Abstract: We previously described clinically relevant reductions in fecal microbiota diversity in patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT). Recipients of high-dose chemotherapy and autologous HCT (auto-HCT) incur similar antibiotic exposures and nutritional alterations. To characterize the fecal microbiota in the auto-HCT population, we analyzed 1161 fecal samples collected from 534 adult recipients of auto-HCT for lymphoma, myeloma, and amyloidosis in an observational study conducted at 2 transplantation centers in the United States. By using 16S ribosomal gene sequencing, we assessed fecal microbiota composition and diversity, as measured by the inverse Simpson index. At both centers, the diversity of early pretransplant fecal microbiota was lower in patients than in healthy controls and decreased further during the course of transplantation. Loss of diversity and domination by specific bacterial taxa occurred during auto-HCT in patterns similar to those with allo-HCT. Above-median fecal intestinal diversity in the periengraftment period was associated with decreased risk of death or progression (progression-free survival hazard ratio, 0.46; 95% confidence interval, 0.26-0.82; P = .008), adjusting for disease and disease status. This suggests that further investigation into the health of the intestinal microbiota in auto-HCT patients and posttransplant outcomes should be undertaken.

Abstract: Patients treated with cytotoxic therapies, including autologous stem cell transplantation, are at risk for developing therapy-related myeloid neoplasms (tMN). Pre-leukemic clones (i.e., clonal hematopoiesis; CH) are detectable years before the development of these aggressive malignancies, though the genomic events leading to transformation and expansion are not well-defined. Here, leveraging distinctive chemotherapy-associated mutational signatures from whole-genome sequencing data and targeted sequencing of pre-chemotherapy samples, we reconstruct the evolutionary life-history of 39 therapy-related myeloid malignancies. A dichotomy is revealed, in which neoplasms with evidence of chemotherapy-induced mutagenesis from platinum and melphalan are hypermutated and enriched for complex structural variants (i.e., chromothripsis) while neoplasms with non-mutagenic chemotherapy exposures are genomically similar to de novo acute myeloid leukemia. Using chemotherapy-associated mutational signatures as temporal barcodes linked to a discrete clinical exposure in each patient's life, we estimate that several complex events and genomic drivers are acquired after chemotherapy is administered. For patients with prior multiple myeloma who were treated with high-dose melphalan and autologous stem cell transplantation, we demonstrate that tMN can develop from either a reinfused CH clone that escapes melphalan exposure and is selected following reinfusion, or from TP53-mutant CH that survives direct myeloablative conditioning and acquires melphalan-induced DNA-damage. Overall, we reveal a novel mode of tMN progression that is not reliant on direct mutagenesis or even exposure to chemotherapy. Conversely, for tMN that evolve under the influence of chemotherapy-induced mutagenesis, distinct chemotherapies not only select pre-existing CH, but also promote the acquisition of recurrent genomic drivers.

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: INTRODUCTION. Bortezomib, lenalidomide and dexamethasone (VRd) is considered a standard of care combination therapy for newly diagnosed multiple myeloma patients. Prior studies show that ~25% of patients treated with 8 cycles of VRd achieve minimal residual disease (MRD) negativity. Recently, 42% stringent complete response (sCR) rates were reported with the use of VRd combined with the CD38-targeted monoclonal antibody daratumumab (VRd-D). Prior studies using 8 cycles of bi-weekly carfilzomib 36 mg/m2 with lenalidomide and dexamethasone (bKRd) combination therapy in newly diagnosed multiple myeloma show ~40% MRD negativity rates. We were motivated to develop a phase 2 study (total N=82) using weekly dosing of carfilzomib 56 mg/m2 with lenalidomide and dexamethasone (wKRd) in combination with daratumumab (wKRd-D). Our study also included a parallel cohort of bi-weekly dosing of carfilzomib 36 mg/m2 with lenalidomide and dexamethasone (bKRd) in combination with daratumumab (bKRd-D). Primary end-point of our study was to rule out 60% and to target up to 80% MRD negativity rate. METHODS. This is a two-arm, Phase II clinical trial based on Simon's optimal two-stage design. The once-a-week carfilzomib (wKRd) (N=41) has the following treatment schedule: 8 cycles of treatment; 28-day cycles with carfilzomib 20/56 mg/m2 days 1, 8, and 15; lenalidomide 25 mg days 1-21; dexamethasone 40 mg weekly cycles 1-4, 20 mg after cycle 4; and daratumumab 16 mg/kg days 1, 8, 15, and 22 cycles 1-2, days 1 and 15 cycles 3-6, and day 1 cycles 7-8. The bi-weekly carfilzomib (bKRd) (N=41): 8 cycles of treatment; 28-day cycles with carfilzomib 20/36 mg/m2 days 1, 2, 8, 9, 15 and 16; lenalidomide, dexamethasone, and daratumumab are given at the same doses/schedules as the weekly cohort. For fit patients, stem cell collection is recommended after 4 to 6 cycles of therapy; DKRd therapy is resumed after collection to a total of 8 cycles DKRd. Treatment response is being assessed with parallel bone marrow-based MRD assays (10-color single tube flowcytometry and invivoscribe IGHV sequencing); per IMWG guidelines both MRD assays allow detection of 1 myeloma cell in 100,000 bone marrow cells (10^-5). Baseline bone marrow samples are evaluated with targeted DNA sequencing for FISH-Seq and somatic mutational characteristics (myTYPE). RESULTS. The first stage of the weekly cohort (wKRd-D) is fully enrolled (N=28) and the second stage of the cohort (N=13) is anticipated to complete enrollment shortly (total N=41). Currently, 29 patients meeting eligibility criteria were enrolled (14 males, 15 females) between October 2018 and August 2019. Baseline characteristics include; median age 59 years (range 36-70 years); 12 (41%) patients had high-risk FISH/SNP signature defined as one or more of the following: 1q+, t(4;14), t(14;16), t(14;20), and 17p-. At the submission of this abstract, 28 patients have completed one or more cycles wKRd-D; among these, 10 patients have completed therapy. The median number of cycles delivered is currently 6 (range 1-8). Seven of the 10 patients who have completed study treatment are MRD negative. So far, additional 8 patients have become MRD negative while on therapy. Thus, among patients treated on the weekly cohort (wKRd-D) and who were evaluable for the MRD primary end-point at this analysis, we found 15/18 (83%) to be MRD negative. We further show no added major clinical toxicities with wKRd-D compared to our institution standard of care bKRd. The bi-weekly carfilzomib cohort (bKRd-D) shows similar results to the weekly cohort (wKRd-D). With a comparable efficacy and safety profile coupled with a substantial reduction of the number of infusions (total of 51 vs 27 infusions with bKRd-D vs wKRd-D, respectively), we conclude that the weekly dosing (wKRd-D) may offer an attractive treatment modality for newly diagnosed multiple myeloma patients. CONCLUSIONS. Among patients evaluable for the MRD primary end-point, in the absence of an autologous bone marrow transplant, we show an unprecedented 15/18 (83%) MRD negativity rate among newly diagnosed multiple myeloma patients treated on the weekly cohort (wKRd-D) using carfilzomib 56 mg/m2 dosing. Our promising results have prompted the development of a large randomized multi-center study ("ADVANCE") evaluating wKRd-D in relation to established standard of care, which is anticipated to start enrollment in Q3/Q4 of 2019. Disclosures Landgren: Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Adaptive: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Other: IDMC; Theradex: Other: IDMC; Abbvie: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees. Lesokhin:GenMab: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; Juno: Consultancy, Honoraria; Janssen: Research Funding; Genentech: Research Funding; Takeda: Consultancy, Honoraria; Serametrix Inc.: Patents & Royalties. Mailankody:Juno: Research Funding; Celgene: Research Funding; Janssen: Research Funding; Takeda Oncology: Research Funding; CME activity by Physician Education Resource: Honoraria. Hassoun:Novartis: Consultancy; Celgene: Research Funding; Janssen: Research Funding. Smith:Fate Therapeutics and Precision Biosciences: Consultancy; Celgene: Consultancy, Patents & Royalties, Research Funding. Shah:Physicians' Education Resource: Honoraria. Landau:Caelum: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Research Funding; Karyopharm: Consultancy, Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Prothena: Membership on an entity's Board of Directors or advisory committees. Scordo:Angiocrine Bioscience, Inc.: Consultancy; McKinsey & Company: Consultancy. Arcila:Invivoscribe, Inc.: Consultancy, Honoraria. Ho:Invivoscribe, Inc.: Honoraria. Roshal:Auron Therapeutics: Equity Ownership, Other: Provision of services; Physicians' Education Resource: Other: Provision of services; Celgene: Other: Provision of Services. Dogan:Corvus Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy; Celgene: Consultancy; Takeda: Consultancy; Novartis: Consultancy; Roche: Consultancy, Research Funding. OffLabel Disclosure: Dara-KRd is not an FDA approved combination therapy for newly diagnosed multiple myeloma.

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.