Citations

Abstract Aims: Autologous stem cell transplantation (ASCT) is an important component in the treatment of newly diagnosed multiple myeloma (MM). However, relapse following ASCT is considered almost inevitable, with a median time to progression (TTP) of approximately 23-26 months (without maintenance) and 40-46 months (with maintenance)(Attal MA et al. N Engl J Med 2012; 366:1782-1791; McCarthy PM et al. N Engl J Med 2012; 366:1770-1781). However, some patients can experience a prolonged period of remission with ASCT. The purpose of this study was to identify and characterize patients who have an exceptional response to upfront ASCT without maintenance therapy, and to determine the frequency of relapse in such patients. Methods: We searched the Mayo Clinic Multiple Myeloma bone marrow transplant database for patients who were diagnosed with MM between Aug 1, 1988 to Jan 3, 2006, and underwent ASCT within 12 months of initial diagnosis. For the purposes of this study, we defined exceptional responders as patients who were free of progression for 96 months or more, which is 2-3 fold more than the median TTP expected in this population. Since maintenance therapy was not standard of care at the time, only a small minority (6) of patients with prolonged TTP had received maintenance therapy; these patients were excluded since the study was focused on exceptional response with ASCT alone. One patient who had a tandem autologous transplant was excluded. Results: 509 patients underwent transplant during the study period. Of those, 46 (9%) met criteria for exceptional response. Twenty seven (59%) were female, 19 (41%) were male. Median age was 57.28 years, range, 31.9-73.0. Of 45 patients with response data available, the best response status was complete response or better in 32 patients (73.3%), VGPR in 4 patients (8.9%), and PR in 8 patients (17.7%). FISH data were available during the disease course for 41 patients. Of these, the majority, 28 patients (68.3%), had no abnormalities detected by the probes used; 3 patients (7.3%) had high risk cytogenetics (t(4;14) in 2 patients and t(14;16) in one patient) , 4 (9.8%) had trisomies; 6 patients had other isolated abnormalities. At last follow up, 23 patients have progressed (50%); 14 (30.4%) have died, including one who died without progression to MM. The median overall survival from time of diagnosis of the exceptional responders was 18.5 years, range 9.2-22 years. From the landmark time of 96 months, the median TTP was 6.2 years, range, 0.4-10.6 years (Figure 1); No plateau was seen in the TTP curve. From the landmark time of 96 months, the median OS was 10.5 years, range, 0.4-14 years. Conclusions: We conclude that approximately 10% of patients with newly diagnosed myeloma have an exceptional response to a single ASCT without maintenance therapy. These patients have a remarkable overall survival, both from diagnosis and from the landmark time point where they are classified as having achieved an exceptional response. Although TTP from the landmark time point is excellent, with median TTP of 6.2 years, there appears to be no plateau in the curve indicating ongoing risk of relapse despite a prolonged period of disease stability. Exceptional responders tended to have normal FISH studies (likely an indicator of responsive, low-tumor burden disease), and nearly 20% achieved this state despite not attaining a complete response. Figure. Figure. Disclosures Gertz: Research to Practice: Consultancy; Apellis: Consultancy; spectrum: Consultancy, Honoraria; Medscape: Consultancy; celgene: Consultancy; janssen: Consultancy; Teva: Consultancy; Abbvie: Consultancy; annexon: Consultancy; Ionis: Honoraria; Alnylam: Honoraria; Prothena: Honoraria; Amgen: Consultancy; Physicians Education Resource: Consultancy. Kumar:KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Dingli:Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Russell:Vyriad: Equity Ownership. Kapoor:Takeda: Research Funding; Celgene: Research Funding.

Abstract Background: The introduction of novel therapeutics has led to improved outcomes in patients with multiple myeloma (MM). MM and its precursor lesion smoldering multiple myeloma (SMM) have traditionally been associated with increased mortality despite treatment. We aimed to assess the impact of a diagnosis of SMM and MM compared to the general population in the context of established prognostic factors. Methods: We studied the overall survival of 1697 patients with smoldering multiple myeloma (SMM, n = 582) and multiple myeloma (MM, n = 1115) diagnosed at Mayo Clinic between 01/2005 and 12/2015. Expected survival accounting for age and sex was calculated using the United States general population (US) as the reference group. Observed and expected overall survival was expressed as the standardized mortality ratio (SMR) of observed to expected deaths. Kaplan-Meier overall survival estimates were calculated and the log-rank test was used to compare overall survival in subgroups. The subgroups of interest were based on the International Staging System (ISS) and the presence of fluorescence in situ hybridization (FISH) high-risk cytogenetics: t(4;14), t(14;16), t(14;20), and del(17p). Proportional hazards regression models were used to assess the associations between the aforementioned prognostic factors and overall survival. P-values below 0.05 were considered statistically significant. Results: The median age at diagnosis in patients with SMM and MM was 65 (32 - 92) and 63 years (24 - 90), respectively. Two hundred forty-nine patients (57%) and 663 (60%) were male. The median follow-up in patients with SMM and MM was 4.7 (0.1 - 11.0) and 2.6 years (0.2 - 9.5). The median overall survival for patients with SMM and MM was 9.0 (95% CI 8.4 - 9.7) and 7.9 years (6.4 - 8.7). With age- and sex-matched population controls as the reference, the SMRs in patients with SMM and MM were 2.6 (95% CI 2.2 - 3.0) and 4.6 (4.1 - 5.2). Among those MM patients with available data on ISS staging and FISH cytogenetics, 30% (236/780) had ISS III and 21% (188/878) had high-risk cytogenetics. Patients with MM (compared to SMM) experienced worse overall survival (HR 1.5, 95% CI 1.2 - 1.8, p < 0.001, n = 1697). Patients with ISS I/II MM (compared to SMM) experienced similar survival (HR 1.0, 95% CI 0.8 - 1.3, p = 0.698, n = 1131). Patients with ISS III MM (compared to MM with high-risk cytogenetics) experienced similar survival (HR 1.3, 95% CI 0.9 - 2.0, p = 0.128, n = 329). Conclusions: Patients with SMM and MM in this cohort experienced excess mortality compared to the general population. In the absence of universal screening the true morbidity and mortality of patients with SMM and MM remains unknown and is likely overestimated in hospital-based cohorts. Overall survival in patients diagnosed with SMM and patients with ISS I/II MM receiving contemporary anti-myeloma therapy was clinically indistinguishable. Patients treated for ISS III MM experienced overall survival similar to patients with cytogenetic high-risk disease. MM remains associated with excess mortality, the magnitude of which varies considerably based on the presence of additional tumor and host factors. The outcomes with modern therapy among the ISS I/II patients highlight the potential for improving outcomes of SMM by early intervention, especially for the higher risk patients. Figure. Figure. Disclosures Lacy: Celgene: Research Funding. Gertz:Medscape: Consultancy; Alnylam: Honoraria; janssen: Consultancy; spectrum: Consultancy, Honoraria; Ionis: Honoraria; annexon: Consultancy; celgene: Consultancy; Teva: Consultancy; Prothena: Honoraria; Apellis: Consultancy; Abbvie: Consultancy; Physicians Education Resource: Consultancy; Amgen: Consultancy; Research to Practice: Consultancy. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Russell:Vyriad: Equity Ownership. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Kumar:Roche: Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract Background : Ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor was approved for the treatment of Waldenstrom Macroglobulinemia (WM) in January, 2015 based on the results of a clinical trial of 63 previously-treated patients with WM. Data on outcomes with ibrutinib outside of clinical trials are limited. Methods : Medical records of patients with WM seen consecutively between 02/01/2015 and 06/01/2018 at Mayo Clinic, MN, FL and AZ were reviewed and those treated with ibrutinib at any point during their disease were included. Refractoriness to prior therapy was defined as disease progression on therapy or within 2 months of stopping treatment. The response rates were assessed by WM VI International Workshop Criteria. Adverse events were graded using National Cancer Institute Common Toxicity Criteria for Adverse Events (AEs) v4.03. All time-to-event analyses were performed from the time of initiation of ibrutinib. Results : Eighty patients [previously treated, n=67 (84%), treatment-naïve, n=13 (16%)] received ibrutinib for active WM. Median follow-up was 18 months (95% CI: 12-19) and the median overall survival (OS) was not reached (NR) (95% CI: 27-NR) for the entire cohort at the date of last follow-up. The median age was 67 years (range: 50-88) and the median ECOG performance score was 1 (range: 0-3) at the time of ibrutinib initiation. Median lines of therapies prior to ibrutinib for the previously-treated patients was 2 (range: 1-9) and 35 patients (44%) had received ≥3 prior lines of therapy. Of the 80 patients, 52 patients (43 previously treated, 9 treatment-naïve) had data for response assessment. The baseline characteristics and laboratory parameters at initiation of ibrutinib are outlined in Table 1a and prior therapies are mentioned in Table 1b. Overall response rate (ORR) was 90% (100% in patients with ibrutinib as primary therapy and 88% in salvage therapy setting); major-response rate (MRR) was 77%. Median time to first and best response was 2.1 months (95% CI: 1.5-3.5) and 5.4 months (95% CI: 3.5-13), respectively. Other clinically relevant endpoints and AEs related to ibrutinib therapy are outlined in Table 2 and 3, respectively. The median time-to-next therapy was 33 months (95% CI: 28-NR). At last follow-up, 25 (32%) patients had discontinued ibrutinib therapy. The reasons for discontinuation was progression (n=8), elevated liver enzymes (n=4), cognitive changes (n=1), inability to achieve better than MR (n=1), atrial fibrillation (n=3), consolidation with autologous stem cell transplantation after PR with ibrutinib (n=1), transition to hospice care due to progressive head and neck cancer (n=1), infection in lower extremity (n=1), transformation to DLBCL (n=1), blistering rash which resolved after ibrutinib discontinuation (n=1), obscure GI bleed that resolved after ibrutinib discontinuation (n=1), fatigue (n=1) and for unclear reasons recorded as treatment intolerance (n=1). Following discontinuation of ibrutinib, 21 patients received salvage therapy. Of these, data regarding the response to salvage therapy was available in 9 (43%) patients (VGPR=2, PR=3, SD=3 and progressive disease=1); median PFS from the salvage therapy following ibrutinib discontinuation was 18 months (95% CI: 2-25). Of the 4 patients who were not treated following ibrutinib discontinuation; 1 elected hospice care due to concurrent head and neck cancer progression, and the other 3 patients elected to be monitored off therapy (one had achieved SD and two had PR from ibrutinib). Fourteen patients were evaluable for IgM rebound following ibrutinib discontinuation. Of those, 5 (36%) had sudden increase in IgM level [median: 158% from the IgM level after ibrutinib discontinuation (range: 22%-1368%)] within a median of 2 months (range: 1-3 months) and 1 patient required plasmapheresis for symptomatic hyperviscosity. Four of 5 patients received salvage therapy between 0-15 months. At last follow-up, 11 patients (14%) had died of whom 3 were on ibrutinib at the time of death [CNS involvement, (n=1), causes unrelated to WM, (n=2)]. Conclusions : Ibrutinib is an effective agent in WM patients with MYD88L265Pmutation. Our data regarding outcomes in non-trial setting appear comparable to the results observed in the pivotal clinical trial. Hematologists should be aware of unique ibrutinib associated toxicities and clinically relevant IgM rebound phenomenon following abrupt discontinuation of ibrutinib. Disclosures Ailawadhi: Celgene: Consultancy; Janssen: Consultancy; Takeda: Consultancy; Pharmacyclics: Research Funding; Amgen: Consultancy. Gertz:janssen: Consultancy; Prothena: Honoraria; Medscape: Consultancy; Teva: Consultancy; celgene: Consultancy; annexon: Consultancy; Alnylam: Honoraria; Physicians Education Resource: Consultancy; spectrum: Consultancy, Honoraria; Apellis: Consultancy; Amgen: Consultancy; Abbvie: Consultancy; Ionis: Honoraria; Research to Practice: Consultancy. Kumar:Novartis: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding. Lacy:Celgene: Research Funding. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Witzig:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Dingli:Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding. Kapoor:Celgene: Research Funding; Takeda: Research Funding.

Abstract Introduction: Prognosis of AL amyloidosis has improved in recent years; however for many patients prognosis remains poor. We aimed to define patient-, disease- and treatment characteristics which are associated with long-term survival. Method: A retrospective chart review of all patients with biopsy-proven systemic AL amyloidosis, who were seen within 90 days of the confirmed diagnosis. Long-term survival was defined as 5-year and 10-year survival from the time of diagnosis. For 5-year survival we selected patients seen between January 1, 2000 and December 31, 2012 (allowing a minimum of 5-year follow-up, n=1331) and for 10-year survival we screened patients seen between January 1, 2000 and December 31, 2007 (allowing a minimum of 10-year follow-up; n=779). Treatment allocation was defined as the first regimen given, irrespective of subsequent treatment modifications. Results: Of the screening population, 498 patients survived ≥5 years from diagnosis (37% of the 5-year screening cohort) and 168 patients survived 10 years or more (22% of the 10-year screening cohort). Five-year survivors and 10-year survivors as compared to their counterparts were (Table): younger, higher proportion of women, more likely to have single organ involvement, less heart/liver/nerve involvement and more kidney involvement. Long-term survivors also had lower bone marrow plasma cell percentage at the time of diagnosis and lower tumor burden measured by the difference between involved to uninvolved light chain (dFLC). Similarly, long-term survivors had lower Mayo stages and higher systolic blood pressure. No difference in light chain isotype was observed between long-term survivors to long term non-survivors. Long-term survivors were less likely to be seen within 30 days of diagnosis compared to their counterparts (52% among 5-year survivors vs 67% among 5-year non-survivor; P<0.001). FISH abnormalities (data available for 555/1331 patients, 42%) were comparable between groups with regard to t(11;14) (50% among 5-year survival compared to 50% among 5-year non-survivors; P=0.93) and 13q abnormalities (34% vs 36%, respectively; P=0.53). However, trisomies were less frequently encountered in the 5-year survivor group (20% vs 29%, respectively; P=0.01), and far less common among 10-year survivors (11% vs 26%, respectively; P=0.04). Autologous stem cell transplantation (ASCT) was more likely to be associated with long-term survival. Of all patients who underwent ASCT, 74% survived more than 5 years and 49% survived more than 10 years. In comparison, among the standard-intensity therapies, 5-year survival rates for melphalan-dexamethasone, bortezomib-based regimens, immunomodulatory drug-based regimens and single agent dexamethasone/ melphalan-prednisone were 29%, 28%, 30% and 10%, respectively. The corresponding 10-year survival rates were 15%, 20%, 20% and 5%, respectively. Conclusions: Long-term AL survivors have distinct favorable baseline characteristics (including those introduced by referral bias) and ASCT as their initial therapy. Identification of these patients, especially the Mayo 2004 stage III and the Mayo 2012 stage III-IV patients who unexpectedly survived 10 years, will allow for further study and insights. Disclosures Gertz: Teva: Consultancy; Prothena: Honoraria; Alnylam: Honoraria; celgene: Consultancy; Ionis: Honoraria; Physicians Education Resource: Consultancy; Research to Practice: Consultancy; Amgen: Consultancy; janssen: Consultancy; Apellis: Consultancy; Medscape: Consultancy; Abbvie: Consultancy; spectrum: Consultancy, Honoraria; annexon: Consultancy. Lacy:Celgene: Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Russell:Vyriad: Equity Ownership. Kumar:KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Roche: Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding.

Abstract Background: The introduction of several novel agents has led to an improvement in response rates and survival outcomes in patients with newly diagnosed multiple myeloma. Despite significant therapeutic advances a subset of patients with multiple myeloma do not achieve a deep response to first-line treatment and biomarkers are needed to identify those at risk. Methods: We studied 472 patients with newly diagnosed multiple myeloma who were treated in clinical practice (n = 280, training cohort) or on prospective clinical trials (n = 192, validation cohort) at Mayo Clinic between 12/2003 and 12/2015. All patients had measurable disease (M-spike ≥ 1.0 g/dL) and received treatment with novel agents. Serum M-spike and free light chains (FLC) were measured before and after the first treatment cycle. The outcome of interest was the best response to first-line treatment (evaluated using the International Myeloma Working Group Uniform Response Criteria). Failure to achieve a deep response was defined as not achieving a very good partial response or better. The serum parameters of interest were the relative decrease in M-spike and absolute free light chain difference (ΔFLC). The Wilcoxon signed-rank test was used to compare the serum parameters before and after the first treatment cycle. Logistic regression models were used to assess the associations between the change in serum parameters after the first treatment cycle and best response to first-line treatment. P-values below 0.05 were considered statistically significant. Results: The median age at diagnosis in the training and the validation cohort were 67 (32 - 94) and 66 years (41 - 86), respectively. One hundred eighty one (65%) and 103 patients (54%) were male, respectively. The three most common regimens in the training cohort were lenalidomide + dexamethasone, lenalidomide + cyclophosphamide + dexamethasone, and bortezomib + lenalidomide + dexamethasone. In the validation cohort, the three most common regimens were carfilzomib + thalidomide + cyclophosphamide, lenalidomide + cyclophosphamide + dexamethasone, and ixazomib + cyclophosphamide + dexamethasone. In the two cohorts, the median baseline M-spike decreased from 3.1 g/dL (1.0 - 10.0) to 1.7 g/dL (0.0 - 6.6) and 3.2 g/dL (1.0 - 8.5) to 1.4 g/dL (0.0 - 4.5) after the first treatment cycle, respectively (p < 0.001 for both comparisons). The median baseline ΔFLC decreased from 31.1 mg/dL (0.0 - 2269.7) to 5.4 mg/dL (0.0 - 785.8) and from 23.3 mg/dL (0.1 - 3579.6) to 4.3 mg/dL (0.0 - 1139.3) after the first treatment cycle, respectively (p < 0.001 for both comparisons). M-spike reduction < 50% during the first treatment cycle was associated with failure to achieve a deep response: OR 4.54 (95% CI 2.72 - 7.58, p < 0.001) in the training cohort and OR 6.68 (95% CI 3.42 - 13.03, p < 0.001) in the validation cohort. Patients with reduction in M-spike < 10% during the first treatment cycle experienced failure to achieve a deep response in 86% (25/29) and 100% (10/10), respectively. ΔFLC reduction < 50% during the first treatment cycle was associated with treatment failure to achieve a deep response: OR 4.83 (95% CI 2.83 - 8.25, p < 0.001) in the training cohort and OR 5.09 (95% CI 2.37 - 10.92, p < 0.001) in the validation cohort. Patients with reduction in ΔFLC < 10% during the first treatment cycle experienced failure to achieve a deep response in 83% (34/41) and 91% (19/21), respectively. Conclusions: Early changes in M-spike and ΔFLC are strong predictors of response to treatment. We established and prospectively validated two readily available biomarkers that can identify patients at risk for treatment failure and may inform treatment decisions in newly diagnosed multiple myeloma. Disclosures Lacy: Celgene: Research Funding. Gertz:Physicians Education Resource: Consultancy; janssen: Consultancy; Teva: Consultancy; Alnylam: Honoraria; Research to Practice: Consultancy; Apellis: Consultancy; Medscape: Consultancy; annexon: Consultancy; Abbvie: Consultancy; celgene: Consultancy; Prothena: Honoraria; Ionis: Honoraria; Amgen: Consultancy; spectrum: Consultancy, Honoraria. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Russell:Vyriad: Equity Ownership. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Kumar:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract Background: It is well known that the staging stratification at diagnosis predicts survival in immunoglobulin light chain (AL) amyloidosis, but there is a paucity of literature delineating the prognostic value of these systems at the time of 2nd-line therapy. Methods: We conducted a retrospective study to evaluate the prognostic value of AL staging among 563 patients with staging data, who initiated a 2nd-line therapy between 2000 and 2015. Both the Revised Mayo 2012 staging system and the European revision of the Mayo 2004 staging system were used. Results: The median time from initial treatment to 2nd-line therapy was 11.6 months. Median follow-up from institution of 2nd-line therapy was 54.1 months. The 1st-line therapy for patients was autologous stem cell transplant (ASCT) in 216 (38%) patients; and 2) non-ASCT therapies in 347 patients. Both staging systems were prognostic with a risk ratio of 9.4 (95%CI: 6.0, 15.1; p<0.0001) between stage IIIb and I, and of 12.2(8.1, 18.5; p<0.0001) between IV and I. At the time of 2nd-line therapy the staging systems' predictive values were independent of what the patients' 1st-line therapies had been despite the fact that the median time from initial treatment to 2nd-line therapy was 19.4 months in ASCT group and 8.0 months in non-ASCT group. Among the patients receiving 2nd-line therapy after ASCT, the 5-year overall survival (OS) from 2nd-line therapy for those with ≤ stage II versus >stage II was 65% and 31% (Mayo 2004) and 70% and 23% (Mayo 2012). The respective numbers for patients relapsing from a non-ASCT therapy were 57% and 26% (Mayo 2004) and 60% and 23% (Mayo 2012). Conclusions: This study indicates that the Mayo staging systems work well at the time of instituting 2nd-line therapy and is independent of whether 1st-line therapy was ASCT based. Figure. Figure. Disclosures Gertz: annexon: Consultancy; Medscape: Consultancy; Apellis: Consultancy; celgene: Consultancy; Prothena: Honoraria; Abbvie: Consultancy; Amgen: Consultancy; Physicians Education Resource: Consultancy; spectrum: Consultancy, Honoraria; Ionis: Honoraria; Research to Practice: Consultancy; Teva: Consultancy; janssen: Consultancy; Alnylam: Honoraria. Kumar:KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding. Lacy:Celgene: Research Funding. Dingli:Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Russell:Vyriad: Equity Ownership. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding.

Abstract Abstract 845 Background: Waldenstrom's macroglobulinemia (WM) is a relatively uncommon plasma cell disorder and most of previous literature is limited to small patient series. We have noted ethnic disparities in multiple myeloma, another plasma cell disorder. We undertook a large Surveillance Epidemiology and End Results (SEER) based analysis to describe outcome disparities in different subgroups of WM patients, with a focus on various ethnicities, so that therapeutic resources can be targeted more effectively. Methods: The SEER 17 Registry data (1973–2008) was utilized for patients with confirmed diagnosis of WM. To avoid bias of under representation of different ethnicities, analysis was restricted to patients with a diagnosis date of 1992 or later. Cases that received a diagnosis at death certificate or autopsy, no follow-up records, as well as lacking documentation on age at diagnosis, sex, or race/ethnicity were excluded. Cox proportional hazards models, adjusted for gender, age, race, year of diagnosis, marital status and stratified by SEER registries were used to evaluate associatio n between patient characteristics and survival. All statistical tests were two-sided and utilized the SAS software (v9.2) with a significance level of 0.05. Results: The final analysis included 2,840 WM patients (1,759 males; 62%, 1,081 females; 38%). The studied age-group cohorts included: 18–64 yrs (845; 30%), 65–74 yrs (795; 28%) and >75 yrs (1,200; 42%). Patients were stratified by race/ethnicity: White (2,471; 87%), African-American (AA) (102; 4%), Hispanic (133; 5%), Asian (129; 5%), and Native American (5; 0.1%). Patients were also stratified based on year of diagnosis (before or after 2002) to study the impact of certain novel agents (proteasome inhibitors, IMiDs) on WM treatment. There was a significant difference in the age at diagnosis of WM patients across different ethnicities, with AA the youngest (median 61.5 years) and Whites the oldest (median 73 years) subgroup (p<0.001). (Figure 1) Cause-specific mortality could not be evaluated due to variable documentation of reported causes of death for WM patients in the database. Survival analysis revealed that for all patients, females had better median overall survival (OS) than males (7.3 years vs. 6.2 years, HR 0.834; 95% CI 0.740, 0.939; p=0.003). Among the different age cohorts, patients with age ≥75 years had a significantly worse median OS (4.1 years) than those 65–74 year-old (7.3 years) or 18–64 year-old (10+ years) (p<0.001). Patients diagnosed after 2002 had a significantly better median OS (7.3 years) as compared to patients diagnosed previously (6.1 years) (p=0.002). Hispanics had the worst median OS (5 years) and Whites had the best median OS (6.8 years) across various ethnicities. In a multivariate model using gender, age, marital status, year of diagnosis and race, a significant interaction was noted between race, age and survival, with Hispanics having a significantly worse OS than Whites (HR 1.86; 95% CI 1.269, 2.726; p=0.003) (Figure 2). Conclusions: Studies of outcome disparities are important for evaluating disease characteristics and management needs of specific patient populations as well as optimal triaging of healthcare resources. We have performed the largest population-based analysis for WM including various ethnicities in the novel therapeutic agent era. We observed that AA patients had a significantly younger age at WM diagnosis. Older patients had worse OS across all ethnic subgroups and patients diagnosed after 2002 had a better OS suggesting an impact of novel therapeutic agents (e.g., proteasome inhibitors, IMiDs). Hispanic WM patients had the worst OS among all ethnicities. This survival difference was more significant and pronounced in patients >75 years. This suggests that the impact of race on survival is influenced by patient's age. These results will help in better understanding of various influences on disease biology and clinical behavior. Disclosures: No relevant conflicts of interest to declare.

Abstract Chimeric antigen receptor T cell (CART) therapy has developed as a powerful and potentially curative therapy in hematological malignancies over the last few years. CD19 directed CART cells have resulted in impressive complete response rates of ~90% in acute lymphoblastic leukemia that are durable for the majority of patients. However, the overall response rates in other malignancies such as chronic lymphocytic leukemia are around 50%. This could be partially related to CART exhaustion and dysfunction induced by leukemia cells. In this study, we aim to evaluate the role of inhibitory receptors/pathways in inducing CART cell dysfunction and exhaustion in hematological malignancies. As a tumor model, we used an acute myeloid leukemia (AML) cell line (MOLM14) and primary AML samples and treated them with CD33 or CD123 directed CART cells (second generation CARs using 4-1BB and CD3z signaling domains and a lentiviral vector). Incubation of primary AML samples or MOLM14 cell line with CD33 or CD123 directed CARTs resulted in a significant up-regulation of PD-L1 on tumor cells after 24 hours of incubation (0% on day 0 vs 80% on day 1, P <0.001), and up-regulation of PD-1 and TIM-3 on T cells 3-7 days post co-culture (8% of T cells expressed PD-1 on day 0 vs 43% on day 3, P=0.03 and 13% of T cells expressed TIM-3 on day 0 vs 71% on day 3, p=0.001, Figure 1). For in vivo experiments, we used NSG (NOD-SCID-g-/-) mice and engrafted them with the MOLM14 cell line. Treatment of these AML xenografts with suboptimal doses of CD33 or CD123 CARTs resulted in initial anti-tumor responses, followed by disease relapses in 40-60% of the mice (Figure 2A). T cells were isolated from the bone marrow of these mice and analyzed for differential expression of inhibitory receptors. There was a significantly increased up-regulation of TIM-3 receptors on T cells isolated from mice with relapsed disease compared with T cells isolated from mice in remission after CART cell therapy (Figure 2B). Next, we investigated the role of adding checkpoint blockade to improve T cell function ex vivo after CART cell therapy. Marrows of mice that relapsed after CART cell therapy contained both residual CART cells and leukemia and were used to model the administration of checkpoint blockade in the setting of CART cell exhaustion. Cells were cultured with PD-1 or TIM-3 blocking antibodies or the combination of both (10 ug/ml for 72 hours). CART cell effector functions such as cytokine production and Ki-67 proliferation marker improved in the presence of checkpoint antagonists especially when both PD-1 and TIM-3 blocking antibodies were combined (figure 2C). Finally, we tested the combination of checkpoint blockade with CARTs in AML xenografts. In this approach, we treated MOLM14 xenografts with suboptimal doses of CD33 or CD123 directed CARTs or with control untransduced T cells (UTD), with or without checkpoint blocking antibodies. NSG mice bearing MOLM14 AML xenografts were established. Engraftment was confirmed by bioluminescent imaging. The tumor bearing mice were then treated with suboptimal doses (0.25-0.5 x106 total T cells I.V) of CD33 or CD123 directed CARTs or with control untransduced T cells (UTD). Mice also received PD-1 blockade, TIM-3 blockade or the combination of both on days 3, 6, 9 and 12 post T cell therapy, with the rationale for early checkpoint blockade being based on our in vitro observations of early upregulation of inhibitory ligands on AML after exposure to CART cells. Mice were then followed with serial imaging to assess disease burden. The addition of checkpoint antagonists to untransduced T cells, in particular anti-TIM3, did not lead to an anti-leukemic effect. However, the addition of PD-1 or TIM-3 blockade to CART cell therapy resulted in a synergistic anti-tumor activity as shown in Figure 3. The durable complete response rate was: 45% for treatment with CART123 alone, 80% for treatment with CART123+PD-1 blockade, 100% for treatment with CART123+TIM-3 blockade, and 80% for treatment with CART123+ both PD-1 and TIM-3 blockade). Our preclinical results indicate that PD-1 and TIM-3 pathways are involved in CART exhaustion and dysfunction in AML. Combination of checkpoint inhibitors with CART cells may lead to enhanced efficacy in AML and other hematological malignancies. Current studies are investigating mechanisms of synergy and the role of these combinations in other hematological malignancies. Figure 1. Figure 1. Figure 2. Figure 2. Figure 3. Figure 3. Disclosures Kenderian: Novartis: Patents & Royalties, Research Funding. Ruella:Novartis: Patents & Royalties, Research Funding. Porter:Novartis: Patents & Royalties, Research Funding. June:University of Pennsylvania: Patents & Royalties: financial interests due to intellectual property and patents in the field of cell and gene therapy. Conflicts of interest are managed in accordance with University of Pennsylvania policy and oversight; Novartis: Research Funding. Gill:Novartis: Patents & Royalties, Research Funding.

Abstract Multiple myeloma (MM) is an age dependent second most common hematopoietic malignancy which remains incurable despite recent advances in therapies. Monoclonal gammopathy of undetermined significance (MGUS) is a common premalignant condition that precedes MM. Dysregulation and mutations of myriad of molecules is implicated in pathogenesis of MM. Cyclins (CCND) are almost universally dysregulated in MGUS and MM, while c-MYC overexpression and sometimes RAS mutations are associated with MGUS to MM progression. c-MYC, because of its strong association in this malignant transformation and it being a master regulatory factor is a logical therapeutic target. But, a therapeutic approach to target c-MYC has not been successful. So a strategy to target either upstream or downstream molecules in c-MYC pathway is worth considering. Ornithine decarboxylase (ODC) is one such downstream effector of c-MYC which regulates polyamine synthesis and thus regulates cell proliferation. ODC is also downstream of RAS which makes it common to two of the important oncogenes involved in MM. To know whether ODC plays a role in MM pathogenesis, we looked into its gene expression profile in the MM patients. In the Mayo cohort of 100 patients we found significant difference in ODC expression as disease progresses from MGUS to MM. We found significant survival difference in MM patients from this cohort which were divided by ODC expression and this survival difference was more pronounced in non-hyperdiploid group (median survival were for ODC < 1 - 66 mo vs for ODC > 1 - 29.5 mo, Figure 1A) which is a known poor prognostic group. When looked at ODC expression among different TC classes in MMRC dataset, we find ODC expression significantly higher in known high risk and poor prognostic groups 4p16 and MAF than other groups. These findings suggest higher ODC expression associated with poor survival. To further strengthen our observation, we analyzed TT3 group of Arkansas cohort and we observe prolonged event free survival (Figure 1B) and overall survival in patients with low ODC expression as compared to patients with high ODC expression (Figure 1C). After establishing poor prognostic role of ODC, we wanted to test it as a potential therapeutic target. For this purpose, we employed DFMO (Difluromethylornithine) which is the enzymatic irreversible inhibitor of ODC. We tested 15 different MM cell lines for proliferation with DFMO, majority of them respond to DFMO and IC 50 ranged from 28uM to 70 uM. DFMO generally halted cell cylce in G1S and had a cytostatic effect. We further tested efficacy of DFMO in combination with standard anti-myeloma agents lenalidomide, bortezomib, Vorinostat, melphalan and dexamethasone. We found these combinations to be synergistic except with melphalan where the combination was antagonistic. We therefore suggest that DFMO, which has a good toxicity profile can be advantageous in MM patients who are relatively old and many times cannot tolerate extensive chemotherapy for its toxicity. Moreover since it is synergistic in preclinical model with two main anti-myeloma agents lenalidomide and bortezomib, it may well be combined with both to decrease the amount of drug needed and hence toxicity. We think it will be especially beneficial to those patients who have high ODC levels. So we propose ODC to be a prognostic marker and therapeutic target in MM. Disclosures Chirackal: Mayo Clinic: Patents & Royalties: Filed a professional US patent for quantifying cellular anti-oxidative capacity. Fonseca:Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Bayer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Onyx/Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Binding Site: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Applied Biosciences: Membership on an entity's Board of Directors or advisory committees.

Abstract Introduction: Customized gene panel sequencing is an attractive approach to genomic tumor characterization in clinical care. Based on published MM exome data we developed a MM Mutation Panel (M3 P) that includes the most commonly mutated genes, actionable drug targets, genes targeted by current standard of care (SOC) therapies and which allows tracking of clonal evolution, copy number and sample purity. Methods and Material: M3 P (v3.0) covers 88 genes (1327 amplicons, 181kb). MM samples from 504 patients (pts) have been analyzed (corresponding germline in 81%) through collaborations between Mayo Clinic and Hospital-12-de-Octubre (Madrid, Spain), the DSMM and GMMG (Würzburg, Ulm, Freiburg and Heidelberg, Germany) and the HOVON trial groups (Rotterdam, The Netherlands). The investigated cohort includes 410 untreated pts (81%), which includes a high risk cohort of 72 pts with del17p, 25 paired samples with later follow up from the same cohort, and 94 relapsed patients, of which 50 were relapsed and refractory. Results: Overall coverage per mutation averaged >500x depth. We identified 945 variants (1.9 per pt) and in 83% of the pts a mutation was found. Clonal heterogeneity was assessed with mutations ranging from 3%-100% variant reads suggesting the presence of a significant number of subclones (e.g. 21% of mutations were in < 10% of reads). The mutation incidence was compared with and closely resembles the most recent MM comprehensive genomic data from the MMRF CoMMpass study: We compare here all pts sequenced by M3 P, untreated pts sequenced by M3 P and CoMMpass: KRAS (24%/23%/24%), NRAS (20%/20%/18%), DIS3 (13%/14%/10%), BRAF (9%/7%/6%), FAM46C (6%/6%/8%) and TRAF3 (6%/6%/7%). TP53 mutation incidence, however, was significantly increased in our cohort (14%/12%/4.2%), a difference explained by the inclusion of del17p (untreated) and relapsed refractory MM in panel sequenced pts, cohorts with elevated incidences of TP53 mutations (32% / 26% respectively). Potentially actionable targets include BRAF mutationsin 43 patients (9%), with druggable p.V600E in 19 or 5%, 8 pts (2%) with FGFR3 (p.R248C and p.G375C one patient each), p.R132 mutation in 4 out of 5 IDH1 (1%) and p.R172K IDH2 mutation in 1 of 3 (1%) pts. Mutations in the MAPK pathway (NRAS, KRAS, BRAF) were detected in 59% of pts, ranging from 36% untreated MM to 72% in refractory MM. Similarly, the CRBN/CUL4B/IKZF1/IKZF3/IRF4 pathway, important for IMiD function, harbored a significant enrichment of mutations in advanced disease (6% untreated vs 17% relapsed), including CRBN mutations (0.5% vs 7%). Nine of 17 IRF4 mutations were located at the p.K123R hotspot, with minor difference between early or late disease (1% vs 3%). Notably, in 8 of 9 pts with CRBN mutation and clinical information, all were unresponsive to IMiD therapy, supporting association of these mutations with resistance to IMiDs. Conversely, M3 P genes related to other SOC therapies, including NR3C1 (targeted by steroids) and 5 proteasome subunit genes (proteasome inhibitors), were rarely mutated across the cohorts not exceeding 1% mutation incidence for each gene. Significant differences in DIS3 and FAM46C mutation incidences were observed across cohorts: DIS3 mutations are more common in untreated pts with a 1.7 fold increased predominance (14% untreated and 8% treated). FAM46C has an expected incidence of 8% but was rarely mutated in untreated del17p high risk disease with only one of 100 patients harboring both mutations. The significance of this finding needs to be determined but implies a possible overlap in function. Finally we assessed impact on survival of the mutation variants identified in 142 untreated Mayo patients and found STAT3 mutations negatively impacting PFS (p=0.034) and OS (p=0.001). This gene is rarely mutated in MM (2% of the total cohort) thus the sample size was small and this finding needs further validation. Conclusion: We here describe 504 MM patients sequenced using the M3 P gene panel, which identified mutations in >80% of investigated patients, overlaps well with published whole exome sequence data and provides clinically relevant information. New findings were the high frequency of minor clones, the relative lack of overlap of del17 and FAM46C mutation, a higher frequency of DIS3 mutation at diagnosis compared to relapse, the prognostic significance of STAT3 mutation and the frequent presence of CRBN pathway mutation in drug resistant relapsed patients. Disclosures Sonneveld: Janssen-Cilag, Celgene, Onyx, Karyopharm: Honoraria, Research Funding; novartis: Honoraria. Mai:Janssen-Cilag: Other: Travel Grant; Onyx: Other: Travel Grant; Mundipharma: Other: Travel Grant; Celgene: Other: Travel Grant. Goldschmidt:Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Onyx: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millenium: Honoraria, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Chugai: Honoraria, Research Funding, Speakers Bureau; Janssen-Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Knop:Celgene Corporation: Consultancy. Kull:Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees. Martinez-Lopez:Novartis: Honoraria, Research Funding; Bristol-Meyer Squibb: Honoraria; Celgene: Honoraria; Janssen: Honoraria. Einsele:Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Amgen/Onyx: Consultancy, Honoraria, Speakers Bureau. Raab:Novartis: Research Funding. Stewart:Oncospire Inc.: Equity Ownership; Celgene: Consultancy; Novartis: Consultancy; BMS: Membership on an entity's Board of Directors or advisory committees.