scholarly journals A Multicenter Study of Ibrutinib Resistance Development and Intervention with Venetoclax in Patients with Chronic Lymphocytic Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3049-3049
Author(s):  
Kerry A Rogers ◽  
Lai Wei ◽  
Seema A. Bhat ◽  
Dan Jones ◽  
Erlene K. Seymour ◽  
...  

Background: Ibrutinib (ibr) for the treatment of chronic lymphocytic leukemia (CLL) has improved progression-free survival (PFS) compared to other treatments, especially in high-risk patients (pts). However, resistance occurs and is associated with mutations in the drug binding target (BTK) and its immediate downstream target (PLCg2). These ibr resistance mutations (IRmut) are detectable months prior to developing progressive disease (PD) and predict clinical relapse. Prospectively determining the time from starting ibr to development of IRmut and from IRmut detection to PD will improve our understanding of how to manage these patients. Venetoclax (ven) is highly effective after ibr and decreases IRmut. Adding ven to ibr for ibr resistance is a rational choice as this combination is safe and effective in CLL. Adding an agent rather than stopping ibr avoids disease flare associated with ibr discontinuation. This phase 2 study was designed to follow CLL pts taking ibr and at high risk for resistance (observation cohort) and to test ven in combination with ibr for those who develop PD (intervention cohort). This will determine: the incidence of IRmut and PD in this population, the ORR with ibr/ven, and the ability of this combination to eliminate IRmut. Trial Design and Methods: This multisite study will open at 4 centers initially. Eligible pts are adults with CLL taking ibr for ≥12 months and at high risk for ibr resistance defined as having ≥2 prior treatments and del(17p)(p13.1) on FISH panel and/or a complex karyotype. Pts with known IRmut or who cannot continue ibr for any reason are excluded. Enrolled pts enter the observation cohort and are followed every 3 months with a clinic visit, blood counts, and testing for IRmut. Pts who develop IRmut will also have CT scans at their visits to detect PD. Those with IRmut who develop PD by iwCLL 2018 criteria will enter the intervention cohort. Pts in the intervention cohort will start ven in addition to ibr. Ven will be ramped-up over 5 weeks to a target dose of 400mg. Pts will take combination ibr/ven for 12 cycles of 28 days in length. After 12 cycles they will undergo response assessment and those achieving a complete remission (CR) with no detectable leukemia (uMRD) in both the blood and bone marrow will stop ven and continue ibr alone. Those who do not achieve CR with uMRD will continue ibr/ven until cycle 24 and undergo a second response assessment. If in a CR with uMRD after 24 cycles they continue on ibr alone. If a CR with uMRD is not achieved after 24 cycles patients continue ibr/ven until PD, intolerance, death, or end of study which is 30 months after the last patient enters the intervention cohort (Figure). In the intervention cohort all pts will be tested for IRmut in the blood every 3 months with bone marrow testing at response assessments. The study has co-primary endpoints of ORR to combination ibr/ven after 12 cycles and the rate of IRmut negative status at that time in the intervention cohort. ORR will be tested first using a single-stage phase 2 design with a null hypothesis that the rate is ≤50% versus the alternative hypothesis that it is ≥75%. Only if the combination is effective in ORR will the rate of IRmut negative status be formally tested. Constraining overall Type I and II errors to 0.10 using this sequential testing strategy, 26 evaluable pts are required and 28 will be accrued. Secondary endpoints for the intervention cohort are the PFS and overall survival since starting the combination ibr/ven and the incidence and type of adverse events with ibr/ven. Secondary endpoints in the observation cohort are the incidence of IRmut during ibr treatment and the PFS after developing an IRmut. We estimate that 180 pt-years of follow up for the observation cohort will be needed. The yearly rate of mutation development in this population is approximately 20%, therefore this will identify 36 pts with IRmut. Of those with IRmut, approximately 80% will remain eligible to enter the intervention cohort. Accrual to the observation cohort will stop once 28 pts enter the intervention cohort. Conclusion: This multicenter phase 2 trial examines the development of IRmut and clinical resistance to ibr in a cohort of high-risk CLL pts and will determine the efficacy of adding ven to ibr in those who develop PD. We expect to determine the natural course of molecular and clinical ibr resistance in CLL and if adding ven is an effective treatment strategy. Figure Disclosures Rogers: Acerta: Consultancy; Genentech: Research Funding; Abbvie: Research Funding; Janssen: Research Funding. Bhat:Pharmacyclics: Consultancy; Janssen: Consultancy. Stephens:Karyopharm: Research Funding; Gilead: Research Funding; Acerta: Research Funding. Ye:Janssen: Research Funding; Karyopharm: Research Funding; Portola: Research Funding; MingSight: Research Funding; Sanofi: Research Funding. Byrd:Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; Genentech: Research Funding; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; Novartis: Other: Travel Expenses, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; BeiGene: Research Funding; BeiGene: Research Funding; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding. Woyach:Janssen: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Research Funding; Karyopharm: Research Funding; Loxo: Research Funding; Morphosys: Research Funding; Verastem: Research Funding. OffLabel Disclosure: This abstract discussion the use of combination ibrutinib and venetoclax in CLL.

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2077-2077
Author(s):  
Elizabeth M. Muhowski ◽  
Amy M. Lehman ◽  
Sean D. Reiff ◽  
Janani Ravikrishnan ◽  
Rose Mantel ◽  
...  

Introduction: Treatment of chronic lymphocytic leukemia (CLL) has been transformed by small molecule inhibitors targeting the B-cell receptor (BCR) signaling cascade. The first-in-class small molecule inhibitor of Bruton's Tyrosine Kinase (BTK), ibrutinib, is FDA approved as a frontline therapy for CLL. However, resistance to BTK inhibition has emerged in patients through acquisition of mutations in BTK or its immediate downstream target, PLCG2, emphasizing the need for alternative targets and therapies. BCR signaling remains intact in the presence of these mutations, making targeted inhibition of proteins downstream of BTK an attractive therapeutic strategy. Protein kinase C-β (PKCβ) is a downstream member of the BCR signaling pathway that we have previously demonstrated as an effective therapeutic target in CLL. MS-553 is a potent, ATP-competitive, reversible inhibitor of several PKC isoforms including PKCβ. Therefore, we evaluated the effects of MS-553 in primary CLL cells. Methods: Primary CLL cells were isolated by negative selection and treated with increasing concentrations of MS-553 to a maximum dose of 10 µM. BCR signaling changes were interrogated by change in target protein phosphorylation by immunoblot following a 24 hour drug incubation with and without phorbol ester stimulation (90 minutes) in CLL samples. Inhibition of CpG-mediated activation of CLL cells was measured using flow cytometry (CD86 and HLA-DR) in ibrutinib refractory patient samples at baseline and post-relapse due to the emergence of the p.C481S BTK mutation. CCL3 and CCL4 expression was measured by ELISA after 24 hours in primary CLL cells in the presence or absence of anti-IgM ligation. TNFα expression was also measured by ELISA in negatively selected, healthy donor T cells treated with MS-553 for 24 hours with or without anti-CD3 and anti-CD28 stimulation. Results: At 24 hours, 5 µM MS-553 inhibited downstream BCR signaling in primary CLL cells, demonstrated by 31% reduced phosphorylation of PKCβ (p=0.08, n=5) and several of its downstream targets including GSK3β (40%, p<.01, n=5) , ERK (46%, p=0.02, n=4) , and IκBα (56%, p=0.04, n=5) compared to vehicle treated, stimulated samples. CpG-mediated TLR9 stimulation increases expression of CD86 and HLA-DR in primary CLL cells. In baseline samples from ibrutinib treated patients, 10 µM MS-553 decreased expression of CD86 by 34% and HLA-DR by 91%. In matched patient samples post-relapse due to ibrutinib resistance, MS-553 (10 µM) maintained the ability to decrease expression of CD86 (49%) and HLA-DR (84%). Pro-inflammatory cytokine expression by primary CLL cells stimulated with anti-IgM decreased in the presence of 5 µM MS-553, with CCL3 decreasing by 36% (p=0.06, n=5) and CCL4 decreasing by 79% (p<.01, n=4) compared to vehicle treated, stimulated controls. TNFα expression by healthy T cells increased with anti-CD3 and anti-CD28 stimulation; 1 µM MS-553 reduced TNFα expression by 97% compared to vehicle treated, stimulated controls (p<.01, n=9). Conclusions: MS-553 is a novel and potent inhibitor of PKC demonstrating in vitro efficacy in CLL. MS-553 is able to inhibit BCR signaling by blocking phosphorylation of PKCβ and its downstream targets. CpG-mediated activation is reduced with MS-553 treatment in ibrutinib refractory patient samples both at baseline and post-relapse. Inflammatory signaling by primary CLL cells is further abrogated by MS-553 in its ability to decrease CCL3 and CCL4 cytokine expression. In an ongoing phase I clinical trial of MS-553, patient samples show a potent and dose dependent decrease in PKCβ activity as measured by a clinical biomarker assay. Together, our results suggest that MS-553 targets PKCβ in primary CLL to inhibit signaling and survival, establishing MS-553 as a potential therapeutic for treating CLL. These data justify continued preclinical and clinical work in the development of MS-553 for the treatment of CLL. Disclosures Niesman: MingSight Pharmaceuticals, Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Zhang:MingSight Pharmaceuticals, Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Byrd:BeiGene: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; Ohio State University: Patents & Royalties: OSU-2S; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; Novartis: Other: Travel Expenses, Speakers Bureau; Genentech: Research Funding; Acerta: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Genentech: Research Funding; Acerta: Research Funding; Novartis: Other: Travel Expenses, Speakers Bureau; BeiGene: Research Funding; BeiGene: Research Funding. Woyach:Verastem: Research Funding; Loxo: Research Funding; Morphosys: Research Funding; Janssen: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Research Funding; Karyopharm: Research Funding.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3377-3377
Author(s):  
Eileen Hu ◽  
Hatice Gulcin Ozer ◽  
Arletta Lozanski ◽  
Tzyy-Jye Doong ◽  
Chi-Ling Chiang ◽  
...  

Introduction: Targeted irreversible Bruton's Tyrosine Kinase (BTK) inhibitors ibrutinib and acalabrutinib, have revolutionized treatment for chronic lymphocytic leukemia (CLL). While BTK inhibition (BTKi) achieves durable responses in 90% of patients, only 10% achieve minimal residual disease (MRD) negative status. MRD positive patients have persistent residual CD5+CD19+ tumor B cells at approximately 1-5 /mm3 in peripheral blood. These cells may represent a subpopulation of B-cell lymphocytosis pre-malignant cells or may carry a BTK C481, PLCG2, or other CLL mutation that is ultimately responsible for disease relapse. Alternatively, MRD could be derived from the original clones present at initial disease presentation that are not dependent on BTK signaling. Readily available clinical DNA sequencing and MRD monitoring techniques lack the ability to characterize these cells adequately due to their rarity in peripheral blood. To address this problem, we developed a novel method for limited-cells using fluorescence activated cell sorting in tandem with next generation sequencing (LC-FACSeq) to characterize rare tumor subpopulations in the blood and bone marrow. LC-FACSeq may be useful not only for CLL but also other leukemias. Methods: LC-FACSeq uses fluorescent activated cell sorting (FACS) to isolate pure populations of rare tumor cells after which targeted deep sequencing is performed to monitor CLL-related mutations in NOTCH1, SF3B1, and TP53, as well as genes associated with BTKi relapse and resistance: BTK and PLCG2. For validation of this method, we generated libraries from DNA isolated from FACS isolated bulk (n >15000) versus n= 50, 100, 300, or 500 CD5+/CD19+ cells from CLL patients (n=5). Results: All samples analyzed had an average read depth of 1212 (SEM=56) per gene and an average coverage uniformity of 88.24% (SEM=.01). We show that showed that 300-cell LC-FACSeq libraries demonstrated comparable variant calling and minimal noise to standard libraries generated from purified DNA from bulk cells. Using samples from patients with previously identified BTK C481S mutations, we found that both sensitivity and specificity of LC-FACSeq for BTK C481S was 100%. Furthermore, LC-FACSeq reliably amplified BTK C481S signals from subclones as small as 6 in 300 total cells (2%) when mutated tumor cells were serially diluted into BTK wild type tumor cells. In using LC-FACSeq to retrospectively analyze four independent patients who developed Ibrutinib resistance, we found that we could see the emergence of small BTKi resistant subclones as early as 10 months before clinical detection. We next extended LC-FACSeq to examine the clonal architecture of long-term (> 12 months) ibrutinib-treated MRD positive patients. Median treatment time was 5 years. BTK C481S mutations were observed in the latest available on-treatment samples of only one patient. Using LC-FACSeq we observed canonical CLL-associated clonal mutations similar to those observed in previous studies. Of the 14 MRD positive patients, 7 showed subclonal changes in TP53, NOTCH1, POT1, SF3B1, and MYD88 over the course of ibrutinib treatment although we found no correlation or consensus in these clonal shifts. Conclusion: LC-FACSeq is a highly sensitive method of characterizing clonal evolution in rare cells. Our data shows that LC-FACSeq is useful for monitoring sequential acquisition of mutations conferring therapy resistance and clonal evolution in long-term ibrutinib treated chronic lymphocytic leukemia (CLL) patients. We also observe that in most cases, MRD clones after long-term ibrutinib treatment are genetically similar to disease clones from pretreatment baseline. Compared to current MRD monitoring strategies, the main advantages of LC-FACSeq are that 1) variants can be confidently called from rare sorted tumor populations and subpopulations, 2) library generation can be completed in less than a day in a diagnostic laboratory compared to the labor-intensive protocols of traditional NGS approaches, and 3) amplicon panels can be easily customized for application to other types of leukemia and lymphoma. (EH is supported by the Graduate Pelotonia Fellowship and the NIH F30) Disclosures Bhat: Janssen: Consultancy; Pharmacyclics: Consultancy. Rogers:Janssen: Research Funding; AbbVie: Research Funding; Genentech: Research Funding; Acerta Pharma: Consultancy. Woyach:AbbVie: Research Funding; Janssen: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; Karyopharm: Research Funding; Loxo: Research Funding; Morphosys: Research Funding; Verastem: Research Funding. Lozanski:Beckman Coulter: Research Funding; Stemline Therapeutics Inc.: Research Funding; Genentec: Research Funding; Boehringer Ingelheim: Research Funding. Muthusamy:Ohio State University: Patents & Royalties: OSU-2S. Byrd:Novartis: Other: Travel Expenses, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; BeiGene: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; BeiGene: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Genentech: Research Funding; Acerta: Research Funding.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2526-2526
Author(s):  
Janani Ravikrishnan ◽  
Tzung-Huei Lai ◽  
Elizabeth Muhowski ◽  
Lindsey Brinton ◽  
Katie Williams ◽  
...  

Patients with Chronic Lymphocytic Leukemia (CLL) have a variety of chromosomal abnormalities and mutations. At diagnosis, about 10% of CLL patients have deletions of chromosome 17 (Del17p) leading to the loss of one allele of tumor suppressor protein TP53, which increases to over 30% in relapsed/refractory disease. Additionally, 83% of patients with a Del17p acquire a mutation on their second TP53 allele at one of several sites within the DNA binding domain. While the consequence of some of these "hotspot" mutations (R175H, R179H, G245D, G248Q/W, Y220, R213X, R273H and R282H) has been described in solid tumors and AML, very little is known of their role in CLL. Clinically, patients with Del17p/Mutp53 have worse overall survival, increased disease progression and are more likely to relapse on the current targeted therapies such as ibrutinib. Although relapse to these treatments is largely due to acquired mutations in Bruton's Tyrosine Kinase (BTK) or its downstream target PLCg2, we hypothesize that the biology of mutant 53 bearing CLL is a key driver of resistance and progression. Specifically, we aim to determine the molecular signature and downstream effectors that allow mutant p53 to drive the adverse biology associated with this subtype. Conversely, we hypothesize that targeting the mutant p53 pathway will lead to better outcomes and overall survival for patients bearing this adverse prognosis marker. We performed high-throughput Sequencing of DNA from 270 CLL patients with high coverage in the exonic regions of TP53 prior to ibrutinib therapy as well as during progression. At baseline, 40% of patients had mutations found in the DNA binding region with the most frequent occurring in R248Q, R175H and R273H. We then characterized each p53 mutant (n=106) functionally in terms of their ability to ability to activate p21, PUMA, and Bax which serve as cell cycle checkpoint and apoptotic effectors of wild type p53 in response to DNA damage. Most mutants were incompetent in upregulating p21, PUMA or Bax at the transcript level. A few mutants upregulated p21 protein in a p53 independent fashion. We then evaluated the consequence of mutant p53 in CLL. We performed chromatin immunoprecipitation (ChIP-Seq), open chromatin signatures (ATAC-Seq) and expression analysis (RNA-Seq) on CLL samples with R248Q or R175H as well as in wild-type (WT) p53 samples. Integration of ChIP, ATAC and RNA Seq profiles indicated that mutant p53 activated a unique transcriptomic profile not shared by wt p53 bearing CLL. Several genes that facilitated survival or progression were downstream targets of mutant p53. Of these, we identified PRKCB (PKC-beta), BCL2L1 (Bcl-xL), EZH2, MLL and MALAT as a potential key downstream effectors of mutant p53. To determine whether mutations at R248Q and R175H in p53 were causal in the observed increases in PKC-beta, Bcl-xL, EZH2, MLL, and MALAT we used CRISPR/Cas9 editing to introduce mutations at R175H and R248Q in the p53 wildtype CLL cell lines HG-3 and PGA-1. These were accomplished by electroporating sgRNA-Cas9 ribonucleoprotein complexes (RNPs). Western blotting of mutants revealed an increase in the mRNA and protein expression of PKC-beta, and BCL-xL in mutant p53 compared to WT. Levels of EZH2 and MLL were not increased in these cells indicating that PKC-beta and Bcl-xL may be direct transcriptional targets upregulated by mutations at R248Q and R175H in p53. Ongoing efforts will characterize the transcriptional profile of all p53 mutants in our cohort to determine whether they all have a unifying transcriptomic profile that confers a gain of function phenotype to this subtype of CLL. Disclosures Byrd: Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; BeiGene: Research Funding; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; Novartis: Other: Travel Expenses, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; BeiGene: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; Novartis: Other: Travel Expenses, Speakers Bureau; Acerta: Research Funding; BeiGene: Research Funding; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; Genentech: Research Funding; Novartis: Other: Travel Expenses, Speakers Bureau. Woyach:Janssen: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Research Funding; Karyopharm: Research Funding; Loxo: Research Funding; Morphosys: Research Funding; Verastem: Research Funding.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3045-3045 ◽  
Author(s):  
Kristin Koenig ◽  
Emily Dotson ◽  
Shane Sheredy ◽  
Seema A. Bhat ◽  
John C. Byrd ◽  
...  

Background B-cell receptor signaling inhibition (BCRi) is an effective treatment (trtmt) for patients (pts) with chronic lymphocytic leukemia (CLL), but resistance develops. Venetoclax selectively inhibits anti-apoptotic protein B-cell lymphoma 2 (BCL-2), and has demonstrated efficacy in relapsed/refractory CLL pts, particularly after BCRi. Venetoclax is started at 20 mg daily and escalated weekly over 5 weeks to the goal dose to avoid acute tumor lysis syndrome. However, we observed that many pts with relapsed/refractory CLL relapsing on BCRi progress more quickly than this schedule allows; they may progress while still taking BCRi or vigorously after its discontinuation. Given the need to promptly attain goal venetoclax dose in this population, we developed a rapid dose escalation scheme for venetoclax and reviewed our experience to understand the feasibility, safety, and efficacy of this approach in a properly equipped university setting. Methods We retrospectively evaluated adult pts with relapsed/refractory CLL presenting to The Ohio State University who were treated with a "rapid dose escalation" of venetoclax. Charts were reviewed for previous and concomitant CLL treatments, tumor burden, prognostic factors, performance status, and co-morbidities. Venetoclax dosing was planned for a shorter time period than the 5 weeks described in the label dosing. The dose was increased as quickly as tolerated following the customary doses (20mg, 50mg, 100mg, 200mg, then 400mg). We reviewed the evaluated safety and efficacy outcomes with this approach. Results We treated 34 pts with rapid venetoclax dose escalation. Median age at venetoclax start was 54 years old and were 73.5% men. Pts had a median of 5 previous CLL trtmts (range 2-18). The most recent trtmt was single-agent BCRi in 18 cases, which overlapped with venetoclax in the majority. Only 6 pts had high tumor burden and the majority had low or medium tumor burden. Cytogenetic abnormalities at venetoclax start included: 17 (50.0%) pts with 17p deletion, 5 (14.7%) with 13q deletion, 6 (17.6%) with 11q deletion, and 3 (8.8%) with trisomy 12. Fifty percent of pts had a complex karyotype, and 76.5% had unmutated IGVH status. 24 (80%, n=30 pts that had testing done) pts had confirmed BTK/PLCу2 mutations. The mean time to goal venetoclax dose was 9.6 days (range 4-31); all but 1 pt reached goal dose. Eighteen (52.9%) pts developed tumor lysis syndrome (TLS) by lab criteria at doses from 20-400 mg, 5 pts developed TLS by clinical criteria, and 1 pt experienced grade 3 severity TLS (per Cairo-Bishop definition). Only 4 pts had an elevated uric acid requiring rasburicase. Seventy-three percent of pts achieved at least a partial remission, and 4 pts each had stable or progressive disease. Three pts died within 30 days: 1 from uncontrolled bleeding and neutropenia, 1 due to neutropenic sepsis with invasive fungal infection and gastric perforation, and 1 due to neutropenic septic shock and respiratory failure. Time to best response was mean 50.7 days (range 2-428). Median time to subsequent trtmt was 279.5 days (range 73-430). 23 pts (67.6%) had not progressed at 1 year, and 26 (76.5%) were surviving at 1 year. Conclusion/summary Rapid dose escalation of venetoclax in this pt population is safe and feasible. Despite a high percentage of patients developing TLS (52.9%), all patients recovered without lasting complications and all but one were able to achieve the goal dose of venetoclax. This dosing scheme achieved disease control with 67.6% remaining progression-free at 1 year and the majority of pts surviving. It is reasonable to implement venetoclax rapid dose escalation in the proper hospital setting with ample ancillary support. This approach may be needed for CLL patients with rapidly progressive disease on BCRi. Disclosures Dotson: Abbvie: Consultancy. Bhat:Pharmacyclics: Consultancy; Janssen: Consultancy. Byrd:Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; Acerta: Research Funding; BeiGene: Research Funding; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Genentech: Research Funding; Acerta: Research Funding; BeiGene: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau. Woyach:Janssen: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Research Funding; Karyopharm: Research Funding; Loxo: Research Funding; Morphosys: Research Funding; Verastem: Research Funding. Awan:Genentech: Consultancy; Sunesis: Consultancy; Gilead: Consultancy; Abbvie: Consultancy, Speakers Bureau; Janssen: Consultancy; Pharmacyclics: Consultancy, Research Funding; AstraZeneca: Consultancy, Speakers Bureau. Rogers:AbbVie: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Acerta Pharma: Consultancy. OffLabel Disclosure: Venetoclax- we will be suggesting a faster increase from starting to maximum/goal dose than the dosing label recommends. This is in order to achieve faster disease control.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2455-2455 ◽  
Author(s):  
Thomas J. Kipps ◽  
William G. Wierda ◽  
Jeffrey A. Jones ◽  
Lode J. Swinnen ◽  
Jianning Yang ◽  
...  

Abstract Abstract 2455 Background: Navitoclax (ABT-263), a novel, orally bioavailable, small molecule, binds with high affinity (Ki ≤1nM) to Bcl-2, Bcl-xL, and Bcl-w, promoting apoptosis. In vitro, navitoclax shows potent targeted cytotoxicity (EC50 ≤ 1μM) against T and B lymphoid malignancies that over-express Bcl-2. A phase 1 trial demonstrated oral navitoclax monotherapy to be well-tolerated and to have anti-tumor activity in patients (pts) with chronic lymphocytic leukemia (CLL). However, thrombocytopenia (TCP) was the dose-limiting toxicity (DLT). Phase 3 studies showed improved outcomes in CLL pts with the fludarabine/cyclophosphamide/rituximab (FCR) combination, and a phase 2 trial showed bendamustine/rituximab (BR) to be effective for pts with relapsed or refractory CLL. Navitoclax enhanced R (monotherapy and in combination with chemotherapy) efficacy in preclinical models of B-cell lymphoma. Methods: This is an ongoing, international, phase 1 dose-escalation study to evaluate the safety and pharmacokinetics (PK) of oral navitoclax in combination with FCR (Arm A) or BR (Arm B) in pts with relapsed/refractory CLL. Secondary objectives are efficacy endpoints (PFS, ORR, TTP, OS, duration of response). Eligible pts had measurable disease, ECOG performance score ≤1, ANC ≥100/μL, platelets ≥100,000/mm3, and hemoglobin ≥9.0 g/dL. Preliminary results are reported. After obtaining informed consent, pts were assigned to Arm A or Arm B based on physician preference, each consisting of 28-day dose-escalation cycles with once-daily, pre-infusion, navitoclax treatment on Days 3–5 of Cycle 1 and Days 1–3 of subsequent cycles. In both arms, R was 375 mg/m2 on Day 1 of Cycle 1; and 500 mg/m2 on Day 2 of Cycle 2 and on Day 1 of subsequent cycles. In Arm A, F 25 mg/m2 and C 175 mg/m2 were dosed on Days 2–4 in Cycles 1 and 2, and on Days 1–3 in subsequent cycles. In Arm B, B was dosed at 70 mg/m2 on Days 2 and 3 of Cycles 1 and 2, and on Days 1 and 2 in subsequent cycles. Navitoclax starting dose was 110 mg daily. Dose escalation to the next cohort (200 mg) was according to a continuous reassessment model. Tumor responses were evaluated using NCI-WG 1996 criteria. Pts could continue on navitoclax therapy for 1 yr in the absence of progressive disease or significant toxicity. Results: As of July 2010, 7 pts enrolled in the initially prioritized Arm B (BR+navitoclax); all completed the first cohort of 110 mg (median age 60 yr [range 55–72]). Study sites are currently enrolling pts in Arm A (FCR+navitoclax); 2 pts have enrolled to date. The median number of prior therapies was 2 (range 1–7). One pt had a DLT of elevated AST (Arm B, 110 mg cohort) and 1 pt had a DLT of neutropenic fever (Arm A, 110 mg cohort). In Arm B, neither TCP nor neutropenia have been DLTs. For the 7 pts with navitoclax-related AEs, the most common were diarrhea (3 pts), nausea (5 pts), and fatigue (3 pts). Seven pts remain on study; 2 pts discontinued due to disease progression and 2 withdrew per physician preference. In Arm B, preliminary antitumor best responses were assessable in 4 pts who received 2 cycles; 1 CRi in a pt with del17p- (based on lymph node [LN] response and no morphologic evidence of CLL in the bone marrow), 2 unconfirmed CRs (based on LN response and no bone marrow at this time), and 1 PR in a pt with del17p- (this pt subsequently received an allogeneic stem cell transplant). Preliminary PK results for the Arm B 110 mg cohort indicated that navitoclax PK was similar in Cycle 1 (navitoclax+BR) and Cycle 2 (navitoclax alone), and appeared comparable to PK in the navitoclax monotherapy study. Conclusions: Early results show that the combination of navitoclax with BR is well-tolerated, without DLTs of TCP or neutropenia, and show evidence of anti-tumor activity. Data are limited in the FCR portion of the study. The maximum tolerated dose of navitoclax has not been reached. Accrual is ongoing and following completion of the dose-escalation components of this study, expanded cohorts of pts will be assessed using the recommended phase 2 dose of navitoclax to further assess the tolerability and dose, and to continue to explore for efficacy signals in combinations. Preliminary data in combination with BR are encouraging. Disclosures: Kipps: Abbott Laboratories: Research Funding; Genentech/Roche: Research Funding. Wierda: Abbott: Research Funding; Genentech: Honoraria, Speakers Bureau. Jones: Glaxo Smith-Kline: Consultancy; Abbott: Research Funding. Swinnen: Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding. Yang: Abbott: Employment. Cui: Abbott: Employment. Busman: Abbott: Employment. Krivoshik: Abbott: Employment. Enschede: Abbott: Employment. Humerickhouse: Abbott: Employment.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1641-1641
Author(s):  
Clive S. Zent ◽  
Betsy R LaPlant ◽  
Wenting Wu ◽  
Timothy G. Call ◽  
Deborah Bowen ◽  
...  

Abstract Patients with very-high risk (purine analogue refractory and TP53 defective) CLL have limited treatment options. In these patients alemtuzumab can be effective against CLL cells in the circulation and bone marrow, and in combination therapy with fludarabine can be active in patients with bulky disease, but these regimens have a high risk of serious infections. Addition of rituximab to alemtuzumab can also improve efficacy but has limited activity against bulky disease. We conducted a phase II clinical trial to determine the efficacy and toxicity of therapy with pentostatin, alemtuzumab, and low dose higher frequency rituximab (PAR) in patients with relapsed/refractory or progressive CLL with 17p13 deletion. The rituximab schedule was designed to decrease the loss of CD20 expression by circulating CLL cells. Methods This two-stage phase II trial study (NCT00669318) conducted at the Mayo Clinic Rochester and University of Iowa with IRB approval had an accrual goal of 38 evaluable patients. Eligibility required a diagnosis of progressive CLL by standard criteria and either previous treatment for CLL (<4 purine analogue regimens) or 17p13 deletion (17p13-). Exclusion criteria were organ failure, poor performance status (ECOG >3), infection with HIV, hepatitis B, hepatitis C, active autoimmune cytopenia, or alemtuzumab therapy within the past 2 months. Rituximab 20 mg/m2 IV M-W-F started on day 1, alemtuzumab started on day 3 with an escalation of 3-10-30 mg/d SQ and then 30 mg M-W-F from day 8, and pentostatin 2 mg/m2 IV every 2 weeks started on day 8. Peg-G-CSF or GM-CSF was used after each dose of pentostatin and patients received Pneumocystis and Varicella prophylaxis. CMV PCR assays were done weekly during treatment and viremia was treated with either valganciclovir or ganciclovir. Cycle 1 was 5 weeks and subsequent cycles were 4 weeks. At the end of cycle 2 patients with a clinical CR had a CT scan and a bone marrow study with immunohistochemical (IHC) staining for residual CLL cells, and therapy was stopped if there was no radiological or IHC evidence of residual CLL (stringent CR). Patients with residual disease received a 3rd cycle of therapy. Results Forty-one patients were enrolled (July 2008 - February 2013) and all 39 who started therapy were evaluable for response: Median age 61 years (range 47-78), 30 (77%) males, 36 (92%) relapsed/refractory CLL (median prior regimens = 2, range 1-10), 3 (8%) previously untreated, 23 (59%) advanced stage (Rai III-IV), 16 (41%) intermediate stage (Rai I-II). Prognostic factors: FISH (hierarchical classification) 15 (38%) 17p13-, 6 (15%) 11q22-, 5 (13%) 12+, 3 (8%) no defects, 8 (21%) 13q14-, and 2 (5%) other abnormalities, IGHV analysis (n=38) 27 (71%) unmutated (<2%), ZAP-70 (n=37) 28 (76%) positive (>20%). Thirty (77%) patients completed planned therapy (28 had 3 cycles, 2 had 2 cycles with stringent CR). Nine patients received one (n=4) or two (n=5) cycles of therapy because of disease progression or complications. Grade 3-4 hematological adverse events (n=37) at least possibly related to treatment included neutropenia (n=22), thrombocytopenia (n=11), anemia (n=2) and hemolysis (n=2). Non-hematological adverse events (n=17) included infections/neutropenic fever (n=8), fatigue (n=3), and hemorrhage (n=2). CMV reactivation was detected and treated in 14 patients (grade 1-2). No patients died during treatment or from treatment related complications. The overall response rate was 56% (95% CI 40-72) with 4 (10%) CR, 7 (18%) CRi, 11 (28%) PR, 7 (18%) SD, and 10 (26%) PD. Four patients (3 CR and 1 CRi) had IHC negative bone marrow studies. Thirteen (33%) patients have died due to progressive CLL (n = 11), sepsis (n=1), and pneumonia (n=1). Median follow up for surviving patients is 23 months (range 3-55). Seven (18%) patients proceeding to RIC allogeneic transplant were censored for time to next treatment. Twenty-one (54%) patients required therapy for progressive CLL and 7 (18%) have required no further therapy. Median progression free survival was 7 months (95% CI: 5-16), time to next treatment 9 months (95% CI: 6-27) and median overall survival has not been reached. Discussion PAR was effective and tolerable therapy for high-risk CLL. This study suggests that alemtuzumab can be used safely in combination with a purine analogue in a short-duration regimen. Disclosures: Zent: Genentech : Research Funding; Genzyme: Research Funding; Biothera: Research Funding; GlaxSmithKline: Research Funding; Novartis: Research Funding. Off Label Use: Pentostatin therapy for CLL, use of lower doses of rituximab.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4065-4065 ◽  
Author(s):  
Shelby Sloan ◽  
Fiona Brown ◽  
JI Hyun Chung ◽  
Alexander Prouty ◽  
Esther Wheeler ◽  
...  

Mantle cell lymphoma (MCL) is an incurable B-cell malignancy characterized by genetic dysregulation of cyclin D1 and activation of signaling pathways driving uncontrolled MCL cell proliferation and survival. Ibrutinib is an FDA-approved irreversible inhibitor of Bruton's tyrosine kinase (BTK), a downstream target of the B-cell receptor (BCR) pathway. While ibrutinib exhibits significant single-agent therapeutic activity in patients with relapsed/refractory MCL, the vast majority of MCL patients on ibrutinib progress with aggressive disease and short survival (3-8 mo). Although ~80% of chronic lymphocytic leukemia patients with acquired ibrutinib resistance have mutations in BTK and PLCγ2, this is uncommon in MCL suggesting alternative mechanisms driving this resistant phenotype. Understanding drug-resistance mechanisms and developing effective therapies for ibrutinib resistant (IR) MCL are urgently needed. The major type II protein arginine methyltransferase enzyme, PRMT5, catalyzes symmetric dimethylation of arginine residues on histone tails (H3R8 and H4R3) and other proteins. PRMT5 regulates a vast array of biologic functions including RNA processing, DNA damage response, signal transduction, and gene expression. Amplified PRMT5 activity drives the expression and activity of key oncogenes (MYC, CYCLIND1, NOTCH1) while silencing expression and activity of tumor suppressors (ST7, RBL2, and p53). Our group has shown PRMT5 is overexpressed and dysregulated in MCL and strategies aimed at selectively targeting PRMT5 show anti-tumor activity in preclinical lymphoma models. Here we describe the development of a novel patient derived xenograft (PDX) of IR-MCL and explore PRMT5 inhibition as an alternative therapeutic option to circumvent IR. Peripheral blood mononuclear cells from a 75 yo male patient diagnosed with acquired classic IR-MCL were engrafted intravenously into NSG mice. After 5 passages, all mice engrafted with 107 MCL cells developed histologically confirmed MCL infiltrating kidney, lymph nodes, bone marrow, spleen and peripheral blood. Circulating human CD5+/CD19+ cells were detectable and quantifiable by flow cytometry by day 21 post-engraftment. Karyotype analysis confirmed the hallmark t(11;14)(q13;q32) of MCL while retaining nearly all cytogenetic abnormalities present in the patient's primary tumor including a deletion of chromosome 9, associated with deletion of MTAP, a therapeutic vulnerability for PRMT5-targeted therapy. Whole exome sequencing confirmed genomic stability with successive passages. Ex vivo cytotoxicity assays and protein pathway analysis further confirmed resistance to ibrutinib (IC50 >1 µM) with maintained hyper-phosphorylation of AKT (Ser473) and ERK (Thr202/Tyr204). Western blot analysis showed elevated levels of c-MYC, CYCLIND1, BCL2, and pERK. After validation of circulating disease at day 25 post engraftment, mice were treated with either a novel small molecule inhibitor of PRMT5 (PRT382, 10 mg/kg orally 4 days on 3 days off) or ibrutinib (75 mg/kg administered in drinking water, n=5 mice per treatment group). Treatment of this PDX model with PRT382 resulted in significantly decreased disease burden and improved median survival compared to control animals from 48 to 83 days, respectively (p=0.0045). We found no significant difference in survival (p= 0.6540) or circulating disease burden with ibrutinib therapy compared to control group. The full BTK occupancy of ibrutinib treated mice was validated using fluorescence resonance energy transfer-based assay. Ex vivo PDX MCL cells from PRT382-treated mice showed loss of symmetric dimethyl arginine with preservation of asymmetric dimethyl arginine levels, reduced H4(Sme2)R3 epigenetic marks, and elevated levels of BCL2, MYC, and pAKT/pERK. We developed a cell line (SEFA) allowing for in vitro mechanistic studies. We are currently investigating potential mechanisms responsible for circumventing IR-MCL by integrating genome-wide changes to chromatin accessibility and whole transcriptome analysis. This IR-MCL PDX mouse model serves as a useful tool to investigate mechanisms of drug resistance, provides a platform to explore novel pre-clinical therapeutic strategies to circumvent IR and demonstrates the therapeutic activity of PRMT5 targeted therapy in this aggressive disease. Disclosures Byrd: Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; Genentech: Research Funding; BeiGene: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Genentech: Research Funding; Acerta: Research Funding; Acerta: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; BeiGene: Research Funding; Genentech: Research Funding; BeiGene: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau. Vaddi:Prelude Therapeutics: Employment. Scherle:Prelude Therapeutics: Employment. Baiocchi:Prelude: Consultancy.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 186-186
Author(s):  
Caner Saygin ◽  
Arletta Lozanski ◽  
Tzyy-Jye Doong ◽  
Shelley Orwick ◽  
Deedra Nicolet ◽  
...  

Normal hematopoiesis is organized in a hierarchical manner and it has been hypothesized that acute myeloid leukemia (AML) is organized in a similar way with leukemia-initiating cells (LIC) at the top of the hierarchy, giving rise to more differentiated blasts to sustain AML. Therefore, elimination of LIC population is critical for cure. This may be accomplished via novel molecular targeted therapies. The mutational composition of LIC and non-LIC compartments in AML has not been fully elucidated and could provide new insights into biology and treatment. We investigated the distribution and variant allelic frequencies (VAFs) of recurrent gene mutations within these compartments in newly diagnosed CD34+ AML patients (pts). We studied a total of 88 pts. CD34- AML cases, defined as &lt;5% positivity on blasts, were excluded. Pre-treatment bone marrow or apheresis samples were sorted and sequenced with our ultrasensitive limited cell (LC)-FACS-seq method. First, we gated on CD45dimLin- leukemic population, followed by isolation of 300 cells from CD34+CD38- (LIC), CD34+CD38+ (non-LIC) and CD34- compartments. To compare with the bulk population, DNA was extracted from 500,000 CD45dimLin- leukemic blasts. All samples were sequenced with a 27-gene targeted panel. Extreme Limited Dilution Analysis (ELDA) platform was used for colony formation assays and estimation of stem cell frequencies. Clinical characteristics are summarized in Table 1. The median frequency of the LIC population was 0.5% (range, 0.01% - 69%). The prevalence of high LIC frequency (≥0.5%) was significantly higher in pts with adverse risk (AR) AML, as compared to intermediate (IR) and favorable risk groups (94% vs 34% vs 16%, respectively, p&lt;.001). When compared to pts with low LIC frequency (&lt;0.5%), those with high LIC frequency had worse overall survival (median, 9 months vs not reached, p=.003) and relapse-free survival (median, 4 vs 15 months, p=.01). In 10 pts who had serial relapse samples, LIC frequencies were increased at the time of relapse (p=.03). We re-validated the commonly used LIC markers with ELDA of primary AML cells. In one IR sample, stem cell frequencies in sorted CD34+CD38-, CD34+CD38+ and CD34- compartments were 1:3, 1:15 and 1:16, respectively (p&lt;.001). In one AR sample, stem cell frequencies were 1:1, 1:8, and 1:12, respectively (p&lt;.001). Using these markers, LICs and non-LICs were enriched and sequenced. The average number of mutations detected by sequencing of bulk samples was significantly lower than sorted LIC (3.17 vs 3.75, p&lt;.05) and non-LIC (3.17 vs 3.96, p&lt;.001) populations indicating the higher sensitivity of our method in detecting subclonal mutations. Mean VAFs were similar between LIC and non-LIC populations for NPM1 (42% vs 47%), DNMT3A (37% vs 41%), IDH1 (41% vs 48%), IDH2 (43% vs 48%), and U2AF1 (37% vs 42%) mutations. Mutations involving signaling pathways were more frequent in non-LICs, including FLT3-TKD (12% vs 23%, p&lt;.01), NRAS (17% vs 26%, p&lt;.01) and KRAS (13% vs 19%, p&lt;.05) mutations, which might be explained by their later acquisition during AML development. In addition, among 22 pts with CEBPA mutation, 16 (73%) harbored the mutation exclusively in non-LICs. Finally, 13 pts with TP53 mutations had different VAFs between compartments. Among 4 pts who had doubling of VAF from LIC to non-LIC compartment, 3 had subclones with del(17p) in LIC pool detected by FISH. LIC subclones harboring both del(17p) and TP53 mutation (i.e. loss of heterozygosity) propagated to drive leukemia. Relapse samples obtained from 6 pts were analyzed and compared with diagnosis. In all cases, we could identify LIC clones that persisted after chemotherapy and led to relapse (see example in Figure). Similarly, 3 pts who were primary refractory showed persistence of LIC clones that were resistant to treatment. On the contrary, 6 pts in whom LIC clones could be eradicated with treatment did not experience disease recurrence. LICs exist at a very low frequency in pre-treatment AML samples. The mutational composition of LIC-enriched compartment shows differences from blasts constituting the bulk of leukemia, which is consistent with the sequence of mutations observed during the evolution of AML. LC-FACS-seq is an ultrasensitive method to detect mutations in a tiny population of residual LICs in pts at remission. Therapies targeting mutations that are concentrated in LICs may re-shape the clonal hierarchy and impact on disease course. Disclosures Behbehani: Fluidigm corporation: Other: Travel funding. Byrd:Ohio State University: Patents & Royalties: OSU-2S; Genentech: Research Funding; Genentech: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; BeiGene: Research Funding; BeiGene: Research Funding; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; BeiGene: Research Funding; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; Ohio State University: Patents & Royalties: OSU-2S; Acerta: Research Funding; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau. Lozanski:Boehringer Ingelheim: Research Funding; Beckman Coulter: Research Funding; Stemline Therapeutics Inc.: Research Funding; Genentec: Research Funding.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3022-3022
Author(s):  
Brian Giacopelli ◽  
Kari G. Chaffee ◽  
Yue-zhong Wu ◽  
John C. Byrd ◽  
Tait D. Shanafelt ◽  
...  

Monoclonal B cell lymphocytosis (MBL) has been shown to be the precursor condition that precedes overt diagnosis of chronic lymphocytic leukemia (CLL). Whereas CLL is classified with greater than or equal to 5 × 109/L B lymphocytes in the peripheral blood, MBL is a clonal expansion of B-cells below this threshold. MBL can be further divided into high- or low-count based on whether the B-cell count is above or below 0.5 × 109/L. Approximately 10% of the population over 40 is estimated to have MBL, increasing to >50% over the age of 90. While low-count MBL is unlikely to progress, 1-2% of high-count (HC) MBL individuals progress to CLL requiring therapy per year. It is debatable if all patients with detectable MBL should be classified as an entity requiring monitoring by a hematologist, especially for low-count MBL. In addition, the diagnosis of leukemia is distressing to patients; therefore, it is important to identify HC MBL patients that are more likely to progress to disease requiring treatment and thus should be monitored more closely. As the majority of MBL cases phenotypically resemble CLL, established prognostic markers including recurrent chromosomal aberrations, beta-2 microglobulin levels, and the mutational status of the Immunoglobulin heavy-chain variable region locus (IGHV) have been shown to predict time to treatment (TTT) and overall survival (OS) in a large retrospective study of MBL1. CLL patients can also be divided into three distinct epigenetic subtypes that reflect progressive DNA methylation changes that occurs during B cell development. These 'epitypes' termed low-programmed (LP), intermediate-programmed (IP), and high-programmed (HP) independently predict clinical outcomes irrespective of disease stage and treatment2. LP-CLL patients follow a generally unfavorable clinical course compared to the more indolent HP-CLL patients, while IP CLL patients display an intermediate outcome. Here we sought to determine if epitype forecasts progression to CLL and eventual clinical outcome for individuals with MBL. We analyzed 66 individuals diagnosed with HC MBL at the Mayo Clinic with a median follow-up of 6.3 years. Developmental epitype was determined using our novel Methylation-iPLEX technique that interrogates 34 CpGs and assigns epitype using a random forest model2. Seventy-seven percent of the MBL cases were assigned to one of the three epitypes: 42.4% HP, 19.7% IP, and 15.2% LP. The residual 23% remained unclassified due to ambiguous (low confidence) epigenetic patterns or insufficient purity (Figure 1A). The overall proportion of HP and IP epitypes in MBL were significantly greater than proportions observed in CLL cohorts (P<0.01). Epitypes remained stable over time as 20/21 cases for which we obtained a high-confidence epitype classification at multiple time points remained unchanged. Epitype significantly predicted MBL individuals progressing to treatment (P=0.001) with LP individuals progressing in a median of 5.6 years (P=0.049 and P=0.0002 versus IP and HP, respectively); median was not reached in HP or IP (Figure 1B). Epitype also predicted overall survival (OS) in MBL (P=0.04), with LP individuals having a significantly shorter OS (median of 11 years versus not reached in IP and HP; P=0.056 and P=0.048 versus IP and HP, respectively). In this study we evaluated a cohort of 66 HC MBL cases and determined that classification using developmental DNA methylation epitypes can be employed in HC MBL to aid in risk stratification. HC MBL patients classified as LP are more likely to progress to requiring treatment and have a significantly reduced OS. The epigenetic classification may help clinicians decide how closely and frequently a HC MBL individual needs to be monitored. Figure 1: (A) Breakdown of the epigenetic subtype assigned to 66 HC MBL samples. (B) Kaplan-Meier analysis of time to treatment and (C) overall survival of MBL patients separated by epitype. 1. Parikh, S. A. et al. Outcomes of a large cohort of individuals with clinically ascertained high-count monoclonal B-cell lymphocytosis. Haematologica103, e237-e240 (2018). 2. Giacopelli, B. et al. Developmental subtypes assessed by DNA methylation-iPLEX forecast the natural history of chronic lymphocytic leukemia. Blood blood.2019000490 (2019). doi:10.1182/blood.2019000490 Disclosures Byrd: Ohio State University: Patents & Royalties: OSU-2S; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; BeiGene: Research Funding; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; Genentech: Research Funding; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding. Shanafelt:Patent: Patents & Royalties: US14/292,075 on green tea extract epigallocatechin gallate in combination with chemotherapy for chronic lymphocytic leukemia; Merck: Research Funding; Polyphenon E International: Research Funding; Pharmacyclics: Research Funding; Genentech: Research Funding; Hospira: Research Funding; Glaxo-SmithKline: Research Funding; Abbvie: Research Funding; Cephalon: Research Funding; Celgene: Research Funding. Parikh:Genentech: Honoraria; Janssen: Research Funding; AstraZeneca: Honoraria, Research Funding; Pharmacyclics: Honoraria, Research Funding; MorphoSys: Research Funding; AbbVie: Honoraria, Research Funding; Acerta Pharma: Research Funding; Ascentage Pharma: Research Funding. Kay:Agios: Other: DSMB; MorphoSys: Other: Data Safety Monitoring Board; Infinity Pharmaceuticals: Other: DSMB; Celgene: Other: Data Safety Monitoring Board.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1852-1852
Author(s):  
Noemi Puig ◽  
Teresa Contreras ◽  
Bruno Paiva ◽  
María Teresa Cedena ◽  
José J Pérez ◽  
...  

Introduction: The GEM-CESAR trial is a potentially curative strategy for high-risk smoldering multiple myeloma (HRsMM) patients (pts) in which the primary endpoint is the achievement of bone marrow minimal residual disease (MRD) negativity. However, other methods of disease evaluation in serum such as heavy+light chain (HLC) assessment, with a potential complementary value to the IMWG response criteria, have also been tested. Aim: To evaluate the performance of HLC assay in HRsMM pts at diagnosis and after consolidation, comparing the results with standard serological methods and Next Generation Flow (NGF) for the assessment of bone marrow MRD. Patients and Methods: Ninety HRsMM pts included in the GEM-CESAR trial received six 4-weeks cycles of carfilzomib, lenalidomide and dexamethasone followed by high dose melphalan and 2 further cycles of consolidation with the same regimen. All pts received maintenance treatment with lenalidomide for up to 2 years. SPEP and IFE were performed using standard procedures. Serum IgGk, IgGl, IgAk and IgAl HLC concentrations were measured using Hevylite (The Binding Site Group Ltd, Birmingham, UK) on a SPA PLUS turbidimeter. HLC concentrations and ratios were considered abnormal if they were outside the 95% reference ranges provided by the manufacturer. MRD was analyzed by flow cytometry following EuroFlow recommendations (sensitivity, 2x10-6). Standard response assignment was carried out as per the IMWG guidelines. Hevylite responses were assigned and HLC-pair suppression was defined as in Michalet et al (Leukemia 2018). Results: Out of 90 HRsMM pts, 75 had monoclonal intact immunoglobulin and samples available at diagnosis (50 IgG and 25 IgA). HLC ratio was abnormal in 98% of IgG pts and in 100% of IgA pts. Response assessment by Hevylite and standard IMWG criteria were available in 62 pts post-consolidation (Table 1). A good agreement was found between the two methods (kappa quadratic weighting = 0,6327 (0,4016 - 0,8638)). Among 46 pts with assigned CR as per the IMWG response criteria, there were 3 and 8 pts in PR and VGPR according to the Hevylite method, respectively. In 62 cases, paired Hevylite and MRD assessment data were available. Concordant results were found in 72.5% of cases (45/62; HLC+/NGF+ in 15 and HLC-/NGF- in 30 cases) while in the remaining 27.4% of cases results were discordant (17/62; HLC-/NGF+ in 6 and HLC+/NGF- in 11 cases). Post-consolidation, 24, 25.8 and 42.3% of the 62 samples were positive by SPEP, NGF and Hevylite, respectively. HLC-pair suppression was identified in 13/62 pts; 10 had severe HLC-pair suppression at the end of consolidation. After a median follow-up of 32 months (8-128), 93% of pts remain alive and progression-free. Three patients that have already progressed had their responses assessed post-consolidation. The first pt was assigned VGPR by the standard IMWG criteria and PR by Hevylite and was MRD positive by NGF; the second pt was assigned CR by IMWG criteria and Hevylite but had severe HLC-pair immunosuppression and was MRD positive by NGF; the third pt was in CR by IMWG and HLC criteria and was MRD positive by MFC. Conclusions: Moderate agreement was found between response assessment by Hevylite and the standard IMWG methods as well as between Hevylite and MRD assessment by NGF. Most discordances were a result of Hevylite detecting disease in samples negative by the standard methods, but longer follow-up is needed to ascertain its clinical value. HLC assessment could have anticipated the progression noted in 2 (out of 3) patients. Disclosures Puig: Takeda, Amgen: Consultancy, Honoraria; The Binding Site: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Paiva:Amgen, Bristol-Myers Squibb, Celgene, Janssen, Merck, Novartis, Roche and Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene, Janssen, Sanofi and Takeda: Consultancy. Rodriguez Otero:Kite Pharma: Consultancy; Celgene Corporation: Consultancy, Honoraria, Speakers Bureau; BMS: Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy. Oriol:Celgene, Amgen, Takeda, Jansse: Consultancy, Speakers Bureau. Rios:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Alegre:Celgene, Amgen, Janssen, Takeda: Membership on an entity's Board of Directors or advisory committees. de la Rubia:Amgen: Consultancy; Janssen: Consultancy; Celgene: Consultancy; Takeda: Consultancy; AbbVie: Consultancy. De Arriba:Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Takeda: Honoraria. Ocio:Celgene: Consultancy, Honoraria, Research Funding; Sanofi: Research Funding; BMS: Honoraria; Novartis: Consultancy, Honoraria; Array Pharmaceuticals: Research Funding; Pharmamar: Consultancy; Seattle Genetics: Consultancy; Mundipharma: Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria; AbbVie: Consultancy; Janssen: Consultancy, Honoraria. Bladé:Janssen, Celgene, Amgen, Takeda: Membership on an entity's Board of Directors or advisory committees; Irctures: Honoraria. Mateos:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmamar: Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; EDO: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive: Honoraria; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees.


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