Citations

AbstractTriple‐class‐refractory multiple myeloma (MM) describes MM refractory to proteasome inhibitors, immunomodulatory agents, and anti‐CD38 monoclonal antibodies. In the Phase IIb STORM study (NCT02336815), oral selinexor plus low‐dose dexamethasone (Sel‐dex) demonstrated a 26.2% overall response rate in triple‐class‐refractory MM. Here, we compare overall survival (OS) of 122 patients with triple‐class‐refractory MM who received Sel‐dex in STORM Part 2 with that of 64 similar patients treated with other available therapies in a Flatiron Health Analytic Database (FHAD) cohort. OS from the date that the patients’ MM became triple‐class‐refractory was longer in STORM versus FHAD, with an unadjusted hazard ratio (HR) of 0.43 (P = .0002; adjusted HR 0.35 [P = .011]). In a subset analysis of highly resistant patients receiving further therapies after their MM first became at least triple‐class‐refractory (i.e., who received Sel‐dex in STORM,n = 64, and non‐Sel‐dex in FHAD,n = 36), the OS was significantly longer in STORM with an unadjusted HR of 0.52 (P = .0331; adjusted HR 0.33 [P = .041]). Within the limits of this analysis, the OS of patients with at least triple‐class‐refractory MM was significantly better with Sel‐dex versus available therapies, suggesting that Sel‐dex may be associated with a meaningful OS benefit in these patients.

AbstractIntroductionLittle is known on continued response following completion of therapy in light chain (AL) amyloidosis.MethodsWe studied 373 AL amyloidosis patients who achieved complete response (CR) or very good partial response (VGPR) to first‐line therapy.ResultsBy end of therapy (EOT), 46% of patients achieved a CR and 54% a VGPR. With no further therapy, 17.5% of patients were upstaged from VGPR to CR (delayed CR), with a median of 9 months. Compared with CR and VGPR at EOT, patients with a delayed CR were characterized by higher proportion of t(11;14) and lower rate of trisomies. Autologous stem cell transplant was more frequent in the delayed CR group. Patients with a delayed CR were characterized by minimal residual disease negativity and organ response rates similar to patients with CR at EOT and higher than patients achieving VGPR at EOT. Patients with a delayed CR had a longer PFS/OS compared to patients with CR or VGPR by EOT (median PFS 149 vs 92 vs 52 months, P < .001; 10‐year OS 87% vs 71% vs 56%, P < .001).ConclusionsThis study characterizes delayed CR in AL amyloidosis, highlights its prognostic impact which is at least similar to those who achieved CR at EOT, and underlines another aspect of response monitoring.

SummaryMeasurable residual disease (MRD) assessment by marrow‐based next‐generation flow cytometry (NGF) following autologous stem cell transplantation (ASCT) may lead to false‐negative results due to patchy marrow involvement and extramedullary disease in patients with multiple myeloma. We assessed the value of simultaneous MRD evaluation with NGF and serum matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MASS‐FIX). Of all 61 complete responders who were NGF‐negative for MRD, around day‐100 post ASCT, 59% were MASS‐FIX‐positive. At median follow‐up of 26 months, 69% of MASS‐FIX(+)/NGF(−) patients were alive and progression‐free versus 96% of MASS‐FIX(‐)/NGF(−) patients, P = 0·02. MASS‐FIX, a simple peripheral blood‐based assay complements marrow‐based NGF to accurately prognosticate patients with myeloma.

Introduction: In general, the use of an immunomodulator (IMiD), proteasome inhibitors (PI) and dexamethasone (dex) for the treatment of MM is associated with better outcomes. The management of elderly patients with multiple myeloma (MM) is challenging due to difficulty in managing their co-morbidities and inability to tolerate treatment side effects. We evaluated therapies and outcomes of elderly patients with newly diagnosed MM. Methods: This is a retrospective study of patients with MM who were &gt;75 years old treated at the Mayo Clinic, Rochester from January 2004 to January 2018. We included patients who were treated on clinical trials as well as off-trials. Patients were classified as receiving treatment with IMiD+PI+dex, alkylator+PI+steroid, IMiD+dex, PI+dex, alkylator+IMid+steroid, and other (alkylator with steroid or steroid only). Treatment response was documented as well as the progression-free (PFS), defined as the time from therapy initiation to disease relapse or death from any cause and overall survival (OS), defined as the time from start of treatment to death from any cause. A multivariate analysis for factors affecting OS was done including the following variables: being on a triplet combination (alkylator+PI+steroid, IMid+PI+dex, or alkylator +IMiD+steroid), revised international staging system (R-ISS)(stage 3 vs. 1-2), bone marrow plasma cell percentage (BMPC%)(&gt;60% vs. ≤60%), and receiving treatment during or after 2010 vs. before 2010. Analysis was done for patients treated off-trials, as well as, including trial patients. Results: We identified 394 patients with MM who were &gt;75 years old and 246 (62%) were male. For non-trial patients (n=350), IMiD+dex (32%) was the most commonly used regimen followed by alkylator with steroid or steroid only (20%), alkylator+PI+steroid (18%), and IMid+PI+dex (13%). The remaining patients were treated with PI+dex (12%) and alkylator +IMiD+steroid (5%). Forty-four patients (11%) were treated in clinical trials with alkylator+IMid+steroid (47%), IMiD+dex (25%), IMiD+PI+dex (14%), and alkylator+PI+steroid (14%). The median follow up was 45.9 months with an interquartile range of 28.2 to 75.6 months. Overall, achieving very good partial response or complete response was more likely in patients who were treated with an IMid+PI+dex (58%) or alkylator+PI+steroid (47%), compared to in other therapies (5-30%)(P&lt;0.0001). The PFS and OS for non-trial patients are displayed in Figure 1 (A,B) and for all, including trial patients in (C,D). Overall, the median OS was significantly longer in patients who were treated with a triplet in non-trial as well as all patients. In a multivariate for OS including non-trial patients, predictors for better OS included receiving a triplet (HR: 0.63, P=0.02) and not having an R-ISS stage 3 (HR: 0.39, P=0.001). This was also found when including trial patients (using a triplet, HR: 0.65, P=0.01 and not having an R-ISS stage 3, HR: 0.35, P=0.0002). Conclusion: In MM patients &gt;75 years old, being able to receive triplet therapy is associated with better survival. This study provides better understanding of the natural history of MM outside of trials in the elderly age group. Disclosures Dispenzieri: Celgene: Research Funding; Alnylam: Research Funding; Pfizer: Research Funding; Intellia: Research Funding; Takeda: Research Funding; Janssen: Research Funding. Dingli:Bristol Myers Squibb: Research Funding; Alexion: Consultancy; Millenium: Consultancy; Rigel: Consultancy; Sanofi-Genzyme: Consultancy; Apellis: Consultancy; Janssen: Consultancy; Karyopharm Therapeutics: Research Funding. Kapoor:GlaxoSmithKline: Research Funding; Amgen: Research Funding; Takeda: Honoraria, Research Funding; Sanofi: Consultancy, Research Funding; Janssen: Research Funding; Cellectar: Consultancy; Celgene: Honoraria. Gertz:Spectrum: Other: personal fee, Research Funding; Janssen: Other: personal fee; Prothena: Other: personal fee; Alnylam: Other: personal fee; Ionis/Akcea: Other: personal fee; Springer Publishing: Patents & Royalties; Proclara: Other; DAVA oncology: Speakers Bureau; Johnson and Johnson: Speakers Bureau; Teva: Speakers Bureau; Sanofi: Other; Research to Practice: Other; Celgene: Other; Abbvie: Other; Aurora Bio: 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. Kumar:Carsgen: Other, Research Funding; Tenebio: Other, Research Funding; BMS: Consultancy, Research Funding; Karyopharm: Consultancy; MedImmune: Research Funding; Sanofi: Research Funding; 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; Adaptive Biotechnologies: Consultancy; 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; Janssen Oncology: 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; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Dr. Reddy's Laboratories: Honoraria; Cellectar: Other; Genecentrix: Consultancy.

Background: Oncolytic virotherapy is a novel immunomodulatory therapeutic approach for relapsed refractory hematologic malignancies. The Indiana strain of Vesicular Stomatitis Virus (VSV) has been engineered to encode interferon beta (IFNβ) and sodium iodine symporter (NIS) to produce VSV-IFNβ-NIS. The virally encoded IFNβ serves as an index of viral proliferation and enhances host anti-tumor immunity. The NIS is inserted as a reporter gene into the viral genome to enable noninvasive monitoring of viral spread using PET/CT imaging. Here we present results of Arm A (patients with low tumor burden) of the Phase I clinical trial (NCT03017820) of intravenous administration of VSV-IFNβ-NIS for patients (pts) with relapsed refractory hematological malignancies: MM, AML, and TCL. Methods: This was a classical 3+3 phase I trial, starting at 5x10^9 TCID50 (50% tissue culture infectious dose) level 1 through 1.7x10^11 TCID50 dose level 4 given as a single IV dose. The primary objective was determining the maximum tolerated dose of VSV-IFNβ-NIS alone; secondary objectives include estimating the safety profile and preliminary efficacy. Correlative objectives include monitoring the pharmacodynamics of viral replication through SPECT/CT imaging with NIS gene, viremia, virus shedding and changes in the immune profile of peripheral blood leukocytes. Adverse events (AEs) are reported based on CTCAE v4; cytokine release syndrome (CRS) grading was based on Lee (Blood 2014; 124(2):188-195) criteria. Results: From April 2017, 12 pts have received IV VSV-IFNβ-NIS in Arm A: MM (7), TCL(4) and AML(1); 3 pts were treated at each dose level (DL) 1 to 4. At DL1, there were five grade 3 hematologic AEs (leukopenia [1], neutropenia [1], lymphopenia [3]) and no grade 3+ non-hematologic AEs. At DL2, three grade 3 hematologic AEs (anemia [2], lymphopenia [1]), four grade 4 hematologic AEs (neutropenia [1], leukopenia [1], lymphopenia [1] and thrombocytopenia [1]). There was 1 event of grade 2 CRS at DL2, two grade 3 non-hematologic AEs (nausea [1], dehydration [1]). At DL3, there was one grade 4 hematologic AE (neutropenia [1]), three grade 3 hematologic AEs (lymphopenia [2], leukopenia [1]), and one grade 3 non-hematologic AE (vasovagal reaction [1]). One grade 2 and grade 1 CRS by Lee criteria were observed. At DL4, there were three grade 3 hematologic AEs (lymphopenia [1], neutropenia [1], thrombocytopenia [1]), and three grade 3 non-hematologic AEs (AST increase [1], skin infection [1], soft tissue infection [1])and two grade 2 CRS. There were no dose limiting toxicities. There was one partial response (DL2) and one complete response (DL4); 3 pts had stable disease, 7 pts progressed. The MM pts receiving VSV-IFNβ-NIS at DL4 had stable disease. Six of the 7 MM pts demonstrated transient reduction in serum level of involved free light chain (LC) after VSV-IFNβ-NIS infusion, with median 20.4% reduction of the involved LC within 48 hrs. Viremia was detectable in all pts at the end of infusion, to varying levels at 30 mins, 1, 2, 4, 24, 48h or 72 hrs post infusion. No persistent viremia was observed. No infectious virus was recovered in buccal swabs or urine and neutralizing anti-VSV antibodies were present by day 29. The IFN levels were detectable within 30 minutes of infusion and peaked between 4 and 48 hrs. The pts with a diagnosis of TCL mounted higher hIFNβ levels within 48 hrs. Remarkably, the TCL pt with CR (DL4) mounted a peak hIFNβ response of 18213.3pg/ml at 48 hrs post infusion, approximately 15-fold higher than any other pt enrolled in the study; and highest neutralizing antibody titer (1:40960). Conclusion: VSV-IFNβ-NIS can be safely administered by intravenous infusion in pts with hematological malignancies, up to a dose level of 1.7 x 1011 TCID50, without dose limiting toxicities and no CRS higher than grade 2. In this small phase 1 study, pts with T-cell lymphoma demonstrated the strongest signal of response, with one confirmed partial response at DL2 and one complete response at DL4. IFNβ is an early biomarker of tumor susceptibility; the magnitude of IFNβ elevation appears to correlate with treatment response. There were no confirmed responses in pts with MM, but the 20.4% transient reduction in LC suggests that combination strategies with VSV-IFNβ-NIS may result in deeper and sustained responses in MM. Future trials investigating combination strategies with immune modulatory drugs are being planned. Disclosures Peng: Imanis: Other: Equity Ownership. Witzig:Karyopharm Therapeutics: Research Funding; Immune Design: Research Funding; Spectrum: Consultancy; Incyte: Consultancy; Acerta: Research Funding; MorphSys: Consultancy; AbbVie: Consultancy; Celgene: Consultancy, Research Funding. Dispenzieri:Intellia: Research Funding; Pfizer: Research Funding; Takeda: Research Funding; Alnylam: Research Funding; Janssen: Research Funding; Celgene: Research Funding. Gertz:Celgene: Consultancy; Annexon: Consultancy; Sanofi: Consultancy; Appellis: Consultancy; Amgen: Consultancy; Medscape: Consultancy, Speakers Bureau; Physicians Education Resource: Consultancy; Data Safety Monitoring board from Abbvie: Membership on an entity's Board of Directors or advisory committees; NCI SPORE MM: Research Funding; Johnson and Johnson: Speakers Bureau; Springer Publishing: Patents & Royalties; Amyloidosis Foundation: Research Funding; Advisory Board for Proclara: Membership on an entity's Board of Directors or advisory committees; Alnylam: Consultancy; Ionis/Akcea: Consultancy; Spectrum: Consultancy, Research Funding; Prothena: Consultancy; DAVA oncology: Speakers Bureau; i3Health: Consultancy; Advisory Board for Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; International Waldenstrom Foundation: Research Funding. Dingli:Rigel: Consultancy; Bristol Myers Squibb: Research Funding; Janssen: Consultancy; Alexion: Consultancy; Apellis: Consultancy; Karyopharm Therapeutics: Research Funding; Millenium: Consultancy; Sanofi-Genzyme: Consultancy. Kapoor:Cellectar: Consultancy; Celgene: Honoraria; Janssen: Research Funding; Sanofi: Consultancy, Research Funding; Amgen: Research Funding; Takeda: Honoraria, Research Funding; GlaxoSmithKline: Research Funding. Lin:Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Legend BioTech: Consultancy; Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Novartis: Consultancy; Celgene: Consultancy, Research Funding; Merck: Research Funding; Takeda: Research Funding; Gamida Cells: Consultancy; Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Vineti: Consultancy. Kumar:Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Cellectar: Other; Carsgen: Other, Research Funding; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Merck: Consultancy, Research Funding; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Sanofi: Research Funding; Dr. Reddy's Laboratories: Honoraria; Adaptive Biotechnologies: Consultancy; 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; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; MedImmune: Research Funding; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Karyopharm: Consultancy; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; BMS: Consultancy, Research Funding; Genecentrix: Consultancy; Tenebio: Other, Research Funding. Russell:Imanis: Other: Equity Ownership. OffLabel Disclosure: This describes of administration of Vesicular Stomatitis Virus Genetically Engineered to Express NIS and human interferon, in Patients with Relapsed or Refractory Hematologic malignacies

Background: PCL is a rare and aggressive form of multiple myeloma (MM). It is associated with high risk cytogenetics, aggressive disease biology and a dismal prognosis. Dara has revolutionized the treatment of MM leading to deep and durable responses as a single agent and in combination with other agents. We evaluated the efficacy of Dara-based regimens in the treatment of PCL. Methods: Clinical charts of primary and secondary PCL patients treated at the Mayo Clinic Cancer Center between 2012-2019 were reviewed. Survival was analyzed with the Kaplan-Meier method. Plasma cell leukemia was defined by ≥5% peripheral blood plasma cells and/or absolute plasma cell count ≥0.5 x109/L (based on IMWG consensus statement).1 Results: Thirty-one patients were identified (55% female) with a median age at PCL diagnosis of 66 y (range 38-83). Fifteen (48%) had primary (p) PCL, while 14 (52%) had secondary (s) PCL. Nineteen (61%) had high risk cytogenetics with 11 (45%) del 17p, 4 (13%) t(14;16), 14 (45%) 1q amplification/duplication and 3(10%) t(4;14). Twelve (39%) had t(11;14). Eighteen (58%) patients had undergone autologous hematopoietic cell transplant (AHCT) with 12 (39%) having undergone AHCT following their diagnosis of PCL. Patients received a median of 2 prior lines of therapy (range 1-9) prior to receiving Dara-based regimens; 15 (42%) were refractory to an immunomodulatory agent (IMiD), 18 (58%) were refractory to a proteasome inhibitor (PI) and 10 (32%) were refractory to both. Twenty-eight (90%) were IMiD exposed, 31 (100%) were PI exposed. Eighteen (58%) were lenalidomide (R) refractory, 5(16%) were pomalidomide (P) refractory, 8 (26%) were carfilzomib (K) refractory and 13(42%) were bortezomib (V) refractory prior to receiving Dara. Four (13%) received Dara + chemotherapy, 8 (26%) received Dara + PI, 11 (35%) received Dara + IMiD, 5 (16%) received Dara + PI + IMiD and 4 (13%) received single agent Dara. Median follow up time was 26 months (m) (95% CI; 13-61) from diagnosis of PCL and 17m (95% CI; 10-23) from initiation of Dara. Overall response rate (ORR) to Dara-based regimens was 65% (20/31 ≥partial response). The median duration of response was 5.5m (95% CI; 5.6-12.7). The median time to first response was 1m (95% CI; 0.57-1.72) and the median time to best response was 1m (95% CI; 0.7-2.5). Since the start of Dara-based treatment, median progression free survival (PFS) was 4m (95% CI; 2-11, Figure 1A) and median overall survival (OS) was 9 m (95% CI; 5-21, Figure 1B). Patients with pPCL had superior PFS (19 m vs. 3m, p=0.0096) and OS (21 vs. 5m, p=0.0068, Figure 1C) following Dara-based treatment compared to those with sPCL, respectively. Being refractory to an IMiD, PI or both when receiving Dara did not affect PFS or OS. Patients with high risk cytogenetics had similar OS as compared to those with standard risk cytogenetics (8m vs.13m, p=0.89) following Dara-based treatment. After performing a landmark survival analysis at 3m, achieving ≥PR to a Dara-based regimen resulted in a trend towards superior OS (13m vs. 9 m, p=0.07, Figure 1D). Patients who underwent AHCT following the diagnosis of PCL had a superior OS (41m vs. 6m, p=0.020) however there were no PFS or OS differences whether Dara-based regimens were given before or after AHCT. Conclusions: Dara-based regimens induce a high ORR in patients with PCL with a rapid time to first response. However, the OS of patients with PCL, particularly sPCL remains dismal. Prospective trials for PCL patients using novel therapeutic strategies are warranted. 1Fernandez de Larrea, et al. Plasma Cell Leukemia: consensus statement on diagnostic requirements, response criteria, and treatment recommendations by the International Myeloma Working Group (IMWG). Leukemia. 2013; 27(4): 780-791. Disclosures Alhaj Moustafa: Acrotech: Consultancy. Kapoor:Janssen: Research Funding; Sanofi: Consultancy, Research Funding; Cellectar: Consultancy; Celgene: Honoraria; Amgen: Research Funding; Takeda: Honoraria, Research Funding; GlaxoSmithKline: Research Funding. Dingli:Millenium: Consultancy; Sanofi-Genzyme: Consultancy; Rigel: Consultancy; Bristol Myers Squibb: Research Funding; Karyopharm Therapeutics: Research Funding; Janssen: Consultancy; Alexion: Consultancy; Apellis: Consultancy. Ailawadhi:Phosplatin: Research Funding; Medimmune: Research Funding; BMS: Research Funding; Cellectar: Research Funding; Pharmacyclics: Research Funding; Janssen: Research Funding; Takeda: Honoraria; Amgen: Research Funding; Celgene: Honoraria.

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: 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&lt;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: 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 (&lt;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 (&lt;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.