Autologous Transplantation Research Articles

A Single Center Real-World Data Comparing Salvage Autologous Hematopoietic Stem-Cell Transplantation, Selinexor Combo and Elranatamab Alone Among Triple Class Refractory Myeloma Patients: Better Efficacy with Elranatamab

Introduction: A vast majority of multiple myeloma (MM) patients may experience relapse and require multiple lines of therapy. The choice of the next treatment depends on multiple factors including the response, tolerance to prior therapies, as well as access to novel treatments. Among triple-class refractory patients, in real-world settings where CAR-T therapies are not available, options are limited. Here we report a single-center experience comparing salvage autologous hematopoietic stem-cell transplantation (sAHCT), selinexor combinations, and elranatamab in this highly unmet needed group. Patients & Methods: Between January 2015 and June 2023, 50 patients at our center underwent sAHCT for treatment of refractoriness to all available drugs. Salvage AHCT is defined as being transplanted for treatment of MM after evidence of disease progression not responding to second-generation proteasome inhibitors (PI), immunomodulating agents (IMID), or antiCD38 monoclonal antibody. We compared the outcomes of these patients with RRMM patients who had exhausted their treatment options and were progressing on their last line of therapy to receive single agent Elranatamab at a step-up dosing starting with escalating to 72 mg once a week for six months and on alternate weeks thereafter. Selinexor was administered with either Bortezomib(n:8) or Pomalidomide(n:9) at a dose of 60-100 mg/week every 5-6 weeks. Response and disease progression were assessed according to the IMWG criteria. Results: Patients' characteristics and the outcomes are shown in Table. The median age of patients was similar in both groups. Patients were heavily treated with a median of 4 prior lines of therapy (1-17) and 7 out of 13 carried high-risk cytogenetics in elranatamab group. All patients were triple-class refractory. Five patients responded to DCEP bridging therapy prior to sAHCT. Selinexor (n: 11, 64.7%) and elranatamab (n:5 patients,38.5%) were administered after sAHCT. One patient underwent sAHCT due to progression under Selinexor treatment. In the sAHCT group, 68% of patients relapsed within a median of 7.4 months. Median DFS was significantly prolonged with single agent elranatamab (NR) compared to sAHCT (7.3 mos) and Selinexor-combos (7.3 mos) (p=0.4) (Figure). Adverse events on selinexor regimens included fatigue, nausea, and thrombocytopenia which were managed with Selinexor dose adjustment and supportive care. All patients received the recommended step-up priming dose elranatamab regimen, 69.2% of our patients experienced a Grade 1 cytokine release syndrome (CRS) during the first cycle. None of these patients had to stop treatment due to toxicity. Early sAHSCT mortality was not observed either. At the time of the analysis, all patients on Selinexor have progressed after a median follow-up of 14.7 months. Elranatamab patients are currently at 5 months follow-up and 7/ 13 are still on treatment. Conclusion: Upfront AHCT is a cost-effective treatment option with a decreasing efficacy in late relapses. In this RWE study, we have been able to confirm the inferiority of AHCT at late stages. As seen in our series cytogenetic profile worsens with an increase in the prior number of lines of treatment which are both highest among patients who have received elranatamab. Despite these unfavorable features, single-agent elranatamab has been able to attain the highest overall response rates, unfortunately not reflecting on PFS yet, due to short follow-up. Furthermore, two of these had progressed while on a BCMA immunotoxin Rx and have responded to elranatamab. In conclusion, even with short follow-up single-agent elranatamab is a tolerable and highly effective regimen

A Compilation of Experiences in Utilizing CAR-T Cell Therapy for Richter's Transformation

Objective:Even with Bruton tyrosine kinase inhibitors (BTKis) and BCL2 inhibitors, the prognosis for Richter's Transformation (RT) remains dismal, with a median overall survival (OS) of only 9-12 months from initial diagnosis. Although there are reports on CAR-T therapy for RT, the sample size is small and the conclusions vary greatly. Methods: We conducted a retrospective investigation of the efficacy of CAR-T cell therapy in treating RT at our center. Each participant provided their informed consent to partake in the “Phase II Clinical Trial of Sequential CAR-T Cell Therapy Targeting Different B-Cell Epitopes for Recurrent, Refractory Aggressive B-Cell Lymphoma”(Protocol number: BR-XG-CART-II, ChiCTR2100055062, Ethical Approval Number 20191225-PJ-003). Before lymphocyte collection, chemotherapy regimen without fludarabine/ Bendamustine is first used to reduce peripheral blood tumor load if peripheral blood tumor cells are higher than 10%. Patients with extramedullary tumor loads of 5cm or larger were treated with tumor reduction chemotherapy between lymphocyte collection and CART cell transfusion. The pretreatment scheme based on Bendamustine or FC scheme was adopted before CAR-T cells were infused. The efficacy and safety of CART cells were observed. Results: Between Feb 1, 2020 and Feb 28, 2023, our center administered CAR-T cell therapy to 16 patients diagnosed with RT, all of whom developed into diffuse large B-cell lymphoma. The patient population had a median age of 59 years (range: 42-69 years), consisting of 62.5% (10/16) males and 37.5% (6/16) females. The ECOG scores varied between 0 and 3. The median number of prior treatment lines was 5 (2-7). 93.8% failed previous BTKis treatment and 75% failed BCL2 inhibitor treatment; 93.8% had undergone chemotherapy (median 6 courses). 1 patient had previously failed universal CAR-T cell therapy, and another relapsed after autologous transplantation. 90% had at least one TP53 abnormality detected by either FISH or second-generation gene sequencing. Extramedullary masses were found in 87.5% (14/16) of patients, with a median maximum diameter of 42.5mm (18-144mm). Masses larger than 5cm were found in 25% (4/16) of cases, marrow involvement was noted in 62.5% (10/16), and cerebrospinal fluid was affected in 18.75% (3/16). None of the patients had central masses observed in their MRIs. During lymphocyte collection, 58.3% of patients showed positivity for peripheral blood tumor cells, with a maximum tumor cell proportion of 5.69%. The median infused CAR-T cell dose was 1.37×10 6/kg. 12 of them were injected with mouse CD19CAR-T, 2 with human CD20CART, and 2 with human CD19CART. CRS occurred in 81.3%of patients, of which, 68.8%were grade 1-2 and 12.5%were grade 3. Central CRS occurred in 6.3% (1/16) of patients. The complete response (CR) rate at the 3-month mark stood at 56.3% (9/16), with an overall response rate (ORR) of 68.8% (11/16). As of July 6, 2023, the median follow-up time was 10.6 months (4.4-33.6m), the 1-year OS was 73.4%, and the 1-year PFS was 68.8%. Median OS and PFS were not reached. One of the five patients who did not respond later underwent allogeneic hematopoietic stem cell transplantation and is still alive. The other four, despite attempts at salvage treatment including second CAR-T cell therapy, all died, with a median OS of only 5.6 months (4.4-8.9m). None of the four patients with extramedullary masses larger than 5cm achieved ORR despite tumor-reducing chemotherapy prior to CAR-T infusion. Only 1 of 3 patients with central involvement achieved CR and experienced grade 3 CRS along the way, while the other 2 did not respond to CAR-T therapy. Among all patients, only one experienced central CRS, and his cerebrospinal fluid showed no signs of tumor cells prior to the administration of CAR-T treatment. A patient who was in CR succumbed to an acute coronary event 19 months following infusion, despite remaining in CR. Conclusion: Even in the presence of TP53 gene abnormalities, resistance to BTK/BCL2 inhibitors, and unsuccessful previous chemotherapy regiments, A single CAR T cell therapy can result in CR in more than half of RT patients. Nonetheless, the prognosis remains bleak for patients presenting with large tumor masses and central nervous system involvement, despite having received chemotherapy aimed at reducing tumor size. The outlook is particularly dismal for those patients who fail to respond to CAR-T cell therapy.

Checkpoint Inhibitors and Allo-SCT in Hodgkin Lymphoma: A Matter of Time - a Study By the SFGM-TC

Introduction: Allogeneic stem cell transplantation (allo-SCT) for patients with relapsed/refractory Hodgkin lymphoma (r/R HL) after autologous transplantation is now an established option. Many patients receive Check-Point Inhibitors (CPI) as relapse treatment. Nevertheless, concerns have been previously reported on higher risk of acute graft versus host disease (aGVHD) after CPI exposure, without any control group to elucidate risk factors. Methods: We conducted a multicentric retrospective case control study on behalf of the Francophone Society for Bone Marrow Transplantation and Cell Therapy to compare outcomes after allo-SCT for patients with r/R HL who were exposed or not exposed to CPI. Results: Between 2015 and 2018, 149 patients underwent allo-SCT for r/R HL in 21 centers. CPI was used for 50 patients (n=48 Nivolumab, n=2 Pembrolizumab). We did not identify any differences regarding baseline characteristics. Reduced intensity conditioning (RIC) was commonly used (90.2%), with Peripheral Blood Stem Cells (75.7%). A majority of patients had haploidentical (44.6%), followed by siblings (28.4%), matched unrelated (24.3%) and mismatched unrelated donors (2.7%). Cumulative incidence (CI) of aGVHD grade ≥II in the whole cohort was 39.6% and 14.8% developed a severe form (grade III-IV). There were no differences between CPI (n=50) and no CPI cohorts (n=99), regarding CI of aGVHD of any grade (respectively 58% and 57.6%, p=1.00), grade ≥II (respectively 36% and 41.4%, p=0.65), severe aGVHD (grade III-IV, respectively 12% and 16.2%, p=0.67) and chronic GVHD (respectively 26% and 34.3%, p=0.24), as described in Table 1. We did not observe excess of mortality from GVHD between both groups. The time interval between the last CPI injection and allo-SCT was found to be the only significant factor associated with a higher incidence and severity of aGVHD, as depicted in Figure 1. The median time from the last CPI injection and allo-SCT was 50 days [33;103]. Specifically, within 30 days, the incidence of severe aGVHD was significantly increased at 41.7% compared to only 2.7% in the control group (p=0.002). No severe forms were observed after 60 days, but it persisted a higher risk of aGVHD grade ≥II even after 60 days of delay. Thus, a higher percentage of patients required systemic therapy for aGVHD within 120 days compared to after 120 days (45% vs 0% respectively, p=0.03). The delay of CPI treatment did not impact the CI and severity of chronic GVHD or CI of relapse after allo-SCT. Of note, post-transplant cyclophosphamide did not reduce CI of aGVHD. With a median follow-up of 34.7 months, the 2-year Overall Survival, Relapse Free Survival and GVHD free, Relapse Free Survival (GRFS) were respectively 69.9% (IC95 41.1-78.5), 67.1% (IC95 58.8-76.7) and 48.5% (IC95 40.3-58.4), without differences between CPI and no CPI cohorts. Two-year non relapse mortality was 17.4% in whole cohort, without hepatic sinusoidal obstruction syndrome nor steroid-requiring febrile syndrome in CPI cohort. Conclusion: CPI use before allo-SCT within 60 days before allo-SCT can lead to significant severe aGVHD, with persisting higher risk of aGVHD grade ≥II even after 60 days of delay. This highlights the importance of exercising caution when administering CPI injections within 60 days before allo-SCT. There is need to develop GVHD prophylaxis strategies in this population at risk. The findings from this study may help inform clinical decision-making and management of HL patients undergoing allo-SCT.

High Efficacy and Safety of Nanobody Based Anti-BCMA CAR-T Cell Therapy in Treating Patients with Relapsed or Refractory Multiple Myeloma

Introduction Refractory or relapsed (R/R) multiple myeloma (MM) is often associated with a poor prognosis following chemotherapy or even transplantation. BCMA-targeted CAR-T therapy has demonstrated notable efficacy in R/R MM. In the past, the overall response rate (ORR) was relatively low at around 60%, but in recent years, advancements in the manufacturing of BCMA-CAR-T products have led to a substantial improvement in efficacy. Here we explore the efficacy and safety of nanobody-based anti-BCMA CAR-T cell therapy in R/R MM from a clinical trial (https://clinicaltrials.gov NCT04447573). Methods Autologous peripheral blood lymphocytes were collected from patients, who subsequently underwent intravenous fludarabine (30mg/m 2/d) and cyclophosphamide (300mg/m 2/d) lymphodepletion chemotherapy from day-5 to day -3. The SL-BCMA CAR molecule, an anti-BCMA CAR-T cell product generated by Senlang Biotechnology, features a structure that includes dual nanobody VHHs targeting BCMA (dVHHs), CD8α hinge region, CD8α transmembrane domain (TMD), co-stimulatory domain (4-1BB), and CD3 zeta domain (CD3ζ). Among them, dVHHs consist of two different VHHs connected by short peptides. The CD8α hinge region provides an effective spatial architecture for the binding of dVHHs and BCMA protein. The first signal of CAR-T cell activation is completed along with the intracellular CD3ζ domain. The 4-1BB intracellular co-stimulatory domain provides co-stimulatory signals for the activation of CAR-T cells. Under the dual signal stimulation, CAR-T cells are activated and expanded. After the BCMA CAR-T cells infusion on day 0, patients underwent evaluations, including immunoglobulin fixed electrophoresis, free light chains in blood and urine, bone marrow penetration, and whole-body PET CT to evaluate the efficacy at the first month, second and third month, and every three months thereafter. Results From April 2021 to May 2023, 21 R/R MM patients in our hospital were treated with SL-BCMA CAR-T, including 10 males and 11 females. The median age is 57 years (30-73 years). Among them, there were 2 cases with Plasma cell leukemia, 10 had extramedullary multiple lesions, and 2 had paralysis caused by central nervous system infiltration. Pre-CAR-T, 11 patients had a prior transplant history including 10 who relapsed after autologous transplantation and 1 who relapsed after allogeneic transplantation. One patient had a rare type of anaplastic Plasma cell tumor. Seven patients presented high-risk factors characterized by FISH abnormalities such as t (4; 14) (p16; q32), t (14; 16) (q32; q23), and 3 had TP53 mutations. The median BCMA expression rate among 19 patients was 53.3% (range: 18.5% -100%), while the remaining 2 patients displayed non-BCMA expression. The median BCMA CAR-T cell dose was 1*10 6/Kg (0.3-2*10 6/Kg). One month following BCMA-CAR-T cell infusion, the ORR was 95%(20/21), and the CR rate was 38% (8/21). The patient who initially showed no response achieved a partial response following a second infusion of BCMA-CAR-T cells. One died at about 2.5 months due to lung infection. Evaluations conducted at the three-month mark showed an ORR of 95% (19/20) and a CR rate of 80% (16/20). One patient relapsed at the second month and underwent salvage allogeneic hematopoietic stem cell transplantation. For the long follow-up data, the median duration of remission was 11 months. Of the 7 deaths, 2 were attributed to infection during disease control, and 5 were due to disease progression. (Figure 1) In terms of side effects, 6 patients developed grade 2 cytokine release syndrome (CRS), and only 1 patient developed grade 3 CRS. Only one patient had grade 1 neurotoxicity. Conclusions The clinical trial demonstrated that BCMA CAR-T therapy, composed of dual nanobody VHHs targeting BCMA (dVHHs), exhibits a high ORR with a manageable safety profile in treating R/R MM patients. This extends even to high-risk patients, such as those with extramedullary lesions, cytogenetics high-risk groups, and patients with plasma cell leukemia or anaplastic plasma cell tumor.

Longitudinal Screening of Mutant Hematopoietic Progenitor Cells (HPC) in Multiple Myeloma (MM) and Its Association with Secondary Primary Malignancies (SPM)

Background: The incidence of SPM in transplant eligible MM patients (pts) receiving lenalidomide maintenance is ≥ 12% and is associated with inferior overall survival (OS). Recent evidence suggests that while clonal hematopoiesis does not increase the risk of SPM, specific TP53 mutant HPC may expand under lenalidomide treatment and give rise to therapy related myeloid neoplasms and acute lymphoblastic leukemia. Genetic screening may facilitate personalized treatment to minimize the risk of SPM. However, there are no longitudinal studies in purified HPC to inform on the evolution of specific gene mutations and its association with clinical outcomes. Aim: Analyze the mutational landscape of HPC at diagnosis and throughout lenalidomide based regimens. Methods: This study included 335 pts: 43 with high risk smoldering MM, 223 transplant eligible and 69 ineligible active MM respectively enrolled in the CESAR, GEM2012MENOS/GEM2014MAIN and CLARIDEX clinical trials. Of the 335 pts analyzed at diagnosis, 60 were further investigated after induction, 30 at day 100 after autologous transplant (ASCT) and 47 during maintenance. Two or more studies were available throughout treatment in 36 pts. Fluorescence activated cell sorting of CD34+ HPC was performed in a total of 500 bone marrow aspirates. DNA was analyzed with a panel of 55 genes recurrently mutated in myeloid neoplasms. Sequencing depth was >1000x in 95% of nucleotides. Criteria to filter out included synonymous, intronic, invalid-transcript, 5'UTR, panel error and single nucleotide polymorphisms. The criteria to filter in was a AMP/ACMG classification of uncertain significance, likely pathogenic or pathogenic. Only the latter two were included in downstream analysis. Results: HPC from 184 of the 335 (55%) pts were mutated. The frequency in high-risk smoldering MM, transplant eligible and ineligible active MM was 46%, 26% and 35%, respectively. The genes more frequently mutated were DNMT3A (n=94, 52%), TP53 (n=29, 16%) and TET2 (n=28, 15%). The median variant allele frequency was 4.9, 7.5 and 7.0, respectively. In a pt-paired analysis between diagnosis and induction, 8 mutations were present in both time points, 25 became undetectable and 22 were acquired during treatment. The latter (eg, PPM1D and SF3B1) were observed in 14 of the 60 (23%) pts. In the 30 pts with paired samples at diagnosis and at day 100 after ASCT, 4 mutations were present in both time points, 48 became undetectable and only 3 were acquired during treatment ( ATRX, MPL and SAMDL9). Thus, the frequency of mutant HPC was higher at diagnosis vs ASCT (23% vs 5%, P <.001). In a pt-paired analysis between diagnosis and maintenance, 13 mutations were present in both time points, 12 became undetectable and 30 were acquired during treatment. The latter (eg, PPM1D and SF3B1) were observed in 24 of the 47 (51%) pts screened at both time points, and after a median of 5 years since diagnosis. With a median follow-up of 6 years, 17 of the 335 (5%) pts developed SPM. Mutant HPC were detected in 13 of the 17 pts. Accordingly, presence of mutant HPC was associated with a 2-fold increased risk of SPM (OR: 2.3; P = .03). Of the 13 pts, 3 showed mutations at diagnosis and in 8 these emerged during maintenance. The only case developing a myeloid neoplasm had a TP53 mutation present during maintenance that was undetectable at diagnosis. Pts with mutant vs non-mutated HPC at diagnosis showed similar OS (6y rates of 86% and 81%, respectively; P =.46). Similarly, there were no differences in OS of pts with emerging mutations vs those without mutant HPC after treatment (6y rates of 85% and 83%, respectively; P =.65). Specific mutations in DNMT3A, TP53 and TET2 and were not associated with inferior OS. Conclusions: To our knowledge this is the first study analyzing the mutational landscape of purified HPC throughout lenalidomide based regimens in high risk smoldering MM as well as transplant eligible and ineligible active MM. Deep sequencing of CD34+ HPC uncovered that the frequency of mutations is similar between precursor and malignant disease, and that TP53 is amongst the top mutated genes. There was considerable volatility with presence of both transient and emerging mutations throughout treatment. Importantly, the detection of mutant HPC was associated with increased risk of SPM without differences in survival. Thus, this study supports the longitudinal screening of HPC for the identification of patients at risk of developing SPM.

Ki-67 Expression of 50% Is the Optimal Cut-Off to Predict Survival Outcomes in Mantle Cell Lymphoma (MCL): A Pooled Analysis from CALGB 50403 (Alliance) and MCL Real-World Study Cohort

Introduction The Ki-67 index has been previously shown to be prognostic, wherein the cut-off of 30% was associated with inferior survival outcomes (Determann O et al, Blood 2008) in newly diagnosed MCL patients (pts). However, this cut-off determination was made in pts treated with CHOP/R-CHOP as the first-line treatment, controlled only for MIPI, and predates the advent of novel agents. Short diagnosis to treatment interval (DTI ≤ 14 days) was recently shown to be prognostic in newly diagnosed MCL but its association with Ki-67 is unknown. We sought to determine the optimal Ki-67 cut-off in MCL and its prognostic relevance in the modern era. Methods This is a pooled analysis of 2 large datasets, one prospective (CALGB 50403) and one retrospective (MCL real world study [MCL-RWS]). CALGB is now part of the Alliance for Clinical Trials in Oncology. CALGB 50403 is a phase II randomized study wherein newly diagnosed MCL pts received intensive induction chemoimmunotherapy (IIC) followed by autologous transplant, and posttransplant rituximab. The MCL-RWS included adult pts (≥18 years [yrs]) with MCL treated from 2000 to 2017 at 12 participating US sites. Pts from sites in the MCL-RWS that enrolled on CALGB 50403 were excluded. Ki-67 was scored by central review in 10% increments in the CALGB 50403 and per institutional standard in the MCL-RWS. We assessed Ki-67 as a continuous variable and used a restricted quadratic spline fit to find an optimal cut-off. We looked at the associations between Ki-67 and other known/ established MCL prognostic markers including MIPI and DTI. The outcome parameters were PFS and OS. Time-to-event endpoints were evaluated by Kaplan-Meier and Cox proportional hazard methods. Results Among the 793 pts (n=666, MCL-RWS and n=127, CALGB 50403) in the pooled analysis, Ki-67 was available in 385 pts (311 from MCL-RWS and 74 from CALGB 50403). The median OS (mOS) and PFS (mPFS) in the entire cohort (n=793) was 11.8 years and 4.7 years, respectively. The two groups (gps), those with and without Ki-67 data, were well balanced including MIPI and DTI. The median age was 62 yrs (range, 32-88), 81% males, 94% with ECOG performance status (PS) 0-1 and 84% with stage 4. We found a Ki-67 cut-off of 50% to be optimal as the relative hazard of death rises after 50%. Pts in the Ki-67 >50% gp had significantly higher proportion with short DTI (36% vs 17%, p<0.001), ECOG PS ≥2 (12% vs 5%, p=0.02), elevated LDH (58% vs 39%, p=0.005), and MIPI ≥6.2 (38% vs 20%, p=0.007) compared to Ki-67 of ≤50%. Ki-67 >50% was associated with significantly inferior PFS with a hazard ratio (HR) of 2.10 (95%CI 1.50-2.92) compared to Ki-67 ≤50% with a mPFS of 2.1 vs 5.3 yrs, respectively, regardless of the age (young [≤65 yrs], 2.6 vs 5.3 yrs or old [>65 yrs], 1.1 vs 5.4 yrs) or receipt of IIC (2.2 vs 5.9 yrs). Figure 1 shows the statistically significant difference in PFS between the Ki-67 gps of ≤10%, >10% to <30%, ≥30 to ≤50%, and >50%. Ki-67 >50% remained prognostic for PFS in multivariable analysis (MVA) after adjusting for significant variables in univariable analysis (UVA) including short DTI, ECOG PS ≥2, stage 4, elevated LDH, and MIPI ≥6.2 with adjusted HR (aHR) 2.19, 95%CI 1.38-3.48, p <0.001. Ki-67 >50% was associated with significantly inferior OS with a HR of 2.10 (95%CI 1.33-3.32) compared to Ki-67 ≤50% with a mOS of 9.4 yrs vs not reached (NR), respectively, regardless of the age or receipt of IIC. Figure 2 shows the statistically significant difference in OS between the Ki-67 gps of ≤10%, >10% to <30%, ≥30 to ≤50%, and >50%. Ki-67 >50% was not prognostic for OS in MVA after adjusting for significant variables in the UVA (MIPI and sex), aHR 1.79, 95% CI 0.92-3.49, p=0.08. Similar findings were seen in multivariable analysis with Ki-67 >30%, which showed no prognostic significance (aHR 1.46, 95%CI 0.82-2.58, p=0.19). Because of disparate datasets, we performed sensitivity analysis looking at the prognostic relevance of in individual datasets (CALGB 50403 and MCL-RWS) and found Ki67 >50% was prognostic for PFS and OS in both of the datasets consistent with the primary analysis. Conclusions This study evaluating the optimal Ki-67 cut off for pts with newly diagnosed MCL in the modern era found that Ki-67 > 50% was prognostic for PFS but not OS in MVA. A potential reason for the lack of prognostic relevance for OS in this more recent dataset is the availability of effective options at relapse. We also found that short DTI was associated with high Ki-67 gp which is a novel finding.

The UK Impact Transplant Trials Network: An Effective National Strategy to Accelerate the Delivery of Randomized Trials in Stem Cell Transplantation

Introduction: Stem cell transplantation (SCT) is an important curative modality in patients with blood cancer whose outcome with chemotherapy is predicted to be poor and is an increasingly important therapy in non-malignant disease. However, even in 2023, 50% of patients are still destined to die after either allogeneic or autologous transplantation, either of relapsed disease or treatment toxicity. In response the transplant community continue to develop innovative strategies designed to improve patient outcome. However, despite the fact that the adoption of new therapies in haemato-oncology is, almost without exception, based on evidence generated by randomized studies fewer than 5% of transplant patients are currently recruited to prospective practice informing trials. Thus, much current transplant practice is based on retrospective registry analyses whose results can often be misleading. There is therefore an urgent need for innovative trial models with the ability to accelerate transplant trial delivery if patient outcomes after SCT are to be improved. Methodology: We reasoned that limited trials capacity at busy centres coupled with the absence of a fit-for-purpose clinical trials network represented potentially tractable barriers to transplant trial recruitment. In 2018 a $5 million grant was secured from UK blood cancer charities in order to directly fund the salaries of research nurses within the IMPACT network covering 11 major UK transplant centres and a linked clinical trials hub. Critically, up-front investment into research nurses at major transplant centres created a catchment region in excess of 20 million. The pre-stated aim of the IMPACT pilot was to recruit 400 patients to 7 new transplant trials over a 4 year period. Results Opened in 2018 the IMPACT network has now randomized 1344 patients to 7 prospective transplant trials over a 5 year period. Trials delivered include COSI, a randomized trial examining the benefit of the addition of Thiotepa to a Fludarabine/Busulphan based conditioning regimen in patients allografted for acute myeloid leukemia (AML) (n=333) and AMADEUS a randomized comparison of the benefit of post-transplant CC486 maintenance (n-326). In conjunction with recruitment to the Pro-DLI trial- a randomized study of prophylactic DLI in patients allografted for high risk AML (n=150)- the IMPACT initiative has resulted in more than 900 patients being recruited to practice informing AML transplant trials over a 5 year period. Importantly, AMADEUS has been designed and delivered in order to generate registration enabling data. Additional trials delivered by the IMPACT network include ALL-RIC the first randomized comparison of reduced intensity conditioning regimens in acute lymphoblastic leukemia (n=102, now in follow-up) and the ongoing MoTD trial a randomized comparison of post-transplant cyclophosphamide GVHD prophylaxis (n=139 to date). Sample return for bolt-on scientific studies has been in excess of 85% allowing prospective analysis of the prognostic significance of pre and post-transplant MRD, molecular determinants of transplant outcome and the biology of disease relapse in patients allografted for AML and ALL. Of note the IMPACT research nurse network demonstrated impressive resilience during the COVID-19 pandemic permitting continued trial delivery despite faltering recruitment to other cancer trials. Conclusions: The funding of a national transplant trials network has transformed recruitment to prospective randomized transplant trials in the UK. The success of the IMPACT pilot, which-out-performed its recruitment metrics by 300%, confirms the importance of innovative trial delivery models in accelerating recruitment to practice informing transplant studies and is a scalable model internationally. At the same time, IMPACT has proved a highly effective mechanism to generate linked translational data with the ability to inform future trial design. Building on similar models in Europe, such as LYSARC, the IMPACT network is now funded by a not-for-profit trials delivery vehicle Accelerating Clinical Trials Ltd (www.act4patients.com) creating a financially sustainable model within the UK for the delivery of a mixed portfolio of industry sponsored and investigator initiated transplant and cell therapy trials.

Venous Thromboembolism in Hematopoietic Stem Cell Transplantation

Background: Venous thromboembolism (VTE) is an underappreciated complication seen amongst allogeneic and autologous hematopoietic stem cell transplant (HSCT) patients and a major cause of morbidity and mortality. Despite these challenges, VTE in HSCT remains understudied, with a paucity of established guidelines on thrombosis surveillance, prevention, and treatment. Balancing risk of bleeding and thrombosis is particularly challenging as HSCT patients are concurrently pancytopenic and coagulopathic. We aimed to describe the incidence, predictors, and adverse events of VTE amongst patients at 90 days post-HSCT. Methods: We conducted a retrospective cohort study of adult patients, age >18-years-old, who underwent HSCT for a hematological malignancy between January 1, 2011 and December 31, 2021 at a tertiary care centre in Canada. Patients were followed from transplant until Day 90 post-transplant, or death. Baseline, transplant, laboratory, and cancer characteristics were analyzed. Results: Four Hundred and Seventy Six (476) HSCT patients were included (age range 18 - 74), 285 (59.9%) of our patients were male, and 191 (40.1%) were female. Three Hundred and Seventeen (317) (66.6%) patients underwent autologous transplant, and 159 (33.4%) patients underwent allogeneic transplant ( Table 1). Forty Seven (47) patients (9.8%) suffered from VTE within 90 days post-HSCT; 74.5% were catheter related. 9.43% of allogeneic, versus 10.09% autologous patients were diagnosed with VTE (p=0.820). 11.9% of allogeneic, versus 4.1% of autologous patients (p=0.001) suffered from bleed unrelated to anticoagulation. There was significant association of VTE post-HSCT with history of unprovoked DVT (p = 0.026), previous treatment with steroids (p = 0.032), infectious complications (including bacteremia (p = 0.025), and skin and soft tissue infection (p < 0.001)), use of peripherally-inserted central catheters (PICCs (p <0.001), left-sided CVC placement (p = 0.007), second central venous line insertion (due to complications from the first) (p < 0.001), and blocked or malfunctioning central venous catheter (p = 0.003). There was no significant association of VTE post-HSCT with transplant graft (autologous versus allogeneic), underlying hematological malignancy, age, BMI, or sex. Mortality rate at 90 days amongst VTE patients was 14.89%, versus 3.27% in non-VTE patients (p < 0.001) ( Figure 1). Conclusion: The majority of VTE post-HSCT were catheter-related and were more frequently associated with use of PICCs. VTE post-HSCT was associated with higher mortality. VTE prophylaxis or active surveillance could be considered in patients with the above-mentioned risk factors balancing the risk of bleeding, particularly in allogeneic stem cell transplant patients, and those who are concurrently thrombocytopenic.

Comparative Transcriptome Analyses in Mantle Cell Lymphoma (MCL): Evidence of E2F1 As a Major Target in Aggressive Blastoid MCL Model

Background Mantle cell lymphoma (MCL) is a highly aggressive B-cell lymphoma characterized by the translocation t(11;14)(q13;q32) which triggers the dysregulation of the cyclin D1 by placing its coding gene CC1ND1 under the control of an immunoglobulin promoter. One of the major consequences of this molecular event is the disturbance of the cyclin D/Rb pathway leading to Rb inactivation and activation the elongation factor E2F1 mainly implicated in cell cycle progression. The mainstay of MCL therapies remains the chemo-immunotherapy followed by autologous transplantation but recently several novel therapies have been developed such as BTK inhibitors, Venetoclax, CDK4/6 inhibitors and more recently CAR-T therapies. However, patients with aggressive forms of MCL exhibit low response rates, requiring the identification of novel therapeutic targets. Materials and Methods We have previously generated an MCL cell line (UPN-1) from a patient with a blastoid variant of MCL presenting unique morphological and cytogenetics characteristics (M'kacher et al, Oncogene 2003). This cell line has been shown to harbor a TP53 mutation and a highly increased sensitivity to radiation despite the absence of functional p53. The molecular basis of this phenomenon has not been explored. In this work, we further characterized UPN-1 cell line using the Clarium S human microarray which has been compared to the gene expression profile of other existing MCL cell lines (GRANTA-519, JEKO-1, JVM-2, MAVEK-1, MINO, REC-1, SP-49, SP-53, Z-138). After mathematical correction, a supervised analysis was performed between triplicate samples of UPN-1 and a group constituted with all other MCL cell lines. We have then set up in vitro assays to determine the effect of a direct E2F1 inhibitor on the proliferative potential of UPN-1. Results The comparative transcriptome analyses revealed a list of 47 genes specifically upregulated in UPN-1. Unsupervised classification allowed to discriminate UPN-1 samples from other MCL cell lines based on the expression of these 47 genes. These data suggested a specific expression profile of UPN-1 as compared to other cell lines. Among the upregulated genes, E2F1 elongation factor was found to be highly upregulated in UPN-1 as compared to other MCL cell lines along with positive enrichment of E2F targets which are mainly implicated in cell cycle progression (Figure 1). Interestingly, UPN-1 has a low level of BCL-2 as compared to other MCL lines that could explain its radio sensitivity. However, other signaling pathways involved in the inhibition of apoptosis were found to be present in UPN-1 by geneset enrichment analysis. The expression of CDKN1A (p21), major cell cycle regulator and known as a marker of aggressive MCL, was found to be low in UPN-1. A repression of immune response pathway such as NFKB with low expression of NFKBIA was identified. Finally, the expression of PIK3CD which encodes for a therapeutic target in MCL (such as PI3KDelta inhibitor Idelalisib) was also significantly repressed in UPN-1 as compared to nine other MCL cell lines. To evaluate the effect of the direct inhibition of E2F1, we treated UPN-1 cells with a targeted E2F1 inhibitor 5‘-Deoxy-5‘-(methylthio)adenosine (MTA) which is a protein methylation inhibitor. MTT assays revealed a 50% reduction of proliferation at + 4 hours in comparison to the vehicle-treated conditions (P<0.0001).Annexin assays showed an increase in early apoptosis (36.6 %) at + 8 hours with subsequent rise in late apoptotic cells (64.5 %) observed after 24 hours of treatment. Interestingly, qRT-PCR analyses of MTA-treated cells exhibited a decrease in the expression of downstream factors associated with E2F1, such as RAD51, BRCA1, CDK2, CCNB2, RANBP1. Conclusions We report here for the first time the comparative transcriptome analysis of the unique aggressive blastoid MCL line UPN-1 as compared to other MCL lines described. This cell line exhibited a major upregulation of E2F1 expression and a down regulation of the cell cycle inhibitor CDKN1A(p21). The potential effects of the direct inhibition of E2F1 using the targeted inhibitor MTA demonstrated a reduction in cell proliferation and induction of apoptosis, suggesting the possibility of associating clinically acceptable E2F1 inhibition strategies to other current therapies.

Clonal Derivation and Dynamics in Rhesus Macaques Following Hematopoietic Stem Cell Transplantation and the Impact of Clonal Hematopoiesis

Microglia (MG) are the resident macrophages of the central nervous system (CNS). Under steady-state conditions, MG play essential roles in immune surveillance; phagocytosis and processing of pathogens, dying cells and protein aggregates; and synaptic pruning to maintain neuronal health. MG dysfunction has been linked to various CNS disorders, including neurodegenerative disorders such as Alzheimer's disease, with multiple pathways implicated, including increased and prolonged activation with excessive release of pro-inflammatory mediators. Lineage tracing studies in mice have demonstrated that yolk sac macrophages form the CNS MG compartment during development, with little ongoing replacement from circulating monocyte/macrophages at steady state or even following hematopoietic stem/progenitor cell (HSPC) transplantation. However, improvements in disease outcomes in human patients with CNS disorders such as adrenoleukodystrophy and metachromatic leukodystrophy following HSPC gene therapies have suggested that adult HSPC-derived cells can contribute to MG function. Recently, Bouzid et al reported that individuals with somatic HPSC mutations in hematopoietic expansion driver genes (clonal hematopoiesis/CH) had a significantly lower risk of Alzheimer's disease (AD). The same study utilized nuclear chromatin profiling of a small set of postmortem brain samples to suggest substantial contribution of CH-derived HSPC to the MG compartment. The authors suggested that enhanced function of CH-derived MG enables them to better clear AD plaques. To more directly investigate the replacement and clonal source of adult CNS resident MG/myeloid cells by HSPC-derived cells and to and assess the impact of CH mutations on MG replacement, we utilized clinically-relevant rhesus macaque (RM) models. Fresh MG and other tissue-resident myeloid cells were purified from the brains of RM that had undergone autologous transplantation 2- 9 years previously with HSPCs transduced with a barcoded lentiviral vector expressing GFP following ablative total body irradiation (TBI, n=6) (Koelle et al, Blood, 2017) or busulfan (n=1, vector without GFP)(Abraham et al, MTMCD, 2023); or HSPCs engineered to carry TET2 mutations using CRISPR/Cas9 (n=2)(Shin et al, Blood, 2022). In addition, we studied an aged RM with natural CH ( RUNX1 mutation) in order to investigate MG replacement in the absence of conditioning and transplantation. We optimized RM MG (CD45+CD11b+CX3CR1+) and CNS myeloid cell (CD45+CD11B+CX3CR1-) purification. To ensure separation of bona fide tissue-resident CNS cells away from perivascular cells or contaminating blood, we incorporated CD45-specific antibody serial intravascular staining (SIVS) (Mortlock et al., 2022) and sorted SIVS- parenchymal MG, SIVS- perivascular MG, and SIVS+ myeloid cells. In all 6 TBI-conditioned lentiviral-barcoded animals, at most 2% of tissue-resident SIVS- MG cells were GFP+ (Fig 1A), with a mean ratio of <0.01 compared to the level of GFP+ circulating blood monocytes in each animal (Fig 1B). Barcode analyses demonstrated similar clonal derivation of GFP+ MG cells to peripheral blood (PB) monocytes, representing output from stable long-term multipotent HSPC clones. A higher MG repopulation level was found in the busulfan-conditioned animal by vector copy number. MG replacement with CH-derived cells was no higher absolutely or relative to blood monocytes in the two engineered TET2-CH animals nor in the aged animal with natural CH (Fig 1B). These results demonstrate only low-level replacement of MG from HSPCs even many years following ablative conditioning and autologous transplantation, and no evidence for enhanced repopulation in the setting of engineered or natural clonal hematopoiesis. The clonal ontogeny of the HSPC-derived MG cells matched that of blood myeloid cells. Further characterization of MG derived from transplanted HSPCs versus control MG is ongoing, as is functional characterization of CH versus unmutated macrophages, asking whether mutated cells are hyper-functional. Our clinically-relevant macaque model provides insights into MG ontogeny, and information relevant to improving CNS-directed HSPC gene therapies, as well as information relevant to interpreting a potential protective impact of CH on human AD.

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.

Pregnancy in Patents with CLL Systematic Review

Introduction: Chronic Lymphocytic Leukemia (CLL) is a hematologic malignancy characterized by the clonal expansion of non-functional, mature-appearing lymphocytes in the bone marrow, peripheral blood, and lymphoid tissues. While cases of CLL during pregnancy are rare,it is associated with many complications. It was reported that women with CLL are more susceptible to infections due to a weakened immune system; possibly leading to more complications. There is also increased risk of thrombocytopenia, which can increase the risk of bleeding during pregnancy and childbirth. This review aimed at identifying literature available on the complications in CLL and pregnancy as well as the data available on the potential therapeutic strategies. Methods: A scoping review of case reports that discuss pregnant patients who were diagnosed with CLL were isolated. The effects of the disease on pregnancy outcomes regarding both mother and fetus were identified. Animal studies, reviews or non-original articles, and non-English articles were excluded from our study. FDA labels of medications in CLL were reviewed for data on pregnancy and animal outcomes. Information on those medications in pregnant patients were also identified where available. Results: The search strategy across four databases yielded 448 articles. After eligibility assessment, 14 articles were included in the review. Cases were subdivided according to timing of pregnancy relative to CLL diagnosis (diagnosed before pregnancy or during pregnancy at early or late gestational periods). The pre-pregnancy reports were further subclassified based on the presence or absence of infection during pregnancy. None of the cases reported required immediate initiation of CLL therapy and only one case reported mortality post-delivery. This occurred in a patient with Richter transformation and no prior CLL treatments. There were no reported fetal malformations or severe adverse outcomes related to the infants in any of the reported pregnancies ( Figure 2). The included studies provided insights into various aspects of CLL during pregnancy, including patient demographics, diagnosis timing and methods, acquired infections, changes in white blood cell count, treatment approaches, pregnancy outcomes, and complications for both mother and fetus. From the marketed pharmacological alternatives for CLL, most were not studied in pregnant humans with CLL ( Figure 1). However, venetoclax and rituximab have some data in pregnant patients with non-CLL indications. A case reported a pregnant refractory AML patient who received venetoclax with high dose cytarabine and mitoxantrone at 24 weeks of gestation. Bone marrow at 27 weeks showed complete remission and labor was induced at 28 weeks + 5 days after corticosteroid-induced lung maturation. The infant had hyperbilirubinemia, transient B-cell depletion and required ventilation. The baby recovered from all complications, although possible long-term effects are still unclear. The mother underwent allogeneic hematopoietic stem cell transplant. In a 30-year-old female (pregnant at 28 weeks) with primary CNS lymphoma, weekly rituximab was given for 4 weeks with dexamethasone. After delivery through C-section at 31 weeks, the patient started definitive treatment with chemotherapy and autologous transplant. The infant required brief mechanical ventilation and had transient B-cell depletion at delivery until 4 months post-delivery. The baby required a course of post-exposure acyclovir despite not developing an infection. Both mother and baby survived with good outcomes at last follow-up (4 years post-delivery) Conclusion: Despite the rarity of CLL occurrence during pregnancy, there is evident need of further studies and management guidelines in this population. This review provides insights into the possible pregnancy-related concerns in women with CLL at different disease stages. While watchful waiting is generally recommended due to CLL's slow progression, individual evaluation is crucial. If treatment is necessary, delaying therapy until the second or third trimesters may help mitigate the risk of fetal malformations. The increased susceptibility to infections resulting from the combined immunosuppressive effects of CLL and pregnancy should be carefully considered

Fluorescent in Situ Hybridization Analysis in Multiple Myeloma: Enhancing Risk Stratification, Autologous Transplant Utilization and Treatment Decisions in Limited-Resource Settings

Introduction: Multiple myeloma (MM) is a heterogeneous and incurable disease with a high risk of relapse. Recent advancements in MM treatment, such as proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs), and monoclonal antibodies, have improved outcomes. Risk stratification plays a crucial role in prognosis, with cytogenetic abnormalities being an important predictor. However, conventional karyotyping is limited in its sensitivity, while interphase Fluorescent In Situ Hybridization (FISH) has emerged as a powerful prognostic marker. In lower- and middle-income countries (LMICs), where MM management faces challenges, identifying high-risk patients through FISH can guide treatment decisions and improve outcomes, even in the absence of novel drugs like Daratumumab. Methods: We conducted a retrospective study on newly diagnosed MM (NDMM) patients from January 2016 to December 2022 in two South Indian centres. Patients receiving at least 16 weeks of induction chemotherapy ± autologous stem cell transplant (ASCT) were included. The cohort was divided into two groups: those with FISH results evaluable (FRE group) and those with FISH results unavailable (FRU group). FISH analysis used 5 probes (Del13q14.3, TP53/ CEN 17, IgH (14q32.3)/ FGFR3 (4p16), IgH (14q32.3)/CCND1 (11q13), IgH (14q32.3)/MAF (16q23)) till March 2020 and 7 probes (XL CDKN2C/CKS1B, XL t(4;14) FGFR3/IGH DF, XL 5p15/9q22/15q22 Hyperdiploidy, XL t(11;14) MYEOV/IGH, XL IGH BA, XL t(14;16) IGH/MAF DF, XL TP53/17cen) from April 2020. Data collected included demographics, International Staging System (ISS), mSMART 3.0-based FISH risk stratification, induction regimen, ASCT, maintenance, relapse and response. Survival analyses employed Kaplan-Meier (KM) and log-rank tests. IBM SPSS Version 26 Software was used for analysis. Results: Of the 427 screened NDMM patients, 333 were included: 192 (57.7%) in FRE and 141(42.3%) in FRU group. Baseline characteristics were comparable, except for hypercalcemia being significantly higher in FRE (p-0.015). In FRE, 128(66.67%) had standard risk, and 64 (33.33%) had high-risk MM. VRd induction was more frequently used in FRE (p-<0.001) with no significant difference in induction response. A higher percentage of FRE patients underwent ASCT (22.9% vs. 9.93%, p<0.002), achieving more complete responses post-transplant (p<0.001). FRE group also showed an increased use of doublet maintenance (p-0.014). No significant difference observed in the mortality (p-0.069). ASCT correlated with better median PFS (64 Vs. 37 months, p-0.013). Conclusions: In this resource-limited setting, the availability of FISH results seemed to have an impact on MM patient management and outcomes. FRE patients received more aggressive induction therapy, resulting in better response rates and increased ASCT utilization. Additionally, dual-agent maintenance was preferred for high-risk patients in FRE. However, it is essential to acknowledge that this was a retrospective analysis, and other factors may have influenced the outcomes, even though both cohorts were mostly matched. Notably, none of the patients had received Daratumumab as induction therapy, suggesting that FISH availability in LMICs may positively impact patient outcomes even in the absence of access to novel drugs. Further validation through multicenter prospective investigations is warranted to strengthen these findings and explore the broader implications of incorporating FISH into risk stratification strategies. By utilizing FISH, LMICs can enhance MM management and form tailored treatment strategies, thereby improving care for NDMM patients.

Eliminating Racial Disparities Among Transplant Patients in Multiple Myeloma after Referral to a Tertiary Center

Introduction: Autologous stem-cell transplantation (ASCT) remains an integral part of therapy for many newly diagnosed and relapsed multiple myeloma (MM) patients. Most tertiary centers rely on age, ECOG status, and multi-organ function evaluation to determine eligibility for ASCT. African Americans (AA) have a higher incidence of monoclonal gammopathy of undetermined significance (MGUS), higher incidence of MM and higher mortality rates than their Caucasian counterparts, mainly due to lower access to care. Furthermore, AA patients are also underrepresented in clinical trials. Studies have shown AA patients have similar to improved progression-free survival (PFS) and overall survival (OS) compared to Caucasian patients when similar therapies are offered to both groups; however, lower rates of transplantation are reported among AA patients. This is likely multifactorial in origin, with varying risk factors, biological influences, and social hindrances leading to racial disparity. We sought to examine the differences in rates of ASCT among African Americans vs Caucasian patients. Methods: We conducted a retrospective chart review of all patients with myeloma referred to our center between 2018 and 2022. Information regarding demographics, referral information, insurance and transplant status obtained for all patients referred and/or transplanted at our center were obtained from this chart review. The diagnosis date was obtained from referral records if they were referred from an outside institution. All patients received therapy at the discretion of treating physicians. Statistics are descriptive. Results: 206 AA patients were referred to our center for transplant evaluation, of which 138 underwent autologous transplantation (67%). Additionally, 141 Caucasian patients were referred to us for transplant evaluation, 98 of which underwent ASCT (69%). The transplant rates were similar across both genders among AA patients, with female AA patients accounting for 49% of all AA transplants. Among Caucasian patients, female patients accounted for 37% of all Caucasian transplants. The median referral delay time was 104 days among AA patients and 85 days among Caucasian patients. The median time from the date of referral to transplant was 128 days for AA patients and 124 days for Caucasian patients. The reasons for non-transplant varied between the two races. For African Americans, the most common reason was medical contraindication followed by patient disinterest in contrast to Caucasian patients, which was patient disinterest followed by medical contraindication. Conclusion: Once referred to a tertiary center, we observed no racial disparities among transplants in AA and Caucasian patients. While the median time from the date of referral to the date of transplant was similar across both groups, we noted an increased referral delay among AA patients.

Artificial Intelligence Enabled ECG Interpretation Informs Outcomes after Autologous Transplantation for Multiple Myeloma

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.

Autologous MPO Knock-out Hematopoietic Stem and Progenitor Cells for Pulmonary Arterial Hypertension

Pulmonary Arterial Hypertension (PAH) is a progressive condition for which there is no cure. Even with substantial pharmacologic advances in the modern treatment era, existing treatments provide only symptomatic relief and survival remains unacceptably poor. Patients who fail to respond to medications usually have the worst prognosis and patients with persistently elevated pulmonary pressure and right heart failure usually die within 5 years. PAH is a severe complication of Systemic sclerosis (SSc) affecting approximately 8%-12% of patients. SSc affects 13.5-44.3 per 100,000 individuals and is complex and diverse, with limited treatment options. SSc-associated PAH is the second largest group of patients with PAH. Once diagnosed, it becomes the leading cause of mortality among this patient population, with a 50% mortality rate within 3 years of PAH diagnosis. Inflammation and endothelial injury being the main components of the syndrome, investigation regarding the underlying mechanisms of this immune response may lead to the development of a new efficient therapy. There is extensive evidence for a pathogenic role for neutrophil myeloperoxidase (MPO) in PAH disease. PAH patients with higher levels of MPO have a poorer outcome. Studies in murine models of PAH demonstrate significant disease amelioration by elimination of neutrophil MPO by hematopoietic stem cell (HSC) transplantation with HSC lacking MPO from germline MPO gene knock-out. We developed a gene therapy approach to PAH in which autologous HSCs will undergo gene editing using CRISPR/Cas9 to achieve bi-allelic disruption of the MPO gene. These MPO-knock-out HSCs will then be autologous transplanted. That autologous transplantation of HSPC in which the MPO gene is disrupted is expected to prevent progression of PAH due to the essential role of neutrophil MPO activity on disease development. We identified a sgRNA that leads to high frequency disruption of MPO in primary human CD34+ hematopoietic stem and progenitor cells (HSPC), leading to efficient elimination of MPO protein in the resultant neutrophils. That sequence was assessed for genome-wide off-target and showed no detectable locus, validating it as a lead candidate for safe gene editing strategy. We validated in an in vitro neutrophil differentiation model the functional efficiency of the knock-out. MPO KO differentiated cells exhibit reduced neutrophil extracellular traps formation (NETosis) and absence of MPO protein. An optimized gene editing protocol for HSC was optimized and showed consistent allelic disruption over 80%. The edited cells retain hematopoietic potential and showed no skewing in the generated lineages in an in vitro colony forming assay. We developed a surrogate gene editing protocol for murine cells and optimized electroporation to achieve high allelic disruption of the murine MPO gene in lineage negative murine hematopoietic cells. The protocol will be tested in a hypoxia-induced PAH murine model. The presented work can represent a major improvement for PAH patient. The limited therapeutic options and severity of the disease urges to develop new approaches. The gene therapy protocol developed showed promising result in vitro and rely on clinical evidences for the implication of MPO in the disease. Results will be tested in a pre-clinical murine model

The Treatment of Burkitt Lymphoma with the Berlin-Frankfurt-Münster Protocol with Rituximab and Autologous Transplantation

Intensive treatment approaches are required for adult Burkitt lymphoma (BL), although a univocal standard of care still does not exist. The use of frontline autologous transplantation is debated. Between 2004 and 2020, 50 HIV-negative BL patients were treated with the Berlin-Frankfurt-Münster (BFM) protocol at our institution. Treatment plan consisted of 3 blocks, A (ifosfamide, vincristine, methotrexate, etoposide, cytarabine), B (vincristine, cyclophosphamide, methotrexate, doxorubicin) and C (vindesine, methotrexate, etoposide, cytarabine), each repeated twice, every 28 days. Patients elder than 60 years did not receive block C, thus blocks A and B were repeated 3 times. Rituximab was given at day 1 each block. Intrathecal prophylaxis was given once per each block. Autologous stem cells were reinfused (ASCT) at the end of the 6-blocks after BEAM (carmustine, etoposide, cytarabine, melphalan) conditioning, when feasible. Median age at onset was 38 years (range 16-72); 38 patients were male and 12 female. Stage III-IV disease was observed in 82% of cases; bulky disease occurred in 44% of the patients, with B-symptoms in 38%. Two patients did not receive rituximab because of adverse reaction and early death. Intrathecal prophylaxis was given in 96% of patients. Stem cell harvest was performed in 70% of patients, who all received a subsequent ASCT. The full 6-blocks treatment was completed in 70% of the patients; 8% received 5 cycles and 22% received ≤ 3 cycles. Early treatment interruption occurred because of disease progression (12%), toxicity (8%), death (4%) or other causes (4%). The overall response rate was 74%, with a complete response rate of 60%. Three patients could not be evaluated because of early progression/death. Ten-year overall survival and progression-free survival were 83.7% and 76.0%, respectively, with both curves exhibiting a plateau (Figure). Ten-year disease-free survival was 80.3%. Eight patients had died because of disease progression (3 patients), infection or sepsis (4 patients) or cardiac arrest (1 patient). Grade 3-4 neutropenia, thrombocytopenia, anemia and mucositis were seen in 96%, 60%, 32% and 24% of patients. Infections occurred in 60% of patients; grade 4 and fatal sepsis in 14% and 8% of cases. Intensive treatment according to BFM protocol, with rituximab and ASCT, appears feasible, safe and highly effective in adult patients with BL, as confirmed by long-term survival rates.

The Clinical Complexity of Langherans Cell Histiocytosis in Adult Patients: Experience of the Institute of Hematology of Bologna

Langerhans cell histiocytosis (LCH) in adult patients is a rare disease with protean manifestations, including single system unifocal (SSU) or multifocal (SSM) presentation or multisystemic (MS) involvement. Clinical care of adult patients is based on case series and reports. Regimens applied in pediatric patients show unacceptable toxicity in the adult setting. Our single-center experience with LCH is presented. Data on 30 patients diagnosed between 1997 and 2022 have been reviewed. Patients with isolated pulmonary histiocytosis were excluded. Responses to any treatment were classified according to the acknowledged criteria. Progression-free survival (PFS) after frontline treatment was calculated on all treated patients. Overall survival (OS) was determined on the whole cohort irrespective of any treatment received. Eighteen male and 12 female patients received a diagnosis of LCH at a median age of 46 years (range 20-75). Sixteen patients had single system (SS) disease, with SSU involvement in 12 cases and SSM involvement in 4 cases. The skeleton was the mostly involved system (Figure), while SSU extra-skeletal disease was detected in 25% of cases. Fourteen patients had MS disease: axial skeleton, lungs, hypophysis, skull, skin and appendicular skeleton were the predominantly involved sites, in this order. Ten patients with SS disease received chemotherapy because of symptoms (mostly bone pain) or due to multifocal dissemination. Two patients underwent radiotherapy (RT), 2 had their disease completely excised and 1 received systemic steroids. One patient was observed. A complete response (CR) was obtained in 60% of treated cases, while a partial response (PR) in 27%. Four patients relapsed after frontline therapy and were rescued with RT or autologous transplant. Among patients with MS disease, chemotherapy (MACOP/VNCOP-B, cladribine, vinblastine) was applied in 6 cases; 2 patients received RT and 1 systemic steroids. One patient underwent surgery and 4 were observed because of asymptomatic disease. A CR was obtained in 70% of treated patients and a PR in 10%. Five patients relapsed, with symptomatic disease requiring treatment (chemotherapy and RT) in 3 cases. Median PFS among all treated patients was 177 months. OS was 91% at 20 years. Appropriate treatment based on disease extension, site involvement and clinical manifestations yields high remission rates and long term PFS and OS. The optimal approach to relapsed patients remains undefined.

Efficacy and Safety of Chidamide Combined with BEAM Conditioning Regimen in Autologous Transplantation for T-Cell Lymphoma

Background: T cell lymphoma (TCL) is a group of highly heterogeneous aggressive non-Hodgkin lymphomas with different pathogenesis and clinical prognosis. Despite the survival benefits of anthracycline-based chemotherapy bridging autologous stem cell transplantation (ASCT), 40% to 50% of TCL patients fail to respond to treatment and relapse or die within a short period of time. Chidamide is an oral selective histone deacetylase inhibitor (HDACi), interferes with epigenetic regulation by deacetylating nuclear transcription factors, affects proliferation and differentiation of tumor cells, and regulates cytokines in the tumor microenvironment. Chidamide combined with chemotherapy has promising clinical applications in ASCT. Aims: This prospective Phase II trial aims to evaluate the efficacy and safety of chidamide in combination with carmustine, etoposide, cytarabine, and melphalan (Chi-BEAM) conditioning regimen in ASCT of TCL patients received CR/PR to first-line chemotherapy. Method: In this study, eligible patients with TCL (except IPI 0-1 ALK+ anaplastic large cell lymphoma) aged 18-65 years were enrolled. All patients received Chi-BEAM conditioning regimen before ASCT. 30mg of chidamide was administered twice a week for at least 2 years after ASCT.The primary end point was 2-year progression-free survival (PFS) rate, and the secondary end points were 2-year overall survival (OS) rate and safety evaluation. Results: At the time of data cut off, a total of 18 patients were enrolled, with a median age of 48 (15-65) years. The 1-year PFS rate and OS rate after ASCT were 90.0% and 100.0%, respectively. The median implantation time of neutrophils was 10 days (9-13 days), and the median implantation time of platelets was 17 days (11-25 days). Most of the adverse reactions (AEs) were tolerable, including controlled grain deficiency with fever, electrolyte disturbance, and abnormal liver function. Conclusion: Chidamide combined with BEAM as a conditioning regimen for ASCT can significantly improve PFS and OS in TCL patients, and the AEs are controllable. The study is ongoing and further results will be continuously released.

Deletion 1p at Time of Diagnosis of Multiple Myeloma Portends Inferior Outcomes

Background: Multiple myeloma (MM) is associated with several cytogenetic abnormalities (CA) that influence the disease course, response to treatment and survival. Trisomies and immunoglobulin H chain translocations are primary CA while del(17p), gain(1q), del(1p) and others are secondary CA. Gain (3 copies) and amplification (>3 copies) 1q have been recognized as adverse prognostic markers and incorporated into the second revision of the International Staging System (R2-ISS). However, the role of del(1p) is less well defined, especially in the era of modern myeloma therapeutics. We aimed to analyze the outcomes of newly diagnosed MM (NDMM) patients (pts) with chromosome 1 abnormalities, mainly del 1p, treated with autologous hematopoietic cell transplant (AHCT) consolidation at The Ohio State University. Methods: We identified and reviewed the medical records of all NDMM pts who were treated with AHCT from 1/1/2015-2/13/2019 (n=511). High-risk cytogenetics (HRC) was defined by the presence of del(17p), t(4;14), or t(14;16) similar to R-ISS; standard-risk cytogenetics (SRC) were defined as the absence of HRC. Modified HR cytogenetics (mHRC) included gain/amp 1q and/or t(14;20) in addition to HRC, while ultra high-risk (uHRC) included 2 or more mHRC risk factors. Results: The baseline pt characteristics are presented in Table 1. Of 511 pts transplanted, 453 had cytogenetic data from diagnosis. SRC were seen in 353 pts (77.9%), while 100 (22.1%) had HRC, 156 (34.4%) had mHRC, and 43 (9.5%) had uHRC. Thirty-two (7.1%) pts had del(1p) while 105 (23.2%) had gain 1q and 30 (6.6%) had amp 1q. As expected, compared to SRC pts, pts with HRC, mHRC and uHRC had higher risk of relapse or death. Patients with gain and amp 1q had inferior outcomes in terms of PFS (HR 1.35; 95% CI 1.06-1.73, p=0.016), TTNT (HR 1.84; 95% CI 1.40-2.42, p<0.001) and OS (HR 1.47; 95% CI 1.06-2.02, p=0.02), consistent with published literature. The median PFS, TTNT and OS from AHCT in pts with gain/amp 1q was 3.17 years (y), 3.95y and 7.13y, respectively, compared to 4.01y, 7.60y and 8.21y in pts without gain/amp 1q. Pts with del(1p) had inferior PFS (median 2.43y versus 3.98y; HR 1.75; 95% CI 1.16-2.64, p=0.008), TTNT (median 2.72y versus 6.17y; HR 1.96; 95% CI 1.22-3.14, p=0.005) and OS (median 4.11y versus 8.38y; HR 2.19; 95% CI 1.34-3.58, p=0.002) from AHCT compared to those without del(1p). (Figure 1). Conclusions: In this cohort of NDMM pts that underwent AHCT, del(1p) at diagnosis was an independent predictor of shorter PFS, TTNT and OS. Despite advances in induction regimens, AHCT consolidation and maintenance therapy, del(1p) continues to portend inferior outcomes. Larger analyses are needed to validate the prognostic value of del(1p) and investigate its role in predicting outcomes in MM.