Hayman, Suzanne R.

Background: The treatment of Multiple Myeloma (MM) has evolved significantly in the past decade with the introduction of novel agents and drug combinations, thus enhancing treatment efficacy and allowing more patients to achieve complete response (CR). This has created a need to identify surrogates for depth of treatment response. Serum free light chain (sFLC) ratio normalization has been shown to be prognostic for progression free survival as well as overall survival in patients achieving a complete response to therapy. Consequently, it has been incorporated as a defining feature for stringent CR, along with lack of clonal plasma cells by immunohistochemistry (IHC) or low sensitivity flow cytometry. The routine use of multiparametric flow cytometry with higher sensitivity to detect residual disease than IHC or the older 4-color flow cytometry, has raised the question as to whether sFLC ratio is still a valid indicator of response depth. Moreover, in nearly half of the patients with an abnormal sFLC ratio after treatment, the abnormality is secondary to suppression of one or both serum light chains. Therefore, we designed a retrospective study to address these issues. Patients and Methods: This is a retrospective study using the Multiple Myeloma Database at Mayo Clinic, Rochester. We included patients who, after any line of therapy, had negative serum and urine immunofixation and absence of clonal bone marrow plasma cells by flow cytometry (PC-PRO), which has a sensitivity of >10-4. Simultaneous sFLC data was also extracted. Patients were grouped into three categories based on their sFLC ratios: 1) normal ratio (normal), 2) abnormal ratio due to suppression of the uninvolved light chain (LC), involved LC, or both (Abn-suppressed) and 3) abnormal ratio due to elevation of the involved LC (Abn-inv elevated). The primary endpoint was the median time to next treatment (TTNT), defined as the time from sample collection to the time of initiation of the subsequent therapy or time of last follow up if a subsequent line of treatment was not initiated. Results: The cohort consisted of 510 patients. 285 (56%) were males and 225 (44%) females. Median age was 61 years (IQR: 55-67). Median Follow-up was 41 months. The last treatments administered prior to data collection included stem cell transplant (SCT) (with or without maintenance) in 290 (57%) patients, and non-SCT regimens in the others. The sFLC ratio was normal in 337 (66%) and abnormal in 173 (34%) patients. Among the patients with abnormal sFLC ratios, 81 had elevated involved LC, 25 had suppression of the involved LC, 45 had suppression of the uninvolved LC and 22 had suppression of both LCs. We first examined the TTNT for the three groups and found that the TTNT was identical for those with a normal ratio and those with an abnormal ratio due to suppression of one or both light chains (Figure 1). So, we combined these two groups (Normal-Abn suppressed) and compared their outcomes to the patients with abnormal sFLC ratio due to elevated involved LC. The Abn-inv elevated group had a shorter TTNT as shown in Figure 2 (log-rank 0.06, Wilcoxon <0.01). The Abn-inv elevated group also had decreased overall survival compared to the other group (log-rank: 0.05, Wilcoxon: 0.01) (Figure 3). Conclusion: This study provides 2 important observations. First, patients with an abnormal ratio due to suppression of one or both LCs have outcomes similar to those with a normal ratio, suggesting a need to clarify the current definition of stringent CR. Second, the study suggests an important prognostic value for an abnormal sFLC ratio due to elevated involved LC, suggesting this as an important surrogate for depth of response. Disclosures Kapoor: Janssen: Research Funding; Takeda: Honoraria, Research Funding; Cellectar: Consultancy; Celgene: Honoraria; Sanofi: Consultancy, Research Funding; Amgen: Research Funding; Glaxo Smith Kline: Research Funding. Dispenzieri:Akcea: Consultancy; Intellia: Consultancy; Janssen: Consultancy; Pfizer: Research Funding; Takeda: Research Funding; Celgene: Research Funding; Alnylam: Research Funding. Gertz:Ionis: Honoraria; Alnylam: Honoraria; Prothena: Honoraria; Celgene: Honoraria; Janssen: Honoraria; Spectrum: Honoraria, Research Funding. Lacy:Celgene: Research Funding. Dingli:Karyopharm: Research Funding; Rigel: Consultancy; Millenium: Consultancy; Janssen: Consultancy; alexion: Consultancy. Leung:Takeda: Research Funding; Aduro: Membership on an entity's Board of Directors or advisory committees; Prothena: Membership on an entity's Board of Directors or advisory committees; Omeros: Research Funding. Kumar:Celgene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Takeda: Research Funding.

Introduction: Several patient and disease biology characteristics that impact overall survival (OS) outcomes of patients with newly diagnosed multiple myeloma (NDMM) have been well described. However, several prior population-based registry studies in the US such as SEER and NCDB databases have demonstrated the negative prognostic impact of socio-economic (SE) factors such as low median household income based on US national census bureau data for zip code of residence as well as absence of marital support on the OS of NDMM patients. Whether such SE factors are independent of established host and disease biology related factors remains unknown due to the absence of detailed patient-level data in population-based cancer registries. Thus, we evaluated whether such SE factors independently affected the OS of NDMM patients in our institution when accounting for patient and disease biology related factors. Methods: We analyzed a retrospective cohort of consecutive NDMM patients seen at the Mayo Clinic from January 2005 to December 2015. Median household income for each patient's area of residence was estimated by matching their home zip code at diagnosis with data available through the US National Census Bureau. Median household income < $63,000 for a zip code were used to classify patients as having low income based on the National Cancer Database classification of the bottom three quartiles. Absence of marital support was considered in patients divorced, single or widowed at the time of diagnosis. Survival estimates were calculated using the Kaplan-Meier method. Patient and disease biology related factors taken into consideration included age, FISH cytogenetics, ISS stage and LDH levels. Survival estimates were compared between groups using the log-rank test. Multivariable adjusted proportional hazards regression models were fit for the association between known prognostic factors and OS. Results: A total of 2,621 MM patients were analyzed from the Mayo Clinic cohort of which 60% were male and the median age was 64 (22 - 96) years with 14% being 75 years of age or older. In this cohort, 541 (33%) patients had ISS 3 disease and 370 (22%) had high risk cytogenetics by FISH. The median OS based on estimated average household income was 65 months for the group of patients with low household income (N = 32%) and 80 months for the remainder (P = 0.001) (Fig 1A). The median OS based on marital support was 59 months for those without marital support at diagnosis (N = 21%) versus 76 months for remainder (P = 0.003) (Fig 1B). However, in a multivariable analysis that included the aforementioned SE factors and patient and disease biology characteristics , only age of 75 years or older (p < 0.001), the presence of high-risk FISH cytogenetics (p < 0.001), presence of ISS 3 disease (p < 0.001) and elevated LDH (p = 0.005) retained independent statistical significance in predicting for worse OS. Lower household income (p = 0.264) and absence of marital support (p = 0.054) were not independent predictors of worse OS. Conclusions: With the caveat of patient selection bias in a tertiary academic center, SE factors such as estimated average household income and marital support at diagnosis do not appear to impact OS of NDMM patients when considered in the context of traditional host and disease biology risk factors. These findings are in contrast to those suggested by population based registry studies; nevertheless, similar patient-level assessments should be considered in patient cohorts from non-tertiary medical centers as these results may likely be different. Disclosures Dispenzieri: Akcea: Consultancy; Intellia: Consultancy; Janssen: Consultancy; Pfizer: Research Funding; Takeda: Research Funding; Celgene: Research Funding; Alnylam: Research Funding. Dingli:alexion: Consultancy; Janssen: Consultancy; Millenium: Consultancy; Rigel: Consultancy; Karyopharm: Research Funding. Lacy:Celgene: Research Funding. Kapoor:Amgen: Research Funding; Glaxo Smith Kline: Research Funding; Sanofi: Consultancy, Research Funding; Celgene: Honoraria; Janssen: Research Funding; Cellectar: Consultancy; Takeda: Honoraria, Research Funding. Leung:Prothena: Membership on an entity's Board of Directors or advisory committees; Aduro: Membership on an entity's Board of Directors or advisory committees; Takeda: Research Funding; Omeros: Research Funding. Russell:Imanis: Equity Ownership. Gertz:Medscape: Consultancy, Speakers Bureau; Research to Practice: Consultancy; Springer Publishing: Patents & Royalties; Ionis/Akcea: Consultancy; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Alnylam: Consultancy; Prothena Biosciences Inc: Consultancy; Celgene: Consultancy; Janssen: Consultancy; Spectrum: Consultancy, Research Funding; Annexon: Consultancy; Appellis: Consultancy; Amgen: Consultancy; Physicians Education Resource: Consultancy; Abbvie: Other: personal fees for Data Safety Monitoring board; Teva: Speakers Bureau; Johnson and Johnson: Speakers Bureau; DAVA oncology: Speakers Bureau; Proclara: Membership on an entity's Board of Directors or advisory committees; i3Health: Other: Development of educational programs and materials; Amyloidosis Foundation: Research Funding; International Waldenstrom Foundation: Research Funding. Kumar:Celgene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Takeda: Research Funding.

Background: Lenalidomide maintenance therapy post-autologous stem cell transplantation (ASCT) is associated with improved progression-free survival (PFS) and possibly overall survival in multiple myeloma (MM). However, almost all patients do relapse as a result of residual multiple myeloma cells that remain after the high-dose chemotherapy. In the myeloma setting it has been found that the hedgehog (Hh) pathway is essential for maintaining a subset of tumor causing stem cells. LDE 225 (Sonidegib) is a potent selective oral bioavailable antagonist of Smoothened (SMO), a component of the Hh signaling pathway. In in vitro experiments, LDE225 treatment of myeloma cell lines resulted in a modest inhibition of cell proliferation at increasing doses. When LDE225 was combined with lenalidomide, a more than additive effect was observed in terms of cell proliferation, an effect that was more pronounced in the context of myeloma cell lines growing in co-culture with marrow derived stromal cells. These findings form the basis of evaluation of LDE 225 as a strategy to enhance the activity of lenalidomide in the post-transplant maintenance setting. The minimal residual state post SCT provides the most optimal situation for evaluation of a drug that is likely to work by inhibiting the tumor cells that escaped high dose therapy. Methods: Multiple myeloma patients without evidence of progression, who were 60 - 120 days after a single autologous stem cell transplant (SCT), performed within 1 year of diagnosis were eligible for the study. Maintenance therapy was started approximately 3 months after SCT. Treatment consisted of lenalidomide 10 mg days 1-21 and LDE225 400 mg days 1-28 in 28-day cycles for a total of 18 cycles. The goal of the study was to assess toxicity of this combination, complete response rate (CR) progression free survival (PFS) at 1 and 2 year and overall survival (OS). CR and PFS were estimated using an exact binomial distribution and Kaplan Meier curves respectively. Results: A total of 28 patients were accrued from Jan 2014 to Aug 2016, 1 patient canceled prior to treatment and 1 patient was deemed ineligible resulting in 26 evaluable pts for CR and PFS. The median age of all pts (n=26) was 60 years (range 43-69) and 50% were males. Seventy-three percent of patients reported one treatment regimen prior to SCT, while 27% reported 2 or more prior regimens. The other characteristics of the patient are summarized in Table 1. Twenty seven pts received at least one cycle of treatment and are evaluable for toxicities (AE). Patients were treated for a median of 12.5 (range 1-18) cycles. While 10 pts (38.5%) completed protocol treatment (18 cycles), the remaining 16 pts went off treatment due to AEs (6, 23%), disease progression (3, 11.5%), refusal of further treatment (3, 11.5%) and other reasons (4, 15.4%). A grade 3 or higher AE at least possibly attributed to either drug was seen in 63%. Grade 3+ hematologic toxicities were noted in 30%, with 7% neutropenia and 4% thrombocytopenia. Notable grade 2+ non-hematologic toxicities with more than 5% incidence were dysgeusia 22%, alopecia 11%, and anorexia 7%. Grade 3+ non-hematologic toxicities were fatigue, myalgia and arthralgia each at 7%. The CR rate in evaluable patients was 46% (5 CRs and 7 sCRs) with a 95% CI of 27% - 66%. CR rate improved from 31% to 46%. VGPR or better improved from 42% to 85%. The 24-month PFS (time from SCT to progression or death due to any cause) was 73% (95% CI: 57.9 - 92.3%) with a median time to censoring of 38 months. Conclusion: Lenalidomide in combination with LDE225 as posttransplant maintenance therapy was associated with some toxicity but manageable. The combination improved the depth of response after autologous stem cell transplant. Long-term follow-up is needed to determine overall survival. Disclosures Lacy: Celgene: Research Funding. Dispenzieri:Celgene: Research Funding; Takeda: Research Funding; Pfizer: Research Funding; Janssen: Consultancy; Intellia: Consultancy; Akcea: Consultancy; Alnylam: Research Funding. Gertz:Ionis: Honoraria; Alnylam: Honoraria; Prothena: Honoraria; Celgene: Honoraria; Spectrum: Honoraria, Research Funding; Janssen: Honoraria. Kapoor:Glaxo Smith Kline: Research Funding; Amgen: Research Funding; Janssen: Research Funding; Cellectar: Consultancy; Takeda: Honoraria, Research Funding; Celgene: Honoraria; Sanofi: Consultancy, Research Funding. Dingli:alexion: Consultancy; Janssen: Consultancy; Millenium: Consultancy; Rigel: Consultancy; Karyopharm: Research Funding. Russell:Imanis: Equity Ownership. Kumar:Janssen: Consultancy, Research Funding; Takeda: Research Funding; Celgene: Consultancy, Research Funding. OffLabel Disclosure: Sonidegib (LDE 225) is a selective oral bioavailable antagonist of Smoothened (SMO), a component of the hedgehog signaling pathway.

Abstract Background: Modern clinical practice places time restrictions on the amount of information and processing that can be done in a typical office visit. Meeting patient needs within the healthcare system is challenging, contributing to patient (pt) and clinician dissatisfaction and potential suboptimal outcomes. We developed an electronic point-of-care case management system for cancer patients. The system's goal is to obtain patient-reported quality of life (PROQOL) outcomes and provide clinicians with information regarding QOL issues to address. We tested this system in a prospective randomized study against usual care (UC). The primary objective was to determine if PROQOL system would improve mean QOL over time. Methods: Eligible pts were adults with multiple myeloma (MM) or light amyloidosis (AL), seen at Mayo Clinic. Pts were randomized 2:1 to PROQOL system or usual care. PROQOL system was offered prior to every visit. Pts select from various categories about their single biggest concern, and receive a printed list of actionable resources based on selected concern. Clinicians also receive the PROQOL results to review with pts. Providers and pts randomized to PROQOL completed a "was it worth it survey" (WIWI). An 8 item Linear Analogue Self-Assessment was used to assess QOL, the primary endpoint. Secondary endpoints included distribution of choices of most important concern and their relationship to demographic and clinical variables. The study was powered to detect a 0.5 standard deviation difference in QOL between groups. Results: There were 233 patients enrolled (171 MM, 62 AL) in this study between July 1, 2016 and April 17, 2018. Median age was 65 years (range 31-87), and 59% were male. Median time from diagnosis to study consent was 37 months (PROQOL 36.3 versus UC 39.6). Median follow up for all patients was 15 months (range: 0.7-22 months), and median follow up for PROQOL pts was 16 months and 14 months for UC pts (p=0.027). There were 25 pts that have died since enrollment and 208 alive. No statistical significant difference in QOL between PROQOL and UC (median QOL 7 vs 7, p=0.75). The most prevalent main concerns selected were Physical Health (37%) and Cancer and Diagnosis (27%), the pattern remained even when pts were given the option to pick a second major concern 26% and 20% respectively. No other concern was listed more than 8% at baseline. All category selections and percentages are shown in the Figure. The average time to complete the instrument was 6 minutes. Pts found the PROQOL system was worth their time (75%), they would choose it again (87%) and recommend it to others (82%). Eighty-two percent of clinicians did not think the PROQOL tool negatively impacted their practice and 75% believed they may see improvement in pt wellbeing. Discussion: The PROQOL system was well received by pts and clinicians but did not improve QOL relative to UC in this study. The PROQOL demonstrates that majority of patients strongly desire more information regarding ongoing therapy, clinical trials, prognosis and toxicity. Further investigation is needed to understand whether communication is limited by time or mechanism of information delivery, such as verbal or written, or whether it should be undertaken in a separate allied health care visit. Figure. Figure. Disclosures Gertz: spectrum: Consultancy, Honoraria; Abbvie: Consultancy; Research to Practice: Consultancy; annexon: Consultancy; Medscape: Consultancy; Physicians Education Resource: Consultancy; Amgen: Consultancy; janssen: Consultancy; Alnylam: Honoraria; Teva: Consultancy; Apellis: Consultancy; Ionis: Honoraria; celgene: Consultancy; Prothena: Honoraria. Kumar:Novartis: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Lacy:Celgene: Research Funding. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding.

Abstract Abstract 448 Background: POEMS syndrome is a rare form of plasma cell dyscrasia that presents with polyneuropathy and various other systemic findings. Patients with 1–3 lesions and bone marrows without clonal plasma cells have been given targeted radiation as the initial and potentially definitive therapy. Outcomes of patients treated thus have not been systematically studied. Patients and Methods: One hundred and forty-six patients with POEMS syndrome were seen at the Mayo Clinic in Rochester, MN between January 1999 and September 2011. Charts of patients with research authorization were reviewed with IRB approval. Patients who had been given targeted radiation as their initial primary therapy were eligible for this study. Thirty-eight patients satisfied criteria and comprise the study population. Three patients had either short or poorly documented follow-up and were excluded from the response and time to next treatment analyses. Patients were categorized by systems that were involved at diagnosis, time of radiation, response after radiation, and the need for further therapy. Statistical analyses were performed using JMP statistical software (SAS, Carey, NC). Results: The median age was 50, with 76% of the population being male. Median time from diagnosis to radiation was 0.7 months, ranging from 0 to 9.4 months. 20, 14, 11 and 2 patients had immunosuppressive therapy with corticosteroids, IVIG, plasmapheresis, or rituximab, respectively, directed at a prior presumptive, but incorrect, diagnosis of CIDP. Five patients had one cycle or less of alkylator, lenalidomide, or bortezomib, prior to receiving what was hoped to be definitive radiation therapy. The median number of bone lesions was 1, range 1–6. In total 55 lesions of the possible 64 were irradiated being mostly found in the pelvic bones including the sacrum, ileum, ischium, and pubis. The median dose of radiation given was 45 Gy range 35 Gy to 54 Gy. Forty-nine percent had clinical improvement, 26% had a mixed clinical picture, 3% merely stabilized, and 23% had a clinical worsening. 29% had a complete hematologic response, 9% had a very good partial hematologic response, 9% had a partial hematologic response, 26% had no hematologic response, and the remaining were either non- or oligo-secretory or undocumented. 11% had a complete FDG-PET response, 11% had a partial FDG-PET response, 11% had no FDG-PET response, and the remaining had no documented FDG-PETs to analyze. 11% had a complete VEGF response, 3% had partial VEGF response, 14% had no VEGF response, and the rest were either not documented or unevaluable. The median follow up of living patients is 30 months, and the 4-year OS is 95%. Forty-eight percent of patients went on to receive additional therapy after their radiation (Figure). The median time to next therapy (TTNT) for these patients was 7.6 months (range 2.2 –73 months). Subsequent therapies included high dose chemotherapy with autologous hematopoietic stem cell transplant (n=10), low dose alkylator (n=2), thalidomide/lenalidomide (n=3), and more radiation (n=3). None of the baseline characteristics predicted for whether a patient would receive (or require) subsequent therapy, including the number of bone lesions at baseline. Conclusion: The results show that radiation is sufficient to produce clinical improvements and hematologic and radiographic responses approximately 50% of patients, even those with as many as 3 lesions. Disclosures: No relevant conflicts of interest to declare.

Abstract Introduction Del(17p) detected by fluorescence in situ hybridisation (FISH) of bone marrow plasma cells (BMPCs) is an adverse prognostic factor in patients with multiple myeloma (MM). While the natural history and prognostic factors in patients with del (17p) detected at diagnosis have been studied, the outcomes of patients who acquire del (17p) later in their course are not known. We aimed to define the outcomes of MM patients who acquire del(17p). Methods We reviewed the Dysproteinemia database at Mayo Clinic, MN to identify 80 patients with MM who had their first FISH test negative for del (17p), but acquired del(17p) later in the course of the disease. Sixty (75%) patients had their first FISH within 6 months (mo) of diagnosis; 20 (25%) patients had their first FISH more than 6 mo after diagnosis of MM. Del(17p) included del(17p13.1) and/or monosomy 17. We identified 2 control patients for each case, who were diagnosed during the same time period, but did not demonstrate del (17p) at any time during follow-up. Results Characteristics of patients at acquisition of del(17p) are shown in Table 1. Of these, 76 patients had relapsed and/or refractory MM; in 4 patients, del (17p) was detected after having attained a response to prior therapy. Seventy (87.5%) patients had del (17p13.1); 5 (6.3%) patients had monosomy 17; 1 (1.2%) patient had both del (17p13.1) and monosomy 17. Four (5.0%) patients had relative loss of 17p. High-risk translocations (HRT) [t(4;14), t(14;16) and t(14;20)] were present in 14 (17.5%) patients. The percentage of PCs with del(17p) were available in 75 patients. The median percentage of PCs with del(17p) was 76 (range, 9-100). Sixty two (77.5%) patients received exclusively chemotherapy as subsequent treatment; stem cell transplant (SCT) was part of the next treatment in 16 (20%) patients (allogeneic SCT in 1). Among 71 evaluable patients, ≥very good partial response and ≥partial response were attained in 24 (33.8%) and 35 (49.2%) patients respectively. The median progression free survival (PFS) from detection of del (17p) was 5.7 mo (95% CI, 3.5-7.8); overall survival (OS) was 18.2 mo (CI, 13.1-27.5). From a comparable time point, the OS for 160 controls was 56.2 mo (CI, 37.1-75.3) (P<0.001). The results were similar when patients were stratified based on variables at diagnosis such as age, presence of HRT, international staging system (ISS) stage, serum lactate dehydrogenase (LDH) and PC proliferative rate, and proteasome inhibitor (PI)-containing induction and SCT within a year of diagnosis and before acquisition of del(17p). Evaluating outcomes from initial diagnosis, PFS in the acquired del (17p) and control groups were 23.0 (CI, 20.2-25.8) and 30.2 (CI, 26.7-33.9) mo (P=0.028) and OS were 68.2 (CI, 50.8-74.8) and 111.6 (CI, 103.4-127.8) mo respectively (P<0.001). High LDH at baseline [OR- 4.31 (CI, 1.34-13.86)] predicted acquisition of del(17p) while presence of HRT showed borderline significance [OR- 2.02 (0.90-4.54)]. Age ≥65 yrs, ISS III vs. I/II stage, t(11;14), any trisomy, monosomy 13, BMPC%, initial therapy and SCT in first year and before acquiring del (17p) were not predictive. We performed univariable analysis with variables at detection of del(17p) such as age ≥65 vs. <65 years, serum creatinine >2 vs. ≤2 mg/dL, BMPC% ≥50 vs. <50%, ISS III vs. I/II stage, elevated vs. normal LDH, presence vs. absence of a HRT, presence vs. absence of monosomy 13, presence vs. absence of any trisomy, high vs. low PC proliferation rate, PI and immunomodulatory drug (IMiD)-refractoriness and percentage of PCs with del(17p) as independent variables to determine their association with PFS and OS. ISS stage III, high PC proliferative rate and PI and IMiD-refractoriness were selected after univariable analysis and included in the multivariable Cox proportional hazards model. A higher PC proliferative rate alone predicted shorter OS. None of the above factors were associated with shorter PFS. The median OS in those with high PC-proliferative rate from detection of del(17p) was 10.9 mo (CI, 6.0-17.1) vs. 37.2 mo (CI, 18.2-47.5) in those with low PC proliferative rate (P=0.005). Conclusion The prognosis of patients who acquire del (17p) is poor with OS of 6.5 years against 9 years from diagnosis in patients who do not acquire del (17p). This was valid across prognostic sub-groups. High PC proliferative rate was the only factor which impacted OS once patients acquired del(17p). Disclosures Kapoor: Celgene: Research Funding; Takeda: Research Funding. Gertz:Research to Practice: Consultancy; Teva: Consultancy; Ionis: Honoraria; annexon: Consultancy; Physicians Education Resource: Consultancy; Abbvie: Consultancy; spectrum: Consultancy, Honoraria; Prothena: Honoraria; Alnylam: Honoraria; Apellis: Consultancy; Medscape: Consultancy; Amgen: Consultancy; janssen: Consultancy; celgene: Consultancy. Lacy:Celgene: Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Millennium Takeda: Research Funding. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Russell:Vyriad: Equity Ownership. Kumar:AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract The plasma cell proliferative index (PCPI) provides an insight into plasma cell biology in plasma cell disorders. It recognizes cells that are actively synthesizing DNA and gives an indication of the proliferative rate of the malignant plasma cells.The PCPI has been shown to be a prognostic tool in patients with multiple myeloma and amyloidosis. We conducted a retrospective review analyzing the prognostic impact of PCPI in 306 patients with smoldering multiple myeloma (SMM). The median age was 66 (56-73) years and 61% (n=186) were males. The median follow-up for the entire cohort was 10.2 years (95% confidence interval: 9.0-10.9). One-hundred sixty-nine (55%) patients were alive at the time of study analysis while 118 (39%) had progressive disease. The median time to progression was 5.9 years (95% confidence interval: 4.8-8.2). Symptomatic events at the time of progression included anemia in 41% (n=48), bone complications in 37% (n=44), renal complications in 9% (n=11), hypercalcemia in 2% (n=2) and development of amyloidosis in 2% (n=2). Seventeen patients (14%) were categorized as having progression due to rapid progressive elevation in the serum free light chains (sFLC) and/or progressive increase in the size of their M-spike. The median time between the diagnosis and PCPI date was 0 months (interquartile range 0-1). An elevated PCPI was defined as a level >0.5%. Seventy-nine (26%) patients had an elevated PCPI. Patients with an elevated PCPI were significantly older (median age: 69 years for elevated PCPI vs 64 years for low PCPI (p= 0.008) and predictably had more proliferative disease with a higher rate of patients with bone marrow plasma cells >20% (48% for elevated PCPI vs 34% for low PCPI, p=0.03). An elevated PCPI predicted a shorter time to progression (TTP); median 3.0 years versus 7.1 years for those with a low PCPI (p= 0.0004). Within 24 months, the progression rate was significantly higher for patients with an elevated PCPI; 49% versus 20% (p<0.0001). We constructed two multivariable models using the conventional and recently proposed Mayo risk stratification tools. In both models, an elevated PCPI was an independent predictor of to multiple myeloma. PCPI is a valuable tool in risk stratifying patients with SMM and identifies patients with earlier progression who may benefit from closer follow up and consideration of early intervention trials. Disclosures Dispenzieri: Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Gertz:Research to Practice: Consultancy; spectrum: Consultancy, Honoraria; Abbvie: Consultancy; Amgen: Consultancy; janssen: Consultancy; Physicians Education Resource: Consultancy; Teva: Consultancy; celgene: Consultancy; annexon: Consultancy; Alnylam: Honoraria; Prothena: Honoraria; Medscape: Consultancy; Apellis: Consultancy; Ionis: Honoraria. Lacy:Celgene: Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding. Kapoor:Celgene: Research Funding; Takeda: Research Funding. Kumar:Oncopeptides: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract Introduction: IgM light chain amyloidosis (AL) is a rare complication of IgM associated disorders, with very limited data on biology and outcomes. Our study compares the clinical characteristics, laboratory findings and outcomes in a large cohort of patients with IgM vs. non-IgM AL to delineate the underlying disease biology of this entity. Methods: Patients with newly diagnosed AL (2006-15) were identified from a prospectively maintained institutional database and grouped by IgM heavy chain. Bone marrow (BM) morphology was reviewed by an expert hematopathologist (RLK). FISH testing included probes for t(11;14) and trisomies of odd numbered chromosomes. MYD88L265P testing was carried out by allele specific PCR and CXCR4WHIM mutation testing was performed by bridged nucleic acid (BNA)-enhanced Sanger sequencing. Results: Patients with IgM AL comprised 6.6% (75/1128) of the study cohort. Baseline characteristics are listed in Table 1. IgM AL patients were older and had a higher proportion of males. They had less frequent cardiac involvement (60 vs. 75%) and less frequent involvement of > 1 organ. Light chain burden was lower in this group (dFLC 12.5 vs. 22.7 mg/dL), while there was no difference in BM clonal cell percentage (10% each). Morphology: BM morphology in 71 patients with IgM AL revealed a pure plasma cell disorder (PPCD type) in 25% (n=18); low-grade B-cell lymphoma (LGBCL) with plasmacytic features (LPL type) in 62% (n=44) [well defined LPL: 38% (n=27), LGBCL with plasmacytic features: 24% (n=17)]; LGBCL, other: 6% (n=4). In the remaining 7%, three patients had other diagnoses and no BM disease in two patients. Median clonal cell % in LPL vs. PPCD type IgM AL was 20% vs. 5%, p<0.001. Genetics: In patients with IgM AL vs. non-IgM AL, t(11;14) was present in 27% vs. 49%, p=0.009 and trisomies in 9% vs. 24% of patients, p=0.06, respectively. In the IgM AL cohort, MYD88 mutation was seen in 56% (23/41) & CXCR4 mutation in 15% (5/34; S388 type: 3, other: 2) of patients. Importantly, MYD88 and CXCR4 mutations were found only in patients with LPL morphology, while t(11;14) was found only in the PPCD morphology group. There were no patients with both t(11;14) and MYD88 abnormalities (N=26 for both tested). Mutations seen in the LPL vs. PPCD type IgM AL were: MYD88, 88% (22/25) vs. 0% (0/14), p<0.001 and CXCR4, 26% (5/19) vs. 0% (0/13), p=0.02. Conversely, t(11;14) was seen in 0% (0/18) in LPL type vs. 60% (9/15) in PPCD type IgM AL, p <0.001. Treatment details were known in 63 patients with IgM AL; rituximab-based: 21 (33%), bortezomib/alkylator: 16 (25%), transplant 17 (27%), steroids: one and no treatment: 8 (13%). Treatment in IgM AL LPL type (n=36) was: rituximab based: 16 (44%),bortezomib/alkylator: 5 (14%), transplant: 10 (28%) and none: 5 (14%). In PPCD type [n=17), treatment was rituximab based: 2 (12%), bortezomib/alkylator: 8 (47%), transplant: 7 (41%). At 6 months, very good partial response or better was observed in 26% (10/39) vs. 41% (270/660) of patients with IgM vs. non-IgM AL, p=0.05. There was no difference in overall survival (OS) when all patients with IgM AL were compared to non-IgM AL (Fig 1a). However, when stratified by early (Stage 1/2) or advanced (stage 3/4) 2012 Mayo stage, patients with IgM AL fared worse (Fig 1b-c). On multivariate analysis, IgM AL was an independent predictor for inferior OS [HR with 95% CI: 1.6 (1.1-2.4), p=0.02] after adjusting for age, Mayo 2012 stage and type of therapy (transplant vs. not). However, when OS was adjusted for 6 month VGPR, there was no difference in OS for IgM AL vs. non IgM AL, p=0.2. In the IgM AL cohort, patients with LPL type IgM AL had inferior OS compared with PPCD type IgM AL, 21 vs. 82 months, p=0.01 (Fig 1d). Conclusions: Patients with IgM AL have distinct clinical and genetic features, with lower rates of cardiac involvement and a lower frequency of t(11;14) or trisomies compared with non-IgM AL. Even though IgM AL is a rare entity, we were able to delineate two distinct sub-types of IgM AL: LPL type and PPCD type, with implications for therapy and outcomes. Along with unique morphologic findings, presence of MYD88 and CXCR mutations was only seen in LPL type IgM AL and t(11;14) in PPCD type IgM AL. Despite lower cardiac involvement, IgM AL was associated with inferior OS outcomes, likely due to lower response rates, particularly in LPL IgM AL group, which had the lowest OS. Therapeutic approaches targeted towards disease biology to achieve deep responses are needed in this disorder. Disclosures Sidana: Janssen: Honoraria. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Lacy:Celgene: Research Funding. Kumar:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Roche: Research Funding; Novartis: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Gertz:Abbvie: Consultancy; Ionis: Honoraria; spectrum: Consultancy, Honoraria; Apellis: Consultancy; Amgen: Consultancy; Prothena: Honoraria; Teva: Consultancy; Alnylam: Honoraria; celgene: Consultancy; Medscape: Consultancy; janssen: Consultancy; Research to Practice: Consultancy; Physicians Education Resource: Consultancy; annexon: Consultancy.

Abstract Introduction Autologous stem cell transplantation (ASCT) plays a central role in the treatment of multiple myeloma (MM), even in the era of novel therapies (Gonsalves et al, 2018). Given the efficacy of the latter, as well as for logistical reasons, many patients opt to store their stem cells and delay ASCT until the time of progression. Delayed transplant does not appear to affect overall survival (OS) (Attal et al, 2017). However, in the "salvage" setting, the impact of treatment with additional chemotherapy prior to ASCT is unknown. One study, albeit in the front-line, suggested that in patients achieving less than a partial response (PR), additional induction prior to ASCT did not improve survival (Vij et al, 2015). The present study investigates the role of induction therapy prior to salvage ASCT. Methods We identified 380 patients who underwent ASCT >12 months after being diagnosed with MM from January 1, 2006 to July 1, 2017 at Mayo Clinic Rochester. 121 had a delayed ASCT, but no International Myeloma Working Group (IMWG) progression prior to ASCT and were excluded. Another 17 patients achieved less than PR prior to ASCT, thus were deemed primary refractory and excluded. Finally, 8 patients were excluded because they received a planned tandem ASCT. Thus, 234 patients were included in the present study, which was approved by the Mayo Clinic Institutional Review Board, in accordance with the Declaration of Helsinki. We refer to the time of progression prior to ASCT, after which we examined the use of pre-ASCT therapy, as T0 to avoid confusion. Time to next therapy (TNT) was defined as the time from ASCT (stem cell infusion, Day +0) to the initiation of a new therapy, not including planned consolidation or maintenance. Patients who were alive and had not received any new therapies, or died before receiving another therapy were censored at the time of last follow up, as of May 15, 2018. OS was defined as the time from Day +0 to death from any cause, with living patients censored at the time of last follow-up. TNT and OS were estimated using the Kaplan-Meier method and compared using the log-rank test. A Cox proportional hazard model was used for univariate and multivariate analysis. High-risk cytogenetics were defined as del(17/17p), t(4;14), t(14;16), and t(14;20). The Mann-Whitney U test and Fisher's Exact test were used to compare continuous and categorical variables, respectively. Statistical analysis was completed using JMP 13.0 (SAS Institute Inc., Cary, NC, USA). Results Of the 234 patients who underwent salvage ASCT, 188 were treated with additional chemotherapy after T0 (hereafter referred to as "pre-ASCT induction"), whereas 46 patients went directly to ASCT. Baseline characteristics were comparable, however more patients in the pre-ASCT induction group had >1 progression prior to ASCT (28% vs. 9%, p= .0065) and had a trend towards a shorter duration of response (DOR) prior to T0 (14.7 vs. 18.5 months, p= .12). Intuitively, the pre-ASCT induction group had a longer time from T0 to ASCT (5.3 vs. 2.3 months, p< .0001). The median TNT for the entire cohort of 234 patients from Day +0 was 17.2 months (95% CI, 14.8-19.7); median OS was 50.4 months (95% CI, 43.3-60.7). TNT and OS were comparable between the two treatment groups (Figure 1). After adjusting for other significant prognostic factors, such as DOR prior to T0 and the presence of high risk cytogenetics, treatment with pre-ASCT induction did not significantly affect TNT or OS (Table 1). However, among the 188 patients treated with pre-ASCT induction, the subsequent depth of response prior to ASCT significantly affected TNT (Figure 2A) and OS (Figure 2B). TNT at 1-year post ASCT was 79.2% for patients achieving a ≥VGPR, 62.1% in those who achieved a PR or stable disease, and 45.7% for patients who had relapsed/refractory MM at the time of ASCT or received >2 lines of pre-ASCT therapy (p= .0003). Interestingly, the time from diagnosis to T0 was comparable between these 3 groups (27 vs. 28 vs. 26 months, respectively, p= .26). Conclusions Many patients with MM do not undergo ASCT until disease progression. In our cohort of 234 patients who underwent salvage ASCT, outcomes were similar whether patients received pre-ASCT induction or not. However, among the 188 patients treated with pre-ASCT induction, deeper responses correlated with significantly longer TNT and OS after ASCT. Further research into the role of chemotherapy prior to delayed ASCT in the era of novel agents is warranted. Disclosures Gertz: annexon: Consultancy; Apellis: Consultancy; Medscape: Consultancy; Teva: Consultancy; janssen: Consultancy; Amgen: Consultancy; Physicians Education Resource: Consultancy; Alnylam: Honoraria; Research to Practice: Consultancy; Ionis: Honoraria; spectrum: Consultancy, Honoraria; celgene: Consultancy; Prothena: Honoraria; Abbvie: Consultancy. Lacy:Celgene: Research Funding. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Kapoor:Celgene: Research Funding; Takeda: Research Funding. Kumar:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract Background Limited data exist with respect to outcome and optimal therapeutic strategies in patients with central nervous system (CNS) involvement in multiple myeloma (MM). We present a single center experience of patients with myelomatous CNS involvement in newly diagnosed and relapsed / refractory MM. Methods Of 4060 patients with MM seen at Mayo Clinic, Rochester, MN between January, 1st 1998 and December, 31st 2012, 26 patients had identifiable CNS involvement confirmed by biopsy / presence of plasma cells in the cerebrospinal fluid (CSF) and/or identification of intraparenchymal or meningeal involvement by imaging (MRI/CT). Patients were risk stratified by mSMART (Mayo Stratification for Myeloma And Risk-adapted Therapy) criteria. Overall survival (OS) from diagnosis and the time of CNS involvement was calculated using the Kaplan-Meier method. Results Myelomatous CNS involvement occurred in 26 (0.6%) patients with MM of whom 3 were newly diagnosed. The median time to detection of CNS involvement was 24 months (range: 0-125) from diagnosis of MM. Median age at CNS myeloma diagnosis was 58 years (range 37-80) and 73% were male. Abnormally high LDH was observed in 11 out of 22 patients at the time of CNS involvement. Lumbar puncture was performed on 16 patients, 13 (81%) of whom had plasma cells in the CSF detected by cytology/flow-cytometry. Two patients, without evidence of plasma cells, had abnormally high CSF protein and 1 had normal CSF analysis. Of the 25 patients who underwent MRI, 16 (64%) had at least one of the following significant abnormalities; intraparenchymal disease (37%), leptomeningeal enhancement (68%) or direct extension of MM (31%). The neurological symptoms at or after diagnosis of CNS myeloma included headache (38%), cranial nerve palsy (38%), visual disturbance (38%), gait disturbance (35%), paresthesias (35%), limb weakness (31%), confusion (30%), nausea/vomiting (15%), dysarthria (12%), seizures (8%) and urinary incontinence (4%). Fluorescent in-situ hybridization (FISH n=7), cytogenetics (n=8) and/or plasma cell labeling index (PCLI n=12) were available in 18 patients prior to the diagnosis of CNS disease. Ten (56%) out of those 18 patients had high-risk features at least by one criterion. At the time of CNS involvement, six additional patients demonstrated high risk features [5 by PCLI (≥ 3%) and 1 by FISH]. Overall, 16 out of 26 (62%) patients were classified as high risk by mSMART criteria prior to or at the time of CNS involvement. Four (27%) out of 15 had a deletion p53 or monosomy 17 chromosomal abnormality. Median OS was 42 (95% CI, 19-55) months from the diagnosis of MM and 3 months (95% CI: 1-7.9) from the time of CNS involvement (Figure). OS of patients with high risk features was significantly worse (27 months) compared to standard risk disease (67 months, p=0.02) from diagnosis of MM. Eighteen patients received radiation therapy for CNS myeloma. Five of those patients also received intrathecal (MTX and ARA-C) therapy. One patient received intrathecal and systemic chemotherapy. Four patients did not receive any treatment. Novel agents, including bortezomib (23%), thalidomide (15%), and pomalidomide (4%) were administered to the patients post diagnosis of CNS disease. Six (23%) patients underwent autologous stem cell transplant post diagnosis of CNS disease with a median OS of 19 months (95% CI: 10-122 months) from the time of CNS involvement. Conclusion CNS involvement is a rare complication of MM that portends a poor survival outcome. It is likely that the rates in this study are an underestimate of the true incidence due the perceived futility of CNS directed therapy in this disease. Among those recognized, high-risk genetic and markers of increased proliferative activity, including deletion p53 / monosomy 17 and elevated PCLI (≥ 3%) appear to cluster in this cohort. Current therapeutic approaches are largely ineffective in managing this aggressive subset of myeloma patients. Disclosures: No relevant conflicts of interest to declare.