Citations

AbstractSymptomatic hyperviscosity is a well‐established phenomenon in Waldenström macroglobulinemia (WM). Monoclonal IgM can variably impact intrinsic serum viscosity, leading to widely disparate symptomatic thresholds for development of hyperviscosity‐related symptoms. Data regarding the predictors of symptomatic hyperviscosity and outcomes related to this complication remain scarce and a recent study proposed that IgM >6000 mg/dL be considered a new criterion for initiating therapy in otherwise asymptomatic (smoldering) WM to pre‐empt hyperviscosity‐related injury. Herein, we attempt to identify predictors of the development of symptomatic hyperviscosity and its impact in patients with WM. Of 997 WM patients evaluated from January, 1996 through June, 2017, symptomatic hyperviscosity was observed in 130 (13%) patients. Overall survival (OS) of these 130 patients was similar to that of patients without symptomatic hyperviscosity (median: 11.5 vs 11.6 years; P = 0.63). On multivariate‐analysis, only viscosity >1.8 cp (risk ratio: 4.0, P = 0.02) assessed at the time of WM diagnosis was an independent predictor for the development of subsequent symptomatic hyperviscosity. Among patients with smoldering WM and IgM >6000 mg/dL at diagnosis (n = 13) who were managed expectantly, the median time‐to‐initial therapy was 6.9 years and only 15% developed hyperviscosity‐related symptoms subsequently. In summary, the occurrence of symptomatic hyperviscosity does not impact OS. Serum viscosity at diagnosis of WM, and not IgM concentration, represents the single most important independent predictor for development of subsequent hyperviscosity‐related symptoms. Patients with smoldering WM and high serum IgM can be safely observed in the absence of any indications per the Consensus recommendations to initiate WM‐directed therapy.

Abstract Introduction: Hyperdiploidy on FISH portends a good prognosis in myeloma. We compared hyperdiploidy determined by MFC to that by conventional FISH. Methods: We studied 1711 patients with plasma cell disorders who had simultaneous FISH and DNA index testing. Monotypic plasma cells in bone marrow are identified by MFC with antibodies to CD19, CD38, CD45, CD138, kappa and lambda; followed by staining by DAPI. DNA index is determined by dividing the measured DNA content of the G0/G1 abnormal plasma cells by the DNA content of the normal G0/G1 plasma cells present. Plasma cells with DNA content index of <0.95 are hypodiploid and G0/G1 DNA content index of >1.05 are considered hyperdiploid. Results: Distribution DNA index and FISH results are described in Table 1. Sensitivity and specificity of DNA index by hyperdiploidy was 86% and 83%. Cohen's Kappa coefficient for concordance was 0.69. Sensitivity increased to 94% for those with 2 or more trisomies and 97% for 3 or more trisomies. Of the 104 patients with trisomy and non-hyperdiploid DNA index, 62% patients had monosomy (mono) or deletion (del) 13q. Overall, DNA index was lower in patients with mono 13/del 13q (1.01; 0.97-1.11) compared to those without (1.07; 1.0-1.19), p<0.001. After excluding patients with mono 13/del 13q, sensitivity and specificity of hyperdiploidy by DNA index were 92% and 82%, kappa = 0.73. Hyperdiploidy was seen in 55% of 272 patients with newly diagnosed myeloma. Sensitivity and specificity were 88% and 93%, kappa = 0.78. After median follow-up of 2.3 yrs, those with hyperdiploid DNA index had better progression free survival at 2,3 and 5 years, 62%, 45% and 21% compared to 50%, 33% and 13% in non-hyperdiploid group, p=0.05. Median overall survival (OS) was not reached; estimated 2, 3 and 5 year OS was 83%, 76% and 63% vs. 76%, 64% and 44%, respectively; p=0.08. Conclusions: DNA index by MFC is a rapid method to determine hyperdiploidy, with potential for replacing trisomy testing by FISH, especially when coupled with monosomy FISH probes. Hyperdiploid N=768 n/N (%)Diploid N=762 n/N (%)Hypodiploid N=78 n/N (%)P1P2Any trisomy 619/765 (81)96/758(13)8/76 (11)<0.001<0.001One chromosome42587733191429-111362Others12204Two chromosomes8525-Three or more chromosomes492131Any translocation124/744 (17)566/748 (76)53/74 (72)<0.001<0.001t(4;14)106313t(11;14)2240127t(14;16)5325t(14;20)38-t(6;14)8104Unknown partner76524Trisomy + Translocation95/743 (13)60/744 (8)6/74 (8)0.0090.002Monosomy 13/17 or deletion 13q/17p252/759 (33)295/744 (40)54/74 (73)<0.0010.0001Monosomy 13/Deletion 13q208/717 (29)282/718 (39)20/70 (29)Monosomy 17/Deletion 17p70/749 (9)50/735 (7)20/72 (28)P1= three groups; P2= hyperdiploid vs. non-hyperdiploid Citation Format: Surbhi Sidana, Nidhi Tandon, Dragan Jevremovic, Rhett P. Ketterling, Angela Dispenzieri, Morie A. Gertz, Francis K. Buadi, Martha Q. Lacy, William Morice, Curtis A. Hanson, Michael Timm, Patricia Greipp, Linda B. Baughn, David Dingli, Suzanne R. Hayman, Wilson I. Gonsalves, Prashant Kapoor, Robert A. Kyle, Nelson Leung, Ronald S. Go, John A. Lust, S.Vincent Rajkumar, Shaji K. Kumar. Hyperdiploidy in plasma cell disorders using multi-parametric flow cytometry (MFC) vs. FISH [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 655.

Abstract Multiple myeloma (MM) is an incurable malignancy of plasma cells. It is the second most common hematologic cancer, affecting nearly 30,000 people in the United States annually. Substantial progress has been made in the past fifteen years in the treatment of MM due to the approval of several new classes of drugs. However, patients inevitably relapse and become refractory to existing therapies. Hence, there is an immediate unmet need to develop novel therapies for MM based on a better understanding of the disease biology. Mutations in RAS have been found to occur in about 40% of newly diagnosed MM patients, with the frequency increasing to around 70% in relapsed/refractory patients. Such mutations are absent in patients with the premalignant conditions monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM). Clearly, RAS mutations contribute to both disease progression and relapse. However, targeting the MEK/ERK pathway has been unsuccessful in MM patients to date. Given the high frequency of RAS mutations in MM, we hypothesized that targeting this pathway could still be a promising strategy when combined with existing agents that have multifaceted mechanisms to promote tumor cell death, such as the recently approved histone deacetylase (HDAC) inhibitor LBH589 (panobinostat). Our results clearly demonstrate that low doses of LBH589 in combination with the MEK inhibitor AZD6244 induce BIM-dependent synergistic cell death in several MM cell lines and patient cells. Our studies also suggest that mutations in RAS/RAF could serve as a predictive biomarker for sensitivity to AZD6244/LBH589. RAS/RAF mutations appear to confer Mcl-1 dependence in MM cells, in part by driving up the phosphorylation of Mcl-1. The AZD6244/LBH589 combination is able to decrease the phosphorylation of Mcl-1 at several sites, which dissociates BIM-Mcl-1 complexes, ultimately leading to activation of the intrinsic apoptosis pathway. Additionally, we identified that wild-type RAS/RAF cells have relatively lower levels of phospho-Mcl-1, as well as higher levels of Bcl-2 and phospho-Bcl-2 when compared to mutated RAS/RAF cells. This seems to confer functional Bcl-2 dependence. Consequently, we found that wild-type RAS/RAF cells are sensitive to the BH3-mimetic ABT199 (venetoclax) when combined with LBH589. Through ongoing experiments, we hope to further confirm the mechanism of action of both these combinations, identify the particular HDAC that is required to be inhibited for the observed synergy, and validate RAS/RAF mutational status as a biomarker for predicting sensitivity to either combination. Our findings have broad therapeutic potential given the prevalence of RAS mutations in MM. Moreover, the ABT199/LBH589 combination could emerge as a targeted therapy for wild-type RAS patients, perhaps broadening the scope and capacity of Bcl-2 inhibition in MM. Citation Format: Kevin C. Miller, Jessica Haug, Teresa Kimlinger, Sanjay Kumar, Wilson Gonsalves, S. Vincent Rajkumar, Shaji K. Kumar, Vijay Ramakrishnan. HDAC inhibition in combination with MEK or BCL-2 inhibition as novel therapeutic strategies in multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3909.

Abstract Oncology has undergone major changes in systemic treatment options, from chemotherapy to antiangiogenic agents to tyrosine-kinase inhibitors to immunotherapy. Historically, a therapeutic agent is tested in separate trials as monotherapy or combined with investigational or approved agents/modalities, to determine antitumor activity in each histology based on the premise that each histology responds differently to the same treatment. This paradigm is time consuming and may or may not make use of molecular characterization to test each agent in each histology. However, with the expansion of biologic understanding and development of various biomarkers, e.g., estrogen receptor and Her 2 amplification, we move beyond the basic paradigm of general histology to one in which treatment is based upon molecular characteristics of the tumor. Examples of recent discoveries from this more modern paradigm are (1) multiple histologies sharing a common molecular profile and (2) a subset within a single histology having a given molecular characteristic. Various agents have been tested singularly in terms of molecular aberrations and histology, e.g., ALK inhibitors and NSCLC. However, with the rapid increase in the number of targeted agents in development, more facile and efficient clinical trial designs are needed. The National Cancer Institute (NCI) and ECOG-ACRIN Cancer Research Group (ECOG-ACRIN) collaborated in designing the Molecular Analysis for Therapy Choice trial (NCI-MATCH or EAY131), the first large-scale signal-finding precision medicine oncology trial in the United States to incorporate centralized NGS testing to direct patients to parallel (nonrandomized) phase II treatment arms under a master protocol. The trial is being conducted by the NCI National Clinical Trials Network (NCTN), with ECOG-ACRIN leading the trial. More than 100 investigators from across the NCTN adult cancer-oriented member groups (Alliance for Clinical Trials in Oncology, ECOG-ACRIN, NRG Oncology, and SWOG) have worked collaboratively to design and lead what is currently 30 treatment arms (subprotocols), with more arms in development. Wide-scale NCTN investigator involvement ensures use of the latest knowledge to define the actionable mutations required for eligibility and to make evidence-based selections of experimental agents. In NCI-MATCH, patients are assigned treatment based on the genomic alterations found in their tumors through genomic sequencing and other tests at the time of initial enrollment for screening. Unlike other phase II trials, each arm is open to advanced solid tumors, lymphomas, or myeloma that share a set of molecular aberrations, not restricted to a single histology. This strategy accommodates and encourages enrollment of rare tumors for which there are often no standard treatments and limited clinical trial options. NCI-MATCH has 10-30 concurrent treatment arms available to patients at any given time, testing both investigational agents and FDA-approved drugs for new indications. Most treatment arms have an enrollment goal of 35 patients, with some arms that address tumor gene variants of higher prevalence expanded to 70 patients. Together, the NCTN and NCI Community Oncology Research Program provide infrastructure for many clinical sites (>1100) to participate, providing ready access to physicians and patients; screening enrollment has occurred in all 50 states in the U.S, the District of Columbia, and Puerto Rico. A specific assay was developed for the trial (the MATCH assay), and a laboratory network was organized to rapidly process the tissue and efficiently interrogate for mutations. NCI and ECOG-ACRIN statisticians developed the analysis plan and are currently maintaining data that are closely monitored by safety experts for any adverse event signals. Lastly, a bioinformatics system (MATCHbox) was developed to coordinate molecular data collection and support rule-based decision-making based on those data. Because genomics in oncology is rapidly expanding and evolving, NCI-MATCH required flexibility to accommodate brisker screening accrual than anticipated, and adaptation to constantly emerging information about new drugs and new molecular alterations. The goal to sequence the tumors of 6,000 patients with NCI funding was achieved two years ahead of schedule, but that cohort was not sufficient to fill all the arms—in particular, those aimed at the most rarely occurring tumor gene aberrations. Currently, the goal for the trial is to complete the open treatment arms by allowing for designated commercial and academic laboratories to notify ordering physicians when genomic tests they ordered to guide clinical care indicate a potential eligibility to a NCI-MATCH arm with a rare variant and allow for enrollment to the relevant treatment subprotocol if the patient meets all subprotocol eligibility criteria. The tissue confirmation of the molecular abnormality on the MATCH assay by the central laboratories will be accomplished after subprotocol enrollment so that patient treatment will not be delayed for confirmation. A demonstration project is now under way to test the applicability of this approach and potentially develop common standards for future use. With tumor sequencing becoming a more and more common practice in oncology, this may allow patients with mutations of low prevalence to have investigational treatment options. NCI-MATCH is expanding its panel and definition of actionable mutations to allow greater flexibility to incorporate in real time new mutations supported with adequate levels of evidence. The valuable genomic and clinical outcome data collected in the trial will permit evaluation of efficacy of targeting certain actionable mutations with a specific agent. In addition, biospecimens are being collected to build a rich resource for conducting auxiliary biology studies that may answer questions about prevalence of mutations in the metastatic setting, prevalence of mutations in rare histologies, and resistance mechanisms of various targeted therapy. At this meeting, two abstracts will provide an overall trial update and present information about the prevalence of mismatch repair deficiency (dMMR) in the centrally screened population. Citation Format: Alice P. Chen, Peter J. O'Dwyer, Lyndsay Harris, Barbara A. Conley, Stanley R. Hamilton, Mickey Williams, Robert J. Gray, Shuli Li, Lisa M. McShane, Lawrence V. Rubinstein, Susanna I. Lee, Shaji Kumar, Edith P. Mitchell, James A. Zwiebel, Constantine A. Gatsonis, Lalitha K. Shankar, Paolo F. Caimi, Carlos L. Arteaga, A John Iafrate, Jeffrey Sklar, Richard F. Little, Keith T. Flaherty. NCI-MATCH: A new paradigm in the era of genomic oncology [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr PL03-01.

AbstractDetection of myeloma progression (PD) relies on serial 24‐h urinary M protein measurements in patients without measurable serum M spike. We examined whether serial difference free light chain (dFLC) levels could be used as a surrogate for serial 24‐h urine M protein measurements in monitoring for PD in patients with baseline measurable urine M protein. We studied 122 patients who had serial measurement of urine M protein and serum FLC and had demonstrated PD. The median increase in dFLC with progression as defined by urine M spike was 110% (IQR: 55‐312) and median absolute increase was 74 mg/dL; while 89% of patients had dFLC increase ≥ 25%, 94% had absolute increase in dFLC > 10 mg/dL, and 98% met at least 1 of these 2 criteria at PD. In patients with baseline measurable serum FLC (n = 118), 89% had increase in dFLC ≥ 25%, 97% had dFLC increase of > 10 mg/dL, and 98% had 1 of the 2. We conclude that serial dFLC assessments can be used in place of serial 24‐h urine protein assessments during myeloma surveillance to monitor for PD. Once patients have an absolute increase in dFLC of >10 mg/dL from the nadir, a 24‐h urine collection can then be assessed to document PD as per the International Myeloma Working Group criteria.