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Introduction Up to 40% of pts with diffuse large B-cell lymphoma (DLBCL) relapse after first-line chemo-immunotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). CELMoD agents such as GOLCA potently degrade target proteins Ikaros/Aiolos, resulting in antiproliferative, apoptotic, and immunomodulatory activity. GOLCA preferentially distributes to tissues and lymphoid organs. In a phase 1 study, GOLCA demonstrated a manageable safety profile with promising clinical activity as monotherapy in relapsed/refractory non-Hodgkin lymphoma (Michot et al. Blood 2021). CC-220-DLBCL-001 (NCT04884035) is an ongoing open-label, multicenter, dose escalation and expansion trial to assess safety and preliminary efficacy of CELMoD agents + R-CHOP for untreated a-BCL. GOLCA demonstrated a manageable safety profile in the dose escalation phase (Munoz et al. ICML 2023 abstract 438); we report combined results from the GOLCA dose escalation and expansion phases. Methods Eligible pts were ≥ 18 years, had untreated a-BCL with measurable disease (Lugano 2014), ECOG performance status ≤ 2 and International Prognostic Index (IPI) score 0-5 (2-5 in dose expansion). Pts were treated with R-CHOP plus GOLCA in 21-day (D) cycles (C) for up to 6C, or until disease progression/unacceptable toxicity/study withdrawal/physician decision. During dose escalation, pts received GOLCA at dose levels (DL): 0.2 mg D1-7 (DL-1), 0.4 mg D1-7 (DL1), and 0.4 mg D1-10 (DL2). DL2 met the dose-limiting toxicity threshold and was not continued in the expansion phase. During dose expansion, pts were randomized 1:1 to R-CHOP plus GOLCA at DL-1 or DL1. The primary endpoint for the expansion phase was safety of GOLCA at the recommended phase 2 dose (DL1) (based on adverse events [AEs]); secondary endpoints included overall response rate (ORR) and complete metabolic response (CMR) rate (assessed at end of treatment [EoT] by PET-CT [Lugano 2014]). Circulating tumor DNA (ctDNA) was measured at C1D1, C2D1, C3D1, and EoT using the PhasED-Seq assay. Results Across escalation and expansion, 78 pts were treated (DL-1, n = 35; DL1, n = 37; DL2, n = 6). Median age was 63.0 years, 56.4% were male, most had high-intermediate/high IPI (3-5) score at diagnosis (64.1%), Ann Arbor stage III-IV disease (83.3%), and germinal center B cell as cell of origin (51.3%); 83.3% pts had DLBCL histology. At data extraction (May 25, 2023), across escalation and expansion, 38 pts had treatment ongoing, 31 completed treatment, and 35 continued to follow-up. A total of 3 pts discontinued due to AEs, 1 each at DL-1, DL1, and DL2. In the safety population (n = 78), median GOLCA relative dose intensity (RDI) was 99.4%; 82.1% of pts received RDI ≥ 85%. RDI for CHOP components was > 90%. A total of 73 (93.6%) pts had ≥ 1 treatment-emergent AE (TEAE); 70 (89.7%) pts had ≥ 1 TEAE considered related to GOLCA; 65 (83.3%) pts had ≥ 1 grade 3/4 TEAE, 62 (79.5%) pts had ≥ 1 grade 3/4 TEAE considered related to GOLCA. The most frequently occurring grade 3/4 TEAEs were neutropenia (76.9%) and thrombocytopenia (32.1%) ( Table). A total of 30 (38.5%) pts had serious TEAEs, most frequently febrile neutropenia (preferred term: 11 pts, 14.1%); 12 (15.4%) pts had serious TEAEs of infection or infestation (system organ class); 6 pts (7.7%) had venous thromboembolisms considered related to GOLCA (4 deep vein thrombosis, 1 superficial thrombosis, 1 pulmonary embolism). Treatment-related AEs leading to GOLCA dose reduction or discontinuation occurred in 11 (14.1%) pts and 6 (7.7%) pts, respectively. After a median follow-up time of 4.1 months (range 0.3-12.3) and among all treated pts with EoT response available, 21/25 had CMR; together, 14/14 pts who received GOLCA 0.4 mg (DL1 and DL2) achieved CMR at EoT ( Figure). Among efficacy-evaluable pts (n = 56), ORR was 91.1% (95% CI 80.4-97.0). Pts treated with GOLCA at DL-1 and DL1 who were ctDNA high-risk (≥ 2.5 log hGE/mL) responded to study treatment (CMR-PMR) and had early decreases in ctDNA (Kaplan et al. ASH 2023). Conclusions GOLCA demonstrated a manageable safety profile, showed good combinability with R-CHOP, and did not compromise delivery of curative treatment. Efficacy results and substantial ctDNA decrease indicate robust clinical activity in frontline DLBCL, with a high CMR rate at EoT, particularly among patients treated at DL1. Study support Bristol Myers Squibb.

Introduction: Immune-mediated graft failure (also termed graft rejection) is a feared complication of hematopoietic stem cell transplant (HSCT) and there is no effective intervention. Multiple pre-transplant risk factors for graft failure are known and recent studies from our groups identified interferon gamma (IFNγ) as a mechanistically important and pharmacologically targetable cytokine involved in graft failure pathophysiology. CXCL9, a downstream marker of IFNγ production, was also identified as a biomarker. We describe an international multicenter retrospective pooled analysis of emapalumab (EMA), an IFNγ neutralizing agent, for the prevention/treatment of immune-mediated graft failure after HSCT. Methods: The safety and preliminary efficacy of EMA were studied in predominantly pediatric patients who received EMA using two different strategies: 1) graft failure treatment and 2) graft failure prophylaxis. Patients at US centers were treated with EMA if they developed clinical and laboratory signs of graft failure after HSCT. All treatment patients met 2 or more of the following criteria: 1) HLA mismatched donor and/or prior graft failure, 2) unexplained fever >39°C (or >38°C if prior history of graft failure) after HSCT, 3) absolute neutrophil count decline after initial engraftment, 4) delayed neutrophil engraftment after HSCT, 5) real-time CXCL9 > 2.5x upper limit of normal (ULN). Temperature and CXCL9 cutoffs were based on a prior graft failure biomarker publication (Sabulski et al, Blood Advances 2021). Patients treated at European centers received prophylactic EMA to prevent graft failure if they were deemed at high-risk prior to transplant. High-risk patients had a prior history of graft failure after HSCT or had two or more of the following established risk factors: a) affected by a disease with high risk of graft failure, including acquired severe aplastic anemia, thalassemia, primary HLH; b) ex-vivo T cell-depleted stem cell product; c) transplant from unrelated cord blood unit or mismatched related/unrelated donor. Results: Thirty-six HSCTs used EMA for graft failure treatment or prophylaxis and were included in this study.EMA was used for graft failure treatment in 25 HSCTs wherein patients developed clinical and laboratory signs of graft failure (Table 1). Most HSCTs in the treatment cohort were performed for bone marrow failure syndromes (n=16). All patients tolerated EMA without complications and no side effects or infections were attributed to EMA. Fifty six percent (14/25) of patients treated with EMA for impending graft failure engrafted and had resolution of graft failure concerns, while the remaining 44% suffered graft failure. Responders had a median ANC of 0.29 x10 3 cells/μL (range 0.05-0.79) prior to EMA, which increased to a median of 0.6 x10 3cells/μL (range, 0-5.1) and 2.97 x10 3 cells/μL (range, 0.85-8.7) on days 3 and 7 after EMA dosing. Eighty percent (20/25) of CXCL9 levels were elevated in the treatment cohort prior to EMA dosing. The median CXCL9 level prior to EMA dosing was elevated 2.4 x ULN (range, 0.3-157.8). The median pre-EMA CXCL9 level in patients who ultimately suffered graft failure in the treatment cohort was 3.3x ULN (range, 0.7-157.8) compared to a median of 2.2x ULN (range, 0.3-30.4) in subjects who had signs of graft failure but did not suffer graft failure (p=0.24). Eleven patients received prophylactic EMA based on a prior history of graft failure or other pre-transplant risk factors. EMA was well tolerated in these patients and 91% (10/11) of patients engrafted while one patient with prior history of graft failure suffered recurrent graft failure. The pre-HSCT (day -2) CXCL9 level in the lone prophylactic patient who suffered graft failure was 4x the ULN. Conclusions: This study reports the largest cohort of HSCTs that used EMA therapy for the novel purpose of treating or preventing graft failure. EMA was well tolerated in all patients. Efficacy conclusions are preliminary and limited by the study design, however our treatment study successfully identified a cohort of patients with a markedly high graft failure rate (44%) and we show preliminary evidence to suggest emaplaumab prevented graft failure in patients who had signs of impending graft failure at the time of treatment. The safety and preliminary efficacy observations in this study support a larger prospective study of IFNγ blockade for graft failure prevention after HSCT.

Background: Tumor mutational burden (TMB), defined as the number of nonsynonymous mutations per megabase (Mb) in the coding regions of a tumor genome, has been associated with improved response to immune checkpoint blockade treatments and more broadly with overall survival (OS) in many cancers. Limited prior studies have found that TMB is higher in diffuse large B-cell lymphoma (DLBCL) compared to many other cancers. However, only two studies have evaluated TMB and prognosis in newly diagnosed DLBCL patients. The prognostic role of TMB in diffuse large B-cell lymphoma (DLBCL) remains unclear as prior studies have been limited to panel sequencing of cancer genes and/or lacked matched germline-tumor samples for filtering. Methods: We characterized TMB from whole exome sequencing (WES) in newly diagnosed DLBCL patients with matched diagnostic tumor-normal samples prior to treatment with standard immunochemotherapy (IC). Tumor DNA was extracted from formalin-fixed, paraffin embedded tissue sections and germline DNA from peripheral blood. We evaluated the association between TMB and event-free (EFS) and OS using Cox regression adjusted for the international prognostic index (IPI) and other factors including cell of origin (COO), MYC double hit (DH) with BLC2 or BCL6 by FISH, and TP53 mutation status. EFS and OS were defined as time from diagnosis to earliest of treatment failure (EFS only), death, or last follow-up; EFS at 24 months (EFS24) was also modeled as a marker of early aggressive DLBCL. An optimal high/low TMB cutpoint was determined based on EFS using maximally selected rank statistics; sensitivity analyses used an 20/80 percentile to define the threshold. We also evaluated the association of driver tumor mutational load (driverTML) with EFS and OS, defined as the total number of mutations in 292 DLBCL driver genes. Results: In the analysis cohort of 394 DLBCL patients, the median age at diagnosis was 65 years (interquartile range: 56-73), 43% were female, 62.2% had IPI 0-2, and 57.4% germinal center B-cell COO. MYC was DH in 7.5% and TP53 was mutated in 16.2% of patients. Through a median follow-up of 7.5 years, there were 141 events and 122 deaths. EFS24 was achieved in 75.1% of the cohort; 5-year EFS was 69% (95% CI 64-74%) and 5-year OS was 75% (95% CI 71-80%). Median TMB in our cohort of DLBCL patients was 3.6 mutations/Mb, which was the fifth highest compared with 32 cancers in The Cancer Genome Atlas. As a continuous variable, increasing TMB (mutation/Mb) was associated with superior EFS (HR=0.89, 95% CI 0.81-0.98) and OS (HR=0.89, 95% CI 0.81-0.99) after adjustment for IPI. Spline analyses confirmed linear associations of TMB with EFS and OS. The optimal modeled cutpoint based on EFS was 4.5 mutations/Mb, with 31% classified as high TMB (>4.5). No significant ( P >.05) differences were observed between high and low TMB patients with clinical (i.e., age, sex, IPI category) or molecular (cell of origin, MYC DH, TP53 mutated) factors. In Cox regression, high-TMB was significantly protective for EFS and for OS compared to low-TMB after adjustment for each clinical factor ( Figure 1), with simultaneous adjustment for all these factors associated with superior EFS (HR=0.52, 95% CI 0.33-0.84) and OS (HR=0.59, 95% CI 0.36-1.00). TMB (high/low) combined with IPI (0-2, 3-5) was significantly ( P =.001) associated with EFS in Kaplan-Meier analysis ( Figure 2). Among patients with IPI 3-5, high TMB was significantly associated with superior EFS (HR=0.47, 95% CI 0.27-0.81) and OS (HR=0.57, 95% CI 0.33-0.99). Among patients with IPI 0-2, we also observed longer EFS (HR=0.62, 95% CI 0.34-1.11) and OS (HR=0.62, 95% CI 0.32-1.20) in high TMB patients, although the associations were not statistically significant ( P >.05). In sensitivity analyses, a 20/80 percentile TMB threshold found similar results for EFS (HR=0.64, 95% CI 0.41-1.03) and OS (HR=0.69, 95% CI 0.42-1.12) as in our main analyses. TMB and driverTML were significantly correlated ( R=0.65, P <10 -16) and we found similar effect sizes for EFS (HR=0.45, 95% CI 0.22-0.91) and OS (HR=0.55, 95% 0.27-1.13) as in our main analyses. Conclusions: In a large and well-defined cohort of IC treated DLBCL patients, we found DLBCL patients with higher TMB had superior EFS and OS after adjustment for other clinical and molecular prognostic factors, and the prognostic association for TMB was robust to threshold and gene set.

Introduction: With rapid treatment advances in multiple myeloma (MM), more patients receive the 3 main classes of MM treatments (immunomodulatory imide drug [IMiD] agents, proteasome inhibitors [PIs], and anti-CD38 monoclonal antibodies [mAbs]) in earlier lines of therapy and become TCE. This is a prerequisite for subsequent treatment with some novel therapies eg, anti-B-cell maturation antigen (BCMA) agents. Published evidence of RW clinical outcomes in patients with TCE MM is scarce in the evolving RRMM treatment landscape. The objective of this study was to assess RW clinical outcomes in patients with TCE RRMM who received treatment post-TCE. Methods: In this observational study, we analyzed de-identified patient data derived from electronic health records (EHRs) from 2 key United States (US) MM longitudinal databases (Flatiron Health MM [FHMM] and COTA Vantage MM [CVMM]). We identified patients who became TCE between November 2015 and March 2021 and received a subsequent treatment post-TCE; the earliest available end date of the 3rd treatment class was considered the date patients became TCE. The start date of the 1st treatment post-TCE (index treatment) was defined as the index date. We analyzed patient demographics, disease characteristics, prior treatment exposure, refractory status, and index treatments patterns/classes. Clinical endpoints assessed were response rates (overall and complete), overall survival (OS), progression-free survival (PFS), and time to progression (TTP). Results: The FHMM and CVMM databases included 1,319 and 1,118 TCE patients, respectively, of whom 897 and 795 received an index treatment post-TCE. Median (range) follow-up for patients who received an index treatment was 18.1 (0.1-82.0) and 15.5 (0.03-72.3) months for FHMM and CVMM cohorts, respectively. Median age for both RW cohorts was 68 years, more than half of patients were men and the majority were White. Patients received a median of 3 lines of prior treatment (range, 1-14 and 1-12 for FHMM and CVMM cohorts, respectively). In both RW cohorts, >75% of patients who received an index treatment were triple-class refractory and approximately 10% were penta-refractory, having received treatment with 2 IMiD agents, 2 PIs, and an anti-CD38 mAb. Approximately 67% and 79% of patients in the FHMM and CVMM cohorts, respectively, had ECOG performance status 0 or 1. Approximately 54% and 61% had received prior stem cell transplantation. IMiD agents either alone or in combination with a PI and/or anti-CD38 mAb constituted the main regimens for index-treated patients. In the CVMM cohort, the overall and complete response rates were 15.2% and 1.7%, respectively; response data were not available in the FHMM cohort. Median OS (22.3 and 20.4 months), median PFS (4.8 and 4.9 months), and median TTP (5.9 and 5.9 months) were comparable for both FHMM and CVMM cohorts. Conclusions: In this observational cohort study of 2 US RW EHR databases, patients became TCE with a median of 3 prior lines of therapy. Post-TCE, most patients with RRMM still received the same 3 treatment classes with poor response and survival outcomes on their treatments. Despite advances in MM management, this study highlights the need for more efficacious novel treatments for patients with TCE MM and serves as a RW benchmark in the literature for appraising emerging data from novel agents in patients with RRMM.

Introduction A single ide-cel infusion showed significantly longer median progression-free survival (PFS) vs std regimens (13.3 vs 4.4 months [mo], HR 0.49, 95% CI 0.38-0.65, P < 0.001) with deep, durable responses in heavily pretreated TCE RRMM at an interim analysis (IA) of KarMMa-3 (NCT03651128); safety data were consistent with prior studies (Rodríguez-Otero et al. NEJM 2023). Ide-cel benefits were consistent across pts in high-risk subgroups and across 2-4 prior lines of therapy (Tx). Results of the preplanned final PFS analysis of KarMMa-3 with 12.3 mo additional follow-up are reported. Methods In the phase 3 KarMMa-3 trial, pts with RRMM who received 2-4 prior regimens, including an immunomodulatory agent, proteasome inhibitor, and daratumumab, and were refractory to last regimen were randomized 2:1 to ide-cel or a std regimen (DPd, DVd, IRd, Kd, or EPd). In the ide-cel arm, pts could receive ≤ 1 cycle of optional bridging Tx for disease control. Pts in the std regimens arm could receive ide-cel after confirmed disease progression (PD). The primary endpoint was IRC-assessed PFS in the ITT population; final PFS was planned to be analyzed with ~289 events. Key secondary endpoints were IRC-assessed overall response rate (ORR) and overall survival (OS); other secondary endpoints included complete response rate (CRR), duration of response (DOR), minimal residual disease (MRD) status, time to next anti-myeloma Tx (TTNT; time from randomization to next anti-myeloma Tx [MTx]), event-free survival (EFS; time from randomization to first PD, next MTx or any-cause death, whichever is first), PFS2 (time from randomization to second objective PD or any-cause death, whichever is first), safety, and health-related quality of life (QOL). Results Of 386 randomized pts (ide-cel, n = 254; std regimens, n = 132), 225 received ide-cel and 126 received a std regimen. Baseline characteristics were generally balanced. Median follow-up from randomization to data cutoff (April 28, 2023) was 30.9 mo (range 12.7-47.8). Ide-cel significantly improved median PFS (95% CI) vs std regimens (13.8 [11.8-16.1] vs 4.4 [3.4-5.8] mo), representing a 51% reduced risk of PD or death (HR 0.49, 95% CI 0.38-0.63; Figure); 18 mo PFS rates were 41% vs 19%, respectively. Ide-cel significantly improved ORR vs std regimens (71% vs 42%) with deeper (CRR 44% vs 5%; ≥CR and MRD negative status [sensitivity level 10 -5], 22% vs 1%), more durable responses (median DOR 16.6 vs 9.7 mo; Table). PFS and ORR benefits of ide-cel vs std regimens were consistent with the IA. Interim OS will be included in the presentation. In pts who received ide-cel (n = 225) or a std regimen (n = 126), median PFS (95% CI) was 15.7 (12.5-18.9) vs 4.4 (3.4-5.8) mo, respectively. In the ITT population, median TTNT, EFS, and PFS2 were numerically longer with ide-cel vs std regimens. Median (range) TTNT was 20.9 (16.6-24.2) vs 7.0 (5.3-8.5) mo. Median (95% CI) EFS was 13.3 (11.3-15.7) vs 3.9 (3.0-5.3) mo. Median PFS2 (95% CI) was 23.5 (18.4-27.9) vs 16.7 (12.2-20.3) mo; ide-cel was next MTx in 70 (53%) pts in the std regimens arm. In the treated population, grade (gr) 3/4 infections occurred in 66/249 (27%) pts in the ide-cel arm vs 25/126 (20%) in the std regimens arm. In the ide-cel safety population, any gr cytokine release syndrome occurred in 197/225 (88%) pts, gr ≥ 3 in 11 (5%); median time to first onset was 1 d (1-14), median duration was 4 d (1-51). Any gr investigator-identified neurotoxicity occurred in 34/225 (15%) pts, gr ≥ 3 in 7 (3%); median time to onset was 3 d (range 1-317); median duration was 2.5 d (range 1-252). Ide-cel continued to demonstrate durable, clinically meaningful improvements in pt-reported outcomes, including symptoms, functioning, and QOL vs std regimens. Conclusions In this final PFS analysis of KarMMa-3, significantly longer PFS was maintained with ide-cel; PD or death risk reduced by 51%; responses were deeper and more durable vs std regimens. CRR with ide-cel increased since the IA, indicating a deepening response, but were unchanged with std regimens. A single ide-cel infusion vs continuous treatment with std regimens resulted in longer median TTNT and PFS2, indicating improved long-term disease control. The ide-cel safety profile was consistent with previous reports, with no parkinsonism or Guillain-Barré syndrome reported. These data continue to support use of ide-cel in pts with TCE RRMM. Study support 2seventy bio and Celgene, a Bristol-Myers Squibb Company.

Background Differences in quality of life (QoL) after coronary artery bypass grafting (CABG) compared with percutaneous coronary intervention (PCI) are not well characterized. We aimed to compare the short‐ and long‐term effects of CABG versus PCI on QoL. Methods and Results We performed a systematic review and meta‐analysis of randomized controlled trials comparing CABG versus PCI using the Seattle Angina Questionnaire (SAQ)‐Angina Frequency, SAQ‐QoL, SAQ‐Physical Limitations, EuroQoL‐5D, and Short‐Form Questionnaire. We calculated mean changes within each group from baseline to 1, 6, 12, and 36 to 60 months (latest follow‐up) and the weighted mean differences between groups using inverse‐variance methods. A total of 10 760 patients were enrolled in 5 trials. From baseline to 12 months and 36 to 60 months, the mean change in SAQ‐Angina Frequency was >22 points (95% CI, 21.0–25.6) after both PCI and CABG. The mean difference in SAQ‐Angina Frequency was similar between procedures at 1 month and at 36 to 60 months but favored CABG at 12 months (1.97 [95% CI, 0.68–3.26]). SAQ‐QoL favored PCI at 1 month (−2.92 [95% CI, −4.66 to −1.18]) and CABG at 6 (2.50 [95% CI, 1.02–3.97]), 12 (3.30 [95% CI, 1.78–4.82]), and 36 to 60 months (3.17 [95% CI, 0.54 5.80). SAQ‐Physical Limitations (−12.61 [95% CI, −16.16 to −9.06]) and EuroQoL‐5D (−0.07 [95% CI, −0.08 to −0.07) favored PCI at 1 month. Short‐Form Questionnaire‐Physical Component favored CABG at 12 months (1.18 [95% CI, 0.46–1.90]). Conclusions Both PCI and CABG improved long‐term disease‐specific and generic QoL.

Abstract Acute myeloid leukemia (AML) with TP53 mutations (TP53Mut) has poor clinical outcomes. We investigated whether this AML subtype harbors a distinct gene expression profile (GEP) and whether this GEP is prognostic in TP53 wild type (TP53WT) AML. We applied a supervised machine-learning approach to detect the TP53Mut GEP. We divided the samples in the Beat-AML dataset into training and testing datasets. The TCGA LAML dataset was used as a validation dataset. We trained a ridge regression machine learning model to classify TP53Mut and TP53WT cases. This model was highly accurate in distinguishing TP53Mut versus TP53WT cases in both the test and validation datasets. Additionally, we identified TP53WT samples with high ridge regression scores. These high-scoring TP53WT samples also have poor overall survival, suggesting they share clinical and GEP features with TP53Mut AML. We defined these TP53WT samples as TP53Mut-like. Using drug sensitivity data in the Beat AML dataset, we found TP53Mut-like AMLs have distinct drug sensitivity patterns that phenocopy TP53Mut cases. Finally, we identified a 25-gene signature that can identify TP53Mut-like AML. This signature could be used clinically to identify this novel subset of poor-prognosis AML.

Abstract Immunomodulatory drugs (IMiD) are a backbone therapy for multiple myeloma (MM). Despite their efficacy, most patients develop resistance, and the mechanisms are not fully defined. Here, we show that IMiD responses are directed by IMiD-dependent degradation of IKZF1 and IKZF3 that bind to enhancers necessary to sustain the expression of MYC and other myeloma oncogenes. IMiD treatment universally depleted chromatin-bound IKZF1, but eviction of P300 and BRD4 coactivators only occurred in IMiD-sensitive cells. IKZF1-bound enhancers overlapped other transcription factor binding motifs, including ETV4. Chromatin immunoprecipitation sequencing showed that ETV4 bound to the same enhancers as IKZF1, and ETV4 CRISPR/Cas9-mediated ablation resulted in sensitization of IMiD-resistant MM. ETV4 expression is associated with IMiD resistance in cell lines, poor prognosis in patients, and is upregulated at relapse. These data indicate that ETV4 alleviates IKZF1 and IKZF3 dependency in MM by maintaining oncogenic enhancer activity and identify transcriptional plasticity as a previously unrecognized mechanism of IMiD resistance. Significance: We show that IKZF1-bound enhancers are critical for IMiD efficacy and that the factor ETV4 can bind the same enhancers and substitute for IKZF1 and mediate IMiD resistance by maintaining MYC and other oncogenes. These data implicate transcription factor redundancy as a previously unrecognized mode of IMiD resistance in MM. See related article by Welsh, Barwick, et al., p. 34. See related commentary by Yun and Cleveland, p. 5. This article is featured in Selected Articles from This Issue, p. 4