Usmani, Saad Z.

PURPOSE Outcomes for patients with newly diagnosed multiple myeloma (NDMM) are heterogenous, with overall survival (OS) ranging from months to over 10 years. METHODS To decipher and predict the molecular and clinical heterogeneity of NDMM, we assembled a series of 1,933 patients with available clinical, genomic, and therapeutic data. RESULTS Leveraging a comprehensive catalog of genomic drivers, we identified 12 groups, expanding on previous gene expression–based molecular classifications. To build a model predicting individualized risk in NDMM (IRMMa), we integrated clinical, genomic, and treatment variables. To correct for time-dependent variables, including high-dose melphalan followed by autologous stem-cell transplantation (HDM-ASCT), and maintenance therapy, a multi-state model was designed. The IRMMa model accuracy was significantly higher than all comparator prognostic models, with a c-index for OS of 0.726, compared with International Staging System (ISS; 0.61), revised-ISS (0.572), and R2-ISS (0.625). Integral to model accuracy was 20 genomic features, including 1q21 gain/amp, del 1p, TP53 loss, NSD2 translocations, APOBEC mutational signatures, and copy-number signatures (reflecting the complex structural variant chromothripsis). IRMMa accuracy and superiority compared with other prognostic models were validated on 256 patients enrolled in the GMMG-HD6 (ClinicalTrials.gov identifier: NCT02495922 ) clinical trial. Individualized patient risks were significantly affected across the 12 genomic groups by different treatment strategies (ie, treatment variance), which was used to identify patients for whom HDM-ASCT is particularly effective versus patients for whom the impact is limited. CONCLUSION Integrating clinical, demographic, genomic, and therapeutic data, to our knowledge, we have developed the first individualized risk-prediction model enabling personally tailored therapeutic decisions for patients with NDMM.

Background: The management of multiple myeloma (MM) continues to evolve with the emergence of new classes of therapy, most recently including BCMA-targeted therapies. Considering the expanding MM treatment armamentarium, we sought to identify contemporary practice patterns among healthcare professionals (HCPs) for MM and compare them with those of experts using an online decision support tool. Methods: An online decision support tool was developed with input from 5 experts providing therapy recommendations for 192 unique patient case scenarios based on considerations including disease setting, treatment history, access to therapy, and specific comorbidities. HCP tool users entered specific patient criteria to define a case along with their intended management for that case. The tool then showed the 5 expert recommendations for that same case scenario, and users were asked if the recommendations impacted their intended approach. An analysis of expert recommendations and user-selected therapy was performed. Results: Between April 2023 and July 2023, 207 patient cases were entered by 144 participating HCPs. HCP and expert treatment recommendations were frequently discordant, regardless of treatment setting (Table). The highest concordance between HCP and expert recommendations (47%; P <.0001) was in the induction setting (n = 111). In this setting, experts were more likely to recommend quadruplet regimens compared with HCPs (62% vs 27%, respectively; P <.0001). Treatment selection concordance was lower in the maintenance (n = 17; 24%; P <.0001) and relapsed/refractory settings (n = 79; 20%; P <.0001). The lowest concordance (10%; P <.0001) between HCP and expert treatment recommendations was noted in the relapsed/refractory setting specifically among patients who were refractory to earlier lines of therapy (n = 41; P <.0001). For patients who are refractory to earlier lines of therapy, experts were more likely to recommend an anti-CD38-based combination regimen compared with HCPs (81% vs 32; P <.0001). When recommending treatment for patients with triple- or penta-refractory disease, experts were significantly more likely to recommend BCMA-targeted agents (83% vs 39%; P <.0001). For HCPs whose treatment plan did not match expert recommendations in these scenarios, 53% of respondents indicated that expert recommendations confirmed or changed their intended therapy, but 31% indicated that there were barriers to implementing those recommendations. Conclusions: These data suggest ongoing challenges with incorporating the newest therapies and combinations across the spectrum of MM into patient care, particularly multidrug regimens in the induction and maintenance settings and BCMA-targeted therapies in those with triple- or penta-refractory disease. Continued education and development of resources for HCPs, including online decision support tools, may be increasingly important as the treatment of MM continues to grow in complexity.

Background: Despite the development and approval of effective therapies for multiple myeloma (MM), MM remains an incurable disease. Moreover, patients with high-risk cytogenetics, like translocation t(4;14), continue to have a poor prognosis compared to standard-risk patients. No novel agents have been approved specifically for this population. There remains an unmet need for precision therapies for MM that can target specific drivers of high-risk MM like t(4;14). Multiple myeloma SET domain-containing protein (MMSET) overexpression observed in 100% of patients with t(4;14) acts through the MMSET-H3K36me2 axis, which promotes malignant transformation through regulation of multiple oncogenic programs. KTX-1001, a methyl transferase inhibitor, is a novel, first-in-class, potent, oral, small molecule that inhibits MMSET and the methylation of lysine K36. KTX-1001 had favorable drug-like properties, demonstrated in vivo activity, and was well tolerated in non-clinical studies. Based on these data, KTX-1001 is now being studied in a Phase 1 dose escalation and expansion study in relapsed and refractory multiple myeloma (RRMM). Study Design and Methods: This multi-country, Phase 1, open-label study (NCT05651932) is designed to assess the safety, tolerability, and initial clinical activity of KTX-1001. The study will also examine the recommended phase 2 dose (RP2D), pharmacokinetics (PK) and pharmacodynamics (PD). Part A of this trial includes an accelerated titration, followed by 3+3 dose escalation with backfill of cohorts for dose optimization prior to moving to Part B, which is an expansion phase at the RP2D (please see Figure 1 for study design schematic). The expansion phase will only include patients with t(4;14). KTX-1001 will be administered orally daily and given until disease progression, unacceptable toxicity, or withdrawal from the study. Estimated enrollment for Parts A and B will be approximately 60 patients. The study will enroll patients with RRMM who have received ≥3 prior lines of therapy, including a proteasome inhibitor (PI), immunomodulatory drug (IMiD), and anti-CD38 antibody. Patients must have measurable disease, be ≥18 years of age, have an Eastern Cooperative Oncology Group score of ≤2, and adequate bone marrow, liver, and kidney function. Key exclusion criteria include history of or current plasma cell leukemia, active central nervous system (CNS) disease, or active unstable cardiovascular function. The primary endpoints of safety and tolerability include incidence of dose-limiting toxicity (DLTs), treatment-emergent adverse events (AEs), and treatment-related AEs. Secondary endpoints include plasma concentrations of KTX-1001 and efficacy outcomes such as objective response rate (ORR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Exploratory biomarker and pharmacodynamic assessments will also be performed. The sample size was not determined by formal statistical methods but will be sufficient to provide preliminary information on safety, PK, PD, and efficacy. Statistical analyses will be primarily descriptive. Conclusion: This Phase 1 study will evaluate a potential treatment for RRMM utilizing KTX-1001, which is a novel, first-in-class, potent, oral small-molecule MMSET inhibitor. The study is open and actively enrolling patients at centers in the United States, Spain, France, and Canada.

Introduction Patients (pts) with multiple myeloma (MM) have a higher risk of progression/death following an inadequate response to frontline ASCT (van de Velde Eur J Haematol 2017). Therapies (Tx) with novel mechanisms of action may further improve response outcomes. Ide-cel previously demonstrated frequent, deep, and durable responses in KarMMa (Munshi N Engl J Med 2021) and significantly improved median progression-free survival (PFS) and overall response rate (ORR) versus standard regimens in KarMMa-3 (Rodríguez-Otero N Engl J Med 2023) in pts with triple-class-exposed relapsed and refractory MM. KarMMa-2 (NCT03601078) is a multicohort, phase 2, multicenter trial evaluating the efficacy and safety of ide-cel in pts with MM; cohort 2c included pts with NDMM who had an inadequate response to frontline Tx with ASCT. In cohort 2c, with a median follow-up of 27.9 months, ide-cel demonstrated deep and durable responses; complete response (CR) rate was 74.2% (ORR, 87.1%), with a 24-month PFS rate of 83.1% (Dhodapkar Blood 2022). Here, we report results with an additional 11.5 months of median follow-up for updated efficacy and safety data, and health-related quality of life (HRQoL) outcomes in cohort 2c. Methods Eligible pts had NDMM, received ≥ 3 cycles of induction Tx (including a proteasome inhibitor, an immunomodulatory agent, and dexamethasone), had < very good partial response (VGPR) 70-110 days after ASCT (single/tandem), and had Eastern Cooperative Oncology Group performance status ≤ 1. Pts received a single infusion of ide-cel (dose range: 150-450 × 10 6 CAR+ T cells) after lymphodepletion and could receive maintenance Tx post-infusion at investigator's discretion. The primary endpoint CR rate and secondary endpoints ORR, duration of response (DOR), PFS, overall survival (OS), safety, and patient-reported outcomes on HRQoL, assessed via European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Core 30 Questionnaire (QLQ-C30) and EORTC Quality of Life Multiple Myeloma Module 20 Questionnaire (QLQ-MY20), are reported. The exploratory endpoint of minimal residual disease (MRD) negativity (sensitivity, 10 -5) is also reported. Results At data cutoff (May 3, 2023), with a median follow-up of 39.4 (range, 31.6-44.7) months, all 31 pts who were infused with ide-cel were alive; 28 (90.3%) remained in follow-up, with 3 (9.7%) having discontinued due to disease progression. The ORR and CR rates were 87.1% and 77.4%, respectively ( Table); best overall response in 1 pt improved from VGPR to stringent CR. The median DOR was not reached (NR; 95% CI, NR-NR), neither was median PFS (95% CI, 38.0-NR) or median OS (95% CI, NR-NR); the 36-month event-free rates were 80.9%, 76.8%, and 100.0%, respectively. In pts who did not receive lenalidomide (LEN) maintenance, 9 (29.0%) had disease progression; of the 8 pts who received LEN maintenance post ide-cel infusion, none experienced disease progression. At 36 months, MRD negativity was confirmed in 9/14 (64.3%) evaluable pts; all 9 achieved ≥ CR. In this extended follow-up, safety results were generally consistent with the previous data cutoff. All pts experienced ≥ 1 any-grade adverse event (AE), most commonly hematologic, including neutropenia (80.6%), anemia (38.7%), leukopenia (32.3%), and thrombocytopenia (29.0%); infection and infestation AEs occurred in 74.2% of pts. No grade 5 AEs were reported. Incidence of any-grade cytokine release syndrome (58.1%; no grade ≥ 3) was unchanged and there were no additional reports of parkinsonism since the previous report. Overall, HRQoL improved ( Figure) and MM disease symptoms were stable over time based on the EORTC QLQ-C30 and QLQ-MY20, respectively, following ide-cel treatment; by month 3, > 75% of pts had improved or stable global health status/QoL. Conclusions Ide-cel continued to demonstrate deep, durable responses in pts with an inadequate response to frontline ASCT, no new safety signals were observed with extended follow-up, and no deaths were reported. No pts who received LEN maintenance post ide-cel experienced disease progression. Ide-cel treatment resulted in stable or improved HRQoL. Overall, ide-cel continued to demonstrate a favorable clinical benefit-risk profile in NDMM after ASCT. Study support 2seventy bio and Celgene, a Bristol-Myers Squibb Company.

Background: Dex is a key component of induction regimens for NDMM despite common toxicities including insomnia and anxiety. The E4A03 randomized trial (Rajkumar, Lancet Oncol 2010) demonstrated that dex dosed at 40 mg weekly outperformed higher-intensity dex and established this regimen as the standard of care for NDMM. In standard practice as well as clinical trials, however, dex doses are often reduced to 20 mg weekly or lower (if not stopped entirely) among older patients or among patients experiencing toxicities. As a first step toward establishing the equipoise of planned dex dose reductions in NDMM, we investigated outcomes with patients from two previous SWOG trials to understand the impact of dex dose reductions on post-induction outcomes. Methods: This was a secondary analysis of data from two completed NDMM studies, S0777 (comparing VRd vs Rd) and S1211 (comparing Elo-VRd vs VRd). For this secondary analysis, we analyzed the subset of patients who completed all eight 3-week cycles of induction (or six 4-week cycles in the S0777 Rd arm). As shown in Figure 1A, we defined DEX fullDose as patients for whom the starting dex dose (either 40 mg once per week or 20 mg on Days 1, 2, 4, 5, 8, 9, 11, and 12 of 21-day cycles) did not change during induction. In contrast, DEX lowered was defined as patients for whom the end-of-induction dex dose and/or frequency were lower than their starting values. As an exploratory analysis, we also compared PFS and OS between the DEX fullDose (no changes to dex strength during induction) and DEX veryLow (dex dosing reduced ≥50% during induction) subgroups. All analyses were landmarked from the end of induction, defined as 24 weeks from registration, to account for the time-dependent nature of dex treatment received. Survival curves were based on the Kaplan-Meier method and comparisons were made using the log-rank test. Results: Of 541 evaluable patients ( n = 441 from S0777, n = 100 from S1211), dex was reduced during induction in 76% ( n = 410). Compared to DEX fullDose patients, DEX lowered patients were more likely to be anemic (37% vs 26%, p = 0.02) but had similar distributions of age ≥70 (24% of DEX lowered vs 26% of DEX fullDose), Performance Status > 1 (15% vs 12%), ISS stage 3 disease (33% vs 27%), ≥ 60% bone marrow plasma cell burden (37% vs 31%), M-spike > 3 g/dL (48% vs 48%) platelets < 150,000 cells/mm 3 (18% vs 14%), baseline LDH ≥ 190 U/L (36% vs 41%), and baseline CRP ≥ 8 mg/L (27% vs 30%). PFS (Figure 1B) was comparable between DEX lowered (median 36 months, 95% CI 29 to 39 months) and DEX fullDose (median 33 months, 95% CI 24 to 48 months) with p = 0.90. Similarly, OS (Figure 1C) was comparable between DEX lowered [median 77 months, 95% CI 68 months to not reached (NR)] and DEX fullDose (median 92 months, 95% CI 65 months to NR) with p = 0.93. In the DEX veryLow subgroup with ≥50% reduction in dex dosing during induction, median PFS was 39 months (95% CI 34 to 50 months) and median OS was NR (95% CI NR to NR). As shown in Figure 1D and Figure 1E, PFS and OS were comparable between these patients and DEX fullDose patients. Discussion: To our knowledge, this is the first analysis of dex dosing strength in NDMM since E4A03. In two separate randomized trials, over half of patients required dex reductions below a starting dose of ~40 mg weekly. Dex dose reductions during induction had no impact on post-induction PFS and OS, even in the subset of patients who required significant dose reductions. Limitations of our post hoc analysis include heterogeneity between dex dosing schedules and lack of cytogenetic data for all patients. We could not discern specifically why dex was lowered, and it is possible that dex might have been lowered disproportionately commonly in patients who had achieved early responses and thus independently did better. Regardless, these results strongly suggest that maintaining dex 40 mg weekly for the entirety of NDMM induction may be unnecessary in the modern era. Cooperative efforts to study a planned dex de-escalation protocol (i.e., once no longer needed for symptom management or as a pre-medication) alongside patient-reported outcome assessments of symptom burden are being planned. Funding: NIH/NCI/NCTN grants U10CA180888, U10CA180819, U10CA180821, U10CA180820; and in part by Millennium Pharmaceuticals, Inc. (now part of Takeda Pharmaceutical Company), and by Celgene.

High dose chemotherapy followed by autologous hematopoietic cell transplantation (auto HCT) is a standard therapy for patients with plasma cell disorders (PCD). A barrier to improving candidate selection for auto HCT is appraisal of risk for transplant related complications. Electrocardiography (ECG) is a standard pre-HCT test to evaluate the potential for arrhythmia and structural heart disease. We hypothesized that an artificial intelligence (AI) based interpretation of ECG waveform data (AI-ECG) could enhance risk prediction for cardiac-specific and other outcomes following auto HCT for patients with PCD. To test this hypothesis, we used several AI-ECG tools developed using a deep-learning based approach that were trained to predict comorbidity (Attia et al, Lancet 2019 & Grogan et al, Mayo Clin Proc 2021). Model outputs include a scaled prediction value indicating increasing risk for atrial fibrillation/flutter (AF), reduced ejection fraction (EF), or cardiac amyloidosis. We evaluated this tool in 9,225 ECGs obtained from 849 patients (median 6 ECGs/patient, inter-quartile range: 3-12) who underwent first or subsequent auto HCT at Memorial Sloan Kettering Cancer Center between 2016-2022 and who had a diagnosis of multiple myeloma (N = 810), amyloidosis (N = 37), or other PCD (N = 2). The endpoints were to determine whether baseline AI-ECG prediction of AF risk correlated with peri-transplant AF events, and to explore whether model outputs correlated with survival and other cardiac clinical outcomes. The mean age of patients was 61.0 years (range 23.7 - 81.2) and median follow up was 2.7 years post auto HCT. Contributing cardiovascular risk factors included a prior history of AF (N = 101, 11.9%), coronary or cerebrovascular disease (N = 95, 11.2%), and diabetes mellitus (N = 98, 11.5%). Reduced dose melphalan (< 200 mg/m 2) was administered in 26%. The HCT-comorbidity index (HCT-CI) was high risk (≥3) in 52.7%. The one-year overall survival and progression-free survival in the whole cohort was 94% (95% confidence interval (95% CI): 92 - 95%) and 86% (84 - 89%), respectively. Among patients not in AF at pre HCT evaluation, the 90-day cumulative incidence of AF was 5.6% (4.2 - 7.3%). In univariable competing risk regression, baseline pre HCT AI-ECG appraisal of AF risk was strongly correlated with incidence AF in patients who were in sinus rhythm before HCT (hazard ratio (HR): 25.1, 95% CI: 11.7 - 53.7, p < 0.001). In a multivariable model adjusting for patient age and HCT-CI, AI-ECG AF predicted risk remained associated with incidence of post HCT AF (HR: 13.4, 95% CI: 5.9 - 30.4, p < 0.001). Considering a decision threshold identified during original model training, AI-ECG predicted AF events with an accuracy of 75% (Mcnemar's p < 2 x 10 -16). The precision, recall, and F1-score were 0.94, 0.77, and 0.85, respectively. AI-ECG predicted age correlated highly with actual patient age (Spearman rho = 0.59, p < 2 x 10 -16). Amyloid risk scores were highly correlated with a known clinical history of amyloidosis (median 0.45 versus 0.05, Wilcoxon rank-sum p < 0.001). Patients with EF < 50% had greater prediction scores for cardiomyopathy compared to patients with normal EF (median 0.23 versus 0.01, Wilcoxon rank-sum p <0.001). In univariable analysis, increasing AI-ECG predicted age (HR 1.02, CI: 1.003 - 1.04, p = 0.02) and predicted AF risk score (HR: 3.2, CI: 1.4 - 7.2, p = 0.006) were associated with risk for death, whereas predicted amyloid score and predicted low EF were not associated with decreased survival. In multivariable analysis of all patients that considered patient age, hematopoietic comorbidity index, and remission status at HCT, increasing predicted AF score trended towards association with increased risk for death (HR: 2.3, 95%CI: 1.0 - 5.5, p = 0.059). Predicted AF score correlated highly with the HCT-CI and patient age. Finally, we examined whether risk prediction for low EF correlated with peri-HCT fluid overload (FO) defined by absolute weight gain. The incidence of ≥ 10% weight gain (grade 2 FO) and ≥ 20% weight gain (grade 3 FO) at 180 days post HCT was 7.4% (95% CI: 5.8%, 9.3%) and 1.0% (95% CI: 0.5%, 1.8%), respectively. Predicted low EF was not associated with development of either grade 2 or grade 3 FO in this population. In summary, AI-ECG predicts episodes of AF in patients undergoing auto HCT for PCD and may augment transplant risk appraisal when considered in conjunction with other measures of comorbidity.

Introduction: BCMA-directed CAR-T and Bispecific T-cell engager (BiTE) therapies have shown remarkable overall response rates in heavily pretreated patients with relapsed/refractory multiple myeloma (RRMM). This has led to the approval of idecabtagene vicleucel, ciltacabtagene autoleucel and teclistamab by the FDA, EMA and other regulatory agencies. We performed a global survey on accessibility, practice patterns, and toxicity management of commercially available CAR-T and BiTE therapies. Methods: An online survey was completed by clinicians attending the International Myeloma Society's Immune Effector Cell Therapies in Multiple Myeloma Workshop, in-person or virtually, made available for 30 days after the meeting held in March 2023, Boston, MA. Results: 87 clinicians from 16 countries completed the survey, most practicing in an academic practice (86%) and in an urban environment (89%). Sixty-four percent of the respondents practice in North America followed by Europe (25.3%) including Germany, United Kingdom, Ireland, Italy, Netherlands, Spain, France, Greece, and Cyprus, and 6.9% from Asia and 3.4% from Australia. Seventy-seven percent reported CAR-T cell therapy was approved in their country with 44.8% treating 1-5 patients and 14.9% treating >5 patients per month; 67% reported BiTE therapy was approved in their country with 14.9% treating >5 patients per month. Of evaluable responses (n = 40), 62% administered CAR-T therapy inpatient and 15% administered CAR-T therapy outpatient ≥ 50% of the time. Length of time between decision to treat with CAR-T therapy to infusion was 6-12 weeks for 42% of responders and <6 weeks for only 20%. Most (75%) reported inpatient administration of BiTE therapy step-up dosing; 17.5% reported outpatient step-up dosing administered ≥ 50% of the time. Use of institutional or practice SOPs for CAR-T and BiTE therapy patient selection was reported by 85% and 58%, respectively, with the factors influencing SOP outlined in Table 1. Of available CAR-T therapies, 53% prefer cilta-cel and 23% reported CAR-T therapy preference depended most on patients' co-morbidities/frailty (89%), timing of next available apheresis (67%), age (56%), CNS disease (44%) and other factors. Maintenance therapy after CAR-T therapy was reportedly used by 25% and 5% of respondents in 1-10% and 11-50% of their patients, respectively, to “maintain level of response achieved” (50%) or “achieve a deeper level of response” (25%). About half (43%) of the respondents reported using an SOP or particular criteria for secondary Hemophagocytic Lympho-Histiocytosis/Macrophage Activation Syndrome/CAR-related-HLH (sHLH/MAS/CarHLH) management that varied between the use of ASTCT Working Group IEC associated HLH-like syndrome Criteria (47%) (Hines 2023), CARTOX HLH Criteria (24%) (Neelapu 2017) and HLH-2004 criteria (6%). Tocilizumab was used as cytokine release syndrome (CRS) prophylaxis only by one responder. Keppra neurologic prophylaxis was used by 47.5% and 15% of responders for CAR-T and BiTE therapy, respectively. Delayed neurotoxicity with CAR-T was reported in 1-5% of patients by 57.5% of responders and 6-10% of patients by 15% of responders; most common manifestations were other movement/neuromuscular disorder (62%), nerve palsy (55%), and Parkinsonism (45%). Infectious prophylaxis was used to protect against HSV (92.5%), PJP (90%), bacterial pathogens (55%), fungal pathogens (60%), and IVIG (77.5%). However, criteria for infectious prophylaxis use varies widely incorporating IgG levels, infectious history, CD4+ count, B-cell aplasia and cytopenias (48.1 - 88.9%). Most respondents (46.3 - 86.5%) reported completing an infectious work-up including CMV, EBV, Hep B/C, and HIV ( Table 2). Conclusions: Trends of CAR-T and BiTE therapy use and patterns of concurrent prophylactic and supportive care in MM vary widely among academic centers across the globe, demonstrating a need for further understanding of toxicity pathogenesis, toxicity management and consistent guidelines. This survey also demonstrates the great unmet need for access beyond urban centers among the international myeloma community. Prospective studies and claims data analysis should be utilized to evaluate the longitudinal cost of care, quality of life, duration of response and management of infectious disease, neurological or related complications of CAR-T and bispecific TCE therapies.

Introduction: Preclinical studies have suggested synergism between lenalidomide (LEN) and ibrutinib (IBR) in multiple myeloma (MM). Both downregulate IRF4, a master transcriptional factor that regulates myeloma cell survival. Single agent oral IBR combined with dexamethasone proved well tolerated and active in advanced, steroid refractory relapsed MM as part of a large Phase1/2 study in 60 patients, with durable stabilization and minimal response seen in most evaluable patients (Richardson PG et al, BJH 2018). LEN is considered a standard of care in newly diagnosed MM, as maintenance and in relapsed disease, and a backbone of oral therapy in the MM treatment paradigm (Laubach JP et al, Leukemia 2016). Methods: We therefore conducted a 3+3 phase I trial to determine the maximum tolerated dose (MTD) of IBR in combination with LEN + dexamethasone (DEX) in patients with relapsed/refractory (RR) MM who had at least 2 prior lines of therapy. Three dose levels (DL) were planned. Cycle length was 28 days. IBR was administered orally daily at 560mg on DL1-2 and 840mg on DL3, LEN orally days 1-21 at 15mg on DL1 and 25mg on DL2-3, and DEX orally days 1, 8, 15, and 22 at 40 mg if age < 75 or 20 mg if ≥75 for DL1-3. Patients with GFR ≥ 30 and < 60 were treated according to manufacturer's instructions with lenalidomide dosed at 10mg/d. Dose limiting toxicities (DLT) included grade 4 thrombocytopenia; grade 4 neutropenia lasting more than 5 days or febrile neutropenia; grade 4 nausea, vomiting or diarrhea; grade 3 thrombocytopenia with bleeding or platelet transfusion; grade 3-4 hyperglycemia or thrombotic/embolic event, treatment delays ≥ 21 days for toxicity; and treatment related death. Due to changes in standard of care during the study, eligibility was modified to allow the enrollment of patients with RRMM who had at least 1 prior line of therapy. Response was assessed using IMWG/Uniform Criteria. Results: Fourteen patients (DL1-6 pts; DL2-3 pts; DL3-5 pts) registered to the study from March 2019 to May 2023, prior to its closure due to slow accrual. One patient on DL3 cancelled participation prior to start of treatment due to disease progression (PD). The remaining 13 patients are included in summary of toxicities and response but 2 patients on DL3 are excluded from determination of MTD due to discontinuing cycle 1 treatment due to COVID and receiving 280 mg/day of IBR instead of assigned 840 mg/day dose during cycle 1, respectfully. Twelve patients were evaluable for response. The median number of prior lines of therapy was 3 (range: 2-9), reflecting a heavily pretreated relapsed and refractory population. One of the 6 patient on DL1 developed a DLT, grade 3 non-viral hepatitis. None of the 3 patients on DL2 or the 2 patients on DL3 had a DLT. One patient on DL1 remains on treatment with stable disease for 42+ cycles. The median number of cycles administered was 3 (range: 1-42+). Severe toxicities reported included grade 3 lymphocytopenia (3), anemia (2), alanine aminotransferase increase (1), aspartate aminotransferase increase (1), blood bilirubin increase (1), hypocalcemia (1), hypokalemia (1) hypophosphatemia (1), febrile neutropenia (1), chronic kidney disease (1), non-viral hepatitis (1), soft tissue infection (1), and fatigue (1); grade 4 lymphocytopenia (1), and grade 5 sepsis (1). End of treatment reasons included: PD (7), toxicity (2), death [soft tissue infection that turned into sepsis considered to be likely related to DEX] (1), and concomitant conditions (2). Stable disease (SD) or better was achieved in 10 of 12 evaluable patients (83%), including one patient who achieved disease control for over 3.5 years. One patient (8%) on DL3 had a complete response (CR) but stopped treatment after 2 cycles due to reversible toxicity and comorbid conditions, based upon physician advice and patient choice. Conclusions: The combination of lenalidomide with Ibrutinib as an all-oral approach in RR MM proved feasible and generally tolerable, with the majority of discontinuation seen in this Phase I study due to disease progression. No COVID related - mortality was seen. SD or better was achieved in 83% of patients, including one CR. Potential future directions include combination approaches with next generation IMids such as pomalidomide, as well as other orally bioavailable novel agents with potent immune activating properties, such as CelMoDs. Support: AFT; Pharmacyclics; Clinicaltrials.gov Identifier: NCT03702725