Citations

Background: The past two decades have seen an explosion in the development of new drugs for the treatment of myeloma, and previous studies have shown that these advances have translated into improved survival. It is unclear if we have continued to maintain the pace of improvement in the recent years. We designed this study to examine the patterns of survival in patients with newly diagnosed MM, specifically examining the impact on patient subgroups by age and disease risk. Patients and Methods: We included patients with newly diagnosed MM, who were seen at Mayo Clinic, Rochester between 2004 and 2018. We grouped them into three 5-year groups: group 1 (2004-2008), group 2 (2009-2013) and group 3 (2014-2018) to assess the trends over time. Only those who were seen within 6 months of diagnosis were included in the current cohort. Fluorescence in situ hybridization (FISH) was performed using clg based approach as previously described and high risk (HR) was defined as those with t(4;14), t(14;16), t(14;20) and del17p. Survival was estimated using the Kaplan-Meier method and curves were compared using the log rank test. The Cox proportional hazards model was used to examine the prognostic impact of various clinical and laboratory factors. Results: The study cohort had 3783 patients: 61% were male, median age was 64 years (range 22-96), 47% were ≥65 and 14% ≥75 years. There was no change over time in the median age or the gender distribution. No clear trends were evident across the groups in terms of the disease characteristics including high risk status. The patients in the cohort were divided into three 5 year groups: Group 1(2004-2008; n=1045), Group 2(2009-2013; n=1237) and Group 3(2014-2018; n=1501). The initial treatment regimen changed over time to include proteasome inhibitors (PI) and immunomodulatory drug (IMiD) based regimens with a PI-IMiD combination being 2%, 18% and 55% respectively in groups 1, 2 and 3 (Figure 1). The median follow-up for the entire cohort was 6.8 years (95% CI; 6.5,6.9), and for groups 1, 2 and 3 were 13 years, 8 years and 3.2 years respectively. The median OS for the entire group was 6.8 years (95% CI; 6.4, 7.2). The median OS from diagnosis has improved over time with the groups 1, 2, and 3 having a median OS (95% CI) of 5.5 years (5.1, 6.1), 7.3 years (6.7, 8.0) and NR respectively(P=0.0001) (Figure 2). We specifically looked at the 1, 2 and 3-year survival over the years and found a steady trend for improvement (Figure 3). When examining trends by age, those under 65 years had improvement in survival from group 1 to 2; median OS was 7.3 years, 10 years and NR for groups 1, 2 and 3 respectively (P=0.0001) . Those above 65 had major improvement from group 2 to 3; median OS was 4.4 years, 5.2 years and NR for groups 1,2 and 3 respectively (P=0.0001). When examined by FISH risk status, improvement in OS was seen among with Standard Risk (SR) status, especially during the last 5-year period. The median OS for patients with HR status was 3.5 years, 4.5 years and NR (P=0.07); and 7.6 years, 8.6 years and NR in patients with SR status (P=0.0012) for groups 1, 2 and 3 respectively. Conclusion: In a large cohort of patients with newly diagnosed MM, we have been able to demonstrate sustained improvement in OS over the years, likely driven by introduction of new drugs and continued use of transplant. The impact of newer generation of drugs, especially monoclonal antibodies is not reflected in this analysis and will likely become obvious over the next five years. The data will help identify the areas that require focus for continued improvements in order to derive the maximum impact on outcomes. Disclosures Kapoor: Celgene: Honoraria; Amgen: Research Funding; Sanofi: Consultancy, Research Funding; Janssen: Research Funding; Cellectar: Consultancy; GlaxoSmithKline: Research Funding; Takeda: Honoraria, Research Funding. Gertz:Alnylam: Other: personal fee; Prothena: Other: personal fee; Teva: Speakers Bureau; Johnson and Johnson: Speakers Bureau; DAVA oncology: Speakers Bureau; Proclara: Other; Aurora Bio: Other; Springer Publishing: Patents & Royalties; Sanofi: Other; Research to Practice: Other; Celgene: Other; Physicians Education Resource: Other: personal fee; Medscape: Other: personal fee, Speakers Bureau; Amgen: Other: personal fee; Appellis: Other: personal fee; Annexon: Other: personal fee; Spectrum: Other: personal fee, Research Funding; Janssen: Other: personal fee; Ionis/Akcea: Other: personal fee; Abbvie: Other. Dispenzieri:Intellia: Research Funding; Alnylam: Research Funding; Takeda: Research Funding; Pfizer: Research Funding; Janssen: Research Funding; Celgene: Research Funding. Dingli:Rigel: Consultancy; Bristol Myers Squibb: Research Funding; Apellis: Consultancy; Alexion: Consultancy; Sanofi-Genzyme: Consultancy; Karyopharm Therapeutics: Research Funding; Millenium: Consultancy; Janssen: Consultancy. Russell:Imanis: Other: Equity Ownership. Lin:Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Takeda: Research Funding; Legend BioTech: Consultancy; Merck: Research Funding; Vineti: Consultancy; Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gamida Cells: Consultancy. Kumar:Carsgen: Other, Research Funding; Adaptive Biotechnologies: Consultancy; Tenebio: Other, Research Funding; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Cellectar: Other; Genecentrix: Consultancy; Dr. Reddy's Laboratories: Honoraria; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Novartis: Research Funding; Kite Pharma: Consultancy, Research Funding; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; MedImmune: Research Funding; Sanofi: Research Funding; Karyopharm: Consultancy; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; BMS: Consultancy, Research Funding; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Merck: Consultancy, Research Funding; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments.

Background: BCMA targeted immunotherapy has yielded promising results for relapsed/refractory multiple myeloma (RRMM). TNB-383B is a BCMA x CD3 bispecific T-cell redirecting antibody incorporating a unique anti-CD3 moiety that preferentially activates effector over regulatory T-cells and uncouples cytokine release from anti-tumor activity, as well as 2 heavy-chain-only anti-BCMA moieties for a 2:1 tumor associated antigen to CD3 stoichiometry. Results from the ongoing phase 1 dose escalation and expansion First-in-Human (FIH) study of TNB-383B are presented (NCT03933735). Methods: Eligible patients have RRMM and have been exposed to at least 3 prior lines of therapy including a proteasome inhibitor, an immunomodulatory drug, and an anti-CD38 monoclonal antibody. Patients have been treated with escalating doses of TNB-383B infused IV over 1-2 hours Q3W (without step-up dosing). The primary objectives are to determine the safety/tolerability and clinical pharmacology of TNB-383B and to identify the MTD/RP2D. The study used a 3+3 design for dose escalation, with additional patients enrolled on cleared dose levels. Patients on earlier dose cohorts were allowed to increase to the highest cleared dose with investigator consensus. Responses were assessed by IMWG criteria and Adverse Events (AEs) were graded according to CTCAE v5.0. Minimal residual disease (MRD) assessment was performed via NGS on bone marrow samples in patients achieving a complete response (CR). Results: As of 13 July 2020, 38 subjects have been dosed with TNB-383B (0.025 - 40 mg). Demographics and disease characteristics at study entry are summarized in Table 1. The most common Gr 3/4 AEs were anemia (6/38; 16%) and thrombocytopenia (5/38; 13%). The most common drug-related AEs were CRS (8/38; 21%) and headache (5/38; 13%). One case of Gr 2 CRS was observed at 0.075 mg; all other CRS events were seen at 5.4 mg and above. Cases of CRS were grade 1 (5/8) or 2 (3/8) and occurred only after the first dose of TNB-383B. All but 3 subjects were managed with fluids and acetaminophen (the other 3 received 1 dose each of tocilizumab). One DLT, Gr3 confusion that resolved within 6 hours without sequelae was seen at the 20 mg dose in an additional patient enrolled on this cohort. No IRRs were observed. Dose modification was necessary in 1 subject for Gr 3 neutropenia associated with CRS; the subject escalated to their full dose after tolerating subsequent doses without incident. 5 subjects died from their underlying disease during follow-up. 15 subjects discontinued treatment, all of them for progressive disease. Preliminary PK data support Q3W dosing of TNB-383B. Activity was observed in one patient each at 0.2 mg and 1.8 mg; at doses of 5.4 - 40 mg an ORR of 52% (12/23) was observed. Depth and duration of response are summarized in Table 2. Conclusions: TNB-383B is well tolerated at doses up to 40 mg, without the need for step/split dosing. A preliminary ORR of 52% (12/23) was observed at doses ≥ 5.4 mg, including deep (6 PR / 3 VGPR / 3 CR) and durable (up to 24 weeks) responses despite dosing only every 3 weeks. Enrollment into the dose escalation arm is ongoing; updated data will be presented at the meeting. Disclosures Rodriguez: BMS, Takeda, Amgen: Consultancy, Speakers Bureau. D'Souza:Amgen: Research Funding; Akcea: Consultancy; Pfizer: Consultancy; Teneobio: Research Funding; Imbrium: Consultancy; Merck: Research Funding; Janssen: Consultancy. Shah:GSK, Amgen, Indapta Therapeutics, Sanofi, BMS, CareDx, Kite, Karyopharm: Consultancy; BMS, Janssen, Bluebird Bio, Sutro Biopharma, Teneobio, Poseida, Nektar: Research Funding. Voorhees:Bristol-Myers Squibb: Other: Personal fees; Adaptive Biotechnologies: Other: Personal fees; Novartis: Other: Personal fees; Celgene: Other: Personal fees; Janssen: Other: Personal fees; Oncopeptides: Other: Personal fees; TeneoBio: Other: Personal fees; Levine Cancer Institute, Atrium Health: Current Employment. Buelow:Teneobio, Inc.: Current Employment, Current equity holder in private company. Kumar:Karyopharm: Consultancy; Tenebio: Other, Research Funding; Sanofi: Research Funding; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Genecentrix: Consultancy; Dr. Reddy's Laboratories: Honoraria; Adaptive Biotechnologies: Consultancy; Merck: Consultancy, Research Funding; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; BMS: Consultancy, Research Funding; Cellectar: Other; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Carsgen: Other, Research Funding; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Novartis: Research Funding; MedImmune: Research Funding; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Kite Pharma: Consultancy, Research Funding.

Introduction: Daratumumab (DARA) is a human, CD38-targeting, IgG1κ monoclonal antibody approved as monotherapy in relapsed/refractory multiple myeloma (RRMM) and in combination with standard of care for RRMM and NDMM. The addition of DARA to standard-of-care regimens in phase 3 studies has consistently improved progression-free survival (PFS) and led to deep and durable responses, including higher rates of minimal residual disease (MRD) negativity compared with standard of care. In the primary analysis of the phase 3 MAIA study (median follow-up, 28.0 mo), D-Rd vs Rd significantly improved PFS and MRD-negativity rates in transplant-ineligible NDMM (Facon T, N Engl J Med 2019). With longer follow-up (36.4 mo), D-Rd maintained a PFS benefit and deeper and more durable responses vs Rd alone (Bahlis N, Blood 2019. 134[Suppl 1]:1875). Here, we report updated efficacy and safety findings from MAIA after approximately 4 years of follow-up. Methods: Patients with NDMM ineligible for high-dose chemotherapy and autologous stem cell transplantation due to age ≥65 years or comorbidities were randomly assigned (1:1) to receive Rd ± DARA. Stratification factors included International Staging System stage (ISS [I vs II vs III]), region (North America vs other), and age (<75 vs ≥75 years). All patients received 28-day cycles of Rd (R: 25 mg orally once daily on Days 1-21; d: 40 mg orally on Days 1, 8, 15 and 22). In the D-Rd arm, DARA (16 mg/kg intravenously) was given weekly for Cycles 1-2, every 2 weeks in Cycles 3-6, and every 4 weeks thereafter. Patients were treated until disease progression or unacceptable toxicity in both treatment arms. The primary endpoint was PFS. Key secondary endpoints included overall response rate (ORR), MRD-negativity rate (10‒5 sensitivity, clonoSEQ® version 2.0), and safety. PFS on the next line of therapy (PFS2), defined as the time from randomization to progression on the next subsequent line of therapy or death, was also measured. Results: A total of 737 patients were randomized (D-Rd, n = 368; Rd, n = 369). Patient baseline characteristics were well balanced between the two treatment arms. Median (range) age was 73 (45-90) years, with 44% of patients ≥75 years of age. 27%, 43%, and 29% of all patients were ISS stage I, II, and III, respectively. Among 642 patients evaluable for FISH/karyotyping analysis, 86% had standard and 14% had high cytogenetic risk. After a median follow-up of 47.9 months, 176 (48%) and 273 (75%) patients discontinued study treatment in the D-Rd vs Rd groups, respectively, with 85 (23%) and 113 (31%) patients discontinuing treatment due to progressive disease. PFS remained improved for D-Rd vs Rd (median, not reached [NR] vs 34 mo; HR, 0.54; 95% CI, 0.43-0.67; P<0.0001; Figure). The estimated 48-month PFS rate was 60% with D-Rd vs 38% with Rd. The PFS benefit of D-Rd in prespecified subgroups, including patients with high cytogenetic risk, was generally consistent with overall results. Adding DARA to Rd continued to result in deeper responses with higher rates of ≥CR and ≥very good partial response (VGPR; Table). Median duration of response among responders was NR with D-Rd vs 44 months with Rd. Median PFS2 was NR vs 51 months with D-Rd vs Rd, respectively (HR, 0.65; 95% CI, 0.52-0.83; P=0.0005); follow up is ongoing. 107 (29%) patients in the D-Rd group and 132 (36%) in the Rd group have discontinued the study due to death. Grade 3/4 treatment-emergent adverse events (TEAEs; D-Rd/Rd) occurring in ≥10% of patients were neutropenia (53%/37%), pneumonia (18%/11%), anemia (16%/21%), lymphopenia (16%/11%), hypokalemia (12%/10%), leukopenia (11%/6%), and cataract (11%/10%); grade 3/4 infection rates were 40%/29%. The most common serious TEAE was pneumonia (17%/11%). 11% of patients in the D-Rd arm and 22% in the Rd arm discontinued treatment due to an adverse event. The complete updated data set will be presented at the meeting with additional efficacy endpoints, including MRD-negativity rate. Conclusion : After 48 months follow up, the addition of DARA to Rd continues to demonstrate a superior PFS benefit. More patients continued to have deeper and more durable responses with D-Rd vs Rd alone. No new safety concerns were observed with longer follow-up. These results continue to support the use of D-Rd in the first line of treatment for patients with transplant-ineligible NDMM. Disclosures Kumar: Sanofi: Research Funding; Carsgen: Other, Research Funding; Cellectar: Other; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Novartis: Research Funding; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Karyopharm: Consultancy; Merck: Consultancy, Research Funding; Kite Pharma: Consultancy, Research Funding; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Tenebio: Other, Research Funding; BMS: Consultancy, Research Funding; MedImmune: Research Funding; Genecentrix: Consultancy; Dr. Reddy's Laboratories: Honoraria; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Adaptive Biotechnologies: Consultancy. Facon:Celgene, Janssen, Takeda, Amgen, Roche, Karyopharm, Oncopeptides, BMS, Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Usmani:Abbvie: Consultancy; Janssen: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; Takeda: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Celgene: Other; GSK: Consultancy, Research Funding; Merck: Consultancy, Research Funding; BMS, Celgene: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; Amgen: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; SkylineDX: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Pharmacyclics: Research Funding; Incyte: Research Funding; Array Biopharma: Research Funding. Plesner:Janssen: Consultancy. Orlowski:Founder of Asylia Therapeutics, Inc., with associated patents and an equity interest, though this technology does not bear on the current submission.: Current equity holder in private company, Patents & Royalties; STATinMED Research: Consultancy; Laboratory research funding from BioTheryX, and clinical research funding from CARsgen Therapeutics, Celgene, Exelixis, Janssen Biotech, Sanofi-Aventis, Takeda Pharmaceuticals North America, Inc.: Research Funding; Amgen, Inc., AstraZeneca, BMS, Celgene, EcoR1 Capital LLC, Forma Therapeutics, Genzyme, GSK Biologicals, Ionis Pharmaceuticals, Inc., Janssen Biotech, Juno Therapeutics, Kite Pharma, Legend Biotech USA, Molecular Partners, Regeneron Pharmaceuticals, Inc.,: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi-Aventis, Servier, Takeda Pharmaceuticals North America, Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees. Touzeau:Takeda: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; Abbvie: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Amgen: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; GlaxoSmithKline: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Research Funding. Bahlis:BMS/Celgene and Janssen: Consultancy, Honoraria, Other: Travel, Accomodations, Research Funding; Genentech: Consultancy, Honoraria; GSK: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Karyopharm Therapeutics: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria. Goldschmidt:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants and/or provision of Investigational Medicinal Product:, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Johns Hopkins University: Other: Grants and/or provision of Investigational Medicinal Product; Incyte: Research Funding; University Hospital Heidelberg, Internal Medicine V and National Center for Tumor Diseases (NCT), Heidelberg, Germany: Current Employment; GlaxoSmithKline (GSK): Honoraria; Adaptive Biotechnology: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants and/or provision of Investigational Medicinal Product, Research Funding; Mundipharma GmbH: Research Funding; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding; Novartis: Honoraria, Research Funding; Chugai: Honoraria, Other: Grants and/or provision of Investigational Medicinal Product:, Research Funding; Dietmar-Hopp-Foundation: Other: Grants and/or provision of Investigational Medicinal Product:; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants and/or provision of Investigational Medicinal Product:, Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants and/or provision of Investigational Medicinal Product:, Research Funding; Molecular Partners: Research Funding; Merck Sharp and Dohme (MSD): Research Funding. O'Dwyer:Celgene: Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); BMS: Research Funding; Carrick Therapeutics: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Janssen: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); AbbVie: Consultancy; ONK Therapeutics: Consultancy, Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Venner:Celgene, Amgen: Research Funding; Janssen, BMS/Celgene, Sanofi, Takeda, Amgen: Honoraria. Weisel:Adaptive: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria; GlaxoSmithKline: Honoraria; Takeda: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria. Hulin:Celgene/Bristol-Myers Squibb, Janssen, GlaxoSmithKline, and Takeda: Honoraria. Karlin:GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, personal fees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, personal fees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, personal fees; Celgene: Other: Personal fees; Sanofi: Honoraria; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support. Preis:Janssen: Other: for factor XI inhibitor. Broyl:Janssen, Celgene, Takeda, Amgen: Honoraria. Hansson:Amgen, Celgene, Takeda, Janssen Cilag: Consultancy. Krevvata:Janssen: Current Employment. Wang:Janssen: Current Employment. Van Rampelbergh:Janssen: Current Employment. Ukropec:Janssen: Current Employment, Current equity holder in publicly-traded company. Uhlar:Janssen: Current Employment, Current equity holder in publicly-traded company. Kobos:Janssen: Current Employment, Current equity holder in publicly-traded company. Perrot:Amgen, BMS/Celgene, Janssen, Sanofi, Takeda: Consultancy, Honoraria, Research Funding.

Background: Within the heterogeneous genomic landscape of multiple myeloma (MM), clonal evolution including the acquisition of risk-defining mutations and chromosomal abnormalities is a recurrent event and can be detected by fluorescence in situ hybridization (FISH). The effects of acquired abnormalities on clinical outcomes have not been well defined. We previously reported that patients who acquired 17p deletion [del(17p)] during the course of their disease had a significantly reduced overall survival (OS) by 38 months compared to patients who did not acquire del17p (Lakshman et al 2019). Similarly, while de novo gain of the long arm of chromosome 1 (1q22 gain) is a known high-risk aberration associated with significantly shorter OS and progression-free survival (PFS) in MM, the prognostic significance of acquired 1q22 gain has not been described. The primary objective of this study was to analyze factors predictive for acquired 1q22 gain and determine its impact on survival. Methods: We identified MM patients from the Mayo Clinic Dysproteinemia Database who had at least one follow up FISH performed ≥6 months from diagnosis. The clinical characteristics, concomitant cytogenetic abnormalities, first line treatments administered, and OS were compared between patients with acquired 1q22 gain and patients who did not acquire this abnormality. The Mayo Clinic IRB approved this study. Results: A total of 1041 MM patients met the inclusion criteria. Of these, 63 patients (6.1%) had acquired 1q22 gain, defined as being negative for 1q22 gain on initial FISH at diagnosis and having this abnormality detected on subsequent FISH. Median age at diagnosis was 59 years and 56% were male. Median time to acquisition of 1q22 gain was 60 months (range 8-140 months). We identified one control patient for each case who was diagnosed within one year of the case and had a subsequent FISH performed at a similar duration from diagnosis. Patients with acquired 1q22 gain had similar baseline characteristics except for a higher proportion of high-risk (HR) FISH at diagnosis [t(4;14), t(14;16), t(14;20), and del(17p13)] when compared to controls (27% HR FISH versus 6% HR FISH; P<0.01). 1q22 gain was concomitantly present with trisomies in 33 patients (54%), monosomy 13 in 24 patients (39%), t(4;14) in 8 patients (13%), and del(17p13) in 7 patients (12%). All patients received treatment prior to acquisition of 1q22 gain. Of the 63 patients, first line induction therapy consisted of proteasome inhibitor (PI) with steroid in 43%, immunomodulatory drugs (IMiD) with steroid in 40%, and PI + IMiD with steroid in 17% of patients. 54 patients (85%) received upfront stem cell transplant (SCT) (median 5.9 months to SCT), compared to 50 patients (79%) in the control group who received SCT. The median follow up of all 126 patients was 6.8 years. There was a statistically significant reduction in median OS from diagnosis in patients with acquired 1q22 gain compared to the control group (10.8 years versus 13.0 years; P = 0.02; Figure 1). Predictors of acquisition of 1q22 gain were identified using a case-control method. Age ≥70 at diagnosis and presence of HR FISH at baseline appeared to increase the risk of acquiring 1q22 gain. Conclusion: Acquisition of 1q22 gain is a relatively uncommon occurrence, but notably reduced OS by 2.2 years compared to patients who did not acquire 1q22 during the course of their disease (P = 0.02). Older age and the presence of HR FISH at diagnosis increased the risk of acquisition of 1q22 gain. The presence of high-risk translocations at baseline suggests that acquisition of 1q22 gain occurs in the context of more aggressive disease biology. Disclosures Kapoor: Cellectar: Consultancy; Celgene: Honoraria; Janssen: Research Funding; Sanofi: Consultancy, Research Funding; Amgen: Research Funding; Takeda: Honoraria, Research Funding; GlaxoSmithKline: Research Funding. Dispenzieri:Alnylam: Research Funding; Pfizer: Research Funding; Celgene: Research Funding; Takeda: Research Funding; Intellia: Research Funding; Janssen: Research Funding. Gertz:Prothena: Consultancy; Celgene: Consultancy; Johnson and Johnson: Speakers Bureau; DAVA oncology: Speakers Bureau; Advisory Board for Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Advisory Board for Proclara: Membership on an entity's Board of Directors or advisory committees; i3Health: Consultancy; Springer Publishing: Patents & Royalties; Amyloidosis Foundation: Research Funding; International Waldenstrom Foundation: Research Funding; NCI SPORE MM: Research Funding; Ionis/Akcea: Consultancy; Physicians Education Resource: Consultancy; Medscape: Consultancy, Speakers Bureau; Amgen: Consultancy; Appellis: Consultancy; Annexon: Consultancy; Spectrum: Consultancy, Research Funding; Janssen: Consultancy; Sanofi: Consultancy; Data Safety Monitoring board from Abbvie: Membership on an entity's Board of Directors or advisory committees; Alnylam: Consultancy. Dingli:Apellis: Consultancy; Rigel: Consultancy; Millenium: Consultancy; Bristol Myers Squibb: Research Funding; Karyopharm Therapeutics: Research Funding; Sanofi-Genzyme: Consultancy; Alexion: Consultancy; Janssen: Consultancy. Lin:Novartis: Consultancy; Celgene: Consultancy, Research Funding; Bluebird Bio: Consultancy, Research Funding; Juno: Consultancy; Merck: Research Funding; Takeda: Research Funding; Gamida Cells: Consultancy; Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Vineti: Consultancy; Legend BioTech: Consultancy; Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding. Kumar:Cellectar: Other; Genecentrix: Consultancy; Dr. Reddy's Laboratories: Honoraria; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; BMS: Consultancy, Research Funding; Sanofi: Research Funding; Karyopharm: Consultancy; MedImmune: Research Funding; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Novartis: Research Funding; Kite Pharma: Consultancy, Research Funding; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Adaptive Biotechnologies: Consultancy; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Merck: Consultancy, Research Funding; Carsgen: Other, Research Funding; Tenebio: Other, Research Funding.

Introduction: First degree relatives of patients with monoclonal gammopathy of undetermined significance (MGUS) or multiple myeloma (MM), and African Americans, have an increased risk of having MGUS and MM compared to the general population. However, current guidelines do not advocate for screening family members of MM for plasma cell disorders (PCD). Understanding the epidemiology of familial plasma cell disorders (PCDs) is essential in order to identify people at highest risk of developing PCDs who may benefit from targeted screening strategies. The aims of this study were to assess the prevalence of MM patients with a family history of PCD, and the implications of a family history of PCD on the overall survival (OS) of MM patients. Methods: We retrospectively reviewed the electronic medical records of patients with symptomatic MM followed at Mayo Clinic and diagnosed between January 1989 and June 2019. Clinical notes were reviewed for documentation pertaining to family history of PCDs. Kaplan Meier survival analysis was used to assess the OS, where OS was calculated from the date of diagnosis of symptomatic MM until death; patients were censored if they were alive at the date of last follow up. A Cox proportional hazards model was used to provide risk estimates for OS. Results: A total of 8403 patients with symptomatic MM were included in this study. Family history was documented in 1521 patients, and 291 patients (3.5% of all patients, 19% of those with any documented family history) had a documented family member with a PCD. The median age at diagnosis of symptomatic MM was significantly lower in patients with (n=291) versus without (n= 8112) a family history of PCD (60.9 versus 63.6 years, p<0.0001). The median OS of MM patients with a family history of PCD was significantly longer than MM patients without a family history of PCD (8.1 versus 4.9 years, respectively, with p<0.0001, see figure 1). Using a multivariable Cox proportional hazards model, MM patients with a family history of PCD had a significantly lower risk of death compared to those without a family history of PCD (HR 0.66, 95% CI 0.55-0.78, p<0.0001) even after adjusting for sex, age at diagnosis (above versus below age 65), self-reported race (African American versus not African American), or date of diagnosis (before versus after 2010). When restricting the analyses to the 1521 patients with clearly documented family history, the survival benefit amongst patients with versus without a family history of PCD was similar. In probands with a PCD family history, 182 (63%) had a first degree relative with PCD, whereas 109 (37%) had a second degree relative with PCD. The most common reported PCD amongst family members was MM (figure 2). Nineteen (6.5%) probands with a family history of PCD had 2 or more relatives with a PCD (6 MM patients had 2 or more first degree relatives, 5 MM patients had at least 1 first and 1 second degree relative, and 8 MM patients had 2 or more second degree relatives with a PCD history). There was no significant difference in the median OS between MM patients with a first degree versus second degree relative with PCD (HR 1.03, 95% CI 0.74-1.46, p=0.837), or MM patients with 1 versus 2 or more relatives with PCD (HR 1.01, 95% CI 0.53-1.96, p=0.962). Conclusion: We reviewed patients with symptomatic MM seen at Mayo Clinic over the last 30 years and found that the prevalence of patients with a documented family history of PCD was 3.5%. MM patients with a family history of PCD were diagnosed with MM at a younger age and survived longer than patients without a family history of PCD. Further work is needed to understand factors underlying the survival benefit in patients with a family history of PCD, and whether they present with less aggressive or less advanced disease at diagnosis. Disclosures Dispenzieri: Intellia: Research Funding; Alnylam: Research Funding; Pfizer: Research Funding; Takeda: Research Funding; Celgene: Research Funding; Janssen: Research Funding. Kapoor:Sanofi: Consultancy, Research Funding; Cellectar: Consultancy; Janssen: Research Funding; Amgen: Research Funding; Takeda: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Celgene: Honoraria. Gertz:Spectrum: Other: personal fee, Research Funding; Janssen: Other: personal fee; Abbvie: Other; Amgen: Other: personal fee; Physicians Education Resource: Other: personal fee; Medscape: Other: personal fee, Speakers Bureau; Prothena: Other: personal fee; Teva: Speakers Bureau; Celgene: Other; Research to Practice: Other; Sanofi: Other; DAVA oncology: Speakers Bureau; Annexon: Other: personal fee; Appellis: Other: personal fee; Ionis/Akcea: Other: personal fee; Alnylam: Other: personal fee; Aurora Bio: Other; Proclara: Other; Johnson and Johnson: Speakers Bureau; Springer Publishing: Patents & Royalties. Kumar:Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Novartis: Research Funding; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Carsgen: Other, Research Funding; Cellectar: Other; Dr. Reddy's Laboratories: Honoraria; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; BMS: Consultancy, Research Funding; Karyopharm: Consultancy; MedImmune: Research Funding; Sanofi: Research Funding; Tenebio: Other, Research Funding; Kite Pharma: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy; Genecentrix: Consultancy; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Merck: Consultancy, Research Funding; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments.

Introduction: Since 2018, immunoenrichment-based matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), termed MASS-FIX, has replaced immunofixation for the detection and isotyping of serum monoclonal proteins at Mayo Clinic. MASS-FIX has advantages including increased sensitivity, specificity, and the ability to distinguish therapeutic monoclonal antibodies. Herein, we report the laboratory characteristics and distribution of diagnoses of patients tested clinically at Mayo Clinic. Methods: MASS-FIX was performed on patient samples as previously described (Kohlhagen et. al. Clin Chem Lab 2020). Demographics and laboratory data, including quantitative M-spike, serum free light chains (FLC), and quantitative immunoglobulins at the time of MASS-FIX were recorded. For patients with multiple samples during the study period, only the initial MASS-FIX was evaluated. We identified 9195 unique patients with MASS-FIX performed between 7/24/2018 and 3/6/2020. Seven-thousand nine hundred and forty-six patients provided consent for study enrollment, and 7689 had data available on index diagnosis. Given considerable variability in the interpretation of diagnostic criteria for light chain (LC) MGUS, patients with this diagnosis (1360, 18%) were excluded. Patients were considered to have negative results (2211 in total) on MASS-FIX if: 1) no monoclonal protein was identified (1081, 49%); 2) the interpretation was "cannot rule out monoclonal protein" (945, 43%); 3) multiple, nonspecific spectral peaks were identified consistent with immune reconstitution (29, 1%); or 4) the only monoclonal protein identified was consistent with a therapeutic monoclonal antibody (156, 7%). Results: The final cohort consisted of 4118 patients with a positive MASS-FIX and 2211 patients with a negative MASS-FIX, all in the setting of underlying PCDs. Figure 1 illustrates the numbers and percentages of patients who are MASS-FIX positive versus MASS-FIX negative by diagnosis. MGUS and multiple myeloma (MM) were the most common diagnoses overall, and both were more common in the MASS-FIX positive cohort. More than 90% of patients with Waldenstrom's macroglobulinemia (WM), smoldering WM, smoldering MM, and cold agglutinin disease were positive by MASS-FIX. For MASS-FIX positive patients, IgG isotype was identified in 2575 patients (63%), IgA in 703 (17%) and IgM in 710 (17%). Bence Jones proteinemia was identified in 283 patients (7%) with lambda restriction being the most common (57%). 3625 patients (88%) had a monoclonal pattern, 228 patients (6%) had a bi-clonal pattern, and 7 (<1%) had a tri-clonal pattern. The majority of patients (58%) were kappa LC restricted by MASS-FIX, 222 (5%) had N-glycosylated LC, and 2 patients (<1%) had a heavy chain with no light chain. Conclusions: This single institution experience illustrates the practicality of MASS-FIX in detecting and following monoclonal proteins for a wide range of PCDs in a tertiary center. In this cohort, the percentage of patients who were MASS-FIX positive varied by diagnosis, reflecting cross sectional sampling of patients throughout their disease course. Disclosures Gertz: Research to Practice: Other; Springer Publishing: Patents & Royalties; Aurora Bio: Other; Johnson and Johnson: Speakers Bureau; Sanofi: Other; Amgen: Other: personal fee; Appellis: Other: personal fee; Annexon: Other: personal fee; Spectrum: Other: personal fee, Research Funding; Janssen: Other: personal fee; Prothena: Other: personal fee; Alnylam: Other: personal fee; Ionis/Akcea: Other: personal fee; Proclara: Other; DAVA oncology: Speakers Bureau; Celgene: Other; Teva: Speakers Bureau; Abbvie: Other; Physicians Education Resource: Other: personal fee; Medscape: Other: personal fee, Speakers Bureau. Kumar:AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Dr. Reddy's Laboratories: Honoraria; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Carsgen: Other, Research Funding; Karyopharm: Consultancy; Merck: Consultancy, Research Funding; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Kite Pharma: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Genecentrix: Consultancy; Adaptive Biotechnologies: Consultancy; Novartis: Research Funding; MedImmune: Research Funding; Sanofi: Research Funding; Tenebio: Other, Research Funding; Cellectar: Other; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments. Kapoor:Sanofi: Consultancy, Research Funding; Amgen: Research Funding; Takeda: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Cellectar: Consultancy; Janssen: Research Funding; Celgene: Honoraria. Dingli:Karyopharm Therapeutics: Research Funding; Bristol Myers Squibb: Research Funding; Rigel: Consultancy; Alexion: Consultancy; Sanofi-Genzyme: Consultancy; Janssen: Consultancy; Apellis: Consultancy; Millenium: Consultancy. Lin:Merck: Research Funding; Legend BioTech: Consultancy; Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Gamida Cells: Consultancy; Takeda: Research Funding; Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Vineti: Consultancy. Murray:The Binding Site: Patents & Royalties: Patent Use of Mass Spec to identify monoclonal proteins licensed to The Binding Site. Dispenzieri:Alnylam, Intellia, Janssen, Takeda, Pfizer, Prothena, Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Introduction Amyloidosis is a disease caused by aggregates of misfolded insoluble proteins that accumulate extracellularly and impair organ function. The most common type of systemic amyloidosis is immunoglobulin light chain (AL), which typically involves the heart, kidneys, nerves, liver, gastrointestinal tract and soft tissue. Retroperitoneal involvement in the setting of systemic AL amyloidosis is rare and only published as case reports. Aim To report characteristics and outcomes of AL amyloidosis patients that had retroperitoneal deposition of amyloid in the novel agent era. Methods Retrospective study of all consecutive systemic AL amyloidosis patients with retroperitoneal involvement at all three Mayo Clinic sites and at Davidoff cancer center, a tertiary hospital in Israel. All patients were diagnosed with retroperitoneal involvement based on computerized tomography (CT) scans. All patients had biopsy proof of amyloidosis with Congo red staining. Patients that were diagnosed with localized amyloidosis of the bladder or ureter and patients that did not receive systemic treatment were excluded. Results We identified 11 patients with systemic AL amyloidosis and retroperitoneal involvement between January 2001 and December 2018. Median age at diagnosis was 65 years (range 50-72). Ten were male (91%) and one was female. Five patients had amyloid secondary to B cell lymphoma (4 Waldenstrom macroglobulinemia and 1 had follicular lymphoma). The involved light chain was lambda in 7 patients and kappa in 4 patients. All patients were diagnosed with retroperitoneal involvement of amyloidosis at presentation (not at progression). In 10 out of the 11 patients, amyloidosis in the retroperitoneum was confirmed by a core biopsy of the retroperitoneal tissue. Significant unintentional weight loss (more than 5 kg) at presentation was documented in six patients (55%). Seven patients (64%) had enlarged lymph nodes on the CT scan. Three patients had CT finding of calcifications, and the distribution pattern was diffuse in 7 patients (64%), while 4 patients presented with a mesenteric mass. Six patients (55%) had evidence of amyloid deposits in the bone marrow and 3 patients (27%) had a positive fat pad. Periorbital purpura was observed in one patient and none had macroglossia. Therapy regimens used are described in table 1. Five patients underwent an autologous stem cell transplantation (ASCT). Eight patients (72%) presented with unilateral (N=2) or bilateral (N=6) hydronephrosis and 7 had nephrostomy tubes or stents inserted. The median follow-up from stent/nephrostomy tube insertion was 33 months (IQR 8-91). Regression of the deposition was documented in one patient and one patient was able to have his nephrostomy tube removed. One patient (9%) developed end stage renal disease requiring dialysis. Data regarding hematologic response rates were available for 9 patients and all responded and achieved hematologic PR or better. The median follow-up for all surviving patients was 91 months (IQR 27-179). Seven of the patients are currently alive. The median OS from diagnosis was 150 months. Figure 1 shows typical diffuse retroperitoneal involvement of AL amyloidosis on a CT scan. Review of the literature revealed 5 cases of retroperitoneal involvement of systemic AL amyloidosis. Most were reports published before routine typing of amyloid. Four of the five cases (80%) were male. The ages ranged from 46 to 80 years. Four of the five cases (80%) presented with weight loss. Two patients had calcifications on the CT scans, and one had a large pleural effusion. Conclusions We report a multicenter case series of 11 patients diagnosed with systemic AL amyloidosis with retroperitoneal involvement, all received systemic chemotherapy. We found male predominance in our cohort. Eight patients presented with hydronephrosis, and only one patient had the nephrostomy tube removed successfully after systemic therapy. ORR was 100% and median OS from diagnosis was 150 months, suggesting that retroperitoneal deposition might confer improved prognosis compared to the general amyloid population. Disclosures Kumar: Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Merck: Consultancy, Research Funding; Dr. Reddy's Laboratories: Honoraria; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Sanofi: Research Funding; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Karyopharm: Consultancy; BMS: Consultancy, Research Funding; Carsgen: Other, Research Funding; Genecentrix: Consultancy; Cellectar: Other; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Adaptive Biotechnologies: Consultancy; MedImmune: Research Funding; Novartis: Research Funding; Kite Pharma: Consultancy, Research Funding; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Tenebio: Other, Research Funding; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments. Dispenzieri:Intellia: Research Funding; Janssen: Research Funding; Celgene: Research Funding; Takeda: Research Funding; Alnylam: Research Funding; Pfizer: Research Funding. Dingli:Rigel: Consultancy; Bristol Myers Squibb: Research Funding; Alexion: Consultancy; Apellis: Consultancy; Millenium: Consultancy; Sanofi-Genzyme: Consultancy; Janssen: Consultancy; Karyopharm Therapeutics: Research Funding. Kapoor:Amgen: Research Funding; Sanofi: Consultancy, Research Funding; Janssen: Research Funding; GlaxoSmithKline: Research Funding; Celgene: Honoraria; Cellectar: Consultancy; Takeda: Honoraria, Research Funding. Gertz:DAVA oncology: Speakers Bureau; Appellis: Other: personal fee; Proclara: Other; Medscape: Other: personal fee, Speakers Bureau; Springer Publishing: Patents & Royalties; Annexon: Other: personal fee; Research to Practice: Other; Celgene: Other; Prothena: Other: personal fee; Spectrum: Other: personal fee, Research Funding; Physicians Education Resource: Other: personal fee; Abbvie: Other; Johnson and Johnson: Speakers Bureau; Teva: Speakers Bureau; Janssen: Other: personal fee; Amgen: Other: personal fee; Alnylam: Other: personal fee; Ionis/Akcea: Other: personal fee; Aurora Bio: Other; Sanofi: Other.

Background: Multiple myeloma (MM) remains an incurable plasma cell (PC) malignancy. Despite improvements in clinical outcomes, variability in treatment response exists. Some patients experience innate resistance, while others develop resistance over the course of treatment. Identifying signatures of treatment response and resistance is essential to predicting effective treatment strategies. Given the phenotypic clonal heterogeneity observed in MM, we hypothesize that resistant and sensitive subpopulations have unique phenotypic signatures. We used mass cytometry (CyTOF) to characterize primary MM samples and correlated their phenotypic signatures with treatment response. Methods: We characterized 102 primary MM samples by CyTOF using 37 antibodies (see figure). Frozen whole BM specimens were thawed, stained with antibodies, barcoded, and analyzed on a Helios mass cytometer. Data was processed using Cytobank or Pathsetter and analyzed using t-distributed stochastic neighbor embedding (t-SNE) algorithm. T-SNE plots for CD45+ cells were created using lineage defining markers. T-SNE plots of neoplastic PCs (CD138+,CD3-,CD16-,CD19-,cytoplasmic kappa or lambda+) were created using all remaining markers. A differential analysis of each sample's clusters was performed against all other events. Z-score values, representing marker changes from the differential analysis, for each cluster were used to group similar clusters across all samples, allowing us to compare sub populations of PCs between patients (see figure). From these groups of clusters with similar changes in markers, we calculated the proportion of cells with increases or decreases in markers for each sample. Results were compared to IMWG 90-day response criteria using a random forest model. Results: We performed mass cytometry on 102 samples from 68 unique MM patients. Median age was 66 years (range 34-95) with a 1.5:1 male:female ratio. 37 (36%) had NDMM, 55 (54%) had RRMM, 2 (2%) had SMM and 8 cases (8%) had unknown status. FISH studies revealed 47 (46%) had hyperdiploidy without a recurrent primary IgH rearrangement, 31 (30%) had t(11;14), 13 (13%) had t(4;14), 5 (5%) had 14;16 or 14;20, 3 (3%) had hyperhaploidy and 3 (3%) had an undefined primary. 54 (53%) had 1q gain/amp, 22 (22%) had TP53 deletion, 22 (22%) had a MYC rearrangement and 71% had high mSMART risk. Nearly all patients received an immunomodulatory compound, a proteasome inhibitor and dexamethasone. 2 (2%) had complete response (CR), 10 (9.8%) very good partial response (VGPR), 36 (35%) had partial response (PR), 14 (14%) had minimal response (MR), 13 (13%) had stable disease (SD) and 17 (17%) had progressive disease (PD). Characterization of CD45+ cells identified a relatively conserved and reproducible map from each patient. Notable differences included an ~2-fold reduction in the percentage of total B cells (CD45+,CD3-,CD19+)/total CD45+ cells in cases with high risk mSMART, RRMM and TP53 deletion compared to cases with standard risk, NDMM or normal TP53 status. Similar B-cell reductions were found in RRMM vs. NDMM samples from matched-patients. In contrast to the conserved t-SNE structure of the CD45+ population, the neoplastic PC population displayed dramatically reduced t-SNE structural consistency. Heterogeneity between patient samples and between the same patient samples over time was observed. We focused our analysis on 22 patients with serial samples. The proportion of each t-SNE group present in each patient sample was calculated and then correlated to the 90-day response metric. We identified a phenotypic group whose proportion increased in relation to disease progression (R2=0.85). This group had elevated BCL-2, pSTAT3, CD56 levels and reduced CD45 and CD81 levels. Evaluating individual markers, we found an increase in the proportion of cells with elevated BCL-2, pS6, Ki67, and IKZF1 levels in relation to disease progression. We also observed an increase in the proportion of cells with reduced pCREB levels and a reduction in the proportion of cells with reduced CD147 levels in relation to disease progression. Conclusions: We have utilized CyTOF to characterize phenotypic and functional markers in MM cells on a single cell level and can identify unique subgroups that change in relation to disease progression. Future analysis will correlate phenotypic signatures with ISS stage, mSMART risk, cytogenetic abnormality and type of treatment. Figure 1 Disclosures Kumar: Kite Pharma: Consultancy, Research Funding; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Sanofi: Research Funding; MedImmune: Research Funding; Karyopharm: Consultancy; Merck: Consultancy, Research Funding; Carsgen: Other, Research Funding; Cellectar: Other; Novartis: Research Funding; Adaptive Biotechnologies: Consultancy; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Genecentrix: Consultancy; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Tenebio: Other, Research Funding; BMS: Consultancy, Research Funding; Dr. Reddy's Laboratories: Honoraria.

Background: Lytic bone lesions are one of the most common clinical characteristics of patients with multiple myeloma (MM) and identification of bone lesions help distinguish between patients with smoldering multiple MM and active MM. Given this, the most recent update of the diagnostic criteria for MM incorporates advanced imaging approaches for distinguishing between the two entities. Several small retrospective studies have compared conventional skeletal survey (SS) with whole-body low dose computed tomography (WBLDCT) scan or the CT portion of a positron emission tomography (PET) scan. Conducting prospective studies comparing these two modalities side by side is limited by the radiation exposure. We undertook this study to provide a comparison between these two imaging modalities in terms of their ability to recognize lytic bone lesions in patients with MM. Patients and methods: This was a retrospective study of consecutive patients with the diagnosis of MM treated at Mayo Cinic Hospital during 2004- 2018. Patients were included if they had a conventional skeletal survey no more than 3 months before MM diagnosis or any time after diagnosis and also had a WBLDCT or PET-CT within a 12-month period following the skeletal survey. We chose this approach since it is unlikely that a patient would have had both modalities done at the same time as part of standard of care (SOC). This approach was also facilitated by a gradual change in our SOC for skeletal imaging from conventional skeletal survey to WBLDCT. To measure the robustness of our findings, we performed a sensitivity analysis in patients who had the exam ≤6 months apart. Proportions were compared using a chi-square test and survival estimates were calculated using the Kaplan- Meier methodology and compared using log rank test. Results: The overall study cohort had 1040 patients, median age was 62 years at diagnosis (range, 24-94), 61% were male and 39% were female. The median time to the skeletal survey was 8 months from diagnosis (range, 0-160) and the median time to WBLDCT or PET-CT from SS was 2 months (0-12). A PET-CT was available in 789 (76%) of patients and WBLDCT in 251 (24%) of patients. Among the 300 patients with no lesions identified by SS, 188 (63%) had lytic lesions identified by CT, while in 60/740 (8%) patients with a positive SS did not have lytic lesions observed on the CT (p<0.0001). Overall, CT identified lytic lesions in 868 (84%) patients compared with 740 (71%) patients with lytic lesions seen on SS. Although the proportion of lytic lesions was slightly higher with PET compared to WBLDCT, the analysis did not reach statistical significance (65% vs. 56%; p = 0.17; Table 1a). After restricting the analysis to those with ≤6 months gap between low dose CT and SS (n=737), the result did not change (Table 1b). Further examination demonstrated that presence of lytic lesions by SS had no impact on OS from diagnosis, detection of lesions on the CT exam was associated with an inferior survival (112 vs. 81 months, p<0.0001). (Figure 1) Conclusion: Skeletal survey has been the screening technique of choice for evaluation of bone involvement in MM for decades. However, CT based approaches have higher sensitivity with lytic lesions identified in a higher proportion of patients. The prognostic value of lytic disease is evident with CT based detection, again suggesting that this provides a more accurate estimate of the skeletal disease burden. Low dose CT rather than conventional radiographs should be the modality of choice for monitoring disease-progression and diagnosing active multiple myeloma. Disclosures Kapoor: Cellectar: Consultancy; Janssen: Research Funding; Sanofi: Consultancy, Research Funding; Amgen: Research Funding; Takeda: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Celgene: Honoraria. Gertz:Abbvie: Other; Celgene: Other; Physicians Education Resource: Other: personal fee; Medscape: Other: personal fee, Speakers Bureau; Janssen: Other: personal fee; Spectrum: Other: personal fee, Research Funding; Johnson and Johnson: Speakers Bureau; Teva: Speakers Bureau; Annexon: Other: personal fee; Research to Practice: Other; Sanofi: Other; Proclara: Other; DAVA oncology: Speakers Bureau; Springer Publishing: Patents & Royalties; Appellis: Other: personal fee; Amgen: Other: personal fee; Prothena: Other: personal fee; Aurora Bio: Other; Alnylam: Other: personal fee; Ionis/Akcea: Other: personal fee. Dispenzieri:Takeda: Research Funding; Pfizer: Research Funding; Janssen: Research Funding; Intellia: Research Funding; Alnylam: Research Funding; Celgene: Research Funding. Dingli:Alexion: Consultancy; Janssen: Consultancy; Sanofi-Genzyme: Consultancy; Millenium: Consultancy; Bristol Myers Squibb: Research Funding; Rigel: Consultancy; Apellis: Consultancy; Karyopharm Therapeutics: Research Funding. Lin:Merck: Research Funding; Takeda: Research Funding; Legend BioTech: Consultancy; Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Vineti: Consultancy; Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gamida Cells: Consultancy. Kumar:Dr. Reddy's Laboratories: Honoraria; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Sanofi: Research Funding; Novartis: Research Funding; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Merck: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Carsgen: Other, Research Funding; Cellectar: Other; MedImmune: Research Funding; Karyopharm: Consultancy; BMS: Consultancy, Research Funding; Tenebio: Other, Research Funding; Genecentrix: Consultancy; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Kite Pharma: Consultancy, Research Funding.

Background: Patients with newly diagnosed MM can be quite symptomatic as a result of end organ damage related to MM as well as presence of other comorbidities in this relatively older patient population. Prior studies have shown that the performance score as well as other quality of life (QOL), frailty and comorbidities scores can have prognostic value in these patients. However, many of these questionnaires are lengthy and complex, and not practical in a busy outpatient practice. We implemented a three question symptom assessment score in 2010 in our outpatient practice. Here we present the results of the analysis looking at the impact of this measurement in patients with newly diagnosed MM. Patients and Methods: Patients seen in the outpatient Hematology practice at Mayo Clinic, Rochester MN, were asked to grade the symptoms of fatigue, pain, and QOL on a 0 to 10 scale during the past 7 days, with 10 being the worst and the QOL on a similar scale but with 10 being the best. For the purpose of the current analysis the QOL score was reversed.These three scores were added for a total score. We looked at the impact of the baseline score as well as the score after four cycles of therapy, at the time of best response, and at the time of the first progression, wherever they were available. Survival curves were generated by the Kaplan-Meier method and compared using the log rank test. The Cox proportional hazards model was used for assessment of the impact of different prognostic variables. Results: Data from 735 patients with newly diagnosed MM seen at Mayo Clinic between 2011 and 2018 were available from baseline. The median total score was 10 (0-30), and for fatigue, pain and QOL were 4, 3 and 7 respectively, all with range of 0-10. Based on the baseline scores, patients were grouped into tertiles (Group 1 with score < 8, group 2 with score 8 to 14 and group 3 with a score ≥ 15). There were 256 (34%), 272 (37%) and 207 (28%) patients in groups 1, 2 and 3 respectively. The median overall survival (OS) (95% CI) from diagnosis was NR (7.9, NR), 7.7 (6.2, NR) and 5.4 (4.2, 6.9), respectively for groups 1, 2 and 3 (P < 0.0001) (Figure 1a). The prognostic value of the score was independent of age, FISH based risk status and the ISS stage. When evaluated after 4 cycles (n=325), the OS was significantly different for the 3 groups (P<0.01) (figure 1b). We then examined the impact of the score at best response to initial therapy (n=446) on OS from that timepoint and saw similar trend, but the results were not statistically significant (P=0.09) (Figure 1c). When evaluated at the time of first disease progression, the score again identified three groups with different OS from progression (P<0.001) (Figure 1d). Conclusions:Patient-reported outcomes are associated with survival in patients with MM. This simple, easy to complete patient-reported outcome 3-item scale can be easily completed in a busy practice and is a clinically useful tool to assess potential outcomes of patients at various disease stages, including at diagnosis and at relapse. Disclosures Kumar: Adaptive Biotechnologies: Consultancy; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Kite Pharma: Consultancy, Research Funding; Novartis: Research Funding; Sanofi: Research Funding; MedImmune: Research Funding; Karyopharm: Consultancy; Tenebio: Other, Research Funding; BMS: Consultancy, Research Funding; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Carsgen: Other, Research Funding; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Cellectar: Other; Genecentrix: Consultancy; Merck: Consultancy, Research Funding; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Dr. Reddy's Laboratories: Honoraria. Kapoor:Janssen: Research Funding; Cellectar: Consultancy; Sanofi: Consultancy, Research Funding; Amgen: Research Funding; Takeda: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Celgene: Honoraria. Gertz:Proclara: Other; Springer Publishing: Patents & Royalties; Abbvie: Other; Celgene: Other; Aurora Bio: Other; Medscape: Other: personal fee, Speakers Bureau; Sanofi: Other; Teva: Speakers Bureau; Johnson and Johnson: Speakers Bureau; DAVA oncology: Speakers Bureau; Amgen: Other: personal fee; Appellis: Other: personal fee; Annexon: Other: personal fee; Spectrum: Other: personal fee, Research Funding; Janssen: Other: personal fee; Prothena: Other: personal fee; Physicians Education Resource: Other: personal fee; Research to Practice: Other; Ionis/Akcea: Other: personal fee; Alnylam: Other: personal fee. Dispenzieri:Alnylam: Research Funding; Intellia: Research Funding; Janssen: Research Funding; Takeda: Research Funding; Celgene: Research Funding; Pfizer: Research Funding. Dingli:Rigel: Consultancy; Millenium: Consultancy; Alexion: Consultancy; Janssen: Consultancy; Apellis: Consultancy; Sanofi-Genzyme: Consultancy; Karyopharm Therapeutics: Research Funding; Bristol Myers Squibb: Research Funding. Lin:Novartis: Consultancy; Celgene: Consultancy, Research Funding; Bluebird Bio: Consultancy, Research Funding; Juno: Consultancy; Legend BioTech: Consultancy; Merck: Research Funding; Takeda: Research Funding; Gamida Cells: Consultancy; Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Vineti: Consultancy; Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding.