Richter, Joshua R.

Abstract Introduction: Patients (pts) with soft tissue plasmacytomas noncontiguous with bone (true extramedullary disease [EMD]) have poor outcomes with standard therapies shown by low overall response rates (ORRs), which are not durable. Talquetamab (Tal; anti-GPRC5D×CD3) and teclistamab (Tec; anti-BCMA×CD3) are first-in-class bispecific antibodies (BsAbs) approved as monotherapies for triple-class exposed (TCE) relapsed/refractory multiple myeloma (RRMM). Primary analysis from the RedirecTT-1 (NCT04586426) dedicated phase 2 EMD cohort (March 2025 data cut; median follow-up [mFU] 12.6 mo) showed Tal + Tec elicited an ORR of 78.9% (assessed by independent review committee) and a 12-mo progression-free survival (PFS) of 61.0%. Here, we report updated efficacy, using investigator assessment, and safety results from the phase 2 RedirecTT-1 EMD cohort with Tal + Tec. Importantly, we report EMD location and a novel analysis of tumor burden as a prognostic indicator of ORR. Methods: Pts had TCE RRMM and true EMD defined as ≥1 nonradiated soft tissue plasmacytoma noncontiguous with bone ≥2 cm in 1 dimension (with or without paramedullary plasmacytomas). Nonsecretory/oligosecretory disease was permitted. Prior CAR-T and non-BCMA/-GPRC5D BsAb therapies were permitted. Pts received Tal 0.8 mg/kg + Tec 3.0 mg/kg Q2W, preceded by step-up doses, with a permitted switch to monthly dosing at investigator's discretion after cycle 6 or after cycle 4 with confirmed ≥VGPR. Response was assessed per IMWG; EMD response was assessed by PET-CT or MRI whole-body scans. Tumor burden was assessed by total EMD tumor volume. Results: As of July 2025, 90 pts received Tal + Tec, with a median follow-up of 16.3 mo (range 0.5–23.7). Baseline characteristics were as previously reported; 39% had nonsecretory/oligosecretory disease, 20% had prior anti-BCMA CAR-T therapy, and 9% had prior BsAb therapy (all anti-FcRH5). The median number of plasmacytomas was 2 (range 1–7); 17 (18.9%), 29 (32.2%), and 74 (82.2%) pts, respectively, had ≥1 nodal, organ, or soft tissue EMD, while 11 (12.2%) also had ≥1 additional paramedullary plasmacytoma. Of 268 EMDs across all pts, 95 (35.4%) were nodal EMD, 77 (28.7%) were organ EMD (most commonly liver), and 64 (23.9%) were soft tissue EMD; 32 (11.9%) were paramedullary. Baseline EMD tumor volume was <25 cm2in 43 (47.8%) pts, 25–50 cm2 in 21 (23.3%) pts, and >50 cm2 in 26 (28.9%) pts. Per investigator assessment, ORR (95% CI) was 77.8% (67.8–85.9); 50.0% had a ≥CR. Median duration of response (DOR) was not estimable (NE; 12-mo DOR rate, 60.1%), 12-mo PFS was 55.6%, and median overall survival (OS) was NE (12-mo OS rate 73.8%). ORR was 90.7% (77.9–97.4; ≥CR 60.5%) in pts with EMD tumor volume <25 cm2, 66.7% (43.0–85.4; ≥CR 52.4%) for 25–50 cm2, and 65.4% (44.3–82.8; ≥CR 30.8%) for >50 cm2. Common adverse events (AEs) included CRS (77.8%; no grade [gr] 3/4) and neutropenia (72.2%; gr 3/4 62.2%). Taste changes (78.9%), non-rash skin AEs (68.9%), and nail AEs (55.6%) were all gr 1/2, and rash AEs (30.0%) were mostly gr 1/2. ICANS occurred in 11 (12.2%) pts (gr 3, 1.1%; gr 4, 1.1%). Infections occurred in 72 (80.0%) pts (gr 3/4 40.0%), most commonly upper respiratory tract infection (26.7%; gr 3/4 5.6%); IVIG was highly recommended to prevent and manage hypogammaglobulinemia and infection. Ten (11.1%) pts discontinued Tal + Tec due to treatment-emergent AEs (4 pts due to infections and 6 due to gr 5 AEs). Two pts discontinued Tal only due to AEs. In total, 11 (12.2%) pts had gr 5 AEs (6 due to infections), 6 of which were deemed to be drug related by investigators. Data will be updated with an additional 4 mo of follow-up for the presentation. Conclusions: With longer follow-up in pts with TCE RRMM with true EMD regardless of baseline tumor characteristics, Tal + Tec efficacy exceeded all approved therapies, including T-cell redirecting and cellular therapies, noting limitations of cross-study comparisons. Lower total EMD tumor volume was associated with a higher ORR but low pt numbers in each group and lack of statistical testing limits robust interpretation. The safety profile of Tal + Tec was generally consistent with each monotherapy; AEs were not exacerbated with the combination. These data continue to highlight the clinical benefit of the novel combination of Tal + Tec in pts with true EMD, a population with high disease burden and significant unmet need.

Introduction: Selinexor is a novel, oral selective inhibitor of nuclear export (SINE) which forces nuclear retention and activation of tumor suppressor proteins. Selinexor plus low dose dexamethasone (Sel-dex) was recently approved in the United States based on data from the STORM study wherein, Sel-dex induced an overall response rate (ORR) of 26.2% in patients with penta-exposed, triple-class refractory multiple myeloma. The presence of high-risk cytogenetic abnormalities is known to have a poor prognosis in multiple myeloma, with transient responses. We performed post-hoc analyses to determine the outcomes in patients with relapsed/refractory myeloma treated with Sel-dex based on the baseline cytogenetic abnormalities. Methods: STORM was a phase 2b, open-label study which enrolled patients with relapsed and refractory myeloma. Selinexor 80 mg in combination with dexamethasone 20 mg was administered orally, twice weekly. The primary endpoint was ORR. For this analysis, we pooled 78 patients (48 quad-refractory and 30 penta-refractory) from STORM, part 1 and 122 patients (penta-exposed and triple class refractory) from STORM, part 2 to compare outcomes between high-risk and standard risk cytogenetics groups. High-risk cytogenetics was defined as having at least 1 of the following abnormalities by fluorescence in-situ hybridization (FISH) at baseline: del(17p), t(4;14), t(14;16), and gain(1q) in >5% of screened plasma cells. The FISH analyses were performed at a central laboratory and used to assess cytogenetic risk status. Results: Of the 200 patients, 122 (61%) had high-risk disease (del(17p): 36%, t(4;14): 18%, t(14;16): 5%, and gain(1q): 36%). The ORR in high-risk patients was 20.5% (very good partial response [VGPR)]: 5.7% and partial response [PR]: 14.8%) and the ORR was 29.5 % (complete response [CR]: 2.6%, VGPR: 3.8%, and PR: 23.1%) in standard-risk patients. The clinical benefit rate (CBR) was 35.2% in high-risk patients compared with 38.5% in standard-risk patients. Median duration of clinical benefit (DOCB) was 4.4 and 6.2 months in the high-risk and standard-risk patients respectively. Median progression-free survival (PFS) was 3.8 and 4.2 months and overall survival (OS) was 8.6 and 9.4 months in the high-risk and standard-risk patients, respectively. Efficacy by specific cytogenetic abnormality is presented in Table 1 below (Due to the small sample size (n=11), data for the t(14;16) subgroup are not presented separately). Conclusions: Sel-dex demonstrated a similar CBR in patients with high risk and standard risk disease and preserved clinical benefit in heavily pre-treated patients who had rapidly proliferative disease and high-risk cytogenetics at baseline. The benefit was maintained across cytogenetic risk subgroups with a higher ORR in the t(4;14) and gain(1q) subgroups. The DOR and OS was similar across all the subgroups. These analyses support the use of Sel-dex in patients with high-risk cytogenetics and warrant further evaluation of selinexor in combination with other anti-myeloma therapies in high-risk disease. Disclosures Nooka: GSK: Honoraria, Other: advisory board participation; Amgen: Honoraria, Other: advisory board participation; BMS: Honoraria, Other: advisory board participation; Janssen: Honoraria, Other: advisory board participation; Spectrum pharmaceuticals: Honoraria, Other: advisory board participation; Adaptive technologies: Honoraria, Other: advisory board participation; Celgene: Honoraria, Other: advisory board participation; Takeda: Honoraria, Other: advisory board participation. Yee:Adaptive: Consultancy; Karyopharm: Consultancy; Takeda: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding. Huff:Karyopharm, Sanofi, MiDiagnostics: Consultancy; Member of Safety Monitoring Board for Johnson and Johnson: Membership on an entity's Board of Directors or advisory committees. Vogl:Karyopharm Therapeutics: Consultancy; Takeda: Consultancy; Celgene: Consultancy; Amgen: Consultancy; Janssen: Consultancy; Active Biotech: Consultancy. Chari:Novartis Pharmaceuticals: Research Funding; GlaxoSmithKline: Research Funding; Array Biopharma: Research Funding; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium/Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Consultancy; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Oncoceutics: Research Funding. Moreau:Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria. Dingli:Karyopharm: Research Funding; Rigel: Consultancy; Millenium: Consultancy; alexion: Consultancy; Janssen: Consultancy. Lonial:Genentech: Consultancy; Karyopharm: Consultancy; Takeda: Consultancy, Research Funding; Amgen: Consultancy; BMS: Consultancy; Janssen: Consultancy, Research Funding; GSK: Consultancy; Celgene Corporation: Consultancy, Research Funding. Dimopoulos:Sanofi Oncology: Research Funding. Vij:Takeda: Honoraria, Research Funding; Sanofi: Honoraria; Karyopharm: Honoraria; Janssen: Honoraria; Genentech: Honoraria; Celgene: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding. Tuchman:Karyopharm: Honoraria; Celgene: Honoraria, Research Funding, Speakers Bureau; Amgen: Research Funding; Merck: Research Funding; Prothena: Research Funding; Roche: Research Funding; Sanofi: Research Funding; Alnylam: Honoraria, Research Funding. Biran:Bristol Meyers Squibb: Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Siegel:Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb Company: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Richardson:Karyopharm: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: 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; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding. Liu:Karyopharm Therapeutics: Employment, Equity Ownership. Joshi:Karyopharm Therapeutics: Employment, Equity Ownership. Shah:Karyopharm Therapeutics: Employment, Equity Ownership. Shacham:Karyopharm Therapeutics Inc: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Kauffman:Karyopharm Therapeutics Inc: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Jagannath:Medicom: Speakers Bureau; Multiple Myeloma Research Foundation: Speakers Bureau; BMS: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Merck: Consultancy.

Introduction: Selinexor is a first-in-class Selective Inhibitor of Nuclear Export (SINE) compound that selectively binds and inactivates XPO1, therefore forcing the nuclear retention and re-activation of cell cycle regulators such as p53, FOXO, IkB, and Rb. Selinexor in combination with low dose dexamethasone (Sel-dex) was recently approved based on data from the STORM study, which induced an overall response rate (ORR) of 26.2% in patients with penta-exposed, triple-class refractory multiple myeloma (TCR-MM). Patients with TCR-MM often present with plasmacytomas along with serological markers of MM. Methods: Here we analyzed the effects of Sel-dex in patients from the STORM study who had baseline plasmacytomas. Results: 122 patients were in enrolled in the STORM study including 27 with a baseline plasmacytoma. The majority of plasmacytomas were soft tissue (22 patients) and 5 patients had soft tissue disease extension from a bone (rib (2), iliac (2), sacral vertebral). The median age of patients with plasmacytomas was 64 years, the median prior therapies were 7 (range 4 - 15), and 8/27 patients with a plasmacytoma had high risk cytogenetics. Of the 27 patients, 11 patients did not have a follow up plasmacytoma assessment: 6 were not evaluable for response as they came off therapy due to clinical progression and/or adverse events, 4 had stable disease (SD) with no evidence of plasmacytoma change, and 1 had progressive disease (PD) on serum M-protein with no evidence of plasmacytoma change. Sixteen of the 27 patients did have follow-up plasmacytoma assessments (methods of measurements included PET, CT, MRI or Clinical). The median days from baseline plasmacytoma evaluation to follow up was 41 days (range 22 - 119). Five patients had objective responses, based upon para-protein and plasmacytoma reductions according to IMWG criteria (1 very good partial response [VGPR], 4 partial responses [PR]) for an ORR of 18.5%. In addition, 2 patients had a minimal response (MR), 4 had SD and 5 had objective PD. Among the 5 patients with ≥PR, 3 plasmacytomas completely resolved, 1 showed near complete resolution, and another showed size reduction with no metabolic activity on PET. Of the 2 patients with a MR, 1 plasmacytoma completely resolved and 1 showed reduced PET uptake. Among the 4 patients with SD, 1 plasmacytomas completely resolved, 1 increased in size and 2 had unknown outcomes as they were assessed clinically. Among the 5 patients with PD, 1 plasmacytomas decreased in size, 1 increased in size, and 3 had unknown outcomes as they were assessed clinically. Conclusions: Of the 16 patients with TCR-MM and a follow up plasmacytoma assessment enrolled on STORM, 9/16 of the plasmacytomas either completely resolved or decreased in size and/or metabolic activity. Effects on plasmacytomas occurred in patients with objective responses (≥PR), as well as in patients with MR, SD and PD. These observations support the finding that Sel-dex is active in patients with plasmacytomas and heavily pretreated TCR-MM. Disclosures Yee: Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Takeda: Consultancy; Karyopharm: Consultancy; Adaptive: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding. Huff:Member of Safety Monitoring Board for Johnson and Johnson: Membership on an entity's Board of Directors or advisory committees; Karyopharm, Sanofi, MiDiagnostics: Consultancy. Chari:Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Research Funding; Oncoceutics: Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium/Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Array Biopharma: Research Funding; GlaxoSmithKline: Research Funding; Novartis Pharmaceuticals: Research Funding. Vogl:Active Biotech: Consultancy; Janssen: Consultancy; Karyopharm Therapeutics: Consultancy; Takeda: Consultancy; Celgene: Consultancy; Amgen: Consultancy. Gavriatopoulou:Genesis: Honoraria, Other: Travel expenses; Amgen: Honoraria; Janssen: Honoraria, Other: Travel expenses; Takeda: Honoraria, Other: Travel expenses. Nooka:Adaptive technologies: Honoraria, Other: advisory board participation; Spectrum pharmaceuticals: Honoraria, Other: advisory board participation; GSK: Honoraria, Other: advisory board participation; Janssen: Honoraria, Other: advisory board participation; Amgen: Honoraria, Other: advisory board participation; Takeda: Honoraria, Other: advisory board participation; Celgene: Honoraria, Other: advisory board participation; BMS: Honoraria, Other: advisory board participation. Moreau:AbbVie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Dingli:Karyopharm: Research Funding; Rigel: Consultancy; Millenium: Consultancy; Janssen: Consultancy; alexion: Consultancy. Lonial:Janssen: Consultancy, Research Funding; GSK: Consultancy; Karyopharm: Consultancy; BMS: Consultancy; Celgene Corporation: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Amgen: Consultancy; Genentech: Consultancy. Dimopoulos:Sanofi Oncology: Research Funding. Vij:Takeda: Honoraria, Research Funding; Sanofi: Honoraria; Karyopharm: Honoraria; Janssen: Honoraria; Genentech: Honoraria; Celgene: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding. Tuchman:Prothena: Research Funding; Amgen: Research Funding; Karyopharm: Honoraria; Alnylam: Honoraria, Research Funding; Sanofi: Research Funding; Merck: Research Funding; Roche: Research Funding; Celgene: Honoraria, Research Funding, Speakers Bureau. Hoffman:Celgene: Speakers Bureau. Costa:Abbvie: Consultancy; Celgene: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Speakers Bureau; GSK: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Research Funding, Speakers Bureau; Fujimoto Pharmaceutical Corporation Japan: Other: Advisor. Biran:Janssen: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria; Bristol Meyers Squibb: Research Funding; Takeda: Consultancy, Honoraria. Siegel:Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb Company: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Shah:Karyopharm Therapeutics: Employment, Equity Ownership. Picklesimer:Karyopharm Therapeutics: Employment, Equity Ownership. Saint-Martin:Karyopharm Therapeutics: Employment, Equity Ownership. Li:Karyopharm Therapeutics: Employment, Equity Ownership. Kauffman:Karyopharm Therapeutics Inc: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Shacham:Karyopharm Therapeutics Inc: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Richardson:Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Jagannath:Multiple Myeloma Research Foundation: Speakers Bureau; Medicom: Speakers Bureau; Merck: Consultancy; Celgene: Consultancy; Novartis: Consultancy; BMS: Consultancy.

e19525 Background: Rearrangements of the immunoglobulin heavy chain (IGH) on chromosome 14 are identified by FISH in about 15-20% of patients (pts) with newly diagnosed multiple myeloma (MM). Historically there is variation on the significance on prognosis of these rearrangements: typically, t(4;14), t(14;16) and t(14;20) have high risk (HR), and t(11;14) have standard risk (SR). A recent study (Kaufman et al, Leukemia. 2016 30:633-9) suggests that t(11;14) may confer a worse prognosis We report the prognostic significance of t(11;14) in a single-institution MM cohort. Methods: 87 pts with t(11;14) by CD 138 selected FISH at diagnosis were identified, pts without symptomatic MM were excluded. Cox regression was used for statistical analysis. Progression free survival (PFS), and overall survivals (OS) from diagnosis and post autologous stem cell transplant (ASCT) were analyzed by Kaplan-Meier. Results: Median age at diagnosis was 62 years, 45 pts (52%) were male, and 24 pts (27%) had ISS 3. All pts received either a proteasome inhibitor or an immunomodulatory agent, and 42 (48%) received triplet treatment as induction. Sixty-nine (79%) pts had ASCT, and overall response rate (ORR, partial response or better) post ASCT was 73%. For pts with HR FISH (defined as t(14;16), p53 del, 1q21 gain or 1p del) compared to SR FISH, the ORR post ASCT was 70% vs 77% (p = 0.67). OS from diagnosis was 93% at 3 years, 74% at 4 years and 51% at 5 years. Seven patients (8%) developed plasma cell leukemia, and there was no association between HR and SR FISH (p = 0.66). In multivariate analysis, ISS stage was an independent risk factor for mortality; pts with stage 3 had 7.3 times (CI: 1.16-36.4) and 5.7 times (CI: 1.63-20.0) the risk of mortality than pts with stage 1 and 2. Having an ASCT reduced mortality by 87% (CI: 0.04-0.41). Conclusions: Despite the use of novel therapies the OS at 5 years of our pts with MM was not significantly improved compared to SEER data from 1992-2013 (51% vs 48.5%). Pts with t(11;14) who had ASCT had increased survival compared to those who did not. Our results suggest that t(11;14) may confer a worse prognosis. Further prospective studies evaluating the risk of t(11;14) are warranted.

8044 Background: Racial disparities of FISH abnormalities in multiple myeloma (MM) have been well described in whites (W) but partially described in minorities (M) (Paulus et al, ASH 2016, 4432). We aimed to explore racial-based differences of FISH abnormalities using the largest cohort of m to date. Methods: CD-138 selected FISH was done on 799 consecutive patients (pts). Pts without symptomatic MM, and biopsy >6 months after diagnosis were excluded. The abnormalities evaluated included standard and intermediate risk: IGH rearrangements (IGH r), t(4;14), t(11;14), and high risk: t(14;20), t(14;16), del13q, del 17p, 1q21. Chi-square was used for statistical analysis. Due to smaller numbers, all m (Hispanic (H), Black (B), Asian (A) and Other (O)) were included into the same group for statistical analysis. Results: 482 pts were eligible, 343 (71%) were W, 52 (10%) H, 50 (10%) B, 19 (3%) A, and 18 (3%) O. Median age was 65 years, 54% were male, and 26% ISS stage 3. There were no were no statistically significant differences in FISH abnormalities between the m (Table1). Overall W had more abnormalities in IGH r, t(4;14), t(11;14), t(14:20), 1q21 gain compared to M. Most notably W had more IGH r (39% vs 28%; p=0.019) and t(11;14) (20% vs 12%; p=0.024). There were no statistically significant differences between W and m in the high risk FISH abnormalities. Conclusions: We had significant differences in FISH compared to M. W had more IGH r and t(11;14) than M, and there was no difference in high risk FISH abnormalities between W and M. This study confirms the biological racial disparities that exist in minorities with MM. Further studies with more inclusion of minorities are needed to elucidate these disparities and its effects on risk stratification and outcomes. [Table: see text]