Lust, John A.

TPS8116 Background: Eukaryotic translation initiation Factor 5A (eIF5A) has been implicated in the regulation of apoptosis and is the only known protein to be modified by hypusination. Hypusinated eIF5A is the predominant form of eIF5A in cancer cells. However, in its unhypusinated form, eIF5A is pro-apoptotic. SNS01-T, designed to treat myeloma, consists of two components: a plasmid DNA expressing eIF5AK50R (human eIF5A containing a lysine to arginine substitution at position 50) which remains pro-apoptotic because it cannot be hypusinated, and an siRNA against an untranslated region of native eIF5A mRNA. When these two components are combined with linear polyethyleneimine (PEI), the nucleic acids are condensed into nanoparticles for protection from degradation in the blood and enhanced delivery to tissues. The eIF5AK50R transgene is under the control of the B29 promoter and enhancer, which restricts expression to B cells. The mode of action of SNS01-T is to use an eIF5A-specific siRNA to deplete the pool of hypusinated eIF5A in myeloma cells while simultaneously adding pro-apoptotic eIF5AK50R. In vitro cell studies and in vivo xenograft studies have demonstrated the efficacy of this approach. Methods: Eligible patients are enrolled sequentially into four cohorts of increasingly higher doses. Each cohort will receive SNS01-T by intravenous infusion twice weekly for 6 consecutive weeks and then be observed every 4 weeks during a 24-week follow-up period. Eligible patients must have been diagnosed with multiple myeloma according to IMWG criteria, have measurable disease, have relapsed disease after two or more prior treatment regimens, have a life expectancy of at least 3 months, and not be eligible to receive any other standard therapy known to extend life expectancy. The primary objective is to evaluate the safety and tolerability of multiple escalating doses of SNS01-T. Secondary objectives include pharmacokinetics, immunogenicity studies, proinflammatory cytokine quantitation, and therapeutic efficacy. Two of the planned 15 patients have been enrolled. (Clinical Trials.gov Identifier: NCT01435720.)

8105 Background: Tumor stage migration can artifactually inflate cancer survival rates and overestimate benefits of newer therapies. We have previously shown a favorable impact of widely used novel agents in MM patients. However, it is not known whether use of well tolerated and easily administrable novel agents results in their introduction at lower levels of MM burden (and therefore add to improved outcome). Our goal was to assess for stage migration in newly diagnosed active MM patients. Methods: We reviewed records of 1,467 patients with active MM at Mayo Clinic, at initiation of therapy from 3 consecutive 5-year intervals: 01/1996-12/2000 (Group 1), 01/2001-12/2005 (Group 2), 01/2006- 12/2010 (Group 3). These intervals reflect the practice changing approaches at our center transitioning from the use of alkylator-based to novel agent-based initial therapy. Traditional parameters and staging systems were used to estimate tumor burden. We performed one way analysis of variance (ANOVA) to assess for differences in these parameters among the groups. A p-value of <0.05 was considered significant. Results: Group 3 shows an upward trend for hemoglobin (Hgb), and lower creatinine and bone marrow plasma cell (BMPC) percent. Compared to other groups, a greater proportion of Group 3 patients are assigned to lower Durie Salmon (DS) stages (Table) suggesting reduced tumor burden at therapy initiation. In contrast, the International Staging System (ISS) which is not used for decisions regarding therapy initiation divides cohorts in similar proportions. Conclusions: Stage migration is evident in our cohort of active MM patients presenting in the time periods of evolving initial therapeutic strategies. Future studies should take into account the bias introduced by this phenomenon in interpreting survival analysis of MM patients. [Table: see text]

8096 Background: The combination of lenalidomide and dexamethasone (Len-Dex) is a commonly used initial therapy for newly diagnosed multiple myeloma. While the short-term outcomes with respect to response and toxicity is well-known, long-term outcome with this combination as initial therapy is not well described. Methods: We studied 286 consecutive patients with newly diagnosed MM seen at our institution, who received initial therapy with Len-Dex, and who had complete follow up records. Data regarding the clinical course was obtained from medical records. Results: The median (range) age at diagnosis was 63 (28-92) yrs; 166 (58% were ≤ 65 yrs and175 (61%) were male. The median estimated follow-up was 3.9 yrs (95% CI, 3.4, 4.2) and 203 (71%) pts were alive at the time of last follow up. The median estimated duration on Len-Dex was 5.3 mos (95% CI, 4.6, 6.4). The best overall response (≥PR) was 72%, including 26% with VGPR or better and 14 (5%) not being evaluable for a response. At last follow up, 41 (14%) patients were continuing on therapy. There were 93 pts (32%) who stayed on therapy for 12 months or more. Among these patients, the ORR was 86%, including 45% with VGPR or better. The median overall survival (OS) for the entire cohort from diagnosis was 7.4 yrs (95% CI; 5.8, NR) and the estimated 5-yr survival was 67%. There were 16 (5.5%) pts who died within a year of diagnosis. The median time to first disease progression, irrespective of transplant status, was 30.2 mos (95% CI, 25, 42). Overall, 143 (50%) of the patients have gone to stem cell transplant. Censoring those patients who proceeded to SCT prior to relapse at the time of BMT, the median TTP was 25.5 mos (95% CI, 22, 29). The median OS was 7.4 yrs for those ≤65 yrs, compared with 6.2 yrs for the older patients (P=0.01). The 5-yr OS estimate for patients in ISS stage 1, 2 and 3 were 82, 65, and 44 months respectively. Conclusions: The current study provides long-term estimates of responses and survival in a series of patients treated initially with lenalidomide and dexamethasone. The median survival of nearly 8 years reflects the efficacy of the novel agents both at diagnosis and at relapse and confirms the survival improvements seen in MM in the last decade.

8116 Background: POEMS syndrome, or osteosclerotic myeloma, is an uncommon plasma cell disorder associated with Peripheral neuropathy, Organomegaly, Endocrinopathy, M protein, and Skin changes, as well as bone lesions, Castlemans disease, and edema. The pathogenesis of POEMS is poorly understood, and its clinical course is distinct from Multiple Myeloma (MM) and monoclonal gammopathy of undetermined significance (MGUS). While various cytogenetic abnormalities have been well described in MM and MGUS, we provide the first report of testing for these abnormalities in POEMS syndrome. Methods: Using a prospectively held dysproteinemia database, we reviewed all cases of POEMS seen at our institution, identifying 36 with metaphase cytogenetic testing results, and 9 with fluorescence in situ hybridization (FISH) testing results. Combined cytoplasmic immunoglobulin/FISH testing (cIg- FISH) was performed with fluorescent-tagged antibodies to kappa/lambda immunoglobulin and FISH probes corresponding to the following anomalies: trisomies 3, 7, 9, 11, 15 and 17; del13/del13q; 14q32 split/del14; and t(11;14). Results: Five patients had insufficient plasma cells for cIg-FISH, and 9 were adequate for testing. Monosomy 13 was seen in 5 of the 9 cIg-FISH samples of which 2 of these cases also had apparent monosomy 14. cIg-FISH in one patient revealed trisomy 3 and 7. No abnormalities were seen at 11q13 (CCND1), 17p13 (p53) or translocations involving 14q32 (IGH). Thrity-eight total karyotypes analyses were attempted, though two showed an insufficient number of suitable metaphases. Of the 36 karyotype analyses, 31 were normal, 2 displayed characteristic plasma cell anomalies (hyperdiploid with structural anomalies), 2 treated patients displayed del20q anomalies and 1 patient had a constitutional 13;14 translocation. Conclusion: We are the first to report del13 as a possibly common abnormality in POEMS syndrome, detected by cIg-FISH in 5 of 9 (55%) samples with sufficient plasma cells, similar to the rate observed in MM and MGUS. The lack of abnormalities at 14q32 (IgH locus) is in contrast to MM and MGUS. Abnormal karyotypes, consistent with dividing plasma cells, are rare in POEMS, observed in only 2 of 36 (5.5%) cases. These observations could possibly lend insight into all three disorders. No significant financial relationships to disclose.

8105 Background: IL-6 is the central myeloma growth factor and we have shown that abnormal production of IL-1beta in the myeloma microenvironment stimulates the generation of paracrine IL-6. A Phase II trial was completed using IL-1ra, which inhibits paracrine IL-6 production, and low dose Dexamethasone (Dex), which decreases IL-1 levels through myeloma cell apoptosis, in patients with smoldering/indolent MM (SMM/IMM). These patients are at the greatest risk for progression to active MM and most likely to benefit from anti- cytokine therapy. Methods: Patients that had ≥ 10% bone marrow plasma cells and/or an IgG or IgA M-spike ≥ 3 g/dL and did not require immediate chemotherapy were eligible. A total of 47 patients received 100 mg of IL-1ra SQ qd for 6 months unless clinical progression occurred. Responding patients were allowed to continue on therapy with IL-1ra alone. Low dose Dex (20 mg qweek) was added after 6 months of IL-1ra in non-responding patients. The primary endpoint was progression-free survival (PFS). Results: The 47 patients were at high risk for progression to active MM with 98% having ≥ 10% plasma cells, 89% generating IL-1 levels consistent with myeloma (≥ 1.0), and 32% having bone lesions. All 47 patients received IL-1ra initially and 25/47 subsequently received IL-1Ra/Dex. For the group of 47 patients, the median overall progression-free survival was 37.5 months. Three patients achieved a minor response (MR) to Anakinra alone; 5 pts achieved a PR and 4 patients an MR after addition of Dex. Seven patients had a decrease in the plasma cell labeling index (PCLI; a marker of myeloma cell growth) on Anakinra alone which paralleled a decrease in the high sensitivity CRP (a marker of serum IL-6 levels). The median PFS for patients without (n=12) and with (n=35) a ≥ 15% decrease in their baseline hsCRP was 6 months and > 3 yrs, respectively (p=0.002). Conclusions: In SMM/IMM patients at high risk for progression to active myeloma, treatment with IL-1 inhibitors (IL-1ra ± Dex) results in an increased PFS in patients that demonstrate a ≥15% reduction in the baseline CRP compared to those that do not respond. No significant financial relationships to disclose.

AbstractThe diagnosis of primary plasma cell leukemia (pPCL) has been made by quantifying circulating plasma cells (cPCs) morphologically on a peripheral blood (PB) smear. However, this technique is not sufficiently sensitive. Multiparametric flow cytometry (MFC) provides a readily available and highly sensitive method to identify and quantify cPCs that could complement PB smear assessment. However, an optimal quantitative cutoff for cPCs by MFC to identify pPCL has not been established. Thus, a total of 591 patients newly diagnosed multiple myeloma (NDMM) patients who had their PB samples evaluated morphologically by PB smear, and immunophenotypically by MFC prior to beginning therapy were evaluated. The presence of ≥200 cPCs/μL by MFC (N = 25 or 5% of the total population) was chosen to identify patients with ≥5% cPCs by PB smear with a specificity of 99% and a sensitivity of 77%. For patients with ≥200 cPCs/μL by MFC compared to the remainder of the cohort, the median Time to next therapy (TTNT) was 18 vs 30 months and the median OS was 38 vs 70 months respectively. Thus, MFC assessment of PB can be utilized in conjunction with the morphological assessment of a PB smear to aid in improving the identification of pPCL among NDMM patients.

Key PointsPatients with an abnormal sFLC ratio because of LC suppression have outcomes similar to those with a normal ratio. sFLC ratio has prognostic value in patients achieving CR who have an absence of clonal BMPCs assessed by MFC.

AbstractOur prior studies identified the prognostic significance of quantifying cPCs by multiparametric flow cytometry (MFC) in newly diagnosed multiple myeloma (NDMM) patients. We evaluated if a similar quantification of cPCs could add prognostic value to the current R‐ISS classification of 556 consecutive NDMM patients seen at the Mayo Clinic, Rochester from 2009 to 2017. Those patients that had ≥5 cPCs/μL and either R‐ISS stage I or stage II disease were re‐classified as R‐ISS IIB stage for the purposes of this study. The median time to next therapy (TTNT) and overall survival (OS) for patients with ≥5 cPCs/μL at diagnosis was as follows: R‐ISS I (N = 110) ‐ 40 months and not reached; R‐ISS II (N = 69) ‐ 30 and 72 months; R‐ISS IIB (N = 96) ‐ 21 and 45 months and R‐ISS III (N = 281) ‐ 20 and 47 months respectively. Finally, ≥ 5 cPCs/μL retained its adverse prognostic significance in a multivariable model for TTNT and OS. Hence, quantifying cPCs by MFC can potentially enhance the R‐ISS classification of a subset of NDMM patients with stage I and II disease by identifying those patients with a worse than expected survival outcome.

Abstract Background: Cytogenetic evaluation using fluorescence in situ hybridization (FISH) at the time of diagnosis is essential for initial risk stratification in multiple myeloma. The presence of specific cytogenetic abnormalities is known to confer a poor prognosis, less is known about the cumulative effect of multiple cytogenetic high-risk abnormalities. We aimed to evaluate the prognostic implications of the presence of multiple cytogenetic high-risk abnormalities at the time of diagnosis. Methods: We studied 226 patients who were diagnosed with multiple myeloma between July 2004 and July 2014 at Mayo Clinic Rochester, underwent FISH evaluation within six months of diagnosis, and presented with cytogenetic high-risk abnormalities. High-risk cytogenetics were defined as t(4;14), t(14;16), t(14;20), del(17p), or gain(1q). Bone marrow aspirates were evaluated for deletions, monosomies, trisomies, and tetrasomies using chromosome- or centromere-specific FISH probes. IGH rearrangements were evaluated using an IGH break-apart probe and evaluating up to five potential partners (FGFR3, CCND1, CCND3, MAF, and MAFB). Kaplan-Meier overall survival estimates were calculated and the log-rank test was used to compare overall survival in patients with single and multiple cytogenetic high-risk abnormalities. A multivariable-adjusted Cox regression model was used to assess the effect of multiple cytogenetic high-risk abnormalities on overall survival adjusting for age, sex, and Revised International Staging System (R-ISS) stage. P-values below 0.05 were considered statistically significant. Results: The median age at diagnosis was 65 years (32 - 90), 129 (57%) of the patients were male. The median overall survival was 3.5 years (3.1 - 4.9) for the entire cohort (n = 226), 4.0 years (3.3 - 5.1) for those with one cytogenetic high-risk abnormality (n = 182, 80%), and 2.6 years (1.7 - 3.1) for those with two cytogenetic high-risk abnormalities (n = 44, 20%). There were no patients with more than two cytogenetic high-risk abnormalities. Ninety-eight patients (45%) had a high-risk translocation, 77 (35%) had del(17p), 39 (18%) had a high-risk translocation plus del(17p), and 5 (2%) had gain(1q) plus either a high-risk translocation or del(17p). Figure 1 shows the Kaplan-Meier overall survival estimates stratified by the number of cytogenetic high-risk abnormalities (n = 226). The presence of two cytogenetic high-risk abnormalities (compared to one) was of prognostic significance after adjusting for age, sex, and R-ISS stage (HR 2.01, 95% CI 1.27 - 3.19, p = 0.003, n = 205). Conclusions: Approximately one in five patients with newly diagnosed high-risk multiple myeloma presented with two high-risk abnormalities at the time of diagnosis. These patients experienced inferior overall survival suggesting a cumulative effect of multiple cytogenetic high-risk abnormalities. The relatively low number of observed gain(1q) was likely related to the fact that not all patients were evaluated for that abnormality. Therefore the presented hazard ratio represents a conservative effect estimate and may underestimate the true effect. Figure 1 Figure 1. Disclosures Dispenzieri: GSK: Membership on an entity's Board of Directors or advisory committees; Jannsen: Research Funding; Alnylam: Research Funding; Celgene: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; pfizer: Research Funding. Kapoor:Takeda: Research Funding; Celgene: Research Funding; Amgen: Research Funding. Kumar:Janssen: Consultancy, Research Funding; BMS: Consultancy; AbbVie: Research Funding; Millennium: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Array BioPharma: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; Kesios: Consultancy; Glycomimetics: Consultancy.