Citations

8541 Background: Achievement of a complete response (CR) to treatment is an important predictor of outcome for patients (pts) with myeloma (MM). The goal of the current study was to assess whether the treatment that resulted in CR has any impact on the outcomes. Methods: We identified 462 pts with MM, who fulfilled the IMWG criteria for CR, seen at Mayo Clinic between 1991 and 2011. The treatment was classified into groups by the regimen that led to CR (Table), and also based on whether an autologous stem cell transplant (ASCT) was part of the regimen. The remaining 21 pts had a variety of regimens and are not included in the Table. Results: The median age at diagnosis was 58.5 yrs (27.1–82.3 yrs) with 56% males. The overall survival (OS) from diagnosis for the entire cohort was 10.7 yrs (95% CI; 9.3, NR). The median interval from diagnosis to the recorded CR was 10.3 mos (range 1- 170), with 272 (58.4%) and 385 (82.7%) obtaining a CR in <12 mos and <24 months from diagnosis. We first compared the outcomes based on whether ASCT was part of the regimen; 328 had an ASCT while 117 pts received only chemotherapy. Median time to progression (TTP) following a CR was 5.1 yrs for the ASCT group compared with 5.5 yrs for the rest (P=0.3). Median OS from CR was 9.1 yrs for the ASCT group and 7.5 yrs for the rest (P=0.5) and OS from diagnosis was 10.1 yrs for the ASCT group and 12.6 for the rest (P=0.5). Examining the outcomes based on the regimen utilized showed that the TTP and OS from CR as well as OS from diagnosis were similar for all the groups (Table). Among pts who had a CR within a year of diagnosis, there were no differences in terms of the TTP or OS from the onset of CR or from diagnosis between the ASCT vs. chemotherapy groups or between the different regimens (P=NS for all comparisons). Conclusions: The current study highlights an important message regarding CR in MM. The results suggest that the prognostic value of CR is independent of the nature of therapy, and likely reflects the contribution of disease biology to obtaining a CR. [Table: see text]

8516 Background: There is consensus that light chain amyloidosis (AL) patients with CRAB criteria (abnormal calcium or renal function, anemia or lytic bone lesions) also have multiple myeloma (MM). These patients are typically excluded from AL trials; however, AL patients with >= 10% bone marrow plasma cells (BMPC) in the absence of CRAB are included in trials along with AL with < 10% BMPC. We postulated that the currently used dichotomy may be incorrect and examined the spectrum of AL with and without MM. Methods: We identified 1,272 patients with AL seen within 90 days of diagnosis, between January 1, 2000, and December 31, 2010. We defined the population of patients with coexisting MM based on the existence of CRAB (AL-CRAB-MM). Patients without CRAB were divided into two groups, AL-only (<10% BMPC) and AL-PC-MM (>=10% BMPC). Results: Among the 1,272 patients, 117 (9%) had AL-CRAB-MM, 476 (37%) had AL-PC-MM, and 679 (53%) had AL only. Their respective median overall survivals (OS) were 16.2, 15.8, and 28.4 months (p<0.0001). Autologous stem cell transplant (ASCT) was performed in 203 (30%), 138 (29%) and 23 (20%) patients respectively. Since the outcomes of AL-CRAB-MM and AL-PC-MM were similar, they were pooled for univariate and multivariate analyses. On multivariate analysis, AL-CRAB-MM and AL-PC-MM retained negative prognostic value independent of age, cardiac stage, prior autologous stem cell transplant (ASCT), beta 2 microglobulin, and dFLC. We next considered whether patients received ASCT as part of their treatment. For those patients who never received ASCT, the 5-year OS were 19%, 14%, and 31%, p<0.001, for AL-CRAB-MM, AL-PC-MM, and AL only respectively. In contrast, for those patients who received ASCT, the respective 5-year OS were 46%, 56%, and 73%, p<0.001. Conclusions: AL patients with >=10% BMPCs have a poor prognosis similar to patients with AL-CRAB-MM and should therefore be considered as AL with MM.

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.