Abstract: Background: The total therapy 3 protocol for multiple myeloma (MM) introduced the use of intensive induction with VDT-PACE, a combination of bortezomib, dexamethasone, thalidomide, cisplatin, adriamycin, cyclophosphamide, and etoposide for newly diagnosed MM patients. This regimen, which demonstrated rapid responses in the first-line setting, has also been used in relapsed disease, to rescue induction failures or for stem cell mobilization. We evaluated the efficacy and toxicity of using VDT-PACE in these clinical settings. Patients and Methods: We identified 84 patients through pharmacy profile review who received at least one cycle of VDT-PACE for the treatment of MM between 1/2007 and 8/2013 at our institution. Patients were grouped into a stem cell collection cohort (C) if stem cell pheresis was performed following VDT-PACE. Remaining patients were analyzed in the relapsed cohort (RR). The primary objective of this study was to determine the overall response rate with combination VDT-PACE. Secondary Objectives include progression-free survival (PFS), overall survival (OS), stem cell collection in patients that underwent chemomobilization, and the extent of toxicity. Results: In the RR group, 45 patients received VDT-PACE after a median of 4 prior therapies (range 1-8) including autologous stem cell transplantation (ASCT) in 79%. The median time between diagnosis and first cycle of VDT-PACE treatment was 35.4 months (range 1.3-163.4). 47% of patients had adverse cytogenetics defined as presence of complex karyotype or FISH with del 17p, t4;14, or t14;16. Patients received a median of 2 cycles of VDT-PACE (range 1-4) with a response rate after all cycles of 51% (2% CR, 22% VGPR, 27% PR). Additional therapy was administered in 82% within 6 months (18% allogeneic SCT, 35% ASCT, 29% chemotherapy regimens). 18% of patients died without additional therapy (13% from disease progression, 5% from toxicity), all within 5 months of their last VDT-PACE cycle. PFS and OS for the RR group was 8.8 months (95% CI 4.6, 13.1) and 10.3 months (95% CI 8.8, 17.4), respectively. Patients that received subsequent lines of therapy following VDT-PACE achieved a median PFS and OS of 9.5 months (95% CI 5.6, 13.3) and 9.5 months (95% CI 7.5, 32.1), respectively, measured from the time of next therapy. In the C group, 39 patients received a median of 2 prior regimens (range 1-4) before starting VDT-PACE and 31% of patients had adverse cytogenetics. Reasons for using VDT-PACE for mobilization included residual or progressive disease (64%), provider discretion (33%), and failure of a prior attempt at collection (3%). The median time between diagnosis and first cycle of VDT-PACE treatment was 7 months (range 2.3-122.7). Patients received a median of 2 cycles (range 1-4) of VDT-PACE. The median number of cells collected was 12.3x106CD34 cells/kg (range 0.21-43.74) and the median number of collection session required was 2 (range 1-6), with 21% of patients requiring plexirafor. Two patients (5%) from this group failed collection. The response rate after all cycles of VDT-PACE was 59% (3% CR, 13% VGPR, 44% PR). 35 out of the 39 patients went to transplant following VDT-PACE (34 ASCT, 1 allogeneic SCT). Of the 4 patients who did not receive transplant, 2 were for toxicity attributed to VDT-PACE, 1 for failure to mobilize, and 1 for personal reasons. The post-transplant response rate was 91% (17% CR, 34% VGPR, 40% PR) with 1 patient (3%) experiencing disease progression immediately after transplant. Median PFS and OS for the C group patients was 34.5 months (95% CI 20.2, n.r.) and 64.8 months (95% CI 26.0, n.r.), respectively. Reported toxicities following treatment included infection (20%), fatigue (19%), nausea (17%), renal complications (6%), thrombosis (4%), and edema (4%), which were seen in 67% and 62% of the RR and C groups, respectively. Hospital readmission for management of side effects occurred in 30% of patients. Conclusions: VDT-PACE is an effective therapy for RR patients and for stem cell mobilization in patients with residual or progressive disease following initial therapy. Importantly, it is also associated with significant morbidity and requires careful monitoring. VDT-PACE does not appear to adversely affect stem cell collection or SCT outcomes. At our institution, this regimen is commonly used for stem cell collection in patients with unfavorable outcomes following initial therapy. Disclosures No relevant conflicts of interest to declare.

Abstract: Background: The aggressive approach to first-line treatment of multiple myeloma (MM) incorporating autologous stem cell transplantation (ASCT) remains widely prevalent, although it is not without controversy in the current era of novel effective agents. Some trials and meta-analysis comparing ASCT to non-myeloabaltive standard therapy or delayed ASCT have failed to show an overall survival (OS) difference between the two arms [Fermand et al. Blood 92:3131-3136 (1998); Koreth et al. BBMT 13:183-196 (2007); Kumar, et al. Cancer 118(6):1585-92 (2012)]. On the other hand, analysis of transplant-eligible patients receiving lenalidomide and dexamethasone induction on the E4A03 trial and then either undergoing ASCT or continuing lenalidomide and dexamethasone showed that ASCT conferred improved OS (Blood 2010;116:38a). This controversy lead us to design a phase II clinical trial comparing continuous lenalidomide and dexamethasone (Ld) versus ASCT followed by lenalidomide maintenance, in patients responding to four cycles of Ld. Methods: Patients with newly diagnosed symptomatic MM as defined by IMWG criteria were enrolled. Patients deemed to be in urgent need of aggressive therapy (e. g. symptomatic bone disease, acute renal failure, hyperviscosity syndrome, etc) were not eligible. Patients received induction with lenalidomide (L) 25 mg PO daily on days 1-21, and dexamethasone (d) 40 mg PO daily on days 1,8,15, and 22 of a 28-day cycle with standard prophylaxis. Patients with POD during induction or SD after four cycles of Ld were taken off study. All other patients had stem cells harvested after four cycles of Ld and were randomized to either the continuous (Ld) arm (L at the last tolerated dose during induction, continued indefinitely until progression or toxicity; and d at 20mg weekly for one year) or the ASCT arm (using melphalan conditioning followed by L maintenance started three months post-ASCT at 10mg daily, escalated to 15 mg daily six months post-ASCT and continued indefinitely until progression or toxicity). Results: Fifty seven patients have been registered to the trial. Two patients did not initiate therapy, one because of a concurrent diagnosis of amyloidosis and the other due to aggressive disease mandating alternative therapy according to the treating physician. At this time, four patients are still receiving induction therapy and are not available for response assessments. Among the 51 remaining patients, the response to initial induction therapy includes 12% CR (n=6), 2% uCR (n=1), 4% nCR (n=2), 14% VGPR (n=7), 51% PR (n=26), 6% SD (n= 3), 4% POD (n=2), and 8 % inevaluable (n = 4 who did not receive at least two cycles of Ld). Thirteen patients were removed from the trial prior to randomization due to POD (n=2), SD after four cycles (n=3), toxicity (n=4), physician discretion (n=2), and withdrawal of consent (n=2). Among these 13 patients, one was lost to follow-up, two continued lenalidomide therapy off protocol (one patient refused ASCT, and one patient had inadequate stem cell collection), and 10 proceeded to alternative induction. All 12 patients achieved a response [25 % CR (n=3), 42 % VGPR (n=5), and 33 % PR (n=4)]; 10 patients proceeded to ASCT without event. Thirty-eight patients were randomized, 20 to Ld and 18 to ASCT. Improvement of response by at least one level occurred in 45% and 65% of patients on the Ld and ASCT arms, respectively. The median follow-up for all surviving patients from time of randomization is 38.3 months. The 1- and 3-year PFS in the Ld arm were 100% and 66%, respectively. The 1- and 3-year PFS in the ASCT arm were 89% and 68%, respectively. The 2- and 3-year OS in the Ld arm were 100% and 92%, respectively. The 2- and 3-year OS in the ASCT arm were 100% and 85%, respectively. Considering the entire population of 51 patients, with a median follow-up of 38 months, the median PFS has not been reached. Conclusions: This interim analysis, with relatively short follow-up, suggests that in transplant-eligible patients responsive to Ld during induction, continuous Ld results in similar PFS and OS compared to patients who undergo ASCT followed by L maintenance. Furthermore, this overall approach based on response-adapted treatment results in 100% of patients reaching at least PR at completion of first-line therapy. The trial remains ongoing. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

Abstract: Introduction: Programmed cell death-1 (PD-1) signaling suppresses the antigen driven activation of T cells upon interaction with its ligands PD-L1 and PD-L2. The PD-1/PD-L1 axis is thought to mediate the resistance of multiple myeloma to conventional therapy (Tamura 2013; Paiva 2015). Nivolumab, a fully human IgG4 monoclonal PD-1 receptor-blocking antibody, has shown clinical activity in a variety of tumor types. Nivolumab has demonstrated a prolonged receptor binding kinetic lasting 〉 100 days that may lead to an efficacy or toxicity signal in the post-treatment period. We therefore evaluated the response of patients with relapsed or refractory multiple myeloma to additional myeloma therapy received within 3 months of the end of nivolumab administration. Methods: The preliminary results of an open-label study that treated patients with relapsed or refractory multiple myeloma using a dose escalation design (1 mg/kg and 3 mg/kg) of nivolumab administered every 2 weeks have been reported previously (NCT01592370, Lesokhin et al., ASH 2014). Here we will report responses and safety data using standard criteria to the next line of therapy received immediately after nivolumab. Results: 8 patients with multiple myeloma from the original open label study were treated at Memorial Sloan Kettering Cancer Center. The disease characteristics and efficacy results are shown in the table. 1 of 8 patients (12.5%) experienced progression while on therapy manifested by development of an isolated plasmacytoma. The patient received radiation and then resumed and completed 97 weeks of therapy with nivolumab. He is currently off therapy without any evidence of disease at 48 weeks after cessation of nivolumab. 3 of 8 patients (37.5%) achieved a partial response to the next line of treatment after nivolumab. 2 of 8 patients (25%) who were exposed and refractory to immunomodulatory drugs (IMiDs) received single-agent, low-dose lenalidomide as the next line of therapy and achieved stable disease lasting approximately 100 days after cessation of nivolumab followed by disease progression. 1 of 8 patients (12.5%) experienced progressive disease despite the next line of therapy, and 1 of 8 patients (12.5%) received an experimental treatment as the next line of therapy and was therefore not evaluable. No new drug-related adverse events occurred in the 3 months after completing treatment with nivolumab. Overall, 6 out of 8 patients derived clinical benefit from post-nivolumab therapy, an unusually high response rate for this population. Conclusions: In a small cohort of patients with relapsed and refractory multiple myeloma, evaluation of response kinetics after cessation of nivolumab supports the notion that long PD-1 receptor binding kinetics may increase the efficacy of subsequent therapy without added toxicity. Larger studies are needed to confirm and expand our findings. Table. Patient Characteristics and Efficacy Age Sex ISS Cytogenetics Prior Lines ASCT IMiD E IMiD R Prot E Prot R Best Response to Nivolumab Next Line of Standard Therapy Best Response to Next Line 52 M 1 S 3 Y Y Y Y Y SD Carfilzomib, Cyclophosphamide, Dexamethasone PR 32 M 1 S 3 Y Y Y Y Y SD None* N/A 80 F 1 S 1 N Y N N N SD Lenalidomide PR 52 F 1 I 3 Y Y Y Y N SD Lenalidomide SD 62 M 1 H 1 Y Y N Y N PD Cyclophosphamide, Bortezomib, Dexamethasone PR 58 M 2 S 5 Y Y Y Y Y PD Lenalidomide SD 57 F 1 S 3 Y Y N Y Y PD None^ N/A 59 F 1 S 3 Y Y Y Y Y PD Lenalidomide, Bortezomib, Dexamethasone PD ISS=international staging system; S=standard cytogenetics; I=intermediate cytogenetics; H=high risk cytogenetics; ASCT=autologous stem cell transplant; IMiD E=IMiD exposed; IMiD R=IMiD refractory; Prot E=proteosome exposed; Prot R=proteosome refractory; PD=progressive disease; SD=stable disease; PR=partial response *Patient completed 97 weeks of nivolumab and continues untreated without any evidence of disease at 48 weeks after cessation of therapy ^Patient received treatment on an experimental protocol Disclosures Funt: Kite Pharma: Equity Ownership. Off Label Use: Nivolumab is FDA approved for use in patients with metastatic melanoma but not in patients with multiple myeloma. . Page:Celgene: Consultancy. Landgren:Bristol-Myers Squibb: Honoraria; Celgene: Consultancy; BMJ Publishing: Consultancy; Bristol-Myers Squibb: Consultancy; BMJ Publishing: Honoraria; Medscape: Consultancy; Medscape: Honoraria; Celgene: Honoraria; International Myeloma Foundation: Research Funding; Onyx: Honoraria; Onyx: Research Funding; Onyx: Consultancy. Borrello:Celgene: Research Funding. Lesokhin:Bristol Myers Squibb: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Aduro: Consultancy; Genentech: Research Funding; Efranat: Consultancy.

Abstract: Background: High-dose chemotherapy followed by ASCT remains the standard of care for patients aged ≤75 years with NDMM. The ability of novel agents, such as lenalidomide and bortezomib, to produce treatment response rates comparable to those seen with ASCT has raised questions about the necessity for upfront ASCT in transplant-eligible NDMM patients. This analysis aimed to compare the efficacy and safety of continuous Ld versus Ld+ASCT in patients with NDMM. Methods: Data were pooled from two randomized clinical trials (NCT01731886 and NCT00807599) that compared Ld alone versus Ld+ASCT in NDMM patients aged ≤75 years. Patients received four 28-day cycles of Ld (lenalidomide 25mg daily on days 1-21; dexamethasone 40mg on days 1, 8, 15, and 22) followed by stem-cell mobilization and collection, and either a) Arm A: continuous Ld (an additional 4 cycles +/- lenalidomide maintenance in NCT01731886, or continuous lenalidomide at the last tolerated dose until disease progression plus dexamethasone 20mg for 1 year following treatment initiation in NCT00807599); or b) Arm B: ASCT conditioned with high-dose melphalan, and followed by lenalidomide maintenance therapy. In both trials, patients were withdrawn if they developed progressive disease (PD) at any time, or had stable disease (SD) after cycle 4 of Ld induction. We evaluated overall response rate (ORR; defined as a partial response or better), progression-free survival (PFS), overall survival (OS), and adverse event (AE) incidence rates, focusing on those randomized patients who responded to 4 cycles of Ld induction. Results: Sixty patients were enrolled into NCT01731886, and 63 into NCT00807599. The analysis included a total of 85 patients who had been randomized and achieved a response to 4 cycles of Ld induction: 41 in Arm A, and 44 in Arm B. Mean ages in Arm A versus Arm B were 61.8 versus 61.7 years; median (range) follow-up times were 3.97 (0.27-6.19) versus 3.71 (0.16-5.66) years. Baseline cytogenetic risk profiles were similar overall, although Arm A contained a higher percentage of intermediate-risk patients (17.1% versus 11.4%). More than half of all patients included in the analysis had International Staging System stage 1 disease: 63.4% of patients in Arm A, and 47.7% of those in Arm B. Median PFS was similar with the two treatment approaches: 4.3 versus 4.4 years (Figure 1; p = 0.9107). OS also did not differ significantly between the two arms (Figure 2). As expected, both treatment regimens were well tolerated. Clinically significant grade 3 and 4 AEs occurring outside of the transplant period included the following: anemia (17.1% Arm A versus 15.9% Arm B); neutropenia (36.6% versus 38.6%); thrombocytopenia (17.1% versus 18.4%); infectious complications (14.6% versus 27.3%); thromboembolic events (7.3% versus 6.8%); and secondary malignancies (7.3% versus 4.5%). Conclusions: The findings of this pooled analysis suggest that, in transplant-eligible patients responsive to Ld induction, continuous Ld results in similar PFS and OS to Ld+ASCT. Larger phase III trials addressing this question are awaited. Figure 1. Figure 1. Figure 2. Figure 2. Disclosures Lentzsch: Celgene: Consultancy; BMS: Consultancy; Novartis: Consultancy; Janssen: Consultancy; Axiom: Honoraria. Landau:Janssen: Consultancy; Spectrum Pharmaceuticals: Honoraria; Prothena: Consultancy, Honoraria; Janssen: Consultancy; Onyx: Honoraria, Research Funding; Takeda: Research Funding. Lesokhin:Efranat: Consultancy; Genentech: Research Funding; Aduro: Consultancy; Janssen: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding. Kewalramani:Celgene: Consultancy; Abbvie: Consultancy; Getchell v Doon East Community Hospital, Alfred Wakeman et al.: Consultancy. Comenzo:Karyopharm: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Janssen: Research Funding; Prothena: Research Funding; Takeda Millennium: Research Funding; Takeda Millennium: Membership on an entity's Board of Directors or advisory committees. Landgren:Celgene: Honoraria; Bristol-Myers Squibb: Honoraria; Medscape: Honoraria; Onyx: Honoraria; International Myeloma Foundation: Research Funding; Onyx: Research Funding; BMJ Publishing: Consultancy; BMJ Publishing: Honoraria; Medscape: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy; Onyx: Consultancy. Hassoun:Novartis: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Takeda: Research Funding.

Abstract: Background: For multiple myeloma (MM) patients, depth of response after induction therapy and after autologous hematopoietic stem cell transplantation (AHCT) has been shown to be important for progression free (PFS) and overall survival (OS) in some studies. Furthermore, the impact of minimal residual disease (MRD) on outcomes and treatment decisions has been widely discussed. We aimed to evaluate outcomes by depth of response after induction and AHCT. Methods: MM patients who received their first AHCT within 1 year of starting induction were identified from the institutional registry. MRD was assessed by non-10 color flow cytometry. Response was defined by the International Myeloma Working Group criteria. Summary statistics were used to describe the population. Kaplan-Meier methodology estimated PFS and OS by response status pre-AHCT and at post-AHCT restaging. Results: Between 2012 - 2014, 182 MM patients met our inclusion criteria, with 83% alive at last follow-up. The median age at AHCT was 60 years (range 29-76) with 57% male. By the International Staging System (ISS), 50% were stage I, 26% stage II, and 24% stage III. High risk cytogenetics were detected in 24%. Isotype was IgG in 55%, IgA 21%, Kappa Free Light Chain (KFLC) 11%, and lambda FLC (LFCL) 9%. First induction therapy included bortezomib in 90% and lenalidomide in 79%. Median time to AHCT was 5.5 months (range 2.8-11.7). The median follow-up from AHCT was 3.7 years (range 0.22 - 4.6 years), with 84% of patients receiving lenalidomide maintenance, and 9% receiving an additional autologous or allogenic transplant at relapse. Response prior to the initial AHCT was a complete remission (CR) in 13.7% (MRD negative 6.6%, positive 4.4%, unknown 2.7%), very good partial remission (VGPR) 38%, partial remission (PR) 40%, stable disease (SD) 5%, and progressive disease (PD) 4%. At post-AHCT restaging, responses had improved to 42% CR (MRD negative 23%, positive 6%, unknown 13%), 35% VGPR, 19% PR, 2% SD, and 3% PD. Median PFS from AHCT for the entire cohort was 3.2 years (95% CI 2.4 - 4 years) with 1-year and 3-year PFS 85% and 52%, respectively. Median OS was not reached (NR) (95% CI 4.4 years - NR) with 1-year and 3-year OS 97% and 88%, respectively (Figure 1). PFS from AHCT was significantly longer in patients with an MRD negative CR prior to AHCT with median PFS not reached (95% CI 1.7 - NR) compared to MRD positive/unknown CR, VGPR, and ≤ PR [3.64 years (95% CI 1.09-3.64), 3.46 years (95% CI 2.4 - NR), and 2.44 years (1.68-3.56 years), respectively, p=0.048] (Figure 2A). From post-AHCT restaging, PFS was also significantly longer in patients with an MRD negative CR prior to AHCT with median PFS not reached compared to MRD positive/unknown CR, VGPR, and ≤ PR [3.49 years (95% CI 0.86-3.49), 3.56 years (95% CI 2.5 - NR), and 2.4 years (1.6-3.33 years), respectively, p=0.026] (Figure 2B). However, there was no difference in PFS based on the post-AHCT restaging with median PFS in MRD negative CR, MRD positive/unknown CR, VGPR, and ≤ PR of 3.49 years (95% CI 2-NR), not reached (95% CI 1.4-NR), 2.96 years (95% CI 1.7-NR), and 2.86 years (95% CI 1.7 - NR) (p=0.78, Figure 2C), respectively. OS from AHCT was not significantly different by pre-AHCT response, and the median was not reached in any group (p=0.33, Figure 3A). Finally, the median OS from post-AHCT restaging by pre-AHCT response or by post-AHCT response was also not reached in any group (p=0.32 and 0.31, respectively; Figure 3B & C). Conclusion: For MM patients, AHCT deepened responses and increased the CR rate. We were unable to show a significant difference in outcomes at post AHCT restaging, which may be due to the effect of maintenance therapy, the small numbers of MRD negative patients, or the sensitivity of the MRD assay available during this time period, though potentially show that MRD positive patients do as well as MRD negative patients after AHCT. We plan to add additional patients treated in the more recent years who were assessed by more sensitive methods. Disclosures Shah: Janssen: Research Funding; Amgen: Research Funding. Korde:Amgen: Research Funding. Lesokhin:Janssen: Research Funding; Genentech: Research Funding; Takeda: Consultancy, Honoraria; Serametrix, inc.: Patents & Royalties: Royalties; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Squibb: Consultancy, Honoraria. Mailankody:Janssen: Research Funding; Physician Education Resource: Honoraria; Takeda: Research Funding; Juno: Research Funding. Smith:Celgene: Consultancy, Patents & Royalties: CAR T cell therapies for MM, Research Funding. Landgren:Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy; Merck: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding.

Abstract: Background: Monoclonal immunoglobulin deposition disease (MIDD) is a rare complication of plasma cell dyscrasias in which deposition of immunoglobulin light and/or heavy chains results in organ dysfunction, most commonly affecting the kidneys. MIDD can present with new onset hypertension, hematuria, renal insufficiency and proteinuria. The rarity of MIDD contributes to the uncertainty regarding optimal therapy (typically targeting the clonal plasma cells), and the relationship between hematologic response and renal outcome. We report here the experience at Memorial Sloan Kettering Cancer Center and New York Presbyterian Hospital/Weill Cornell Medical Center. Methods: An electronic query of pathology records was performed to identify patients with a biopsy-proven diagnosis of MIDD. Patients were eligible for inclusion in this analysis if they had received treatment and had been subsequently followed at either institution. A retrospective review of clinical records extracted patients' baseline characteristics and treatment history. Hematologic responses were assessed according to International Myeloma Working Group uniform response criteria (Kumar, S. et al 2016 Lancet Oncol 17(8): e328-346) and renal organ responses were evaluated based on changes in serum creatinine (SCr), and proteinuria, a modification of criteria previously reported (Kourelis, T. V., et al 2016, Am J Hematol 91(11): 1123-1128.; Nasr, S.H. et al. 2009, J Am Soc Nephrol 20(9): 2055-2064. The primary objective was to determine the rate of hematologic response after initial therapy. Secondary objectives included: (i) Estimation of renal response rate; (ii) Identification of risk factors associated with renal response using the Wilcoxon Rank Sum and Fisher's Exact Tests. Results: Among 54 patients identified who were diagnosed and started treatment between 1/1999 and 1/2016, 29 met criteria for inclusion. Baseline characteristics at diagnosis included: Median age of 50 (range, 32-79); 17 (59%) were male; 22 (75%) had hypertension. Renal parameters at diagnosis: median SCr of 2.4 mg/dl (range, 0.4-19), median CrCl 23 ml/min (range, 4-131), median proteinuria 2383.7mg/24h (range 4.7-13,000), nephrotic-range proteinuria syndrome in 13 (45%), hematuria in 4/25 pts (16%; 4 unknown), 7 were on hemodialysis (HD) prior to initiation of therapy, and 26 (90%) patients had monoclonal kappa light chain deposits. Hematologic parameters included median free light chain ratio of 67.9 (2.8-1179.0), detectable M-spike in 11 pts with a mean level of 0.6 g/dL and median bone marrow plasmacytosis of 20% (range, 0-90%). Induction treatment regimens included bortezomib in 18 (62%), lenalidomide in 6 (21%), cyclophosphamide in 8 (28%), and 21 (73%) underwent autologous stem cell transplant (ASCT) during the course of their treatment. Outcomes are shown in Table 1. Hematologic response among the 29 pts at completion of first line therapy included an overall response rate (ORR) of 93% with sCR (N=14, 48%); CR (N=5, 17%), VGPR (N=6, 20%), PR (N=2, 6.9%), Not available (N=2, 7%). Renal response (Table 1) among 29 patients included CR (N=9, 31%), PR (N=14, 48%) and End Stage Renal Disease (ESRD) (N=6, 21%). Among 7 patients on HD at baseline, 3 remained on HD despite treatment, while 4 stopped HD after treatment, 2 as a result of the treatment and 2 after renal transplant. 3 patients progressed to ESRD and required HD during treatment. Baseline beta-2 microglobulin (B2M), SCr, and eGFR at diagnosis were factors associated with renal response (p 〈 0.05). Hematologic response (CR vs. non-CR) was not associated with renal response (p=0.68) in this cohort. Conclusions: In this cohort, we observed a high rate of hematologic response (65.5% reaching CR) to upfront treatment regimens. A majority of patients received bortezomib-based regimens and ASCT. We observed a large proportion of patients whose renal impairment from MIDD improved significantly after receiving therapy directed at the underlying clonal neoplasm, with 75.8% reaching PR or better, nearly a third of patients achieving a renal CR, and 2/7 patients on HD at diagnosis discontinuing HD after treatment. Our experience presented here serves to inform the treatment approach of patients with MIDD. Given the scarcity of outcome data in MIDD, especially in the era of novel anti-myeloma therapy, prospective studies to optimize the management of these patients are needed. Disclosures Rossi: Celgene: Consultancy. Smith:Celgene: Consultancy, Patents & Royalties: CAR T cell therapies for MM, Research Funding. Korde:Amgen: Research Funding. Mailankody:Janssen: Research Funding; Juno: Research Funding; Physician Education Resource: Honoraria; Takeda: Research Funding. Lesokhin:Squibb: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria; Genentech: Research Funding; Janssen: Research Funding; Serametrix, inc.: Patents & Royalties: Royalties. Landgren:Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Consultancy; Merck: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy; Celgene: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Hassoun:Oncopeptides AB: Research Funding.