn and Syk By Treatment With Dasatinib, Fludarabine, and Rituximab Correlates With Apoptosis and Clinical Response In Patients With Relapsed CLL

Blood ◽

10.1182/blood.v122.21.5300.5300 ◽

2013 ◽

Vol 122 (21) ◽

pp. 5300-5300

Author(s):

Philip C. Amrein ◽

Xin Kai ◽

Carlos Donato ◽

Jon Arnason ◽

Jennifer R. Brown ◽

...

Keyword(s):

Tyrosine Kinase ◽

Clinical Response ◽

Board Of Directors ◽

Research Funding ◽

Single Agent ◽

Annexin V ◽

Hematologic Toxicity ◽

Advisory Committees ◽

Off Label

Abstract Survival, proliferation, and resistance to chemotherapy in CLL cells have been shown to be consistently associated with the activity of the B-cell receptor (BCR) and the associated downstream pathways activated by the BCR. Key molecules in this pathway are LYN and SYK (Spleen tyrosine kinase), as well as PI3K, BTK (Bruton’s tyrosine kinase), and others. Dasatinib, given at standard doses, allows for serum levels well above 11 nM, the IC50 for suppression of LYN kinase. We have previously shown that dasatinib used as a single agent in patients with relapsed CLL results in lymph node responses in 60% of patients and partial responses in 20% of patients as defined by NCI-WG criteria. In the current study, patients with relapsed CLL were treated with a regimen combining dasatinib at 140 mg/day, days 1-14, with fludarabine (F) 25 mg/m2/day, days 1-3, and rituximab (R) 375 mg/m2 per cycle repeated every 28 days, while effective up to 6 cycles. Patients were followed closely for response with CT scans every 2 months initially. Among the first 10 patients treated, all had responses according to IWCLL criteria as follows: The median time to progression was 21 months. In the first week multiple blood samples were taken for analysis of target inhibition and subsequent apoptosis. The schedule of administered agents was altered in the first week to determine which components were associated with which downstream effects. Hence, dasatinib was given on Day 1, no treatment was administered on Day 2, F and R without dasatinib on Day 3, dasatinib with FR on Day 4, and dasatinib with F on Day 5. Initial in vitro studies revealed inhibition of phosphorylation of Lyn at 6 hours after patients were given dasatinib on Days 1 and 4, with recovery by 24 hours. Day 3 treatment with FR but without dasatinib showed no such inhibition at 6 hours. Assessment of global tyrosine phosphorylation in CLL cells showed this same pattern, including that of Syk phosphorylation, specifically. Flow cytometry for annexin-V demonstrated that apoptosis was greatest on Day 4 after 6 hours of exposure to all 3 drugs. We conclude the following: 1) the combination of dasatinib with FR, as seen in the first 10 patients of this study, was associated with excellent responses in blood and lymph nodes as assessed by physical exam, 2) the combination was well tolerated with mainly hematologic toxicity, 3) the inhibition of phosphorylation of Lyn and Syk was associated with apoptosis and clinical response. This combination may have therapeutic promise in advanced CLL and is worthy of further investigation. Disclosures: Off Label Use: Dasatinib use in CLL is off-label. This trial shows that dasatinib may be beneficial in the treatment of CLL. Brown:Pharmacyclics: Consultancy; Genentech: Consultancy; Celgene: Consultancy, Research Funding; Emergent: Consultancy; Onyx: Consultancy; Sanofi Aventis: Consultancy; Vertex: Consultancy; Novartis: Consultancy; Genzyme: Research Funding. Fathi:Seattle Genetics, Inc.: Advisory/Scientific board membership Other, Research Funding; Millennium: Research Funding; Agios: Membership on an entity’s Board of Directors or advisory committees; Teva: Membership on an entity’s Board of Directors or advisory committees.

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Preclinical Evaluation of Gilteritinib on NPM1-ALK Driven Anaplastic Large Cell Lymphoma Cells

Blood ◽

10.1182/blood-2019-130633 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 2865-2865

Author(s):

Sudhakiranmayi Kuravi ◽

Janice Cheng ◽

Kishore Polireddy ◽

Gabrielle Fangman ◽

Roy A Jensen ◽

...

Keyword(s):

Tyrosine Kinase ◽

Board Of Directors ◽

Research Funding ◽

Cell Lymphoma ◽

Large Cell ◽

Advisory Board ◽

Advisory Committees ◽

Apoptotic Protein ◽

Large Cell Lymphoma ◽

Alk Positive

Anaplastic large cell lymphoma (ALCL) is an aggressive type of non-Hodgkin's lymphoma (NHL) comprising 2-8% of adult and 10-20% of pediatric and adolescent NHL. More than three-fourths of anaplastic lymphoma kinase (ALK)-positive ALCL express (nucleophosmin1) NPM1-ALK fusion gene as a result of t(2;5) chromosomal translocation. The self-dimerization of fusion kinase NPM1-ALK mediates constitutive activation of the chimeric tyrosine kinase activity leading to downstream signaling pathways responsible for lymphoma cell proliferation and survival. The current standard treatment regimen for ALK+ ALCL is CHOP (cyclophosphamide, hydroxy doxorubicin, vincristine, prednisone) chemotherapy. Oftentimes, resistance and failure of remission occur with CHOP therapy, making it a suboptimal treatment regimen for many patients. Therefore, an alternative therapeutic approach is warranted to better address the needs of the ALK+ ALCL population. Gilteritinib is a recently FDA approved tyrosine kinase inhibitor for the treatment of FMS-like tyrosine kinase (FLT3) mutation-positive acute myeloid leukemia. Along with inhibition of FLT3, gilteritinib also inhibits other tyrosine kinases such as AXL and ALK. In this study, for the first time, we demonstrated gilteritinib mediated growth inhibitory effects on NPM1-ALK driven ALCL cells. We have used a total of five cell lines in our study: NPM1-ALK endogenously expressing human ALCL cell lines (SUDHL-1, SUP-M2, SR-786, and DEL), and our laboratory generated ectopically overexpressing Ba/F3-FG-NPM1-ALK, a murine cell line. Gilteritinib treatment (5-20 nM) inhibited NPM1-ALK fusion kinase phosphorylation, which resulted in downregulation of downstream survival signaling pathways including AKT, ERK1/2, and STAT3 leading to induced apoptosis and decreased clonogenic survival. Gilteritinib mediated apoptosis was associated with caspase 3/9 and poly (ADP-ribose) polymerase cleavage with increased pro-apoptotic protein BAD and decreased anti-apoptotic protein MCL-1. Increased expression of c-Myc is associated with ALK-positive ALCL and gilteritinib treatment decreased c-Myc levels in a dose dependent manner. Cell cycle analysis demonstrated gilteritinib treatment induced cell cycle arrest at the G0/G1 phase with a concomitant decrease in G2/M and S phases. In summary, our preclinical results suggest gilteritinib has therapeutic potential for the treatment of ALCL cells expressing NPM1-ALK and other ALK /ALK-fusion driven hematologic or solid malignancies. Disclosures Lin: Jazz Pharmaceuticals: Honoraria; Pfizer: Membership on an entity's Board of Directors or advisory committees. Ganguly:Daiichi Sankyo: Research Funding; Seattle Genetics: Speakers Bureau; Janssen: Honoraria, Other: Advisory Board; Kite Pharma: Honoraria, Other: Advisory Board. McGuirk:ArticulateScience LLC: Other: Assistance with manuscript preparation; Juno Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bellicum Pharmaceuticals: Research Funding; Astellas: Research Funding; Novartis: Research Funding; Fresenius Biotech: Research Funding; Pluristem Ltd: Research Funding; Gamida Cell: Research Funding; Kite Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

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Response and Outcomes to Nilotinib at 24 Months in Imatinib-Resistant Chronic Myeloid Leukemia Patients in Chronic Phase (CML-CP) and Accelerated Phase (CML-AP) with and without BCR-ABL Mutations.

Blood ◽

10.1182/blood.v114.22.1130.1130 ◽

2009 ◽

Vol 114 (22) ◽

pp. 1130-1130 ◽

Cited By ~ 1

Author(s):

Jerald P. Radich ◽

Giovanni Martinelli ◽

Andreas Hochhaus ◽

Enrico Gottardi ◽

Simona Soverini ◽

...

Keyword(s):

Board Of Directors ◽

Median Time ◽

Research Funding ◽

Philadelphia Chromosome ◽

Chronic Phase ◽

Cytogenetic Response ◽

Molecular Response ◽

Advisory Committees ◽

Imatinib Resistant

Abstract Abstract 1130 Poster Board I-152 Background Nilotinib is a selective and potent BCR-ABL inhibitor, with in vitro activity against most BCR-ABL mutants (excluding T315I) indicated for the treatment of patients with Philadelphia chromosome positive (Ph+) CML in CPor AP resistant or -intolerant to prior therapy, including imatinib. In a previous analysis of nilotinib in patients with BCR-ABL mutations, mutations occurring at three specific amino acid residues (E255K/V, Y253H, and F359C/V) were shown to be associated with less favorable response to nilotinib. The current analysis is based on mature data with a minimum follow-up of 24-months for all patients. Outcomes of patients at 24 months were analyzed by mutation type. Methods Imatinib-resistant CML-CP (n = 200) and CML-AP (n = 93) patients were subdivided into the following mutational subsets: no mutation, sensitive mutations (including mutations with unknown in vitro IC50). or E255K/V, Y253H, or F359C/V mutations at baseline. Patients with mutations of unknown in vitro sensitivity were classified as sensitive in this analysis based on a previous finding that patients with these mutations responded similarly to nilotinib as patients with sensitive mutation. Patients with baseline T315I mutations were excluded from this analysis. Patient groups were analyzed for kinetics and durability of cytogenetic and molecular response to nilotinib, as well as event-free survival (EFS), defined as loss of hematologic or cytogenetic response, progression to AP/BC, discontinuation due to disease progression, or death, and overall survival (OS). Results In CML-CP and -AP patients with no mutation, sensitive mutations, or E255K/V, Y253H, or F359C/V mutations, hematologic, cytogenetic and molecular responses are provided in the Table. Overall, patients with no mutations responded similarly to patients with sensitive mutations, whereas patients with E255K/V, Y253H, or F359C/V mutations had less favorable responses. This correlation was observed in both CML-CP and CML-AP patients, respectively. Median time to CCyR was 3.3 months (range, 1.0–26.7) for CML-CP patients with no mutations, and 5.6 months (range, 0.9–22.1) for patients with sensitive mutations. At 24 months, CCyR was maintained in 74% of CML-CP patients with no mutation and in 84% of patients with sensitive mutations. One patient with CML-CP and an E255K mutation achieved CCyR at 25 months and maintained until last assessment at 30 months. Median time to MMR was similar at 5.6 months (range, 0.9–25.8) for CML-CP patients with no mutations and 5.6 months (range, 2.7–22.1) for patients with sensitive mutations. No patient with a less sensitive mutation achieved MMR. Median EFS and 24-month estimated OS rate are provided in the Table. Conclusions Imatinib-resistant CML-CP and CML-AP patients treated with nilotinib therapy with BCR-ABL mutations (excluding E255K/V, Y253H, or F359C/V) achieved rapid and durable cytogenetic responses, and estimated EFS and OS at 24 months similar to that of patients with no mutations, respectively. Patients with E255K/V, Y253H, or F359C/V mutations had lower and less-durable responses and shorter EFS than patients with sensitive mutations. Alternative therapies may be considered for patients with these uncommon mutations (E255K/V, Y253H, and F359C/V). Disclosures Radich: Novartis: Consultancy, Honoraria, Research Funding. Hochhaus:Novartis: Research Funding. Branford:Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding. Shou:Novartis: Employment. Haque:Novartis: Employment. Woodman:Novartis: Employment. Kantarjian:Novartis: Research Funding. Hughes:Bristol-Myers Squibb: Advisor, Honoraria, Research Funding; Novartis: Advisor, Honoraria, Research Funding. Kim:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Wyeth: Research Funding. Saglio:Novartis: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau.

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Targeting Brouton's Tyrosine Kinase with PCI-32765 Blocks Growth and Survival of Multiple Myeloma and Waldenström Macroglobulinemia Via Potent Inhibition of Osteoclastogenesis, Cytokines/Chemokine Secretion, and Myeloma Stem-Like Cells in the Bone Marrow Microenvironment

Blood ◽

10.1182/blood.v118.21.883.883 ◽

2011 ◽

Vol 118 (21) ◽

pp. 883-883

Author(s):

Yu-Tzu Tai ◽

Betty Y Chang ◽

Sun-Young Kong ◽

Mariateresa Fulciniti ◽

Guang Yang ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Tyrosine Kinase ◽

B Cell ◽

Board Of Directors ◽

Research Funding ◽

Advisory Committees ◽

Growth And Survival ◽

Equity Ownership ◽

Trap Staining

Abstract Abstract 883 Specific expression of Bruton's tyrosine kinase (Btk) in osteoclasts (OC), but not osteoblasts (OB), suggests its role in regulating osteoclastogenesis. Although Btk is critical in B cell maturation and myeloid function, it has not been characterized in plasma cell malignancies including multiple myeloma (MM) and Waldenström Macroglobulinemia (WM). We here investigate effects of PCI-32765, an oral, potent, and selective Btk inhibitor with promising clinical activity in B-cell malignancies, on OC differentiation and function within MM bone marrow (BM) microenvironment, as well as on MM and WM cancer cells. We further define molecular targets of Btk signaling cascade in OCs and MM in the BM milieu. In CD14+ OC precursor cells, RANKL and M-CSF stimulate phosphorylation of Btk in a time-dependent fashion; conversely, PCI-32765 abrogates RANKL/M-CSF-induced activation of Btk and downstream PLCγ2. Importantly, PCI-32765 decreased number of multinucleated OC (>3 nuclei) by tartrate-resistant acid phosphatase (TRAP) staining and the secretion of TRAP5b (ED50 = 17 nM), a specific mature OC marker. It increased size of OCs and number of nuclei per OC, with significantly defective bone resorption activity as evidenced by diminished pit formation on dentine slices. Moreover, lack of effect of Dexamethasone on OC activity was overcome by combination of Dexamethasone with PCI-32765. PCI-32765 significantly reduced cytokine and chemokine secretion from OC cultures, including MIP1α, MIP1β, IL-8, TGFβ1, RANTES, APRIL, SDF-1, and activin A (ED50 = 0.1–0.48 nM). It potently decreased IL-6, SDF-1, MIP1α, MIP1β, and M-CSF in CD138-negative cell cultures from active MM patients, associated with decreased TRAP staining in a dose-dependent manner. In MM and WM cells, immunoblotting analysis confirmed a higher Btk expression in CD138+ cells from majority of MM patients (4 out of 5 samples) than MM cell lines (5 out of 9 cell lines), whereas microarray analysis demonstrated a higher expression of Btk and its downstream signaling components in WM cells than in CD19+ normal bone marrow cells. PCI-32765 significantly inhibits SDF-1-induced adhesion and migration of MM cells. It further blocked cytokine expression (MIP1a, MIP-1β) at mRNA level in MM and WM tumor cells, correlated with inhibition of Btk-mediated pPLCγ2, pERK and NF-kB activation. Importantly, PCI-32765 inhibited growth and survival triggered by IL-6 and coculture with BM stromal cells (BMSCs) or OCs in IL-6-dependent INA6 and ANBL6 MM cells. Furthermore, myeloma stem-like cells express Btk and PCI-32765 (10–100 nM) blocks their abilities to form colonies from MM patients (n=5). In contrast, PCI-32765 has no adverse effects on Btk-negative BMSCs and OBs, as well as Btk-expressing dendritic cells. Finally, oral administration of PCI-32765 (12 mg/kg) in mice significantly suppresses MM cell growth (p< 0.03) and MM cell-induced osteolysis on implanted human bone chips in a humanized myeloma (SCID-hu) model. Together, these results provide compelling evidence to target Btk in the BM microenvironment against MM and WM., strongly supporting clinical trials of PCI-32765 to improve patient outcome in MM and WM. Disclosures: Chang: Pharmacyclics Inc: Employment. Buggy:Pharmacyclics, Inc.: Employment, Equity Ownership. Elias:Pharmacyclics Inc: Consultancy. Treon:Millennium: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Genentech: Honoraria. Richardson:Millennium: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees. Munshi:Millennium: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Anderson:Millennium Pharmaceuticals, Inc.: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Onyx: Consultancy; Merck: Consultancy; Bristol-Myers Squibb: Consultancy; Actelion: Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

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Identification of Alpha 1-Acid Glycoprotein (AAG) As a Potential Patient Selection Biomarker for Improved Clinical Activity of the Novel KSP Inhibitor ARRY-520 in Relapsed and Refractory Multiple Myeloma (MM)

Blood ◽

10.1182/blood.v120.21.1868.1868 ◽

2012 ◽

Vol 120 (21) ◽

pp. 1868-1868 ◽

Cited By ~ 4

Author(s):

Brian Tunquist ◽

Karin Brown ◽

Gary Hingorani ◽

Sagar Lonial ◽

Jonathan L. Kaufman ◽

...

Keyword(s):

Multiple Myeloma ◽

Board Of Directors ◽

Research Funding ◽

Response Rate ◽

Phase 1 ◽

Clinical Activity ◽

Advisory Committees ◽

Blood Samples ◽

Refractory Multiple Myeloma

Abstract Abstract 1868 Background ARRY-520 is a kinesin spindle protein (KSP) inhibitor that has demonstrated clinical activity in patients with relapsed and refractory multiple myeloma (MM). Although ARRY-520 is administered IV, it displays variable pharmacokinetics (PK) among patients. The degree of binding of certain drugs to serum proteins can alter their free fraction (fu) and PK, with a possible impact on clinical activity. Alpha 1-acid glycoprotein (AAG) is an acute-phase reactant protein that is often elevated in the blood of patients with cancer, including multiple myeloma. We investigated the significance of the interaction of ARRY-520 with AAG, and other relevant blood proteins, using both in vitro models and clinical data. Methods Compound-protein binding was assessed using several in vitro assays. In addition, the effect of increasing concentrations of AAG on MM cell line viability was measured. Patient data were obtained from 3 clinical studies of ARRY-520: a Phase 1 solid tumor study, a Phase 1/2 AML study, and a Phase 1/2 study in MM. The MM Phase 2 portion consists of 2 separate, 2-stage cohorts. Cohort 1 evaluated ARRY-520 administered as a single agent, and cohort 2 investigated ARRY-520 in combination with low-dose dexamethasone (LoDex). The concentrations of multiple proteins, including AAG, and the degree of ARRY-520 total protein binding, were measured in pre- and post-dose blood samples for patients in the analysis. AAG levels in MM patients were further correlated with time-on-study and clinical response rate. Results ARRY-520 exhibits low micromolar affinity for AAG in in vitro assays, but not for other common serum proteins, such as albumin. To investigate whether AAG binding impacts biological activity, we found that increasing AAG concentrations within a clinically relevant range resulted in increasing IC50 values for ARRY-520 on MM cell line viability. Of other MM agents tested, none exhibited high affinity binding to AAG in vitro, and a range of AAG concentrations did not alter the cellular activity of these compounds. Pre-dose concentrations of AAG were measured using blood samples collected from patients on all 3 ARRY-520 studies (0.4 – 4.1 g/L AAG in solid tumor study; 0.5 – 2.4 g/L in AML study; 0.2 – 2.8 g/L in MM study). Post-dose blood samples from the MM study also indicated that AAG levels do not significantly change with time. The fu of ARRY-520 in blood was meaningfully reduced among patients with the highest AAG concentrations. Furthermore, AAG and fu were correlated with changes in clinical PK: CL and Vd decreased with increasing AAG, trends consistent with a lower fu. Among the MM patients, 72 patients were evaluable for AAG determination (27 from the dose-escalation portion, 27 from Cohort 1, and 18 from Stage 1 of Cohort 2). Across all of these cohorts, the group of patients with AAG above an empirically-determined cutoff of 1.1 g/L showed a decreased median time on study (1.5 months vs 4.7 months) and no clinical responses (0/19 vs 12/53) as compared to patients below this cutoff. For example, as reported separately, ARRY-520 in combination with LoDex showed a promising 22% overall response rate (≥PR) in the 1st-stage of Cohort 2. In this cohort, 6 patients were determined to have AAG concentrations above the empirical cutoff. None of these patients had clinical benefit. Excluding these 6 patients would significantly improve the overall response rate (≥PR) from 22% (4/18) to 33% (4/12). Summary AAG has been proposed as a prognostic marker for MM disease severitya. Our preliminary data suggest that AAG levels can affect the free fraction of ARRY-520 in blood over a clinically relevant range both preclinically and in clinical studies. In retrospective analysis, patients with higher AAG levels show a lower fu and therefore may not achieve sufficient exposure to gain therapeutic benefit from ARRY-520. In preclinical analyses, this effect is specific to ARRY-520, suggesting that AAG levels may be predictive for ARRY-520 activity relative to other MM drugs. We hypothesize that prospective screening for AAG may enable exclusion of patients who may not achieve therapeutic exposure to ARRY-520, increasing the overall activity of ARRY-520 and preventing exposure of non-responders to an ineffective therapeutic dose. Further, experiments are currently underway to investigate the relevance of other acute-phase proteins in blood. Disclosures: Tunquist: Array BioPharma: Employment. Off Label Use: ARRY-520 alone and with dexamethasone for the treatment of relapsed/refractory multiple myeloma. ARRY-520 is not currently approved for any indication. Brown:Array BioPharma: Employment. Hingorani:Array BioPharma: Employment. Lonial:Millennium Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Meyers Squibb: 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; Onyx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees. Kaufman:Millenium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Onyx: Consultancy. Zonder:Celgene: Honoraria, Research Funding; Millenium: Honoraria, Research Funding. Orlowski:Array BioPharma: Honoraria, Membership on an entity's Board of Directors or advisory committees. Shah:Array BioPharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx: Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau. Hilder:Array BioPharma: Employment. Ptaszynski:Array BioPharma: Consultancy. Koch:Array BioPharma: Employment. Litwiler:Array BioPharma: Employment. Walker:Array BioPharma: Employment.

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Increasing Expression Of The Efflux Transporter ABCB1 May Predispose CML Cells To Overt TKI Resistance

Blood ◽

10.1182/blood.v122.21.5157.5157 ◽

2013 ◽

Vol 122 (21) ◽

pp. 5157-5157

Author(s):

Laura Eadie ◽

Timothy P. Hughes ◽

Deborah L. White

Keyword(s):

Disease Progression ◽

Board Of Directors ◽

Cell Lines ◽

Research Funding ◽

Resistance Mechanisms ◽

Molecular Response ◽

Advisory Committees ◽

Tki Resistance ◽

Additional Resistance

Abstract Tyrosine kinase inhibitors (TKIs) result in excellent responses in most Chronic Myeloid Leukemia (CML) patients. However, up to 35% of patients treated with imatinib (IM) exhibit resistance and more recently nilotinib (NIL) and dasatinib (DAS) resistance have also been observed. Mutations in the BCR-ABL kinase domain (KD) are the main cause of secondary TKI resistance. Other mechanisms include overexpression of BCR-ABL, LYN and ABCB1. Predicting patients with susceptibility to mutation development and disease progression is crucial, thus we investigated the kinetics of TKI resistance emergence in vitro and in vivo. ABCB1 is implicated in TKI efflux hence we postulated that overexpression of ABCB1 leads to reduced intracellular TKI concentrations, resulting in inferior inhibition of Bcr-Abl predisposing cells to resistance development. Accordingly, 3 CML blast crisis (BC) cell lines (K562, K562-Dox, KU812) were cultured in increasing concentrations of IM to 2 μM, NIL to 2 μM and DAS to 200 nM until we observed overt resistance defined as a significant increase in survival in cytotoxicity assays and p-Crkl dependent IC50. Mechanisms of resistance were investigated in cell line intermediates: BCR-ABL, ABCB1 and LYN mRNA expression levels were determined by RT-PCR and KD mutation sequencing was performed. In our TKI resistant cell lines (Table 1), an increase in ABCB1 mRNA was the initial change observed prior to the development of additional resistance mechanisms (KD mutations, ABCB1 BCR-ABL and LYN overexpression). Interestingly, in 4/6 cells lines ABCB1 mRNA reduced to basal levels or below following establishment of these additional resistance mechanisms. ABCB1 levels were assessed in 37 de novo CML patients treated with IM who achieved major molecular response (MMR) compared with patients who progressed to BC, lost MMR or developed KD mutations. ABCB1 levels were determined in blood at diagnosis and following therapy (selected patients summarized in Table 2). A sustained >2 fold rise in ABCB1 was observed prior to disease progression in 3/3 patients and in 13/16 patients who did not achieve MMR. Importantly, the same was not observed in patients who achieved MMR (1/6 patients). The fold change of ABCB1 mRNA at day 22 vs diagnosis in patients achieving MMR was significantly different to that in patients not achieving MMR (p=0.004). ABCB1 increased by >2 fold post therapy and decreased following mutation development in 3/12 patients, confirming observations made in vitro, while 6/12 patients demonstrated sustained increase in ABCB1 post mutation similar to results observed in progression patients. ABCB1 mRNA did not change during therapy in 3/12 patients with mutations. While we recognize the majority of cells present in patients who achieve MMR are normal rather than leukemic, it is important to note that in patients who do not achieve MMR, ABCB1 expression increases in the remaining leukemic cells. We conclude ABCB1 overexpression acts as an initial mediator of resistance, providing a favorable environment for development of further resistance. Sustained increased levels of ABCB1 may contribute to disease progression and lack of response to IM. Additionally, ABCB1 may serve as a prognostic indicator (eg: level at day 22) and potentially assist in development of treatment strategies using TKIs in combination with other medications to enhance intracellular TKI concentration. 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; CSL: Research Funding. White:Novartis: Research Funding; BMS: Research Funding, Speakers Bureau; Ariad: Research Funding; CSL: Research Funding.

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Selinexor Demonstrates Marked Synergy with Dexamethasone (Sel-Dex) in Preclinical Models and in Patients with Heavily Pretreated Refractory Multiple Myeloma (MM)

Blood ◽

10.1182/blood.v124.21.4773.4773 ◽

2014 ◽

Vol 124 (21) ◽

pp. 4773-4773 ◽

Cited By ~ 4

Author(s):

Christine I. Chen ◽

Martin Gutierrez ◽

David S. Siegel ◽

Joshua R. Richter ◽

Nina Wagner-Johnston ◽

...

Keyword(s):

Board Of Directors ◽

Transcriptional Activation ◽

Nuclear Export ◽

Research Funding ◽

Phase 1 ◽

Advisory Committees ◽

Nuclear Retention ◽

Heavily Pretreated ◽

Equity Ownership

Abstract Introduction: The nuclear export protein exportin 1, (XPO1) is overexpressed in a wide variety of cancers including MM and often correlate with poor prognosis. Selinexor (KPT-330) is an oral Selective Inhibitor of Nuclear Export (SINE) XPO1 antagonist in Phase 1 and 2 clinical studies. Selinexor forces nuclear retention and reactivation of tumor suppressor proteins (TSPs) and reduction of many proto-oncogenes, including MDM2, MYC and Cyclin D. In addition, selinexor potently deactivates NF-κB, through forced nuclear retention of IκBα. Together these effects induce selective apoptosis in MM cells and inhibition of NF-κB dependent osteoclast activation. XPO1 is also responsible for nuclear export of the glucocorticoid receptor (GR). We hypothesized that selinexor will enhance the activity of dexamethasone (DEX)-bound GR, resulting in synergistic tumor cell killing. Methods: In vitro tumor cell viability measurements were based on MTT (CellTiter 96¨/Promega) and combination indices were calculated using CalcuSyn software. For xenograft studies, utilized NOD-SCID mice with subcutaneous inoculation of MM.1s cells. GR nuclear localization was measured with immunofluorescent anti-GR (phosphor-S211) antibody and quantitative imaging. To assess GR transcriptional activation, GR binding to a GCR consensus sequence was measured in nuclear extracts using an ELISA method (GR ELISA kit/Affymetrix). Patients (pts) with heavily pretreated refractory MM were dosed with oral selinexor at doses of up to 60 mg/m2 (8-10 doses/4 wk cycle) as part of a Phase 1 program in advanced hematological malignancies. Response we defined based on the IMWG criteria. The effect of combining DEX with selinexor was analyzed in all pts who received selinexor at moderate to high doses (30-60 mg/m2). Safety and efficacy were analyzed separately in three groups: no DEX, <20 mg DEX and 20 mgs DEX. Results: In MM.1s cells Sel-Dex showed synergy for nuclear retention of the DEX activated GR (Ser211-phosphorylated) and concomitant GR transcriptional activation. Sel-Dex showed highly synergistic cytotoxicity in MM.1s cells in vitro and in vivo, with a corresponding increase in apoptosis. Selinexor alone was potently cytotoxic in the DEX resistant MM cell lines MM.1R and ANBL6, but addition of DEX provided no additional effect. Twenty-eight pts with heavily pretreated refractory MM (16 M, 12 F; median age 62; ECOG PS 0/1: 7/21; median prior regimens: 6) received selinexor at 30 – 60 mg/m2 with either 0, <20, or 20 mgs DEX. All pts have received a proteasome inhibitor and an Imid and the majority of the pts have received pomalidomide (68%) and/or carfilzomib (36%). The most common Grade 1/2 AEs for these three groups were: nausea (82%/86%/70%), fatigue (55%/86%/40%), anorexia (36%/71%/60%), and vomiting (36%/57%/10%). Of the 28 pts treated; 10 heavily pretreated refractory MM pts treated with a combination of selinexor (45 mg/m2 twice weekly) and DEX (20 mg with each selinexor dose) were found to have dramatically improved disease response (n=10, ORR 60%), with one stringent complete response (sCR, 10%), 5 partial responses (PR, 50%) and clinical benefit rate (CBR) rate of 80% (Figure 1). Treatment with ³30mg/m2 selinexor and <20 mg DEX (n=7), resulted in ORR of 14% and CBR of 86%, while treatment with selinexor (30-60 mg/m2) without DEX (n=12) showed best response of stable disease (50%). Sel-Dex was also associated with an increase in time on study relative to selinexor alone, with 7 of out 10 pts in the 20 mg DEX combo group still on study (11-25 weeks). Five additional pts were treated with selinexor at a dose of 60 mg/m2 in combination with 20 mg DEX. Response evaluation is pending. Conclusions: Sel-Dex combination is markedly synergistic in preclinical models, which is supported by the preliminary clinical data presented. One potential mechanism underlying this synergy is the amplification of GR activity due the combined effects of selinexor-induced nuclear retention of activated GR coupled with DEX-mediated GR agonism. These results provide a promising basis for the continuing study of Sel-Dex for treatment of pts with refractory MM. Phase 2 studies of Sel-Dex in pts with MM refractory to both pomalidomide and carfilzomib are planned for early 2015. Disclosures Chen: Celgene: Honoraria; Janssen: Honoraria. Off Label Use: Lenalidomide maintenance therapy after ASCT. Gutierrez:Senesco: PI Other. Siegel:Celgene, Millennium, Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Baz:Celgene: Research Funding; Millennium: Research Funding; Bristol Myers Squibb: Research Funding; Karyopharm: Research Funding; Sanofi: Research Funding. Kukreti:Celgene: Honoraria. Azmi:Karyopharm Therpeutics: Research Funding. Kashyap:Karyopharm Therapeutics: Employment. Landesman:Karyopharm Therapeutics: Employment. Marshall:Karyopharm Therpeutics: Employment. McCartney:Karyopharm Therpeutics: Employment. Saint-Martin:Karyopharm Therpeutics: Employment. Norori:Karyopharm Therpeutics: Consultancy. Savona:Karyopharm Therpeutics: Membership on an entity's Board of Directors or advisory committees. Rashal:Karyopharm Therapeutics: Employment. Carlson:Karyopharm Therapeutics: Employment. Mirza:Karyopharm Therpeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Shacham:Karyopharm Therapeutics Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Kauffman:Karyopharm Therapeutics: Employment, Equity Ownership. Reece:Millennium: Honoraria, Research Funding; Millennium: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Otsuka: Honoraria, Research Funding; Otsuka: Honoraria, Research Funding; Merck: Research Funding; Merck: Research Funding; BMS: Research Funding; BMS: Research Funding; Novartis: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Amgen : Honoraria; Amgen : Honoraria.

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Osteoarticular Pain after Discontinuation of Tyrosine Kinase Inhibitors (TKI): A French Cohort

Blood ◽

10.1182/blood.v126.23.137.137 ◽

2015 ◽

Vol 126 (23) ◽

pp. 137-137 ◽

Cited By ~ 9

Author(s):

Marc G Berger ◽

Bruno Pereira ◽

Charlotte Oris ◽

Sandrine Saugues ◽

Pascale Cony-Makhoul ◽

...

Keyword(s):

Clinical Trials ◽

Tyrosine Kinase ◽

Medical History ◽

Board Of Directors ◽

Tyrosine Kinase Inhibitors ◽

Research Funding ◽

Kinase Inhibitors ◽

Duration Of Treatment ◽

Advisory Committees ◽

History Of

Abstract Context: The Tyrosine Kinase Inhibitors (TKIs) have revolutionized the treatment of chronic myeloid leukemia (CML) increasing dramatically the survival of CML patients and leading to a residual disease with a sustained and deep molecular response. In this subset of very good responder patients, the attempts of stopping treatment in different clinical trials were successfully achieved without relapse. The Swedish team in the EURO-SKI protocol already reported cases of musculoskeletal pain occurring after cessation of TKI (Richter et al., JCO, 2014). Since several clinical trials regarding TKI discontinuation have been also run in France, we decided to retrospectively collect data using the pharmacovigilance system of the different Trials collected prospectively. Method: 428 patients from STIM2 (n=204) and EURO-SKI (n=224) trials were systematically analyzed from the case report from each trial. For the EURO-SKI only French patients were included. Statistical analysis was performed using Stata 13 software (StataCorp LP, College Station, TX, US). Comparisons between the independent groups were realized using the Chi-squared or Fisher's exact tests for categorical variables, and using Student t-test or Mann-Whitney test for quantitative. Multivariate analyses were performed to take into account adjustment on covariates fixed according to univariate results and clinically relevance. Results: Among the 428 patients the main characteristics were as follow i,e; 208 (48.6%) men and 220 (51.4%) women, with a median age of 77.5 years (24-93). Sokal scores (n=449) were low in 187 (41.6%) patients, intermediate in 188 (41.9%) patients and high in 74 (16.5%) patients. A withdrawal TKI syndrome (WS) was reported for 102 (23.8%) patients (100 after imatinib and 2 after nilotinib). 2). The WS consists in bone and articular pains and arthritis and affects the upper limbs, shoulders and cervical rachis, with a grade 1 or 2 in most patients and grade 3 in 22% of patients . The prevalence of WS depends on the trials, 34.8% in EURO-SKI group and 13.8% in STIM2 group (p<0.001). The WS was treated by non-steroidal anti-inflammatory drugs, corticosteroids or by local infiltration. The median duration of WS was 7 months (range: 3-30 months, 24 exploitable cases). We did not observe any difference between WS group and the group without painful syndrome in terms of sex ratio (p=0.92), age (p=0.33), sokal score (p=0.15), BCR-ABL transcript (p=0.42) or duration of CML (p=0.24). However the median duration of TKI therapy appeared longer in this subgroup (median: 88.8 months vs 79.8 months (p=0.02). There was no biological inflammatory syndrome and the results of medical imaging were inconclusive. However, a medical history of osteoarticular pains or disease appeared as predisposing to withdrawal syndrome (22.9% in WS group vs 9.8% in control group; p=0.002). Finally the two factors, duration of treatment and medical history were confirmed using multivariate analysis (RR=1.73 and 1.76 respectively). Among 19 exploitable cases suffering CML relapse and requiring further TKI treatment, pain disappeared in 7 patients (37%) within a median period of 3.5 weeks. Conclusion: About 23% of patients who stopped TKIs experienced a TKI WS and all TKI seems to be concerned. The predisposing factors were a medical history of osteoarticular pain or disease, and the duration of treatment. So patients and physicians should be aware and recommendations should be proposed for patients who have treated longtime with a history of arthritis. Disclosures Legros: Novartis: Research Funding, Speakers Bureau; ARIAD: Speakers Bureau; BMS: Speakers Bureau. Nicolini:Ariad Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Rousselot:Novartis: Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; ARIAD: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau. Rea:Novartis: Honoraria; BMS: Honoraria; Ariad: Honoraria; Pfizer: Honoraria. Mahon:Bristol-Myers Squibb: Consultancy, Honoraria; ARIAD: Consultancy; Novartis: Consultancy, Honoraria; Pfizer: Consultancy.

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