Del 17p Research Articles

Impact of Typical and Atypical Complex Karyotype Subgroups on Outcome of AML Patients Undergoing Allogeneic Stem Cell Transplantation

Introduction Acute myeloid leukemia (AML) with a complex karyotype (CKT) confers an adverse prognosis, even within the subgroup of patients (pts) with adverse risk according to European LeukemiaNet 2022 (ELN22) risk stratification. Mrózek et al. further characterized CKT pts according to distinct mechanisms of leukemogenesis into balanced (presence of ≥1 balanced rearrangement), and unbalanced CKT (CKT ub, exclusively unbalanced cytogenetic abnormalities). Considering the high incidence of deletions (del) of 5q, 7q, and 17p in CKT, CKT ub were further divided in typical CKT ub (with latter abnormalities present), and atypical CKT ub (with exclusively other abnormalities). In the context of consolidating chemotherapy, typical CKT ub was associated with shorter event-free survival (EFS) and overall survival (OS) compared to atypical CKT ub. However, we lack data in the context of allogeneic hematopoietic stem cell transplantation (HSCT) which remains the preferred treatment in eligible pts. Here we aimed to investigate this classification in CKT AML pts consolidated by HSCT. Methods We analyzed 263 pts with AML who were classified as ELN22 adverse risk and underwent an allogeneic HSCT. 105 had a CKT, while 158 fulfilled other ELN22 adverse risk criteria. Of the pts harboring a CKT, median age at HSCT was 61 (range 20 - 76) years. Remission status at HSCT was first complete remission with or without count recovery (CR/CRi, 62%) or refractory AML (38%). Conditioning intensity according to EBMT criteria were myeloablative (19%), reduced intensity (31%) or non-myeloablative (50%). Donors were matched related (16%), haploidentical (2%) or matched (65%) or mismatch unrelated (17%).Cytogenetic analyses at diagnosis were performed using standard techniques of banding and in situ hybridization. Pretreatment genomic DNA was screened for genes recurrently mutated in myeloid malignancies using next generation sequencing. Median follow-up alive was 1.3 years. Results Pts with a CKT had a significantly shorter EFS ( P<.01) and OS ( P<.01) than other ELN22 adverse risk pts. Of all pts harboring a CKT, 17% had a balanced CKT, and 83% a CKT ub. Among CKT ub, 85% were classified as typical (67% with del(5q), 49% with del(7q), 26% with del(17p), Figure 1). Comparing typical and atypical CKT ub, pts with typical CKT ub more often had a monosomal karyotype ( P<.01), had more cytogenetic abnormalities (in typical CKT ub median 8 [range 3-39] vs atypical CKT ub median 6 [range 3-9], P=.04), more often TP53 mutations ( P=.02), less often RUNX1 mutations ( P=.03) and a lower LDH at diagnosis ( P=.03). They also had a higher expression of the leukemic stem cell markers CD34+/CD38- ( P=.01) and GPR56 ( P<.01). However, after allogeneic HSCT, EFS ( P=.50) and OS ( P=.50) did not differ between pts with typical and atypical CKT ub (Figure 2). Next, we looked for other adverse prognostic factors within CKT pts receiving HSCT, which in univariate analyses were the presence of a del(5q) (EFS P<.01 and OS P=.03), a del(17p) (EFS P=.10 and OS P=.02), the presence of ≥5 vs <5 cytogenetic aberrations (EFS P=.03 and OS P=.06), a concomitant TP53 mutation (EFS P=.01 and OS P=.01), and a higher age at HSCT (≥60 years, EFS P=.04 and OS P=.08). In contrast, neither the presence of a del(7q) nor a monosomal karyotype impacted EFS or OS within pts with a CKT. In multivariate analyses for CKT pts, the presence of ≥ 5 cytogenetic aberrations (Hazard Ratio. [HR] 1.7, 95% Confidence Interval [CI] 1.0-3.0, P=.05), higher age at HSCT (HR 1.6, 95% Ci 1.1-2.5, P=.02), and no CR/CRi at HSCT (HR 1.7, 95% CI 1.1-2.7, P=.01) were adverse factors for EFS, while the presence of a del(17p) (HR 2.0, 95% CI 1.2-3.4, P=.01), higher age at HSCT (HR 1.8, 95% CI 1.1-3.0, P=.02), and no CR/CRi at HSCT (HR 1.8, 95% CI 1.1-2.9, P=.02) were adverse factors for OS. Conclusion The presence of a CKT retains its negative prognostic impact after HSCT and differentiates within the ELN22 adverse risk group. However, in contrast to chemotherapy consolidation alone, the subgroup of pts harboring a typical CKT ub did not perform worse than pts with an atypical CKT ub, indicating a potential immune-mediated beneficial effect of HSCT. Within pts with a CKT receiving HSCT, we identified additional prognostic factors including the presence of ≥5 cytogenetic aberrations. These pts are in urgent need for novel post HSCT approaches.

Development and Testing of a Glycoengineered Anti-ROR1 Antibody with Enhanced Capacity for Directing Antibody-Dependent Cellular Cytotoxicity (ADCC) of Chronic Lymphocytic Leukemia Cells

Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is an oncoembryonic surface antigen expressed on the neoplastic cells of patients with chronic lymphocytic leukemia (CLL) or other types of cancer, but not on virtually all normal postpartum tissues (Fukuda T., et al., PNAS, 105:3047, 2008). Zilovertamab (also known as UC-961 or cirmtuzumab) is a humanized anti-ROR1 monoclonal antibody (mAb) currently under clinical investigation; this mAb is capable of blocking ROR1-signaling, which can contribute to cancer-cell migration, proliferation, survival, and self-renewal. We generated a glycoengineered form of zilovertamab (GE- zilovertamab) and examined whether it could mediate enhanced antibody-dependent cellular cytotoxicity (ADCC) against neoplastic cells that express ROR1. Initial studies used Jurkat-Lucia™ NFAT-CD16 cells (Invivogen, San Diego, CA, USA) which express high-affinity CD16A (FcγRIIIA, V158 allotype) as effector cells (EC), and the CLL-cell line MEC1, or MEC1 cells transduced to express ROR1 (MEC1-ROR1), as target cells (TC), which each also express CD20. Co-culture of Jurkat-Lucia cells for 6 hours with the anti-CD20 mAb rituximab and MEC1 or MEC1-ROR1 cells induced Jurkat-Lucia cells to express a luciferase reporter gene under the control of an ISG54 minimal promoter fused to six NFAT response elements; this endowed the Jurkat-Lucia cells with high luminescence activity that was not observed in co-cultures of EC and TC without added mAb. Neither zilovertamab nor GE-zilovertamab endowed Jurkat-Lucia cells with higher than background luminescence activity when co-cultured with MEC1 cells. However, GE-zilovertamab could induce high levels of luminescence activity in Jurkat-Lucia cells co-cultured with MEC1-ROR1 cells that was comparable to that of rituximab, and significantly greater than that of zilovertamab. We generated an orthogonal system with which to examine the relative ADCC activity of each of these mAb, using EC generated from the NK cell line, NK92, which we transduced with a lentivirus encoding a newly-generated high-affinity variant of CD16A (CD16v), which has been modified to block its cleavage by ADAM17. NK92 or NK92-CD16v were used as EC to effect cytolysis of Cr 51-labeled MEC1, MEC1-ROR1, or primary CLL cells in a chromium-release assay. Addition of rituximab to co-cultures of EC with Cr 51-labeled MEC1, MEC1-ROR1, or primary CLL caused mAb-dose-dependent ADCC of each of these TC by NK92-CD16v that was significantly greater than that by parental NK92 cells. Again, neither zilovertamab nor GE-zilovertamab could direct ADCC by NK92-CD16v or NK92 ADCC of MEC1 cells, which lack ROR1. However, GE-zilovertamab directed dose-dependent ADCC of MEC1-ROR1 or primary ROR1 + CLL cells by either NK92-CD16v or NK92 at levels comparable to that directed by rituximab for either EC population; such levels were significantly greater than that directed by zilovertamab. ROR1 + CLL cells harboring del(17p) or mutations in TP53 (del(17p)/m TP53) and/or that were resistant to targeted therapies (e.g., inhibitors of BTK or BCL2), were as susceptible to GE-zilovertamab-directed ADCC as were CLL cells without del(17p)/m TP53 from patients who had not had prior therapy. These data demonstrate that GE-zilovertamab can direct high-level ADCC lysis of ROR1-expressing neoplastic cells with greater activity than zilovertamab, encouraging development of clinical studies to evaluate GE-zilovertamab for therapy of patients with CLL or other ROR1-positive cancers.

Efficacy of Daratumumab-Based Regimens in Anti-CD38 Treatment-Naïve Relapsed/Refractory Multiple Myeloma with High-Risk Cytogenetics

Background: Daratumumab-based combination with proteasome inhibitors (PI) and immunomodulatory drugs (IMiDs) have revolutionized the treatment outcomes of relapsed/refractory multiple myeloma (RRMM). Several daratumumab-based triplet combinations have been approved for the management of RRMM, but outcomes of daratumumab-based triplets in patients with high-risk cytogenetics RRMM (HC-RRMM) are not well described in the literature. This study aimed to evaluate the clinical outcome of daratumumab-based regimens in patients with HC-RRMM who are daratumumab-naïve. Methods: A retrospective review of 110 patients with HC-RRMM who received daratumumab-containing regimens from 6/2016 through 2/2023 at the University of Kansas Medical Center, in collaboration with the U.S Myeloma Innovations Research Collaborative (USMIRC) was conducted. Daratumumab was combined with bortezomib/dexamethasone (DVd), carfilzomib/dexamethasone (DKd), and pomalidomide/dexamethasone (DPd) for treatment of RRMM. HC-RRMM was defined as patients with one or more cytogenetic abnormalities (on FISH panel) including -17/del(17p), t(4;14), t(14;16), t(14;20), or amplification of 1q. Responses to therapy including overall response rate (ORR), complete response or better (≥CR), and very good partial response (VGPR) were evaluated using the International Myeloma Working Group (IMWG) criteria. Descriptive statistics were used to summarize patient and disease characteristics, along with efficacy outcomes. Progression-free survival (PFS) and overall survival (OS) were calculated by Kaplan-Meier methods. Results: Of the 110 patients with HC-RRMM, the median age was 66 years (range 43-84), 83 (75%) were Caucasian, 60 (54%) had IgG isotype, 41 (37%) had revised international staging system (R-ISS) stage III disease, 35 (32%) had extramedullary disease (EMD), 57 (52%) patients had one high-risk cytogenetic (HC) abnormality, 49 (44%) had 2 HC abnormalities, while four (4%) had 3 HC abnormalities. The median number of previous lines of therapy was 2 (1-4). Eighty-eight patients (80%) were lenalidomide refractory, while 53 patients (48%) had double refractory disease to both a PI and IMiD treatment. A total of 19 (17%), 27 (25%), and 64 (58%) patients received DVd, DKd, and DPd, respectively. The overall response rate (ORR) for the entire patient population was 73%, 45% had VGPR or better, and 35% achieved ≥CR. Median follow-up was 28 months (12.07-53.57), the median OS was 28 months (95% CI 23.2 - 43.9) and PFS was 8.03 months (95% CI 5.8 - 12.2) for all treatment groups. The median PFS for 1 HC vs ³ 2 HC was 14.8 vs 4.57 months (HR 1.72, 95%CI 1.17-2.72 p = 0.006), respectively. Similarly, median OS for 1 HC vs ³ 2 HC was 43.93 vs 22.47 months (HR 1.87, 95%CI 1.15-3.05, p = 0.011), respectively. (Figure 1). On multivariate analysis, R-ISS stage III, -17/del(17p), and the presence of more than one HC abnormality were associated with poor OS. The most common cause for treatment discontinuation was progressive disease, accounting for 73% of patients in the whole cohort. As for each daratumumab-based triplet, discontinuation due progression occurred in 78%, 48%, and 83% in DVd, DKd, and DPd, respectively. Other causes of discontinuation included > grade 3 neuropathy, which occurred in 16% of patients receiving DVd, and cardiac events, which occurred in 11% of patients receiving DKd. Treatment-related mortality occurred in 2% of patients in the whole cohort. At the time of evaluation, 14 patients remain on treatment. Conclusion: Advanced stage R-ISS disease at diagnosis, presence of -17/del(17p), and 2 or more HC abnormalities were associated with poor prognosis reflected by worse PFS and OS in HC-RRMM treated with daratumumab-based therapies. A larger cohort or a prospective study in patients with HC-RRMM is needed to compare long-term outcomes between daratumumab-based therapies (DKd, DVd, and DPd).

Relapsed and Refractory Multiple Myeloma with Pleural Involvement: A Case Series

Introduction. Development of novel treatments and immunotherapeutics continue to improve outcomes in patients with multiple myeloma (MM), especially in those patients with standard and intermediate risk disease; patients with high-risk disease continue to have dismal outcomes. Secondary extramedullary disease (sEMD) is a high-risk disease feature associated with an expected survival less than one year (Zanwar, AJH, 2023). Detailed description of patients presenting with sEMD involving the pleural has not been previously published. In the present project, we aimed to identify and characterize this patient population. Methods. This study was approved by the University of Utah (UU) IRB (#00156207). Inclusion was determined by search of the UU Department of Radiology database for all imaging including PET, CT, and MRI; search terms included pleura, pleural, lung, extramedullary, plasmacytoma, and multiple myeloma. Descriptive analysis was completed and included patient demographics, treatment, and outcomes. Survival was described with Kaplan-Meier analysis. Results. Fourteen patients treated at the UU between 2004 and 2023 were identified as having sEMD and pleural involvement. Demographics are highlighted in Table 1. The median age was 59 (range 34-79), 50% of patients were male, 86% were Caucasian, and 8% were Hispanic. Patients were treated with a median of 2.5 (range 1-9) lines of therapy prior to sEMD development and 6 (range 2-13) in total. 50% of the patients were penta-class refractory. The median follow-up after MM diagnosis was 34.5 months (range 13.0-162.0), median follow-up after pleural EMD diagnosis was 9.0 months (range 0.4-92.0), and the median time to development of pleural EMD following diagnosis was 18.2 months (range 3.8-142.8). At initial diagnosis, half of the patients had > 50% bone marrow clonal plasma cells, 29% had R-ISS stage 3 disease and 36% had R2-ISS stage III/IV. Of the 11 patients with available cytogenetic information at the time of sEMD diagnosis, 73% had high-risk cytogenetics (defined as presence of del(17p), t(4;14), t(14;16) and/or +1q). The most common cytogenetic abnormalities were +1q in 73%, including 36% with 3 copies and 36% with > 4 copies, amp(1q), and del(17p) in 36% . Of these patients, 18% had double hit and 18% had triple hit disease. The most frequent concomitant cytogenetic abnormalities were +1q and del(17p) seen in 36% of the patients. On imaging, 79% had additional sites of EMD other than the pleura. The most frequent other sites of sEMD were skin/soft tissue, intrabdominal extrahepatic, and hepatic. Pleural effusion was present in only one patient. Following diagnosis of sEMD with pleural involvement, the overall response rate (ORR) was 93% and the ORR was 88% in patients with 1q21 abnormalities. In this population, the median OS from diagnosis was 2.5 years (range 1.1-14) and mOS from diagnosis of pleural EMD was 0.64 years (range 0.03-7.7). Conclusion. To the best of our knowledge, this is the largest case series focused on the characterization of patients with sEMD and pleural involvement. The survival results align with those recently presented by Zanwar et al., suggesting that pleural involvement does not portend worse prognosis than EMD in general. We highlight that the majority of patients have 1q21 abnormalities and additional sites of EMD. Ultimately, patients with sEMD and pleural involvement have extremely high-risk disease, are responsive to treatments but have a drastically shortened survival.

A Single Center Real World Study of Outcome and Resistance of Bruton Tyrosine Kinase Inhibitors (BTKi) in Chinese Patients with Chronic Lymphocytic Leukeima/Small Lymphocytic Lymphoma

Introduction Acquired BTK/PLCG2 mutations remain to be the driver of Bruton Tyrosine Kinase inhibitor (BTKi) resistance. But the underlying mechanisms need to be further explored. In this study, we retrospectively analyzed clinical and biological characteristics of BTKi-treated CLL patients and report the outcome and resistance in our center (the First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital). Method 262 patients treated with single BTKis continuously were collected and follow up the outcome in our center. Progression-free survival (PFS) was defined as from BTKi initiation to disease progression on BTKi. Next-generation sequencing (NGS) and High sensitivity droplet digital PCR (ddPCR) acquired at treatment initiation /or at the time of disease progression were used to describe mutational landscape. Kaplan-Meier method and the log-rank test were used for analysis. Results A total of 262 patients were enrolled from January 2014 to March 2023, and the median age was 63 (range 28-88) years. Ibrutinib, Zanubrutinib, Orelabrutinib were administered in 55.3%,18.3% and 17.9% of patients respectively, in addition to 6 patients with Acalabrutinib and one with Loxo-305, among them 47.7% (125/262) received BTKi as first line treatment. With a median follow up of 27.3 months, 208 patients were in durable remission while 54 patients relapsed, the median exposure of BTKi was 26.8 (range, 1-73.8) sand 27.7 (range, 3-69.8) months respectively. The median PFS was 5.8 years (5.0-NA, 95% CI) for the whole cohort. Clinical and biological characteristics of both cohorts at initiation of BTKi treatment were described and compared in Table 1. Higher proportion of bulky disease (50.0% vs 23.5%), IGHV unmutated status (84.3% vs 50.5%), del(17p) (44.7% vs 12.9%), TP53 mutation (37.8% vs 15.2%), TP53 aberrations (62.5% vs 24.3%) and complex karyotype (40.5% vs 21.1%) were shown in the BTKi relapsed cohort as compared to responsive cohort. Inferior PFS was observed in patients with TP53 aberration vs without TP53 aberration ( 45.6 mos vs not reached, p<0.0001), unmutated IGHV vs mutated IGHV (56.2 mos vs not reached, p=0.0005), with del(17p) vs without del(17p) (36.1 mos vs not reached, p<0.0001), with complex karyotype and without complex karyotype (69.8 mos vs not reached, p=0.0401), bulky disease vs no bulky disease (45.6 mos vs 69.8 mos, p=0.0006) and elevated LDH vs normal LDH (66.5 mos vs not reached, p=0.0083). Moreover, patients with del(11q) or BTKi given as second or greater line showed a tendency of inferior PFS ( p= 0.1963, p= 0.0735, respectively). Regarding the relapsed cohort, 43 patients displayed CLL progression while 11 patients displayed Richter transformation (RT, including 1 Hodgkin lymphoma [HL]) , the median time from initiation to progression were 33.7 months and 9.5 months, respectively（p<0.0001). BTK/PLCG2 mutations were the most common mutation at the timepoint of disease progression. By integrating NGS and ddPCR results, 54.9% (28/51) relapsed patients acquired BTK/PLCG2 mutation. BTKC481S mutation was the dominant hotspot mutation in all kinds of BTKi relapsed cases. Other mutations at the C481 site included C481R, C481Y, C481F. However, BTKT474 mutation was only detected in Orelabrutinib-resistant cases (Figure 1). 6 patients presented with multi-hit mutations. Treatment after disease progression on BTKis is still challenging. In our relapsed cohort, the median PFS was 5.7 months and poorer in RT as compared with CLL progression (3.0 months vs 6.7 months, p= 0.0874). Venetoclax-based regimen might be an effective salvage therapy which could showed a benefit trend in PFS as compared to other post BTKi therapy (10.1 months vs 3.1 months, p= 0.1818). Conclusion In our real world study, patients with IGHV unmutated status, TP53 aberrations, bulky disease and elevated LDH showed inferior PFS. Acquired BTK/PLCG2 mutations remained to be key drivers of BTKis resistance and BTKC481S mutation was the dominant mutation, while BTKT474 mutation was only detected in Orelabrutinib-resistant patients. The prognosis was rather poor for relapsed patients especially for RTs, treatment strategy after disease progression remains to be optimized.

Validation of ELN 2022 Risk Classification in Patients Diagnosed with AML Undergoing Allogeneic Hematopoietic Cell Transplantation

Background: In 2022, the European LeukemiaNet (ELN) updated their guidelines (Döhner H et al., Blood 2022) for risk allocation of patients with acute myeloid leukemia (AML) based on essential genetic features at diagnosis as defined in the newest classifications (Arber D et al., Blood 2022, Khoury JD et al., Leukemia 2022). Methods: Retrospective analysis of the 147 consecutive patients diagnosed with AML and available genetic information who underwent alloHCT in a complete morphological response (CR) between 2011 and 2021 in a single institution (HCB). Data was collected retrospectively and updated in July 2023. G-banding karyotype, FISH, qualitative and quantitative PCR and targeted Next Generation Sequencing were assessed at diagnosis to classify patients according to ELN 2022 risk classification. Our primary goal was to validate the ELN 2022 risk classification in patients undergoing alloHCT analyzing overall survival (OS). Secondary objectives were analyzing leukemia-free survival (LFS), 24-month cumulative incidence of relapse (CIR) and in the different molecular subgroups within the ELN2022 risk groups. Results: The main patient, disease-related and transplant characteristics are displayed in Figure 1. Overall, the median age was 52 years (range 18-70), 53.7% of the patients males, with 88% of the patients undergoing alloHCT in CR1. Twenty-two patients could not be classified through NGS assessment between 2011 and 2016 and included in the intermediate risk category due to normal karyotype and wildtype recurrent abnormalities measured by PCR. Patients in the adverse-risk group were older (p <0.001) and underwent alloHCT less often with undetectable measurable residual disease (p = 0.006). Moreover, patients in the favorable or intermediate risk group underwent alloHCT more often in CR2 or CR3 (p = 0.02). In addition, alloHCT characteristics were similar for all the patients included. With a 67-month median follow-up for LFS (95CI: 55-76), the median OS and LFS in patients classified into the favorable and intermediate risk groups were not reached (5-year OS and LFS rate in favorable risk group: 81% (95CI: 73-89) and 72% (95CI: 63-81). 5-year OS and LFS rate in intermediate risk group: 62% (95CI: 56-68) and 64% (95CI: 58-70). Patients included in the adverse risk group had an OS and LFS of 23.7 months (15.3-NR, p <0.001 between intermediate and adverse risk. Figure 1B) and 15.2 months (5.79-NR, p=0.015) respectively, with a significant lower 5-year OS rate (40%, 95CI: 34-46), LFS rate (38%, 95CI: 32-44) and a higher CIR (18% in the favorable risk group (95%CI: 11-26) vs. 20% in the intermediate risk group (95%CI: 18-23) vs. 40% in the adverse risk group (95%CI: 38-44), p = 0.024). Based on these results, a subanalysis was conducted in the patients classified into the adverse group. Those patients diagnosed with complex karyotype, inv(3), t(3;3), del(17p) and/or TP53 mutated were reassessed into a new risk category group called: Adverse-Plus (AdvP).No different baseline characteristics between the AdvP patients and the other subgroups were found. AdvP patients presented a shorter OS (NR in the rest of subgroups vs. 8.73 months in AdvP, p < 0.001 for AdvP vs. adverse risk. Figure 1C), LFS (NR in the rest of subgroups vs. 5.2 months, p < 0.001), and a higher CIR (62.5% in the AdvP group, p <0.001 between adverse risk and AdvP). Interestingly, using this four-group classification including AdvP, the other risk groups presented similar OS, LFS, and CIR without statistical differences in between them Summary/Conclussion: ELN2022 risk classification discriminates properly accurate in patients undergoing alloHCT. Reclassifying AML adverse risk patients diagnosed with complex karyotype, inv(3), t(3;3), del(17p) and/or TP53 mutated in a different subgroup should be considered due to a much worse prognosis after alloHCT, although it remains mandatory in first complete response.

Safety and Effectiveness in Treatment Naive CLL Patients with or without High Risk Features Treated with Veno Under Real-World Conditions in Austria, Germany, and Switzerland

Background In chronic lymphocytic leukemia (CLL), the association of genetic markers such as del(17p), TP53 and IGHV status with disease prognosis is well established. In clinical trials, treatment with Venetoclax in combination with Obinutzumab (VenO) has shown promising efficacy and good tolerability in all subgroups 1. However, there is limited real-world data in specific genetic subgroups. Aim Effectiveness and safety data were analyzed for therapy naive patients treated with VenO focusing on CLL patients with or without the genetic risk factors TP53 mut and/or del(17p) as well as IGHV status. Methods VeRVe is a non-interventional, observational, prospective study with 60 study sites in Germany, Austria, and Switzerland. CLL patients treated with VenO according to the local label 2 were included. Study documentation is possible at baseline, weekly during ramp-up, monthly until the end of month 6 and quarterly afterwards up to a maximum of 2 years. Response assessment was documented after ramp-up, 3, 12 and 24 months. Results Until April 12 th, 2023, 101 patients were enrolled and received at least one dose of Venetoclax, 42 % were IGHV unmutated. Baseline characteristics were balanced between the genetic risk groups. Patients with TP53 aberrations were older compared TP53 wildtype patients (71 vs. 66 a). 70% of patients with TP53 aberration, 68% of patients with wt TP53, 74% of patients with IGHVunmutated and 71% of patients with IGHVmut had at least 1 comorbidity. The best overall response rate after 12 months for 88 evaluable patients is shown in the figure. Estimated PFS-rate after 1 year was 93% in the total population, 100% in patients with TP53 aberrations, 91% in patients with wt TP53 95.1% of patients with IGHVunmutated and 82.5% of patients with IGHVmut. Estimated OS -rate after 1 year was identical to the estimated PFS. CTCAE grade AEs 3-5 were reported in 35% of the total population, in 21% in the TP53 aberrant, in 35% in the TP53 wt, in 33% in the IGHVunmutated and 10% in the IGHVmut population. A total of 3 patients had laboratory TLS. No new safety signals were detected. Conclusion In summary, both patients with or without TP53 aberration and with mutated or unmutated IGHV had high rates of best ORR, estimated PFS, and OS. Reassuringly, CR/CRi rates were high in patients with TP53 aberration or IGHV unmutated patients. Treatment was well tolerated. Disclosures DR has received honoraria or research grants from AbbVie, AstraZeneca, Gilead, Janssen, Verastem, Roche, Cellestia. IS has received honoraria from AbbVie, Amgen, AstraZeneca, BeiGene, Janssen, Roche, Servier. HH received speaker or consulting fees from AbbVie, AstraZeneca, Celgene, Janssen, Roche, and Beigene. CL received consulting fees from AbbVie, Amgen. TW received honaria or research funding from Novartis, Celgene, Roche, Bayer, Teva and Abbvie. CL and JH are employees of AbbVie and may own AbbVie stock. BS received speaker or consulting fees from AbbVie, Alexion, Amgen, AstraZeneca, BeiGene, BMS, Hexal, Janssen, Novartis, Pfizer, Sanofi-Aventis and SOBI. PP has received honoraria from Amgen, Gilead, Janssen, Sanofi-Aventis, Takeda. Honorarium paid by AbbVie was not related to authorship of this abstract. No honoraria or payments were made for authorship. AbbVie sponsored this study and contributed to the design, study conduct. AbbVie participated in the interpretation of data, review, and approval of the publication. All authors had access to all relevant data. Statistical support was provided by Daniela Giesder and Anna Eisen of GermanOncology GmbH, which was funded by AbbVie.

Coronado CLL: A Phase Ib/II Trial of Combination Rp-3500 and Olaparib in DNA Damage Repair Pathway Deficient Relapsed/Refract ory Chronic Lymphocytic Leukemia

Background: Genes within the DNA damage repair ( DDR) pathways are frequently mutated in relapsed/refractory ( R/R) chronic lymphocytic leukemia ( CLL) and clinically correlate with decreased response rates and shortened progression-free ( PFS) and overall survivals ( OS). The most commonly affected DDR genetic aberrations include deletion 17p13 [ del(17p)], deletion 11q22.3 [ del(11q)], and mutations in TP53, ATM, SF3B1, XPO1 and POT1. Due to their poor clinical outcomes, patients (pts) with DDR-deficient CLL remain an area of unmet need and the development of novel drugs and combinations will be critical to improving their prognosis. Mechanistically, CLL cells with DDR genetic alterations lack double-stranded DNA breakage repair and major cell cycle checkpoint pathways. Therefore, R/R CLL cells are dependent on single-stranded DNA breakage ( SSB) repair and alternative DNA replication arrest machinery to ensure DNA integrity, strand repair and cell survival. DNA damage at the replication fork is primarily recognized by ataxia telangiectasia and rad3 ( ATR) protein, which ensures mitotic arrest and recruitment of poly (ADP-ribose) polymerase ( PARP) based SSB repair mechanisms. In germline DDR-deficient breast and ovarian cancers with BRCA1/BRCA2 mutations, the use of both single agent PARP inhibitors ( PARPi) and ATR inhibitors ( ATRi) have led to significant disease response and improved OS. Furthermore, combination PARPi and ATRi have demonstrated synergistic activity in preclinical data producing increased apoptosis and cell death in BRCA2-mutated ovarian cell lines. In DDR-deficient CLL primary cell and murine models, single agent PARPi and ATRi have demonstrated significant cell death as compared to wildtype CLL and healthy donor lymphocytes. RP-3500 is a highly potent ATRi. In preclinical data generated in SUM149PT DDR-deficient breast cancer cell lines, combining RP-3500 with the PARPi, olaparib, substantially reduced tumor volume at lower doses than the previously determined maximum tolerated dose ( MTD) of each drug when used as monotherapy. Furthermore, intermittent dosing of both drugs (3 days per week) demonstrated equal cell apoptosis as continuous dosing. Therefore, we hypothesize that the combination of RP-3500 and olaparib will be a highly efficacious treatment for R/R DDR-deficient CLL pts and that the lower dosages and intermittent dosing schedule required of each drug when administered in combination will improve safety of the treatment. Study Design and Methods: This is a multi-site (University of Utah and the Ohio State University), phase Ib/II investigator-initiated clinical trial using combination RP-3500 and olaparib in R/R CLL pts with DDR pathway deficiencies to determine the safety and efficacy of the drug combination (NCT05405309). Primary objectives include determining the MTD in phase Ib leading to the recommended phase 2 dose ( RP2D), and overall response rate ( ORR) in phase II. Key secondary objectives include safety and tolerability, PFS, OS and duration of response of the combination. Eligibility: Key inclusion criteria include a diagnosis of CLL according to the 2018 iwCLL guidelines, age ≥18 years, ECOG performance status of ≤2, R/R after at least 2 prior lines of therapy. Primary CLL cells must exhibit any one of the following abnormalities: a) somatic mutation(s) in TP53, ATM, SF3B1, XPO1 or POT1, or b) positive FISH for either del(17p) or del(11q). Statistical Methods: Phase Ib: The phase Ib of the trial will utilizea keyboard design, which is a novel Bayesian method that typically underestimates the MTD. The target toxicity is 30% with an equivalence interval between 25-33% of pts. With an anticipated 3 dose levels ( DL) and an option for a DL-1, up to 18 pts may be required to determine the MTD and RP2D. Phase II: Any pt treated at the RP2D within phase Ib will be rolled into the phase II analysis for efficacy. With a planned 24 evaluable pts in phase II, the target ORR will be 60%, which was selected due to a recent phase I/II study of pirtobrutinib enrolling a similar CLL pt population demonstrating an ORR of the drug ~63%. ORR will be summarized by the observed proportion and an exact one-sided 95% confidence interval (Clopper-Pearson method). With 24 evaluable pts, the lower bound of the confidence interval will be approximately 17-20% below the observed proportion for observed ORR near 60%, which is an acceptable level of precision in a dose expansion cohort.

Broad Superiority of Zanubrutinib (Zanu) Over Bendamustine + Rituximab (BR) Across Multiple High-Risk Factors: Biomarker Subgroup Analysis in the Phase 3 SEQUOIA Study in Patients With Treatment-Naive (TN) Chronic Lymphocytic Leukemia (CLL)/Small Lymphocytic Lymphoma (SLL) without del(17p)

Introduction Zanu is a Bruton tyrosine kinase (BTK) inhibitor with high potency, selectivity, and efficacy and a favorable toxicity profile. In the phase 3 SEQUOIA study (NCT03336333; Tam et al. Lancet Oncol. 2022), zanu treatment demonstrated superior progression-free survival (PFS) in TN patients (pts) with CLL/SLL and without del(17p) (cohort 1) compared with BR treatment (hazard ratio [HR], 0.42; 95% CI, 0.28-0.63; 2-sided P<.0001). We evaluated PFS in both treatment arms in pt subgroups based on various biomarkers, including several known negative prognostic factors for CLL. Methods Details of the SEQUOIA study were described previously (Tam et al. Lancet Oncol. 2022). A total of 479 pts in cohort 1 were randomized to either zanu (n=241) or BR (n=238). Blood (CLL) or bone marrow (SLL) samples collected at screening were used for fluorescence in situ hybridization for chromosome abnormalities, cytogenetic analysis for complex karyotype (CK), next-generation sequencing (NGS) per the European Research Initiative on CLL (ERIC) for immunoglobulin heavy chain variable (IGHV) gene mutations and expressed clones, and ultrasensitive targeted NGS for mutation analysis of 106 genes. For NGS, all pathogenic mutations with variant allele frequency ≥1% were analyzed. The association between biomarkers and PFS was quantified using the log-rank test and HR and summarized by the Kaplan-Meier method. Data cutoff was October 31, 2022. Results Overall, the CLL features analyzed were similarly distributed between both treatment arms (Table). In pts with cytogenetic abnormalities, zanu demonstrated significantly better PFS than BR in those with del(11q) ( P<.001), del(13q) ( P<.001), trisomy 12 ( P<.01), or CKT ≥3 ( P<.01) (Table). Furthermore, zanu treatment conferred a similar PFS benefit to pts with the negative prognostic factor, del(11q) ( P=.05) or intermediate prognostic factor, trisomy 12 ( P=.40), compared to those without these abnormalities (Table). Notably, in the zanu arm, CKT ≥3 was not associated with worse PFS ( P=.18; Table). Pts with either mutated IGHV (mIGHV) or unmutated IGHV (uIGHV) in the zanu arm had significantly better PFS than pts in the BR arm (uIGHV: P<.0001; mIGHV: P<.01; Table); analysis was confirmed by an ERIC-certified provider. Furthermore, PFS was unaffected by IGHV mutational status in pts treated with zanu ( P=.12). In pts with uIGHV, IGHV1-69 was the most prevalent expressed clone in both arms (zanu: 24.6% [31/126]; BR: 30.7% [39/127]). In the present study, pts with uIGHV harboring IGHV1-69 clones showed significantly better PFS with zanu vs BR ( P<.0001). Across all pts, the most frequently mutated genes were ATM (zanu: 11%; BR: 16%), SF3B1 (zanu: 17%; BR: 21%), NOTCH1 (zanu: 20%; BR: 20%), and BRAF (zanu: 11%; BR: 7%; Table). Pts with mutations associated with poor prognosis in CLL had significantly better PFS with zanu than with BR (eg, ATM [ P=.02], BRAF [ P=.01], NOTCH1 [ P<.001], SF3B1 [ P<.001]; Table). Furthermore, zanu-treated pts with or without mutations in ATM ( P=.58), NOTCH1 ( P=.38), and SF3B1 ( P=.39) had similar PFS. Conclusions TN del(17p)-negative pts with CLL/SLL were evenly distributed between zanu and BR arms in SEQUOIA cohort 1 based on the biomarkers analyzed. PFS in zanu-treated pts was superior to that of BR-treated pts in all biomarker subgroups analyzed, including some known negative prognostic markers in CLL such as del11q, CKT≥3, and uIGHV. Importantly, within the zanu-treatment arm, pts with negative prognostic biomarkers showed comparable PFS benefit to pts without those markers. Like with other BTK inhibitors, ibrutinib and acalabrutinib, IGHV mutational status did not affect PFS outcome (Bartosz et al. Hematology in Clinical Practice 2022). However, contrary to what has been reported for TN or relapsed/refractory pts treated with ibrutinib-based regimens, CKT ≥3 was not associated with worse PFS in zanubrutinib-treated patients (Rigolin et al. Blood. 2021; Thompson et al. Cancer. 2015). This study provides further evidence that zanu is a valuable first-line treatment option for pts with CLL/SLL.

Ibrutinib, Fludarabine, Cyclophosphamide and Obinutuzumab (iFCG) for Firstline Treatment of Patients with CLL with Mutated IGHV and without Del(17p)/ TP53 Mutation: Six-Year Follow-up Analyses

Background Patients (pts) with IGHV-mutated ( IGHV-M) CLL have favorable long-term outcomes after receiving first-line FCR (fludarabine, cyclophosphamide and rituximab). We designed an investigator-initiated, phase II trial with ibrutinib, fludarabine, cyclophosphamide, and obinutuzumab (iFCG) for previously untreated pts with IGHV-M CLL (NCT02629809), and we report here an updated analysis with a median follow-up of 72 months. Methods Inclusion criteria included diagnosis of previously untreated CLL/SLL needing treatment per iwCLL criteria, age ≥18, IGHV-M, absence of both del(17p) and TP53 mutation. Pts received 3 courses of iFCG. Pts achieving CR/CRi with undetectable MRD (U-MRD) in bone marrow (BM) (4-color flow-cytometry, sensitivity 10 -4) after 3 courses of iFCG received ibrutinib with obinutuzumab (iG) for 3 cycles, followed by ibrutinib monotherapy for 6 months. All other pts received iG for 9 cycles (C4-12). Pts with U-MRD (CR/CRi or PR) at end of Cycle 12 stopped all therapy, including ibrutinib. Response assessment was per 2008 iwCLL criteria with BM and CT scans every 3 months during the first year. After completion of all therapy, pts were followed by clinical examination, blood counts and peripheral blood MRD every 6 months. Results Between March 2016 and August 2018, 45 pts initiated treatment. Data cutoff was July 15, 2023. Baseline characteristics are shown in Table 1. All pts per study inclusion criterion had IGHV-M; however, 1 enrolled pt was later reclassified as IGHV-unmutated. A total of 69% pts had del(13q). After three cycles of iFCG, 39/45 (87%) pts achieved marrow U-MRD. Responses improved with continued therapy with 40/45 (89%) and 41/45 (91%) achieving marrow U-MRD after Cycles 6 and 12, respectively. Overall, 44/45 (98%) pts achieved marrow U-MRD as best response at any time during the study. Median follow-up duration is 72 months. 41/45 pts completed 12 cycles of treatment (4 pts came off study prior to Cycle 12). All 41 pts achieved marrow U-MRD and per protocol, discontinued ibrutinib. After a median follow-up of 61 mos post-discontinuing ibrutinib, 8 pts had MRD recurrence (defined as 2 consecutive values of ≥0.01% in peripheral blood by flow cytometry) at a median of 32 mos (range, 20-67 mos) after stopping all therapy. Of the 8 pts with MRD recurrence, 2 pts had clinical relapse (described below); remaining 6 pts are being monitored with no clinical progression or active therapy. The 6-year PFS and OS are 92.2% (95% CI= 77.7-97.4) and 97.7% (95% CI= 84.9-99.6), respectively. Two pts had clinical progression: one pt had IGHV 3-21; MRD recurred 28 mos after discontinuing ibrutinib, with clinical relapse 59 mos after discontinuing ibrutinib; this pt is now in remission with venetoclax-based therapy; the second pt with clinical relapse had IGHV-unmutated CLL, MRD recurred 24 mos after discontinuing ibrutinib, with clinical relapse 48 mos after discontinuing ibrutinib; this pt has not yet required therapy for relapse. No pt had progression to Richter transformation. One pt developed therapy-related myelodysplastic syndrome; this pt is being monitored for 58+ months without any active therapy for MDS with normal blood counts. One pt died from congestive heart failure during month 9 of the study. Conclusions iFCG regimen with only three cycles of combination chemotherapy achieves U-MRD rates of 98% in bone marrow on an intent-to-treat analysis and a 6-year PFS of 92% in IGHV-M CLL. These results are favorable compared to the 5-year PFS of approximately 65% with FCR (CLL10 trial) for the same genomic subgroup. Additionally, these results also appear favorable to the current targeted therapy regimens (such as BTKi, BCL2i+CD20 antibody) for IGHV-M CLL. With the caveat that the role of chemoimmunotherapy in CLL has significantly declined, the iFCG regimen provides for a very high rate of durable remissions among a chemo-sensitive subgroup of pts with CLL.

Curcumin Enhances Ibrutinib Induced Killing Effect Against TP53-Mutated Chronic Lymphocytic Leukemia Cells in Vitro

Introduction TP53 mutation and del (17p) are the most important poor prognostic factors in patients with Chronic Lymphocytic Leukemia (CLL).Patients with deletion 17p or TP53 mutations tend to have lower response rates to standard first-line chemoimmunotherapy and a more aggressive clinical course(Stilgenbauer et. al. Blood 2014). RESONATE-2 study long-term follow-up showing that ibrutinib continues to demonstrate significant and durable clinical benefit in older patients, including those with TP53 mutation(Barr et. al. Blood Adv 2022).However, CLL bearing del(17p) showed inferior OS and time to next treatment compared to non-del(17p)(Mato et. al. Haematologica 2022). A significant proportion of patients treated with single-agent ibrutinib experienced CLL progression.BTK and/or PLCG2 mutations were present in 80.0% of patients progressing with CLL, confirming prior reports on the high prevalence of these mutations in patients with ibrutinib-resistant CLL(Ahn et. al. Blood 2017). Curcumin is a bioactive natural polyphenol compound extracted from the Curcuma longa(Zingiberaceae plant). Curcumin has anti-tumor effect and can induce apoptosis and inhibit the proliferation of a series of tumor cells(Willenbacher et. al. Int J Mol Sci 2019). Curcumin may limit the development of therapy-related toxicity and reduce the financial burden of treatment.In this study, we found that Curcumin inhibits TP53-mutated CLL cells, and eliciting a strong synergistic cytotoxic effect in combination with ibrutinib. Methods The inhibitory effect of ibrutinib combined with curcumin on the proliferation of TP53-mutated Chronic Lymphocytic Leukemia cells was detected by CCK8, and the apoptosis of TP53-mutated CLL cells induced by ibrutinib combined with curcumin was detected by flow cytometry;The differences of gene and signal pathway expression among different treatment groups were analyzed by RNA-seq ;Using Western blot technology to verify the expression of related pathway proteins and explore the mechanism of curcumin increasing the killing effect of ibrutinib against TP53-mutated Chronic Lymphocytic Leukemia cells. Results The CCK8 results showed that the IC50 of ibrutinib for 24 hours was 40.61±2.35μM, while the IC50 of curcumin for 24 hours was 26.6±0.94μM. The IC50 of ibrutinib for 48 h was 14.6 ±0.8307μM, and the IC50 of curcumin for 48 h was 15.7±2.53μM.Cell inhibition of various group for 48h is shown in Figure 1.The CI of ibrutinib combined with curcumin at 24 hours and 48 hours was calculated by CompuSyn software. The results showed that the CI values of ibrutinib combined with curcumin were less than 1 at 24 h and 48 h, suggesting that ibrutinib combined with curcumin has a synergistic killing effect on CLL cells with TP53 mutation;Flow cytometry showed that the IC50 of ibrutinib for 24 hours was 67.20±2.86μM, while the IC50 of curcumin for 24 hours was 144±6.6 μM. The CI value of ibrutinib combined with curcumin was less than 1 at 24 h, suggesting that ibrutinib combined with curcumin has a synergistic promoting apoptosis on CLL cells with TP53 mutation;RNA-seq analysis and KEGG analysis of down-regulated genes of combination group compared with the control group were mainly enrich in PI3K/AKT, Cytokine-Cytokine Recptor signal pathway and so on;4.The results of Western blot showed that the protein expression levels of P65PI3K and p53 in the single drug group and the combination group were down-regulated in varying degrees, especially in the combination group（Figure 2). Conclusion Ibrutinib combined with curcumin has synergistic killing effect on TP53- mutated CLL cells;Curcumin increases the killing effect of ibrutinib on TP53-mutated CLL cells by inhibiting PI3K and NFκB pathway, and degrading p53mt protein.

Understanding Resistance Mechanisms and Growth Kinetics of CLL Treated with Covalent and Non-Covalent BTK Inhibitors

Resistance mechanisms to covalent BTK inhibitors (cBTKi) are well studied, with mutations in BTK at the 481 target binding site most commonly identified, and, less commonly, activating mutations in PLCϒ 2. Second site non-481 BTK mutations have been identified among patients on non-covalent BTK inhibitors (ncBTKi). The present study was designed to further evaluate these resistance mechanisms using dense serial sampling during therapy with both classes of BTKi and using mathematical modeling to analyze the rates of growth and decline of specific mutated clones. We performed whole exome sequencing on matched tumor and normal samples from 19 CLL patients treated with BTK inhibitors (Ibrutinib, Ibr, 42% (8/19); Acalabrutinib, Acala, 21% (4/19) and Pirtobrutinib, Pirto, 37% (7/19)). The median number of longitudinal samples per patient per cohort was 6 for ibr (N=51 total samples), 11 for acala (N=46) and 15 for pirto (N=105). The median number of prior therapies in both the ibr and acala cohorts was 2 and high-risk genomic features del(17p) and del (11q) were both at 50% in acala cohort and 50% and 38% in the ibr group respectively. The ibr cohort had no prior BTKi therapy whereas 1 patient in the acala cohort had received spebrutinib, another cBTKi. The average time to progression (TTP) in the ibr and acala groups was comparable at 44.1 and 44.4 months respectively. The pirto cohort was more heavily pretreated with a median of 3 prior therapies and del(17p) in 28.6% and del(11q) in 42.8%. All patients in this cohort had prior cBTKi (4 patients had 1 and 3 patients had ≥2 cBTKi) and average TTP was shorter at 15.1 months. At progression (PD), mutations in BTK C481S were found in 5 /8 patients (55%) in the ibr cohort with cancer cell fraction (CCF) > 80% in 3 patients. Two of these patients also have mutations in PLCϒ 2 (CCF > 30%). One patient in the cohort has an acquired PLCϒ 2 mutation (D1140N) with CCF>70%, without BTK C481S. Investigation of this patient's resistant clone growth kinetics (using WBC counts) demonstrates that the PLCϒ2 clone which was not detected at baseline takes over the population at ibr progression. Two patients in this cohort did not have either BTK or PLCϒ 2 mutations; however, one patient had 2 expanding subclones with known driver mutations ( TP53, BIRC3, del 8p). All 4 patients in the acala cohort have resistant clones harboring BTK C481S (CCF 16-75%) mutations, with T474I mutations present in 2 patients (CCF 4% and 26%) at progression. Growth kinetics analysis of the C481S clones for 3 patients shows steady increase during acala therapy, suggesting CLL progression in these two patients is driven by the C481S mutations. All but one patient in the pirto cohort had developed PD on cBTKi and 71% (5/7) had BTK C481S mutations prior to starting pirto (CCF 26 - 99%). In all 5 cases, the C481S clone declines on pirto and at PD is replaced by the BTK gatekeeper mutation T474I (CCF 76 - 99%) in 3 patients, the kinase-inactive mutation BTK L528W (CCF 30%) in 1 patient, and mutations in other driver genes ( XPO1, MED12) in 1 patient. Growth kinetics analysis for 1 patient shows exponential decay of the C481S clone under pirto treatment, followed by slow steady growth of the T474I clone, with a sharp increase right before PD. In another patient, exponential growth of the T474I clone occurs during pirto treatment while the C481S clone steadily declines. Interestingly this patient also had an existing PLCϒ 2 mutation (L845F, CCF 42%) at baseline, acquired during ibr treatment, which also steadily decreased on pirto. In another patient previously treated with ibr, with baseline BTK mutations in C481R (CCF 29%), C481S (CCF 18%), and L528W (CCF 2%), the L528W clone steadily increases, while both C481S and C481R clones decrease during PD. This patient exhibits extreme multiclonal diversity of BTK mutations, with 8 different BTK mutations at the DNA level at the C481 site present both at baseline and at PD, with 56% reduction in total wild type reads at PD. Of the remaining two patients without baseline C481S mutations, one patient acquired T474I (CCF 99%) and the other patient acquired 1q gain (MCL1) and t(8;14) at progression. Growth kinetics of different BTKi can vary based on their specific mechanism of action. The approach of combining WES data with growth pattern modeling can help unravel the complexities of tumor evolution and drug resistance for the different classes of BTKi. Data on comparative clone growth rates will be presented at the meeting.

Teclistamab Induces Rapid Responses in Patients with Relapsed/Refractory AL Amyloidosis

Introduction Systemic light chain (AL) amyloidosis is a rare disorder characterized by tissue deposition of amyloid fibrils derived from immunoglobulin free light chains. While daratumumab in combination with cyclophosphamide, bortezomib and dexamethasone (Dara-CyBorD) is the standard for upfront treatment of AL, management of relapsed/refractory (R/R) disease is often challenging, particularly in context of multiorgan dysfunction. Teclistamab was recently approved for treatment of R/R multiple myeloma (MM) and showed an overall response rate (ORR) of 63% (N Engl J Med 2022;387:495). Notable adverse effects (AEs) included cytokine release syndrome (CRS), neurologic, renal and hematologic toxicities, and infections. Efficacy of teclistamab in AL has not been previously reported. Here, we present a series of three patients who received treatment with teclistamab for R/R AL and MM. Methods In this retrospective study, we included all patients with R/R AL and MM who received teclistamab at two US academic centers between October 2022 and July 2023. We recorded all standard metrics, including serologic and biomarker data. Hematologic and organ responses were evaluated based on standard consensus criteria. Toxicity assessment was performed in accordance with the NCI CTCAE v5.0, except for CRS and neurotoxicity, which were graded according to the 2019 ASTCT criteria (BBMT 2019;25:625). Results We identified 3 patients; baseline characteristics are provided in Table 1 and treatment data in Table 2. Median age was 67 years (range, 54-70). All patients were male, and 2 had AL λ-type. At the time of teclistamab initiation, the median number of prior therapies was 7 (5-10), with all patients being refractory to a bortezomib, lenalidomide and daratumumab. Median iFLC was 228 mg/L (45.5-1272) with 10% median bone marrow (BM) plasmacytosis. In one patient with rapidly progressive multiple myeloma, BM FISH showed high-risk cytogenetic changes, including gain 1q, del 1p and del 17p. All patients were hospitalized for treatment initiation and received escalating doses of 0.06 mg/kg, 0.3 mg/kg and 1.5 mg/kg during the ramp-up phase. Subsequent treatment with target dose of 1.5 mg/kg was continued in the outpatient setting on a weekly basis. Monitoring for cytokine release syndrome (CRS) and neurologic toxicity was performed in accordance with institutional protocols. At a median follow-up of 49 days (44-58), 2 patients achieved hematologic responses (HR), with 1 complete hematologic response (CR) and 1 low dFLC PR. Both hematologic responses occurred promptly within 3 weeks of treatment initiation, were deep with iFLC <10 mg/L, and were ongoing at the last follow-up. One patient with rapid renal progression prior to teclistamab also enjoyed a renal response by day 42. The most common toxicity was hematologic, with 1 patient experiencing grade 4 lymphopenia, grade 2 thrombocytopenia and hypogammaglobulinemia. There were no infectious complications or instances of febrile neutropenia, CRS or neurologic AEs. All patients received routine prophylaxis against VZV and PJP, as well as prophylactic IVIg. One patient with heavily pre-treated, high-risk MM had an aggressive clinical relapse with widespread osseous involvement within 6 months of an autologous stem cell transplant (ASCT) and experienced progressive disease as best response to teclistamab, necessitating discontinuation after 29 days in favor of cytotoxic chemotherapy. Conclusion In this series of 3 patients with heavily pre-treated, R/R AL and MM, teclistamab showed an impressive hematologic response rate of 67%. These responses were deep and occurred rapidly within 3 weeks of treatment initiation. One patient also enjoyed a renal response, whereas cardiac responses were non-evaluable in 2 patients. While the most common treatment-related toxicity was hematologic in nature, infections or febrile neutropenia were not observed, likely due to the institution of aggressive prophylactic measures. Importantly, no new safety signals were identified in AL patients. To our knowledge, this is the first report providing preliminary evidence for efficacy of teclistamab in R/R AL, highlighting the need to investigate this strategy in clinical trials.

Real-World Utilization of Daratumumab-Containing Induction Regimen in Transplant Eligible Newly Diagnosed Multiple Myeloma and Its Role in Patients Historically Excluded from Clinical Trials: A Single Institution Experience

Daratumumab is increasingly being used in the treatment of Multiple Myeloma (MM). However, patients with severe anemia (hgb < 7.5), severe hypercalcemia (serum calcium > 14), creatinine clearance < 30 ml/min, and patients aged > 70 years were excluded from the pivotal clinical trials that investigated first line daratumumab. Here we report how daratumumab is utilized in the treatment of real-world transplant eligible (TE) newly diagnosed multiple myeloma (NDMM) and its safety and efficacy in these vulnerable patient populations. Method: We conducted a retrospective chart review of all adult Multiple Myeloma patients who had autologous stem cell transplant (ASCT) at Vanderbilt University Stem Cell Transplant (VUSCT) program between January 2017 and April 2023. Descriptive statistics was used to summarize patient and disease characteristics. Patients with del 17p, t(4;14), t(14;16), 1q gain and 1p deletion were categorized as high risk. Fisher's exact test and Wilcoxon rank sum test was used to compare variables. Kaplan-Meir curves and log rank tests were used to compare PFS and OS. Binary logistic regression was used to evaluate patient and disease variables associated with daratumumab use. A p-value of <0.05 was considered statistically significant. Result: A total of 508 charts were reviewed. Out of 508, 104 patients had daratumumab containing induction regimen, including 44 patients who took daratumumab starting with the first cycle and 60 patients who had daratumumab added or regimen switched to include daratumumab as part of the induction regimen. Patient, disease, and outcomes of these patients is summarized in table 1. Additional 149 patients received daratumumab post-ASCT during subsequent relapses. Occurrence of relapse was the only variable associated with increased risk of death (HR=4.45, (95% CI: 1.94,10.06) with p-value=0.0003). Having standard cytogenetic risk was associated with decreased utilization of daratumumab in the induction regimen (OR=0.49, (95% CI: 0.27, 0897) with p-value of 0.02). Out of the 104 patients induced with daratumumab, patients who had daratumumab added after the first induction cycle had longer diagnosis to ASCT time when compared with patients who take daratumumab starting from cycle 1 of induction (table 1). Median progression free survival (PFS) and overall survival (OS) was not reached in either group. Among populations of interest, there were 7, 2 African American (AA) and 5 white(W), 5 female (F) and 2 male patients, aged between 54 and 67 years, who had hemoglobin < 7.5 (range: 5.4 -7 g/dL) at diagnosis among the patients who had daratumumab containing induction regimen. All 7 of the patients had improvement in their hemoglobin post-induction and they remain in remission post-ASCT. Their hemoglobin trend is depicted on figure 1. There were 11 TE NDMM patients above age 70 (mean: 74, range: 71-77 years) who received daratumumab containing induction regimen. Although there was no statistically significant difference with the rest of the population, all patients had G3 infection within 30 days of ASCT, but no ICU admission or mortality with follow up of up to 39 months (average 18.45 months). We identified 10 patients with mean age of 53.8 years (range 45-65), 30% F, 40% AA, and 50% high-risk patients who had serum calcium >14 mg/dL. Only 1 patient had daratumumab containing induction regimen. Unfortunately, this patient died of disease progress 3 months after ASCT. Four other patients in this group also died between 3 and 54 months (mean: 18 months) from ASCT. Among 54 patients with creatinine > 2 at diagnosis, 8 patients, aged between 45 and 68 (mean = 58.37) years, mean creatinine of 4.95 (range 2.1-13.05) were induced with daratumumab containing regimen. Average creatinine dropped to 2.15 post-induction and 1.91 at 100 days post-ASCT. Three out of 8 died within 11months of ASCT (mean: 7 months) due to COVID infection in 1standard risk and disease progress in 2 high-risk patients. Conclusion: Inclusion of daratumumab at the onset of induction is associated with shorter time between diagnosis and ASCT. Longer follow up is warranted to determine difference in PFS and OS among patients with early and late incorporation of daratumumab containing induction regimen. Our study suggests that daratumumab containing induction regimen is safe and effective for TE NDMM of all ages, including those with severe anemia and creatinine > 2 mg/dL.

Initial Clinical Results and Immune Correlates of a Phase 2 Study of Daratumumab, Bortezomib, Dexamethasone Followed By a Proteasome Inhibitor in-Class Transition ( iCT) to Daratumumab, Ixazomib, Dexamethasone in Relapsed Refractory Multiple Myeloma

Background: The regimen of daratumumab, bortezomib, and dexamethasone (DVd) was approved in relapsed refractory multiple myeloma (RRMM) patients (pts) with >1 line of therapy based on the pivotal phase 3 CASTOR study. Notably in CASTOR, bortezomib was administered for a fixed duration of 8 cycles, and both the parenteral administration route and treatment-related peripheral neuropathy (PN) may limit continuous bortezomib exposure in clinical practice. As an alternative, we conducted a phase 2 study of DVd, followed by daratumumab, ixazomib, dexamethasone (DId) utilizing a proteasome inhibitor (PI) in-class transition ( iCT) with the hypothesis that oral ixazomib may provide a more tolerable and convenient way to deliver continuous PI- and anti-CD38-based therapy to improve efficacy (NCT03763162). Methods: This phase 2 single-center study enrolled RRMM pts with 1-3 lines of prior therapy with disease progression on or following the last line of therapy. Key exclusion criteria included prior ixazomib exposure, refractoriness to anti-CD38 therapy, and refractoriness to bortezomib or carfilzomib therapy at last exposure. Enrolled pts received DVd for 3 cycles on a 21-day (D) cycle with daratumumab on D1, D8, and D15 and subcutaneous (SC) bortezomib 1.3 mg/m 2 on D1, D4, D8, and D11. Starting cycle (C) 4, pts transitioned to DId on a 28-day cycle, with daratumumab on D1 and D15 for C3-C7 and on D1 starting C8 and oral ixazomib 4 mg on D1, D8 and D15. Daratumumab was initially administered intravenously (16 mg/kg) but later changed to SC injection (1800 mg) with a protocol amendment. Bone marrow (BM) aspirates were performed pre-treatment, post-C3, post-C6 (optional), and at progression to evaluate immune correlates of therapeutic response and resistance using 4 16-color multiparameter flow cytometry panels (2 T-cell, 1 NK/myeloid, and 1 B-cell). The primary endpoint of the study was progression free survival (PFS) with planned enrollment of 40 pts. Results: As of 15 May 2023, 36 pts have enrolled with a median of 1 prior line of therapy. Median age was 66, 67% were male, 28% were Black, 97% were lenalidomide-refractory, and 42% had high-risk cytogenetics (Cg; del 17p, t(4;14), t(14;16), and/or +1q21 gain/amplification). Overall response rate was 83%, ≥very good partial response (VGPR) rate was 53%, and ≥complete response rate was 19%. At a median follow-up of 24.8 months, median PFS was 21.1 months and median response duration was 26.2 months. Median PFS among pts with high-risk Cg, 1 line of prior therapy, and 2-3 lines of prior therapy was 21.1 months, 22.8 months, and 14.3 months, respectively. The most common treatment emergent adverse events (TEAEs) of any grade were diarrhea (69%), thrombocytopenia (69%), fatigue (67%), and lymphopenia (67%). The most common ≥grade 3 TEAEs were lymphopenia (42%), thrombocytopenia (42%), and hypertension (31%). Treatment emergent PN occurred in 61% pts (11% ≥ grade 3). The most common reason for treatment discontinuation was disease progression (42%), and 16 (44%) pts remain on study with ongoing responses. Efficacy and safety stopping rules for the study have not been met. Multiparameter flow cytometry immune correlates from BM aspirates demonstrated significantly lower Ki67 + cell frequency and significantly higher PD-1 + cell frequency within the CD8 + T-cell population at baseline in pts with no response versus those with optimal responses (≥VGPR). Among pts with short PFS (<12 months), CD4 +/CD8 + ratio and CD4 + non-T-reg naïve T-cells were significantly higher post-C3 and post-C6 compared to pts with longer PFS (>12 months). Among initial responders who later progressed on therapy, T-regulatory cells were significant increased at progression compared to pre-C4, and NK cell CD16 expression was significantly reduced at progression compared to baseline. Finally, distinct patterns of CD4 + T effector memory (EM) cell subsets were observed with significantly decreased EM1 and increased EM3 subsets at progression compared to baseline. Conclusion: Treatment with DVd followed by DId with a PI iCT from bortezomib to ixazomib is a feasible approach for continuous PI and anti-CD38 therapy, leading to durable responses in RRMM pts, among whom nearly all (97%) were lenalidomide refractory. Immune correlates revealed distinct patterns of T-cell and NK-cell phenotypes when profiled serially in responding and non-responding pts. Additional correlative analyses are ongoing.

Unravelling Transplant-Ineligible Newly Diagnosed Multiple Myeloma Treatment in Real-World Practice in Spain. Carinae Study

Introduction: There is little data regarding real-world treatment patterns and outcomes of transplant-ineligible newly diagnosed multiple myeloma patients (TIE-NDMM) in Spain. In recent years, several treatment regimens have been authorized as effective options for TIE-NDMM, providing patients with better outcomes and quality of life, as evidenced in clinical trials (Mateos et al. Lancet 2020). However, the contribution of incorporating these new treatments into the daily therapeutic arsenal has not been widely explored. Methods: Observational, ambispective, multicenter ongoing study on TIE-NDMM patients who started antineoplastic treatment in the context of daily clinical practice in Spanish hospitals. Group A: started treatment with a combination of ≥2 drugs, between Sep/01/2018 and Aug/31/19. Group B: started treatment with daratumumab in combination with bortezomib, melphalan and prednisone (DVMP group), between Sep/01/19 and Nov/30/20. Here, we present the efficacy and safety outcomes obtained in the second interim analysis after ≈24-month study initiation. Results: 117 patients were recruited, and 108 were evaluable for efficacy in this interim analysis (group A n=51; group B n=57). No significant differences were observed in basal clinical and demographics characteristics between groups (table 1): mean age 76.9 years; male (53.7%); cardiopathy 28.7%; renal failure 25%; pulmonary obstructive disease 8.3%; peripheral neuropathy 2.8%; median ECOG PS 1; most common myeloma type was IgG (49.5%); 13.9% had a high-risk cytogenetic profile, defined by one of the following alterations: t(4;14), t(14;16) and del 17p13; plasmacytoma 24.3 %. More than 90% of the patients in group A started treatment with schemes based on bortezomib, lenalidomide, or both. Median follow-up was 36.3 versus 23.3 months for groups A and B, respectively, since the initiation of first-line treatment (p<0,0001). Probably in relation to the different follow-ups, the median PFS for Group A was 32.78 months and not reached for Group B (p=0,1129), figure 1. The progression rate at 18 months was 27.5% and 10.5% for Group A and B respectively (p=0,0238). Rates of ≥VGPR and ≥CR, were 60% and 30% in Group A whilst 75.4% and 33.3% in Group B, table 2. 36.9% of the patients showed adverse drug reactions (ADR) related to the first-line treatment during the prospective period. 10.6% of the reported ADRs were serious with no significant differences between groups. No unexpected ADRs were observed. Additional data will be presented at the Congress. Conclusions: In this interim analysis, a significant clinical benefit has been identified in patients treated with DVMP, with improved PFS indicators vs. other treatment alternatives. Along with the deeper hematological responses observed, we expect this benefit to be consolidated in the final PFS analysis of the Carinae study. These real-world practice data continue to support the choice of daratumumab regimens in frontline TIE-NDMM patients.

Risk and Response Adapted Approach for Treatment of Myeloma: Pushing Autologous Transplant Down the Hierarchy

Background & Significance: In current recommendations, consolidative autologous stem cell transplant (ASCT) is essential in management of NDMM. The IFM 2009 Trial showed that RVd followed by ASCT with 1-year lenalidomide maintenance was associated with a better PFS vs. RVd with 1-year lenalidomide maintenance alone (Attal M et al, NEJM 2017). A longer follow up (8 years) of IFM trial concluded that a delayed transplant (in 2 nd line) had no impact on the PFS2 (Perrot A et al, Blood 2020). We evaluated the merit of frontline ASCT (CR1) vs. post salvage ASCT (CR2) in light of indefinite maintenance therapy post novel triplet/quadruplet induction. Material & Methods: We conducted this retrospective analysis, of symptomatic myeloma patients who underwent ASCT at Rajiv Gandhi Cancer Centre, Delhi between April 2017 and October 2022. Patients were segregated into 2 cohorts; a) ASCT CR1- who received 4 to 6 cycles of RVd (+/- Anti CD38 antibody) induction followed by transplant and indefinite maintenance and b) ASCT CR2- patients who relapsed after 4-6 cycles of RVd induction+maintenance then salvaged with 2 to 6 cycles of novel agent-based therapy (Carfilzomib/ Pomalidomide/ Daratumumab) followed by ASCT and indefinite maintenance. Patient characteristics were balanced for age, gender, ISS, RISS and high risk cytogenetics (Del p53, t(4;14), t (14;16), 1qGain, 1pDel, 13qDel). Response was assessed as per IMWG criteria. PFS was defined as the time from induction/salvage to progression on next line of therapy or death. Results: Of 161 patients included, we compared outcomes of ASCT CR 1 (N=122) to ASCT CR-2 (N=39). All patients received maintenance (PI/IMID or in combination) post ASCT. Significant patients in ASCT-CR2 received novel salvage therapy (Carfilzomib/ Pomalidomide/ Daratumumab) (CR1-14 % vs CR2-100%, p value- <0.01). 86% patients in ASCT CR1 received RVd. Both groups were substantially exposed to Lenalidomide. Median time from diagnosis to transplant was 5.9 months (range 4-12) in ASCT- CR1 group and 29.5 months (range 18-64) in ASCT CR2 group (p value- 0.004). After a median follow up of 44 months for ASCT CR1 vs. ASCT CR2, the ORR (97% vs. 95.4%, p=0.88) and CR (85% vs. 78%, p=0.67), respectively. 42.6% patients in ASCT CR1 and 38.4% patients in ASCT CR2 relapsed (p value- 0.4%). The median PFS for both groups (ASCT CR1 and ASCT CR2) were similar 45 months and 43 months, respectively, (p value- 1.09). The 1-, 3- and 5-year PFS showed a similar trend across cohorts (CR-1: 95%, 59.1%, 39.7% and CR-2: 84%, 57.1%, 41.3%). Patients with high-risk cytogenetics in ASCT CR 1 (N=50) had a better median PFS (25 months) compared to ASCT CR2 (N=16, median PFS=17.9 months, p=0.059), fig:1 though statistically insignificant. Table:1 No difference in PFS for standard risk noted (p=0.38). On regression analysis, factors predictive of progression were: ISS stage III (univariate only), high-risk cytogenetics, IMID based maintenance therapy. We noted better PFS in patients receiving >24 months of maintenance. Depth of response prior to transplant, Melphalan dosage and remission (CR1 vs CR2) did not predict progression. Conclusion: In the light of above findings, does transplant decision need re-sequencing? Our findings are not in agreement with the hypothesis that exposure to novel agents in relapsed/refractory settings leads to resistant clone selection under stress. The pattern of relapse in standard risk myeloma remains same across lines of therapy. Excellent response rates are observed with novel agents at relapse therefore delaying transplant appears reasonable in standard risk. High-risk myeloma represents a unique subset where patients experience early/aggressive relapse indicating that current therapy offers little modification of kinetics or natural history of disease. Changing treatment paradigm based on disease risk and response appears pragmatic. Myeloma is the disease of elderly with plethora at hand, its time to individualize.

Renal Response of Selinexor, Pomalidomide, Bortezomib and Dexamethasone in Newly Diagnosed Multiple Myeloma Patients with Renal Impairment: A Prospective, Open-Label, Multicenter, Phase 2 Study

Background Renal impairment (RI) is one of the cardinal features of newly diagnosed multiple myeloma (NDMM), contributing to dismal outcomes and high risk of early death. Improved renal function is associated with prolonged survival for NDMM. The triplet combination of pomalidomide with bortezomib and dexamethasone (PVD) has been proven to be effective in MM patients with RI [1] (The manuscript in preparation). However, the best renal overall response rate (ORR) was 78.8% and 21.2% of patients had no renal response to PVD. Here we reported an interim analysis to evaluate the renal and hematologic response of SPVD (Selinexor, pomalidomide, bortezomib, dexamethasone) regimen as first-line therapy in NDMM with RI in this prospective, open-label, multicenter, phase 2 study (ChiCTR2200064695). Methods Eligible NDMM with RI (defined as estimated glomerular filtration rate (eGFR) by MDRD < 40ml/min) were enrolled in the study. Sample size was designed to recruit 62 patients. RI caused by other reasons than tubular nephropathy was excluded. Patients received SPVD (Selinexor 40mg on days 1,8,15, pomalidomide 4mg on days1-14, bortezomib 1.3mg/m2 on days 1,4,8,11, and dexamethasone 20mg on day of and after bortezomib, 21days/cycle) for a maximum of 9 cycles. Autologous stem cell transplantation (ASCT) was administrated after 3 to 6 SPVD cycles for transplant-eligible patients. The primary endpoint was renal ORR at 3 months. Secondary endpoints included major renal response (≥partial response) at 3 months, hematological ORR, minimal residual disease (MRD), progression-free survival (PFS), overall survival (OS), and safety. The definition of both hematological response and renal response was according to the International Myeloma Working Group (IMWG) criteria. Results Between Oct 28, 2022 and Jun 23, 2023, 31 patients were enrolled across 17 centers, with a median age of 61 years (range: 45-80). The proportion of R-ISS III was 35.5%. Median serum creatine level and eGFR were 365μmol/L [interquartile range (IQR): 214.5-508] and 14.5 mL/min (IQR: 10.5-22.64), respectively. There were 10/31 (32.3%) patients requiring dialysis at diagnosis and 8 patients with high-risk cytogenetic abnormalities [t(4;14), t(14;16), or del(17p)]. At the data cut-off date of July 11, 2023, the median number of SPVD treatment cycles was 3 (range: 1-8). The median follow-up time was 4 months. Two patients received first-line ASCT after induction therapy. The primary endpoint of renal ORR at 3 months was 74.2%, including 6.5% renal PR, and 25.8% renal CR (Table 1). The ORR of the best hematological response was 70.9% (45.1% ≥VGPR, 16.1% CR)(Table 1). The most common treatment emergent adverse events (TEAEs) (incidence >10%) were infection (45.2%), myelosuppression (45.2%), hepatic impairment (12.9%), nausea (12.9%), and hypokalemia (12.9%) (Table 2). Grade 3 or more hematologic toxicity was seen in 35.5% of the patients, the most common being thrombocytopenia (19.4%)(Table 2). Dose reduction or interruption of pomalidomide occurred in 5 patients due to myelosuppression and infection events. Three patients had dose reduction of selinexor due to nausea or vomiting. Notably, among non-hematologic toxicities, 4 patients developed hepatic impairment, and of those, one patient suffered tumor lysis syndrom, hepatic failure and severe infection and then died. Median PFS and OS were not reached. Conclusion This study demonstrated SPVD is an effective combination in NDMM patients with RI. The toxicity profile was consistent with the reported research, but hepatic impairment during treatment should be noted with caution. Reference [1] JIAN Y, CHANG L, SHI M, et al. Renal Response of Pomalidomide with Bortezomib and Dexamethasone in Newly Diagnosed Multiple Myeloma Patients with Renal Impairment: A Prospective, Open-Label, Multicenter, Phase 2 Study [J]. Blood, 2022, 140(Supplement 1): 10167-9. doi:10.1182/blood-2022-159361.

Main Treatment Choices in the 2 First Lines of Therapy for Multiple Myeloma in Patients with High Risk Cytogenetics: Lesson from the Real World in the EU5 Countries and the USA

Background Typical approach to initial therapy in multiple myeloma (MM) includes more aggressive combinations early on with triplets. To further improve response rates and survival, quadruplets are moving to frontline, in both stem cell transplant (SCT) eligible and ineligible patients (pts). Defining high risk features is crucial; current international NCCN and IMWG clinical practice guidelines stratify pts based on those criteria proposing more aggressive therapy in this setting. Definitions of high risk are: cytogenetic abnormalities incl. del(17p), some laboratory factors with ISS III and increased LDH, some clinical features including plasma cell leukaemia, extramedullary involvement or age and functional assessment with primary refractory disease and rapid progression within 18 months of diagnosis. Aims Identify in real world setting the main regimens used in first line SCT eligible and ineligible pts as well as in 2nd line high risk pts with MM in EU5 countries (France, Germany, Italy, Spain, UK) and in the USA. Methods Anonymous patient charts were analysed based on data reported by onco-haematologists treating MM pts in EU5 countries and USA. A total of 1,575 unique patient charts in 1st line (530 SCT eligible and 1,045 SCT ineligible pts) and 1,665 unique pts in 2nd line were included in the analysis, from Oct. to Dec. 2022. The analysis focused on pts with high risk cytogenetic features and regimens used in accordance with international clinical practice guidelines. D= daratumumab; V=bortezomib; T=thalidomide; d= dexamethasone; R=lenalidomide; M= melphalan; p= prednisone; K=carfilzomib; Isa=isatuximab Results Mean age in 1st line SCT eligible pts was 59.0 years (n=441) in EU5 and 60.9 years (n=89) in the USA. In 1st line SCT ineligible pts, mean age was 74.0 years (n=838) in EU5 and 65.9 years (n=207) in the USA. Among all 1st line SCT eligible pts, 34% in EU5 and 29% in US had high risk cytogenetic features, with del17p identified in 12% of EU5 cases and 16% of US cases. In 1st line SCT ineligible pts in the EU5 and in the US 14% and 17% respectively were high risk, including 9% and 13% del17p. In the 2nd line setting, 1,208 unique pts were included in the EU5 and 457 in the US with 17% and 14% classified at high risk, respectively, del17p was identified in 9% and 11% of pts. The most frequently used regimens in 1st line SCT eligible pts in EU5 are D-VRd (n=56), VRd (n=69) and D-VTd (n=136) with 41% and 39% of high-risk pts. In the US, the most frequent regimens used in this subset were D-VRd (n=17) and VRd (n=33) with 35% and 39% of pts belonging to the high-risk group. For 1st line SCT ineligible pts in EU5, 40% of patients were high risk, with the most common regimen being VRd (n=67). Pts with del17p were also overrepresented in this subgroup with 15% of total population receiving VRd. Other frequently used regimens were D-VMP (n=95), DRd (n=188), Rd (n=148) and VMP (n=80) but none was preferred in high-risk pts. In the US, the most frequently-used regimen in 1st line SCT ineligible population was VRd (n=73) with 27% of pts with high-risk features (vs. 17% in the overall population). For 2nd line treatment in the EU5, carfilzomib-based combinations are more frequently used in high-risk pts, particularly DKd (n=42) and KRd (n=118), both associated with 35% of pts with high-risk features. Kd was also regularly used in this subset (n=76) with 32% of high-risk pts. Despite a small number of pts (n=29), Isa-Kd triplet is more regularly used in pts with del17p (21% of all pts). In 2nd line setting in the USA, the most frequently used regimen was DKd (n=37) with 30% high-risk pts. In pts with del17p, Kd was regularly used (n=14) with 21% of pts presenting this abnormality. Among other regimens, such as DPd (n=38), Dd (n=30), DRd (n=35) and KRd (n=21), none was preferred in high-risk pts. Conclusion This real-world study reveals quite heterogeneous treatment choices in 1st and 2nd line pts with high-risk cytogenetic features with no large consensus, especially between EU5 and the US. Some trends can be identified between different pts subsets: quadruplets with D-VRd and D-VTd in EU5 and D-VRd in the US are preferred as induction treatment prior to SCT. VRd is regularly used in 1st line SCT ineligible pts in the EU5, particularly in case of del17p. Carfilzomib-based regimens are more common in 2nd line pts in both EU5 and US, especially DKd, KRd and Kd. Those are in line with the main international guidelines and expert recommendations for high-risk pts.

Clinical Characteristics, Treatment Patterns, and Outcomes of Patients with Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL) Refractory to Covalent Bruton's Tyrosine Kinase Inhibitor (BTKi) and Exposed to B-Cell Lymphoma 2 Inhibitor (BCL2i)

Introduction: CLL/SLL patients who failed BTKi and are treated with BCL2i represent a growing population with few standard-of-care treatment options after discontinuing both therapies. Patients who fail both BTKi and BCL2i have poor prognosis, with a median overall survival (OS) of 3.6 months (Lew et al., Blood Advances, 2021). However, real-world evidence for these patients is limited. This study described the characteristics, treatment patterns, and outcomes of CLL/SLL patients who were relapsed or were resistant/refractory/intolerant (R/R/R/I) to BTKi and who were exposed to BCL2i. Among patients who discontinued BCL2i, responses to the treatment immediately after BCL2i were reported. Methods: This retrospective chart review study evaluated Dana-Farber Cancer Institute patients with CLL/SLL (≥18 years old) who were R/R/R/I to BTKi and received BCL2i (in any order). Abstraction took place from 12/2021 to 07/2023. Patients were required to have records available from 6 months before to 12 months after first BTKi initiation. Patients who received non-hormonal antineoplastic therapy for other primary malignancies in the period between CLL/SLL diagnosis and receipt of their first BTKi treatment were excluded. Demographic and clinical characteristics at or before BCL2i initiation were described. Lines of treatment (LOTs) and responses to BCL2i were summarized. Time to treatment discontinuation, real-world PFS (rwPFS) and OS were estimated by Kaplan-Meier analysis. Patients were considered doubly refractory if they were R/R/R/I to BTKi and BCL2i. Overall response rate to first treatment after BTKi and BCL2i was summarized among doubly refractory patients. Results: Among 104 patients who were R/R/R/I to BTKi, 61 (58.7%) received a BCL2i. The patients exposed to both BTKi and BCL2i were observed for a median (interquartile range [IQR]) time of 2.6 (1.1,4.4) years after BCL2i initiation. 57 (93.4%) patients received BCL2i after BTKi and 4 (6.6%) received BCL2i before BTKi. BCL2i was most commonly (23 [37.7%] patients exposed to BCL2i) received in the fourth LOT and all patients received their first BCL2i after their first LOT. Median (IQR) age at BCL2i initiation was 68.4 (63.3-74.4) years. Among patients who were assessed for cytogenetic abnormalities (n=58), the most common abnormalities were del(13q) (55.2%) and del(17p) (36.2%). 36 (61.0%) patients had TP53 mutation. 45 (73.8%) patients discontinued their first BCL2i treatment. IGHV mutation was assessed for 49 patients and 8 (16.3%) had mutation rates ≥ 2%. Median (IQR) time to BCL2i discontinuation for patients receiving BCL2i was 1.5 (0.4, 3.1) years. 40 (76.9%) of the 52 patients with a known first response to BCL2i achieved clinician-assessed complete (CR) or partial response (PR) at first assessment. 25 (41.0%) patients were R/R/R/I to BCL2i at the time of abstraction. Of them, 21 (84.0%) progressed, 7 (28.0%) developed Richter transformation (RT) and 11 (44.0%) died. Primary cause of death was available for 8 (72.7%) patients and, of these, 5 (62.5%) died due to disease progression, 2 (25.0%) died due to a secondary malignancy, and 1 (12.5%) died from unspecified causes. Among doubly refractory patients, median (95% CI) rwPFS was 1.6 (0.7, 2.4) years and median OS was 3.8 (2.3, not reached) years from the initiation of the latter of BTKi and BCL2i treatment. Among doubly refractory patients, 18 (72.0%) received an additional LOT after the latter of BTKi and BCL2i. The therapies received in the first line after BTKi and BCL2i were allogeneic HSCT (4 patients), duvelisib (3 patients), oral CDK9i (2 patients), and 1 patient each with CAR-T, anti-CD20 bispecific antibody, alemtuzumab, vecabrutinib, zanubrutinib; and for patients with RT: venetoclax plus rituximab with anthracycline chemotherapy (2 patients), PI3Ki/PD-1 (1 patient), duvelisib (1 patient) ( Figure 1). Response to the additional LOT was known for 17 patients and unknown for 1 patient. Clinician-assessed CR or PR to treatment immediately after BCL2i and BTKi was achieved for 4 (23.5%) of these patients at first assessment. Conclusions: Patients with CLL/SLL who were failed by BTKi and BCL2i treatment have poor prognosis. Overall response rates to treatment immediately after BTKi and BCL2i treatment are low among doubly refractory patients. More effective treatments are needed to address the unmet therapeutic needs of CLL/SLL patients who are refractory to both BTKi and BCL2i.