Citations

Background: Multiple myeloma (MM) is typically diagnosed in patients (pts) aged 65-74 y (SEER: Myeloma. 2019); therefore, many pts present with concomitant metabolic disorders such as diabetes (18%-22% prevalence of type 2 diabetes [T2D; BMC Cancer. 2020;20:489]). Obesity (body mass index [BMI], ≥ 30 kg/m2) is associated with increased prevalence of T2D (Int J Clin Pract. 2007;61:737), and both are suggested risk factors for MM (Blood. 2012;119:4845; Bone Marrow Transpl. 2014;49:1009). Results from single-center, retrospective studies have shown poorer clinical features and survival outcomes in diabetic pts with MM vs their nondiabetic counterparts (Eur J Haematol. 2012;89:320, Br J Cancer. 2014;111:628). The Connect® MM Registry (NCT01081028) is a large, US, multicenter, prospective observational cohort study of largely community-based pts with NDMM. Reported here is a descriptive analysis assessing differences in baseline (BL) characteristics, treatment patterns, and survival outcomes in diabetic vs nondiabetic pts enrolled in the Connect MM Registry. Methods: Pts with NDMM (N = 3011) were enrolled at 250 community, academic, and government sites. Eligible pts were aged ≥ 18 y with symptomatic MM diagnosed ≤ 2 months (mo) pre-enrollment per International Myeloma Working Group criteria (Leukemia. 2009;23:3). Diabetic pts were defined as those with a history of diabetes and also receiving antidiabetic treatment at BL; those without a history of diabetes and not receiving antidiabetic treatment at BL were defined as nondiabetic pts. Descriptive statistics were used for BL characteristics and treatment regimens. Survival outcomes (progression-free survival [PFS] and overall survival [OS]) were analyzed using Cox regression and adjusted for covariates. Results: Of the 2845 pts included in this analysis, 467 (16%) were diabetic, and 2378 (84%) were nondiabetic. The median age was 69 y for diabetic pts and 66 y for nondiabetic pts, with fewer Black pts (12.2% vs 19.5%) in the nondiabetic group. The proportion of men was higher in the diabetic vs the nondiabetic group (61.9% vs 56.6%). Similar percentages of pts had ECOG PS of 0-1 in both groups (53.3% vs 55.3%). Obesity was more prevalent in diabetic vs nondiabetic pts (55.9% vs 30.4%). More diabetic pts had a history of hypertension requiring treatment vs nondiabetic pts (84.2% vs 52.5%). The prevalence of chromosomal abnormalities was comparable between the groups (within the limitation that data were missing in a substantial number of pts). Among MM-defining criteria, diabetic pts had a higher incidence of hypercalcemia (11.8% vs 8.5%), anemia (50.3% vs 46.5%), and increased creatinine (23.8% vs 19%), whereas measured kidney function was similar. A lower proportion of diabetic than nondiabetic pts received stem cell transplantation (SCT; 28.9% vs 41.5%) and triplet regimens during first induction (48.2% vs 52.8%%). The use of ≥ 2 novel agents during first line (1L) was lower in diabetic than nondiabetic pts (27.8% vs 34.6%), but use of a single novel agent (63.4% vs 60%) and alkylator in 1L (20.6% vs 22.4%) was comparable. The top five 1L regimens were similar for both groups, with lenalidomide + bortezomib + dexamethasone being the most common 1L regimen, and lenalidomide the most common maintenance therapy. Diabetic pts had significantly shorter adjusted median PFS (24.4 vs 31.5 mo; hazard ratio [HR], 1.24; P = 0.001; Fig. 1A) and median OS (60 vs 72.6 mo; HR, 1.29; P = 0.001; Fig. 1B) than nondiabetic pts. In a subgroup analysis by BMI, diabetic pts had significantly shorter OS than nondiabetic pts (for BMI < 30 [50.8 vs 73.1 mo; HR, 1.51; P = 0.0001] and BMI ≥ 30 [56.4 vs 78.6 mo; HR, 1.51; P < 0.0001]). Conclusions: Diabetic pts with NDMM had poorer BL features and were less likely to receive SCT and triplet regimens and/or aggressive upfront treatment. Regardless of BMI, diabetic pts had shorter median OS than nondiabetic pts, suggesting that diabetes might be a stronger factor for survival than obesity. These results support a previous analysis of the Connect MM Registry that identified history of diabetes as a predictive prognostic factor for poor OS (Br J Haematol. 2019;187:602). Limitations of this analysis include limited detail on the care/management of diabetes and steroid use/dosage (which can be challenging for glycemic control). These findings highlight the need to provide better supportive care for diabetes management in MM pts to improve survival. Disclosures La: Celgene BMS: Consultancy. Jagannath:BMS, Janssen, Karyopharm, Legend Biotech, Sanofi, Takeda: Consultancy. Ailawadhi:Amgen: Research Funding; Celgene: Honoraria; Takeda: Honoraria; Janssen: Research Funding; Pharmacyclics: Research Funding; Cellectar: Research Funding; BMS: Research Funding; Medimmune: Research Funding; Phosplatin: Research Funding. Durie:Amgen, Celgene, Johnson & Johnson, and Takeda: Consultancy. Gasparetto:Adaptive Biotechnologies: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Speakers Bureau; Karyopharm: Consultancy, Honoraria, Other: TRAVEL, ACCOMODATIONS, EXPENSES (paid by any for-profit health care company), Speakers Bureau; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; GSK: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Consultancy, Honoraria. Hardin:Celgene Pharmaceutical Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES. Lee:Sanofi: Consultancy; Janssen: Consultancy, Research Funding; GlaxoSmithKline: Consultancy, Research Funding; Genentech: Consultancy; Takeda: Consultancy, Research Funding; Regeneron: Research Funding; Genentech: Consultancy; Amgen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Daiichi Sankyo: Research Funding. Narang:Maryland Oncology Hematology: Current Employment; Beigene: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; J&J: Consultancy, Honoraria. Omel:Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; BMS/Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Rifkin:McKesson: Current equity holder in publicly-traded company, Ended employment in the past 24 months, Other: Stock ownership; Takeda, Amgen, Celgene, BMS, Mylan, Coherus BioSciences, Fresenius: Consultancy; AbbVie: Other: Investigator in AbbVie sponsored clinical trials; Takeda, Amgen, BMS (Celgene): Membership on an entity's Board of Directors or advisory committees. Terebelo:Newland Medical Associates: Current Employment; BMS: Membership on an entity's Board of Directors or advisory committees. Toomey:Celgene/BMS: Membership on an entity's Board of Directors or advisory committees. Wagner:Celgene Inc.: Membership on an entity's Board of Directors or advisory committees; Connect Multiple Myeloma Registry: Membership on an entity's Board of Directors or advisory committees. Dhalla:BMS: Current Employment, Current equity holder in publicly-traded company. Liu:TechData Inc: Consultancy. Yang:BMS: Current Employment, Current equity holder in publicly-traded company. Joshi:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company; Eisai Inc.: Ended employment in the past 24 months. Abonour:Takeda: Consultancy; Janssen: Honoraria, Research Funding; Celgene: Consultancy; BMS: Consultancy, Research Funding.

BACKGROUND: PIs combined with an Rd backbone are the most commonly used triplet combination regimens in patients (pts) with RRMM in the US. The hallmark trials supporting the efficacy of these regimens were predominantly in pts without prior exposure to lenalidomide (R).1,2 Real-world analyses have shown that R-based regimens are increasingly used in the front-line setting.3-5 Thus, real-world treatment patterns in pts with prior R exposure and the real-world comparative effectiveness of PI-Rd triplets in this population with RRMM needs further elucidation. METHODS: A retrospective cohort of RRMM pts initiating IRd, KRd, or VRd in line of therapy (LOT) ≥2 were followed between 7/2007-9/2018 in Optum's deidentified national electronic health records database. RRMM pts were defined as those initiating LOT ≥2 between 1/2014 and 9/2018 and were categorized as having or not having prior exposure to R (R-exposed; no-prior-R) in any prior LOT. Index regimen was the first use of I-/K-/or V-Rd. LOTs were defined via an algorithm developed with MM specialists to proxy the definition of a LOT in RCTs & in accordance with NCCN MM Guidelines.6 Baseline data included: CRAB (hyperCalcemia, Renal insufficiency, Anemia, and Bone lesions); high risk cytogenetics (defined as del[17p], 1q21 gain, t[4;14], or t[14;16]); Charlson Comorbidity Index (CCI) score; and modified frailty score using age and CCI score. Median duration of therapy (DOT) and time-to-next-treatment (TTNT) (a proxy for PFS; defined as time from index regimen start to subsequent LOT or death) were estimated using Kaplan-Meier methods and compared using covariate-adjusted Cox proportional hazard models (FIGURE). Observations were censored at time of loss to follow-up (f/u)/end of study period (9/30/2018). RESULTS: Of 650 pts included, 397 were R-exposed (IRd, n=112; KRd, n=115; VRd, n=170); 253 had no-prior-R (IRd, n=29; KRd, n=62; VRd, n=162). R-exposed pts, overall, were treated in later LOTs (LOT2: 55% v 78%) and had a longer median time from diagnosis to index LOT (26.7 v 13.4 months) than no-prior-R pts; this differed between treatment cohorts (TABLE). In R-exposed pts, more pts with symptomatic relapse (≥1 CRAB symptom, 87%) or high-risk cytogenetics (30%) received KRd than IRd (75% & 23%) or VRd (74% & 16%) (TABLE). More pts treated with IRd were ≥75 years old: 42% (IRd) v 36% (VRd) / 21% (KRd). In R-exposed pts, 35.3% of those receiving VRd in LOT ≥2 had prior V-IMID-based and 53.5% had IMID-based therapy (ie, IMID with no PI nor monoclonal antibody) in LOT1; >98% of LOT1 IMID use was R, across groups. In R-exposed pts, 56.5% of those receiving KRd had prior V-IMID-based and 16.5% had IMID-based therapy in LOT1; in IRd pts in LOT ≥2, 29.5% and 43.8% had prior V-IMID-based and IMID-based therapy in LOT1. In unadjusted analysis, at a median f/u of 11, 11.9, and 14.8 months for I-, K-, and V-Rd, median TTNT for R-exposed pts: 12.3 months (IRd), 7.8 months (KRd), and 13.9 months (VRd) (P=0.50); HRs for TTNTLOT stratified: 0.84 (IRd v KRd), 0.96 (IRd v VRd), 1.15 (KRd v VRd), and median regimen DOTs: 8.4 months (IRd), 7.5 months (KRd), and 9.5 months (VRd) (P=0.75). In no-prior-R pts, HRs for TTNTLOT stratified were significant for IRd v KRd (HR=0.33) and KRd v VRd (HR=1.62) (P<0.01, both); IRd v VRd (HR=0.53; P=0.11). In adjusted analysis, there were no significant differences for R-exposed pts by PI-Rd regimens for TTNT (FIGURE), nor for regimen DOT. For no-prior-R pts, adjusted HR for TTNT was significant for I- v K-Rd (HR=0.36; P=0.03) and for regimen DOT was significant for I- v V-Rd (HR=0.34; P=0.03). CONCLUSIONS: In this real-world study, the majority of pts received a PI-Rd combination after prior VRd or Rd in front-line. After controlling for baseline characteristics, including prior PI-exposure, PI-Rd triplets were comparable in TTNT in R-exposed pts treated in LOTs ≥2. TTNT was significantly longer for I- v K-Rd in pts with no-prior-R, although this is limited by small sample size. Published studies indicate that individualized treatment recommendations may improve real-world outcomes, such as IRd v KRd in frail pts which was associated with significantly longer TTNT.6 Prior-R exposure, in our analysis, does not appear to influence the relative PI-triplet regimen effectiveness in LOTs ≥2. With increasing use of R in earlier LOTs, understanding real-world treatment patterns and subsequent PI-Rd effectiveness in consequent LOTs is key for optimizing RRMM pt management. Disclosures Cherepanov: Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Current Employment. Romanus:Takeda: Current Employment. Raju:Xcenda: Current Employment, Other: Xcenda received research funding from Takeda. Blazer:Xcenda: Current Employment, Other: Xcenda received research funding from Takeda. Farrelly:Xcenda: Current Employment, Other: Xcenda received research funding from Takeda. Stull:Takeda: Current Employment. Ailawadhi:Phosplatin: Research Funding; Celgene: Honoraria; Amgen: Research Funding; Takeda: Honoraria; Janssen: Research Funding; Pharmacyclics: Research Funding; Cellectar: Research Funding; BMS: Research Funding; Medimmune: Research Funding.

Introduction: Daratumumab (D) is an anti-CD38 monoclonal antibody, used frequently in combination with immunomodulatory drugs (IMiDs), lenalidomide (Len) and pomalidomide (Pom). There are no studies comparing DRd to DPd in Len-exposed or refractory multiple myeloma (MM). We present the Mayo Clinic experience of DPd and DRd utilization and outcomes. Methods: We identified consecutive MM pts who received D, between 1/2015 and 4/2019 at Mayo Clinic. We included pts who were exposed (at least one full cycle, 21/28 days) or refractory (progression on full dose or maintenance Len during treatment or within 60 days of stopping Len) to Len prior to D and received 1 to 4 prior lines of therapy. Only Pts who received DRd and DPd were included. Results: Out of 411 evaluable pts 162 met the inclusion criteria; 67 were Len exposed, but not refractory and 95 were Len refractory. Pts' characteristics are shown in Table 1. DRd was used in 76 (47%) and DPd in 86 (53%) pts. Majority of pts (105; 65%) received DPd or DRd in the 2nd or 3rd line and 104 pts (64%) are still alive. In Len refractory pts, the median time from last dose of Len to D initiation was 1 mths (interquartile range 0-6.5). Seventy pts (43%) had high-risk cytogenetics (HR). Only 11 pts (7%) underwent autologous hematopoietic cell transplant after DPd or DRd regimen. There was no significant difference between pts who received DRd and DPd in terms of age (>65 years), gender, race, proportion exposed or refractory to Bortezomib, number of prior lines of treatment (>2), or HR status (p>0.05 for all). Pts who received DPd were 4 times more likely to be Len refractory compared to pts who received DRd, p=0.0008. Median follow up time for the whole cohort from initial diagnosis was 92 mths (CI 95%; 79.5-107), while from D start date was 30 mths (CI 95%; 27-34). Median PFS for the whole cohort was 21 mths (CI 95%; 15-25) and median OS was 138 mths (CI 95%; 111-193). In Len exposed but not refractory pts, n=67, the overall response rate (ORR) was 82% in the DRd group compared to 68% in the DPd group, p=0.2. There was no difference in median PFS; 25.5 mths (CI 95%; 23-NR) for DRd compared to 25 mths (CI 95%; 5-NR) for DPd, p=0.37. Similarly, there was no difference in median OS for DRd compared to DPd; NR mths (CI 95%; 138-NR) and 145.5 mths (CI 95%; 70-NR), respectively, p=0.06. In the 48 Len exposed but refractory pts who received DRd or DPd in 2nd or 3rd line, there was no difference in median PFS; 39 mths (CI 95%; 23-NR) for DRd compared to 21 mths (CI 95%; 3-NR) for DPd, p=0.11. Similarly, there was no difference in median OS for DRd compared to DPd; NR mths (CI 95%; NR-NR) and 145.5 mths (CI 95%; 36-NR), respectively, p=0.13. In Len refractory pts only, n=95, the ORR was 84% in the DRd group compared to 58% in the DPd group, p=0.009. There was no difference in median PFS; 25 mths (CI 95%; 13-32) for DRd compared to 9 mths (CI 95%; 5-15) for DPd, p=0.18. Similarly, there was no difference in median OS for DRd compared to DPd; 103 mths (CI 95%; 78-NR) and 106 mths (CI 95%; 66-183), respectively, p=0.5. In the 57 Len refractory pts who received DRd or DPd in 2nd or 3rd line, there was no difference in median PFS; 25 mths (CI 95%; 13-32) for DRd compared to 13 mths (CI 95%; 5-NR) for DPd, p=08. Similarly, there was no difference in median OS for DRd compared to DPd; 103 mths (CI 95%; 69-NR) and 105 mths (CI 95%; 47-NR), respectively, p=0.35. In the 16 Len exposed but not refractory pts with HR MM who received DRd or DPd in 2nd or 3rd line, the median PFS was better in the DRd group; 24.4 mths (CI 95%; 12-NR) compared to 3.3 mths (CI 95%; 1.9-27.5) for DPd, p=0.0093. However, there was no difference in median OS for DRd compared to DPd; NR mths (CI 95%; 51-NR) and NR mths (CI 95%; 18-NR), respectively, p=0.13. In the 29 Len refractory pts with HR MM who received DRd or DPd in 2nd or 3rd line, there was no statistically significant difference in median PFS; 18 mths (CI 95%; 6-43) for DRd compared to 6 mths (CI 95%; 4-13) for DPd, p=0.22.Similarly, there was no difference in median OS for DRd compared to DPd; 103 mths (CI 95%; 47-NR) and 53 mths (CI 95%; 26-105), respectively, p=0.2. Conclusions: D+IMiD regimens after prior Len exposure/refractoriness are commonly used in real-world, despite the lack of data from prospective clinical trials. Combining D with IMiDs in Len exposed or refractory pts is efficacious, whether the IMiD is Len or Pom. Our study shows that regardless of prior Len use, DRd is at least equivalent to DPd. Prospective studies should be done to confirm these observations. Disclosures Alhaj Moustafa: Acrotech: Consultancy. Larsen:Janssen Oncology: 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. Kapoor:Janssen: Research Funding; GlaxoSmithKline: Research Funding; Cellectar: Consultancy; Celgene: Honoraria; Amgen: Research Funding; Takeda: Honoraria, Research Funding; Sanofi: Consultancy, Research Funding. Fonseca:Amgen: Consultancy; BMS: Consultancy; Celgene: Consultancy; Takeda: Consultancy; Bayer: Consultancy; Janssen: Consultancy; Novartis: Consultancy; Pharmacyclics: Consultancy; Sanofi: Consultancy; Merck: Consultancy; Juno: Consultancy; Kite: Consultancy; Aduro: Consultancy; OncoTracker: Consultancy, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Consultancy; GSK: Consultancy; AbbVie: Consultancy; Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees. Dingli:Karyopharm Therapeutics: Research Funding; Rigel: Consultancy; Bristol Myers Squibb: Research Funding; Millenium: Consultancy; Sanofi-Genzyme: Consultancy; Janssen: Consultancy; Alexion: Consultancy; Apellis: Consultancy. Ailawadhi:Celgene: Honoraria; Amgen: Research Funding; Takeda: Honoraria; Janssen: Research Funding; Pharmacyclics: Research Funding; Cellectar: Research Funding; BMS: Research Funding; Medimmune: Research Funding; Phosplatin: Research Funding.

BackgroundFactors associated with receiving initial care for thyroid cancer (TC) at academic centers (ACs) versus nonacademic centers (NACs) and their impact on patient outcomes have not been reported.MethodsThe National Cancer Database with TC cases from 2004 to 2013 was evaluated for association of type of center for initial care with socioeconomic factors and disease and treatment characteristics, as well as overall survival (OS; all‐cause mortality).ResultsThe patients with TC (n = 200,824) included were predominantly women (74%), non‐Hispanic Whites (85%), and from metro areas (84%). Sixty percent received initial care at a NAC. There were no significant differences between treatment groups by age or gender. Among those treated at an AC, a higher proportion belonged to racial/ethnic minorities (16.5%) versus at a NAC (11.6%). Hormone therapy was used more in an AC versus a NAC (60% vs 47%). Patients with all TC pathologies combined had a lower likelihood of death when they received initial care at an AC (hazard ratio [HR], 0.948; P = .0006). Among individual pathologic subtypes, a lower likelihood of death was noted when initial care was received at an AC for follicular (HR, 0.828, P = .0010) and Hurthle cell cancers (HR, 792; P = .0008), as well as stage II papillary thyroid cancer (HR, 0.828; P = .0026), but not for other histopathologic subtypes.ConclusionsInitial care at an AC was associated with lower likelihood of death for patients with TC, especially for those with follicular or Hurthle cell subtypes. Optimal resource use with consideration of patients' socioeconomic and demographic factors is imperative to ensure the most appropriate management of patients with TC in various treatment settings.

Abstract Introduction: CLR 131 (I-131-CLR1404) is a novel targeted radiotherapeutic that exploits the selective uptake and retention of phospholipid ethers (PLEs) by malignant cells. Based on preclinical and clinical experience and the radiosensitivity of MM, CLR 131 is being examined in relapsed or refractory B-cell malignancies through an open-label, phase 2 trial, CLOVER-1 (NCT02952508); initial results in pts with LPL/WM are reported here. Procedures: The primary objective of this study is to determine the efficacy and safety of CLR 131 in select B-cell malignancies. Eligibility criteria include adult pts with relapsed or refractory chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL), lymphoplasmacytic lymphoma (LPL)/Wadenstrom's macroglobulinemia (WM), marginal zone lymphoma (MZL), mantle cell lymphoma (MCL), or diffuse large B-cell lymphoma (DLBCL). Pts with LPL/WM must have received at least two prior treatment regimens unless ineligible to receive standard agents and have measurable disease: either a nodal lesion > 15 mm, an extranodal lesion > 10 mm, or measurable IgM. Prior external beam radiation therapy is allowed (< 20% of total marrow irradiated). CLR 131 is administered intravenously up to 30 minutes at total body doses (TBD) of <50 mCi, ~50 mCi, and ~75 mCi. Adverse events (AEs) are graded by NCI-CTCAE v4.03; responses are assessed by the 2012 WM Criteria for Response Assessment. Results: Four pts with LPL/WM have been enrolled in the study with data presented as of 1 Mar 2020. The median age was 70 (range 54-81) and included 2 females and 2 males who had a median of two prior regimens (range 1-5). The overall response rate was 100%, including one pt with a complete response, one pt with a partial response, and one pt with a minimal response; one pt remains under evaluation. The primary treatment-emergent AEs across all doses in pts with LPL/WM included neutropenia, thrombocytopenia, nausea, fatigue, anemia, and decreased white blood cell count, in line with experience to date with CLR 131 in other B-cell malignancies. Median time to resolution of cytopenias was 21 days. One pt received two cycles of CLR 131 with a TBD of ~100 mCi. The pt was determined to be a partial response 43 days post initial dose and a complete response at approximately 200 days; this was confirmed radiologically 406 days post initial dose. The duration of response for this pt is currently at 25 months and is ongoing. One pt received ~ 50 mCi CLR 131 and saw an 89% decrease in IgM at 64 days post infusion. One pt received ~ 75 mCi CLR 131 and had a 45% decrease in IgM at 64 days post infusion. One pt received two cycles of CLR 131 with a TBD of ~150 mCi, experiencing a 48% reduction in IgM to date and has not yet completed the evaluation period. Conclusions: CLR 131 is a unique, first-in-class targeted radiotherapeutic in development for multiple B-cell hematologic malignancies. The observed positive signals of efficacy and safety from this preliminary data in relapsed or refractory LPL/WM pts is encouraging and will be further explored. Citation Format: Sikander Ailawadhi, Jarrod Longcor, Kate Oliver, Igor D. Grachev. CLR 131 demonstrates 100% overall response rate in relapsed or refractory lymphoplasmacytic lymphoma (LPL)/Waldenstrom's macroglobulinemia (WM): initial results from ongoing phase 2 trial, CLOVER-1 study [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr PO-25.

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

Aims: To evaluate AMG 701, a BiTE® molecule binding BCMA on MM cells and CD3 on T cells, in RR MM (Amgen, NCT03287908); primary objective was to evaluate safety and tolerability and estimate a biologically active dose; secondary objectives were to characterize pharmacokinetics (PK), anti-myeloma activity per IMWG criteria, and response duration. Methods: Patients with MM RR or intolerant to ≥3 lines [proteasome inhibitor (PI), IMiD, anti-CD38 Ab as available] received AMG 701 IV infusions weekly in 4-week cycles until disease progression (PD). A 0.8-mg step dose was added prior to target doses ≥1.2 mg to prevent severe cytokine release syndrome (CRS). Target dose was achieved by day 8 or sooner with earlier escalation. Exclusion criteria included: solely extramedullary disease; prior allogeneic stem cell transplant (SCT) in the past 6 months; prior autologous SCT in the past 90 days; CNS involvement; prior anti-BCMA therapy. The first 3 cohorts (dose 5-45 μg) had 1 patient each, the next cohorts (0.14-1.2 mg) had 3-4 patients each, and subsequent cohorts (1.6-12 mg) were to have 3-10 patients each. Minimal residual disease (MRD) was measured by next-generation sequencing (NGS, ≤10-5 per IMWG) or flow cytometry (≤3×10-5). Results: As of July 2, 2020, 75 patients received AMG 701. Patients had a median age of 63 years, a median time since diagnosis of 5.9 years, and a median (range) of 6 (1-25) prior lines of therapy; 27% of patients had extramedullary disease, 83% prior SCT, and 93% prior anti-CD38 Ab; 68% were triple refractory to a PI, an IMiD, and an anti-CD38 Ab. Median (Q1, Q3) treatment duration was 6.1 (3.1, 15.3) weeks and median follow-up on treatment was 1.7 (1.0, 3.7) months. Patients discontinued drug for PD (n=47), AEs (adverse events, n=4, 3 CRS, 1 CMV / PCP pneumonia), withdrew consent (4), other therapy (1), investigator discretion (1), and CNS disease (1); 17 patients remain on AMG 701. The most common hematological AEs were anemia (43%), neutropenia (23%), and thrombocytopenia (20%). The most common non-hematological AEs were CRS (61%), diarrhea (31%), fatigue (25%), and fever (25%). CRS was mostly grade 1 (n=19) or 2 (n=21) per Lee Blood 2014 criteria. All grade 3 CRS (n=5, 7%) were assessed as dose-limiting toxicities (DLTs); all were reversible with corticosteroids and tocilizumab, with median duration of 2 days. CRS grade 3 drivers included transient LFT increases in 3 patients and hypoxia in 2 patients. Other DLTs were 1 case each of transient grade 3 atrial fibrillation, transient grade 3 acidosis, and grade 4 thrombocytopenia. Serious AEs (n=29, 39%) included infections (13), CRS (7), and asymptomatic pancreatic enzyme rise (2, no imaging changes, 1 treatment related). There were 4 deaths from AEs, none related to AMG 701 (2 cases of sepsis, 1 of retroperitoneal bleeding, and 1 of subdural hematoma). Reversible treatment-related neurotoxicity was seen in 6 patients, with median duration of 1 day, all grade 1-2, and associated with CRS in 4 patients. The response rate was 36% (16/45) at doses of 3-12 mg; at ≤1.6 mg (n=27), there was 1 response at 0.8 mg in a patient with low baseline soluble BCMA (sBCMA). With earlier dose escalation with 9 mg, the response rate was 83% (5/6, 3 PRs, 2 VGPRs), with 4/5 responders being triple refractory and 1 DLT of grade 3 CRS in this group. Across the study, responses included 4 stringent CRs (3 MRD-negative, 1 not yet tested), 1 MRD-negative CR, 6 VGPRs, and 6 PRs (Table). Median (Q1, Q3) time to response was 1.0 (1.0, 1.9) month, time to best response was 2.8 (1.0, 3.7) months, and response duration was 3.8 (1.9, 7.4) months, with maximum duration of 23 months; responses were ongoing at last assessment in 14/17 patients (Figure). MRD was tested in 4 patients (3 sCR, 1 CR) and all were negative (3 by NGS, 1 by flow); MRD negativity was ongoing at last observations up to 20 months later. AMG 701 exhibited a favorable PK profile in its target patient population of RR MM, with AMG 701 exposures increasing in a dose-related manner. Patient baseline sBCMA levels were identified as a determinant of AMG 701 free drug exposures; at higher doses, encouraging preliminary responses were seen even at the higher end of baseline sBCMA values. Summary: In this FIH study with ongoing dose escalation, AMG 701, an anti-BCMA BiTE® molecule, demonstrated a manageable safety profile, encouraging activity, and a favorable PK profile in patients with heavily pre-treated RR MM, supporting further evaluation of AMG 701. Disclosures Harrison: Janssen: Honoraria; Novartis: Consultancy, Honoraria, Patents & Royalties: wrt panobinostat; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria; CRISPR Therapeutics: Consultancy, Honoraria; Haemalogix: Consultancy; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; F. Hoffmann-La Roche: Consultancy, Honoraria. Minnema:Amgen: Honoraria; Servier: Honoraria; Gilead: Honoraria; Celgene Corporation: Honoraria, Research Funding; Janssen Cilag: Honoraria. Lee:Celgene: Consultancy, Research Funding; Genentech: Consultancy; GlaxoSmithKline: Consultancy, Research Funding; Genentech: Consultancy; Regeneron: Research Funding; Takeda: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Sanofi: Consultancy; Daiichi Sankyo: Research Funding; Amgen: Consultancy, Research Funding. Spencer:AbbVie: Consultancy, Honoraria, Research Funding; Roche: Honoraria; Takeda: Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Secura Bio: Consultancy, Honoraria; Servier: Consultancy, Honoraria, Research Funding; HaemaLogiX: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding, Speakers Bureau; Pfizer: Consultancy, Honoraria; Pharmamar: Research Funding. Kapoor:Cellectar: Consultancy; Amgen: Research Funding; Janssen: Research Funding; Sanofi: Consultancy, Research Funding; Takeda: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Celgene: Honoraria. Madduri:Takeda: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Foundation Medicine: Consultancy, Honoraria; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Speaking Engagement, Speakers Bureau; Kinevant: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Speaking Engagement, Speakers Bureau; Legend: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Speaking Engagement, Speakers Bureau; Celgene: Consultancy, Honoraria. Larsen:Janssen Oncology: 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. Ailawadhi:Cellectar: Research Funding; BMS: Research Funding; Medimmune: Research Funding; Amgen: Research Funding; Takeda: Honoraria; Janssen: Research Funding; Pharmacyclics: Research Funding; Celgene: Honoraria; Phosplatin: Research Funding. Kaufman:Amgen: Consultancy, Honoraria; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Consultancy, Honoraria; AbbVie: Consultancy; Celgene: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Tecnopharma: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi/Genyzme: Consultancy, Honoraria. Raab:Takeda: Membership on an entity's Board of Directors or advisory committees; Heidelberg Pharma: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees, Research Funding. Hari:BMS: Consultancy; Amgen: Consultancy; GSK: Consultancy; Janssen: Consultancy; Incyte Corporation: Consultancy; Takeda: Consultancy. Iida:AbbVie: Research Funding; Merck Sharpe Dohme: Research Funding; Kyowa Kirin: Research Funding; Chugai: Research Funding; Sanofi: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Davies:Celgene/BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotech: Honoraria; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees. Lesley:Amgen Inc.: Current Employment, Current equity holder in publicly-traded company. Upreti:Amgen Inc.: Current Employment, Current equity holder in publicly-traded company. Yang:Amgen Inc.: Current Employment, Current equity holder in publicly-traded company. Sharma:Amgen Inc.: Current Employment, Current equity holder in publicly-traded company. Minella:Amgen Inc.: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Beam Therapeutics Inc.: Current Employment, Current equity holder in publicly-traded company. Lentzsch:Mesoblast: Divested equity in a private or publicly-traded company in the past 24 months; Janssen: Consultancy; Caelum Biosciences: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Magenta: Current equity holder in private company; Sanofi: Research Funding; Karyopharm: Research Funding; Celularity: Consultancy; Sorrento: Consultancy. OffLabel Disclosure: AMG 701, a half-life extended BiTE® (bispecific T-cell engager) molecule is an investigational agent for multiple myeloma.

Background: B-cell maturation antigen (BCMA) is widely expressed on normal plasma cells and malignant plasma cells in multiple myeloma (MM). MEDI2228 is an antibody-drug conjugate (ADC) that targets the extracellular domain of human BCMA with preferential binding to membrane-bound versus circulating soluble BCMA. The ADC is comprised of a fully human antibody to BCMA, site- specifically conjugated to a DNA cross-linking pyrrolobenzodiazepine (PBD) dimer via a protease-cleavable linker. After cell surface binding to BCMA, MEDI2228 is internalized and cleaved in the lysosomal compartment, releasing the active PBD, which cross-links DNA and leads to apoptotic cell death. We report the results from a phase 1, first-in-human, open-label, dose-escalation and expansion trial (NCT03489525) that evaluated the safety, pharmacokinetics (PK), and clinical activity of MEDI2228 in patients (pts) with relapsed/refractory MM (R/R MM). Methods: Eligible pts were ≥18 years old with confirmed R/R MM as defined by International Myeloma Working Group consensus criteria, had measurable disease, and had an Eastern Cooperative Oncology Group performance status ≤1. Pts had to have progressed after treatment with three classes of standard-of-care anti-myeloma drugs, including proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs), and monoclonal antibodies (mAbs). Dose escalation was based on an accelerated titration design, with an mTPI-2 algorithm. During dose escalation, MEDI2228 was administered in sequentially ascending dose levels (0.0125, 0.025, 0.05, 0.1, and 0.2 mg/kg) intravenously every 3 weeks (Q3W). Due to dose-limiting toxicities (DLTs), the dose was de-escalated from 0.2 mg/kg to an intermediate dose level of 0.14 mg/kg. The primary endpoint was safety and tolerability. Secondary endpoints included assessment of preliminary efficacy, PK, and immunogenicity. Results: As of May 15, 2020, 82 pts received MEDI2228 during dose escalation and expansion. All pts had received prior therapy with an IMiD, PI, and mAb: lenalidomide, 76 (94%); pomalidomide, 68 (84%); bortezomib, 77 (95%); carfilzomib, 64 (79%); and daratumumab, 71 (87%). Pts received between 2-11 lines of prior regimens. At 0.2 mg/kg, 2 pts experienced DLTs (grade 3/4 thrombocytopenia) without bleeding; no DLTs were reported for other dose levels. The maximum tolerated dose was 0.14 mg/kg Q3W. Treatment-related adverse events (TEAEs) occurring in ≥20% of pts in the 0.14 mg/kg cohort were photophobia (53.7%), thrombocytopenia (31.7%), rash (29.3%), increased gamma-glutamyltransferase (24.4%), dry eye (19.5%), and pleural effusion (19.5%). No reports of keratopathy or visual acuity loss were observed in the 0.14 mg/kg cohort. The TEAE profiles at lower-dose levels were similar but with lower incidences compared with the 0.14 mg/kg level. Efficacy was demonstrated at all dose levels (dose, objective response rate [ORR], [n]): 0.0125 mg/kg, 33.3% [1/3]; 0.025 mg/kg, 16.7% [1/6]; 0.05 mg/kg, 33.3% [3/9]; 0.10 mg/kg, 27.8% [5/18]; 0.14 mg/kg, 61.0% [25/41]; 0.2 mg/kg, 40.0%, [2/5]. In the 0.14 mg/kg cohort, ORR was 61.0% (95% confidence interval [CI]: 44.5%, 75.8%); there were 10 (24.4%) very good partial responses (VGPRs), 15 (36.6%) partial responses, and 3 (7.3%) minimal responses. Four of the VGPR pts were immunofixation negative. Most (90.2%) pts in the 0.14 mg/kg cohort had received prior daratumumab. Median duration of response (DOR) in the 0.14 mg/kg cohort was not reached. MEDI2228 exhibited linear PK at doses of ≥0.05 mg/kg Q3W that was minimally impacted by circulating levels of soluble BCMA at baseline. There was no difference in BCMA expression by IHC in the bone marrow of responders compared with nonresponders. Thirty-six pts in the 0.14 mg/kg cohort discontinued treatment due to adverse events (n=24), progressive disease (n=8), patient decision (n=2), investigator decision (n=1), or death (n=1). Conclusion: MEDI2228 is a BCMA-targeted ADC that demonstrated clinical efficacy at all dose levels explored. MEDI2228 0.14 mg/kg Q3W had a manageable safety profile and an ORR of 61% in a heavily pretreated population with myeloma that is R/R post PI, IMiD, and mAb therapies. Disclosures Kumar: Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Tenebio: Other, Research Funding; Merck: Consultancy, Research Funding; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Genecentrix: Consultancy; Novartis: Research Funding; Kite Pharma: Consultancy, Research Funding; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; BMS: Consultancy, Research Funding; Karyopharm: Consultancy; MedImmune: Research Funding; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Sanofi: Research Funding; Carsgen: Other, Research Funding; Cellectar: Other; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Dr. Reddy's Laboratories: Honoraria; Adaptive Biotechnologies: Consultancy. Bhutani:Sanofi Genzyme: Consultancy; Takeda: Other: Clinical trial funding to institute, Speakers Bureau; BMS: Other: Clinical trial funding to institute, Speakers Bureau; Amgen: Speakers Bureau; MedImmune: Other: Clinical Trial Funding to Institute; Prothena: Other: Clinical Trial Funding to Institute; Janssen: Other: Clinical Trial Funding to Institute. Spencer:Roche: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Other: Grant/Research Support; Servier: Consultancy, Other: Grant/Research Support; Janssen: Consultancy, Honoraria, Other: Grant/Research Support, Speakers Bureau; Haemalogix: Consultancy, Honoraria, Other: Grant/Research Support; Abbvie: Consultancy, Honoraria, Other: Grant/Research Support; Pfizer: Consultancy, Honoraria; Takeda: Honoraria, Other, Speakers Bureau; Secura Bio: Consultancy, Honoraria; TheraMyc: Consultancy, Honoraria; Antegene: Consultancy, Honoraria; BMS: Honoraria, Other: Grant/Research Support, Research Funding, Speakers Bureau; Pharmamar: Other. Ailawadhi:Cellectar: Research Funding; Pharmacyclics: Research Funding; Janssen: Research Funding; Takeda: Honoraria; Amgen: Research Funding; Celgene: Honoraria; Phosplatin: Research Funding; Medimmune: Research Funding; BMS: Research Funding. Kalff:Amgen: Honoraria; Janssen: Honoraria; Roche: Honoraria; Celgene: Honoraria; CSL: Honoraria. Pore:AstraZeneca: Current Employment, Current equity holder in publicly-traded company. Gibson:AstraZeneca: Current Employment, Other: Paid as a clinical scientist contractor. Wang:AstraZeneca: Current Employment, Current equity holder in publicly-traded company. Cheng:Astrazeneca: Current Employment, Current equity holder in private company. Williams:AstraZeneca: Current Employment, Current equity holder in publicly-traded company. Kinneer:AstraZeneca: Current Employment, Current equity holder in publicly-traded company, Other: Personal fees; BCMA Monoclonal Antibody-Drug Conjugate: Patents & Royalties: Pending. Zonder:Intellia: Membership on an entity's Board of Directors or advisory committees, Other: Personal fees; Alnylam: Membership on an entity's Board of Directors or advisory committees, Other: Personal fees; Oncopeptide: Membership on an entity's Board of Directors or advisory committees, Other: Personal fees; Amgen: Membership on an entity's Board of Directors or advisory committees, Other: Personal fees; BMS: Consultancy, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Other: Personal fees; Janssen: Consultancy, Other: Personal fees; Prothena: Consultancy; Caelum: Consultancy; Celgene: Research Funding. Larsen:Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen Oncology: Honoraria, Membership on an entity's Board of Directors or advisory committees. Yee:Amgen: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; GSK: Consultancy; Janssen: Consultancy; Karyopharm: Consultancy; Oncopeptide: Consultancy; Sanofi: Consultancy; Takeda: Consultancy, Research Funding. Dimopoulos:Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Speakers Bureau.

Introduction: MM is an incurable disease with risk categorizations by cytogenetic abnormalities. Prognostic implications of chromosome translocation t(11;14)+ are important to inform development of biomarker-targeted therapies such as the B-cell lymphoma-2 (BCL-2) pathway inhibitors. This study aims to evaluate MM treatment (Tx) patterns and outcomes of t(11;14)+ compared with other cytogenetic cohorts in US routine clinical practice. Methods: A retrospective observational cohort study of the Flatiron Health database, which comprises de-identified electronic health record-derived patient (pt)-level data from over 280 community and academic cancer clinics in the US. Pts aged ≥18 years who received a first-line (1L) induction Tx within ≤60 days of MM diagnosis from 1/1/2011 to 1/31/2020, and were not enrolled in a clinical trial were identified at the start of each Tx line (index date) and followed up (f/u) until 1/31/2020. Only cytogenetic results by fluorescence in situ hybridization (FISH) were used to stratify the cohort into: t(11;14)+; standard risk, excluding t(11;14)+ (SR); and high risk, (HR; del 17p, t(4;14), t(14;16), t(14;20), chromosome 1 abnormalities as a proxy for 1q gain; and t(11;14) where it co-occurs). Descriptive analyses of pt characteristics and Tx were conducted. Kaplan-Meier analyses were used to evaluate median time to next treatment (TTNT) and overall survival (OS) with log-rank test for significance. The cohort was stratified by age ≤70/>70 years (yrs) as a proxy for transplant eligibility. Results: Of 10,703 pts with MM in the database, 5982, 3059 and 1595 pts were eligible for 1L, second-line (2L), and third-line (3L) analysis, of which 76%, 84%, and 86%, respectively, had FISH test results before Tx initiation. 14% of pts with FISH test results were t(11;14)+, ~55% SR and ~35% HR. Included pts were predominately male (55%), ~90% treated in the community setting and ~16% African-American. Pts in the 3L cohort were younger at diagnosis with a median age (interquartile range) of 67 (59 ̶ 74) yrs compared with 69 (61 ̶ 76) yrs in both 1L and 2L. The 1L Tx pattern was consistent across cytogenetic cohorts with bortezomib (V), lenalidomide (R), dexamethasone (d) as the most common Tx (>42%). Together, VRd, Rd, Vd, and cyclophosphamide (Cy) in combination with Vd represented ≥90% of 1L Tx (Figure 1). Across 2L cytogenetic cohorts, the most common Tx regimens (≥25%) were VRd and Rd. The use of regimens containing carfilzomib (K) and daratumumab (D) was emerging in 2L: KRd in 8% of t(11;14)+ and HR and 5% in SR; Kd 5% in all groups; DRd in 4% of t(11;14)+ and 3% in SR and HR (Figure 1). 3L Tx pattern was fragmented with different Tx regimens. Rd was the most common 3L Tx option: 9% in t(11;14)+, 10% in SR and 7% in HR (Figure 1). Across all lines of Tx, t(11;14)+ had similar Tx outcomes to SR, and HR had poorest outcomes (Table 1). Pts TTNT shortened as they advanced to later lines of Tx (Table 1). Although TTNT did not differ by age across lines of Tx, OS was superior in pts <70 yrs across all 3 cytogenetic risk cohorts, especially in 1L where transplant in those ≤70 yrs vs >70 yrs at diagnosis was 44% vs 11% for t(11;14)+, 47% vs 10% for SR and 49% vs 9% for HR. Conclusions: This study identified cytogenetic subgroups across 1L to 3L in a predominately community setting in the US. MM t(11;14)+ pts had similar 1L and 2L Tx patterns to SR and HR. Across all lines of Tx, the outcomes of t(11;14)+ and SR pts were comparable and better than HR pts. TTNT was reduced as pts advanced to later lines of Tx. Pts continuing to 3L Tx were younger at diagnosis, but there was not a clear-cut standard of care. While TTNT did not differ by age across lines of Tx, OS was superior in pts <70 yrs across all 3 cytogenetic risk cohorts. This study sets the benchmark for novel treatment options, such as BCL-2 pathway inhibitors, primarily wherever available biomarker-driven therapy is considered appropriate. Disclosures Atrash: Takeda, Amgen, Karyopharm, BMS, Sanofi, Cellactar, Janssen and Celgene: Honoraria; BMS, Jansen oncology, Sanofi: Speakers Bureau; Amgen, GSK, Karyopharm.: Research Funding. Flahavan:F. Hoffmann-La Roche: Current equity holder in publicly-traded company; Roche Products Ltd.: Current Employment. Xu:F. Hoffmann-La Roche Ltd: Current Employment, Other: All authors received support for third party writing assistance, furnished by Scott Battle, PhD, provided by F. Hoffmann-La Roche, Basel, Switzerland.. Ma:Genentech, Inc.: Current Employment, Current equity holder in publicly-traded company. Karve:AbbVie: Current Employment, Current equity holder in publicly-traded company. Hong:F. Hoffmann-La Roche: Current equity holder in publicly-traded company; Genentech, Inc.: Current Employment. Jirau-Lucca:Genentech, Inc.: Current Employment; AbbVie: Current equity holder in publicly-traded company; BMS: Current equity holder in publicly-traded company; Celgene: Divested equity in a private or publicly-traded company in the past 24 months. Nixon:Genentech, Inc.: Current Employment, Current equity holder in publicly-traded company; F. Hoffmann-La Roche: Current Employment, Current equity holder in publicly-traded company. Ailawadhi:Takeda: Honoraria; Pharmacyclics: Research Funding; Cellectar: Research Funding; BMS: Research Funding; Medimmune: Research Funding; Phosplatin: Research Funding; Amgen: Research Funding; Celgene: Honoraria; Janssen: Research Funding.