ASTCT Committee on Practice Guidelines Survey on Evaluation and Management of Relapsed/Refractory Multiple Myeloma after Failure of Chimeric Antigen Receptor T Cell Therapy

Chimeric antigen receptor T cell therapy (CAR-T) has revolutionized the management of relapsed and/or refractory multiple myeloma (RRMM). However, CAR-T treatment failure is not uncommon and remains a major therapeutic challenge. There is substantial variability across transplantation and cellular therapy programs in assessing and managing post-CAR-T failures in patients with RRMM. The American Society for Transplantation and Cellular Therapy (ASTCT) Committee on Practice Guidelines conducted an online cross-sectional survey between September 2023 and December 2023 to determine myeloma, transplantation, and cellular therapy physicians' practice patterns for the surveillance, diagnosis, and management of CAR-T failure. The intent of this survey was to understand clinical practice patterns and identify areas for further investigation. Email surveys were sent to 1311 ASTCT physician members, of whom 80 (6.1%) completed the survey. The respondents were 58% white and 66% male, and 51% had >10 years of clinical experience. Most (89%) respondents were affiliated with a university/teaching center, and 56% had a myeloma-focused transplantation and/or cellular therapy practice. Post-CAR-T surveillance laboratory studies were commonly done every 4 weeks, and surveillance bone marrow biopsies and/or imaging surveillance were most commonly done at 3 months. Sixty-four percent of the respondents would often or always consider biopsy or imaging to confirm relapse. The most popular post-CAR-T failure rescue regimen was GPRC5D-directed immunotherapy (30%) for relapses occurring ≤3 months and BCMA-directed bispecific therapies (32.5%) for relapse at >3 months. Forty-one percent of the respondents endorsed post-CAR-T prolonged cytopenia as being "often" or "always" a barrier to next-line therapy; 53% had offered stem cell boost as a mitigation approach. Substantial across-center variation in practice patterns raises the need for collaborative studies and expert clinical recommendations to describe best practices for post-CAR-T disease surveillance, optimal workup for treatment failure, and choice of rescue therapies.

Long term follow up of patients with MNV3 treated with intra-vitreal Aflibercept

PURPOSE

MNV3 or Retinal angiomatous proliferation is a subtype of neovascular age-related macular degeneration (nAMD). We present the 5 year long term visual and anatomical outcomes of patients with MNV3 lesions treated with intravitreal Aflibercept.

METHODS

This is a prospective study of treatment naïve patients with reading centre graded MNV3 lesions. After the loading phase, the patients received intravitreal Aflibercept as per the View study up to year 3, thereafter it was given on a prn basis. At each visit, best corrected visual acuity (BCVA) and optical coherence tomography (OCT) central macular thickness (CMT) was measured.

RESULTS

Thirty one patients reached study completion. Mean BCVA of treated eyes had decreased by 0.6 ETDRS letters at the end of year 5 compared with baseline. At study completion, 81% of eyes had stable vision while 19% of eyes had gained 15 letters or more. At study end, 26% of eyes had BCVA of 6/12 or better, while 19% had lost 15 letters or more (all had central foveal photoreceptor loss). There was a maximal mean reduction in CMT of 164 microns (p = <0.0001) while 68% of maculae were fluid free at study completion. Eighty seven percent of treated eyes developed nascent GA, of which in 74% of eyes was involving the fovea.

DISCUSSION

Despite initial improvement in mean BCVA, the improvement in BCVA was not maintained despite good overall control of the MNV3 lesions. The loss of BCVA was most likely due to the majority of eyes developing centre involving macular atrophy.

Chimeric Antigen Receptor T-Cell Therapy in the Outpatient Setting: An Expert Panel Opinion from the American Society for Transplantation and Cellular Therapy

The first series of chimeric antigen receptor T (CAR-T) cell therapy products were approved in 2017 to 2019 and have shown remarkable efficacy in both clinical trials and the real-world setting, but at the cost of prolonged patient hospitalization. As the toxicity management protocols were refined, the concept of cellular therapy administered in the outpatient setting gained steam, and single institutions began to perform certain aspects of CAR-T monitoring in the outpatient setting for select patients. However, there are many considerations for a successful outpatient program. In anticipation of increasing use of CAR-T-cell therapy in the outpatient setting as a mechanism to overcome frequent hospital bed shortages and high cost of inpatient care, the American Society for Transplantation and Cellular Therapy convened a group of experts in hematology, oncology, and cellular therapy to provide a comprehensive review of the existing publications on outpatient CAR-T cell therapy, discuss selected ongoing clinical trials of outpatient CAR-T, and describe strategies to optimize safety without compromising efficacy for patients treated and monitored in the outpatient setting.

Indication and management of allogeneic haematopoietic stem-cell transplantation in myelofibrosis: updated recommendations by the EBMT/ELN International Working Group

New options for medical therapy and risk scoring systems containing molecular data are leading to increased complexity in the management of patients with myelofibrosis. To inform patients' optimal care, we updated the 2015 guidelines on indications for and management of allogeneic haematopoietic stem-cell transplantation (HSCT) with the support of the European Society for Blood and Marrow Transplantation (EBMT) and European LeukemiaNet (ELN). New recommendations were produced using a consensus-building methodology after a comprehensive review of articles released from January, 2015 to December, 2022. Seven domains and 18 key questions were selected through a series of questionnaires using a Delphi process. Key recommendations in this update include: patients with primary myelofibrosis and an intermediate-2 or high-risk Dynamic International Prognostic Scoring System score, or a high-risk Mutation-Enhanced International Prognostic Score Systems (MIPSS70 or MIPSS70-plus) score, or a low-risk or intermediate-risk Myelofibrosis Transplant Scoring System score should be considered candidates for allogeneic HSCT. All patients who are candidates for allogeneic HSCT with splenomegaly greater than 5 cm below the left costal margin or splenomegaly-related symptoms should receive a spleen-directed treatment, ideally with a JAK-inhibitor; HLA-matched sibling donors remain the preferred donor source to date. Reduced intensity conditioning and myeloablative conditioning are both valid options for patients with myelofibrosis. Regular post-transplantation driver mutation monitoring is recommended to detect and treat early relapse with donor lymphocyte infusion. In a disease where evidence-based guidance is scarce, these recommendations might help clinicians and patients in shared decision making.

Chimeric Antigen Receptor T Cell Therapy for Myeloma: Where Are We Now and What Is Needed to Move Chimeric Antigen Receptor T Cells Forward to Earlier Lines of Therapy? Expert Panel Opinion from the American Society for Transplantation and Cellular Therapy

Since 2021, 2 B cell maturation antigen (BCMA)-directed chimeric antigen receptor T cell (CAR-T) therapies-idecabtagene vicleucel (ide-cel), and ciltacabtagene autoleucel (cilta-cel)-have been approved by the US Food and Drug Administration (FDA) for treating relapsed or refractory multiple myeloma (RRMM) after 4 or more prior lines of therapy, including an immunomodulatory drug, a proteasome inhibitor, and an anti-CD38 antibody. The 2 products have shown unprecedented activity in RRMM, but relapses remain common, and access to and safety of CAR-T therapy in patients with rapidly progressing advanced disease are not ideal. Sequencing CAR-T therapy with other options, including the 2 recently approved BCMA-directed T cell-engaging bispecific antibodies teclistamab and elranatamab, has become increasingly challenging owing to data showing inferior outcomes from CAR-T therapy after prior BCMA-directed therapy. This has led to the consideration of CAR-T therapy earlier in the course of disease for myeloma, when T cells are potentially healthier and the myeloma is less aggressive. To address the question of earlier use of CAR-T therapy, several trials are either ongoing or planned, and results have recently been reported for 2 randomized trials of CAR-T therapy showing improved progression-free survival compared to standard of care therapy in second-line (CARTITUDE-4) or third-line therapy (KarMMA-3). With the anticipation of the FDA possibly expanding approval of CAR-T to earlier lines of myeloma therapy, the American Society for Transplantation and Cellular Therapy convened a group of experts to provide a comprehensive review of the studies that led to the approval of CAR-T therapy in late-line therapy for myeloma, discuss the recently reported and ongoing studies designed to move CAR-T therapy to earlier lines of therapy, and share insights and considerations for sequencing therapy and optimization of patient selection for BCMA-directed therapies in current practice.

Haploidentical donor hematopoietic cell transplantation for myelodysplastic/myeloproliferative overlap neoplasms: results from a North American collaboration

Haploidentical donors offer a potentially readily available donor, especially for non-White patients, for hematopoietic cell transplantation (HCT). In this North American collaboration, we retrospectively analyzed outcomes of first HCT using haploidentical donor and post-transplantation cyclophosphamide (PTCy) in myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) overlap neoplasms (MDS/MPN). We included 120 consecutive patients who underwent HCT using a haploidentical donor for MDS/MPN across 15 centers. Median age was 62.5 years and 38% were of non-White/Caucasian ethnicity. The median follow-up was 2.4 years. Graft failure was reported in seven of 120 (6%) patients. At 3 years, nonrelapse mortality (NRM) was 25% (95% confidence interval [CI]: 17-34), relapse 27% (95% CI: 18-36), grade 3-4 acute graftversus- host disease 12% (95% CI: 6-18), chronic graft-versus-host disease requiring systemic immunosuppression 14% (95% CI: 7-20), progression-free survival (PFS) 48% (95% CI: 39-59), and overall survival (OS) 56% (95% CI: 47-67). On multivariable analysis, NRM was statistically significantly associated with advancing age at HCT (per decade increment, subdistribution hazard ratio [sdHR] =3.28; 95% CI: 1.30-8.25); relapse with the presence of mutation in EZH2/RUNX1/SETBP1 (sdHR=2.61; 95% CI: 1.06-6.44); PFS with advancing age at HCT (per decade increment, HR=1.98, 95% CI: 1.13-3.45); and OS with advancing age at HCT (per decade increment, HR=2.01; 95% CI: 1.11-3.63) and splenomegaly at HCT/prior splenectomy (HR=2.20; 95% CI: 1.04-4.65). Haploidentical donors are a viable option for HCT in MDS/MPN, especially for those disproportionately represented in the unrelated donor registry. Hence, donor mismatch should not preclude HCT for patients with MDS/MPN, an otherwise incurable malignancy. In addition to patient age, disease-related factors including splenomegaly and high-risk mutations dominate outcomes following HCT.

Proceedings of the 2023 Second Annual ASTCT-NMDP ACCESS Initiative Workshop

Here the proceedings from the Second Annual American Society for Transplantation and Cellular Therapy (ASTCT) and National Marrow Donor Program (NMDP) ACCESS Initiative are reviewed to inform the hematopoietic cell transplantation (HCT) and cellular therapy (CT) ecosystem about progress and direction of the collaborative. Highlights from the meeting, including updates on the progress of projects from the Awareness, Poverty, and Racial Inequity Committees, are presented. The ACCESS Initiative continues to evolve and will remain dependent on the HCT/CT ecosystem's continued dedication to reduce barriers and improve outcome disparities for all patients in need of HCT/CT.

Updated Indications for Immune Effector Cell Therapy: 2023 Guidelines from the American Society for Transplantation and Cellular Therapy

The American Society for Transplantation and Cellular Therapy (ASTCT) published its guidelines on indications for autologous and allogeneic hematopoietic cell transplantation (HCT) and immune effector cell therapy (IECT) in 2020. Since then, we have witnessed rapid advancements in the field of IECT, resulting in several new chimeric antigen receptor T cell (CAR-T) products and disease indications being approved by the US Food and Drug Administration (FDA). To keep abreast of these practice changes, the ASTCT Committee on Practice Guidelines commissioned a focused update covering CAR-T therapy indications. Here we present updated ASTCT recommendations on indications for CAR-T therapy. Only FDA-approved indications for CAR-T were recommended and categorized as "standard of care," where the indication is well defined and supported by evidence. The ASTCT will continue to periodically review these guidelines and update them as new evidence becomes available.

A simple prognostic system in patients with myelofibrosis undergoing allogeneic stem cell transplantation: a CIBMTR/EBMT analysis

To develop a prognostic model for patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) for myelofibrosis (MF), we examined the data of 623 patients undergoing allo-HCT between 2000 and 2016 in the United States (the Center for International Blood and Marrow Transplant Research [CIBMTR] cohort). A Cox multivariable model was used to identify factors prognostic of mortality. A weighted score using these factors was assigned to patients who received transplantation in Europe (the European Bone Marrow Transplant [EBMT] cohort; n = 623). Patient age >50 years (hazard ratio [HR], 1.39; 95% confidence interval [CI], 0.98-1.96), and HLA-matched unrelated donor (HR, 1.29; 95% CI, 0.98-1.7) were associated with an increased hazard of death and were assigned 1 point. Hemoglobin levels <100 g/L at time of transplantation (HR, 1.63; 95% CI, 1.2-2.19) and a mismatched unrelated donor (HR, 1.78; 95% CI, 1.25-2.52) were assigned 2 points. The 3-year overall survival (OS) in patients with a low (1-2 points), intermediate (3-4 points), and high score (5 points) were 69% (95% CI, 61-76), 51% (95% CI, 46-56.4), and 34% (95% CI, 21-49), respectively (P < .001). Increasing score was predictive of increased transplant-related mortality (TRM; P = .0017) but not of relapse (P = .12). The derived score was predictive of OS (P < .001) and TRM (P = .002) but not of relapse (P = .17) in the EBMT cohort as well. The proposed system was prognostic of survival in 2 large cohorts, CIBMTR and EBMT, and can easily be applied by clinicians consulting patients with MF about the transplantation outcomes.

Association between the choice of the conditioning regimen and outcomes of allogeneic hematopoietic cell transplantation for myelofibrosis

Allogeneic hematopoietic cell transplantation (allo-HCT) remains the only curative treatment for myelofibrosis. However, the optimal conditioning regimen either with reduced-intensity conditioning (RIC) or myeloablative conditioning (MAC) is not well known. Using the Center for International Blood and Marrow Transplant Research database, we identified adults aged ≥18 years with myelofibrosis undergoing allo-HCT between 2008-2019 and analyzed the outcomes separately in the RIC and MAC cohorts based on the conditioning regimens used. Among 872 eligible patients, 493 underwent allo-HCT using RIC (fludarabine/ busulfan n=166, fludarabine/melphalan n=327) and 379 using MAC (fludarabine/busulfan n=247, busulfan/cyclophosphamide n=132). In multivariable analysis with RIC, fludarabine/melphalan was associated with inferior overall survival (hazard ratio [HR]=1.80; 95% confidenec interval [CI]: 1.15-2.81; P=0.009), higher early non-relapse mortality (HR=1.81; 95% CI: 1.12-2.91; P=0.01) and higher acute graft-versus-host disease (GvHD) (grade 2-4 HR=1.45; 95% CI: 1.03-2.03; P=0.03; grade 3-4 HR=2.21; 95%CI: 1.28-3.83; P=0.004) compared to fludarabine/busulfan. In the MAC setting, busulfan/cyclophosphamide was associated with a higher acute GvHD (grade 2-4 HR=2.33; 95% CI: 1.67-3.25; P<0.001; grade 3-4 HR=2.31; 95% CI: 1.52-3.52; P<0.001) and inferior GvHD-free relapse-free survival (GRFS) (HR=1.94; 95% CI: 1.49-2.53; P<0.001) as compared to fludarabine/busulfan. Hence, our study suggests that fludarabine/busulfan is associated with better outcomes in RIC (better overall survival, lower early non-relapse mortality, lower acute GvHD) and MAC (lower acute GvHD and better GRFS) in myelofibrosis.

Immune Effector Cell-Associated Hemophagocytic Lymphohistiocytosis-Like Syndrome

T cell-mediated hyperinflammatory responses, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), are now well-established toxicities of chimeric antigen receptor (CAR) T cell therapy. As the field of CAR T cells advances, however, there is increasing recognition that hemophagocytic lymphohistiocytosis (HLH)-like toxicities following CAR T cell infusion are occurring broadly across patient populations and CAR T cell constructs. Importantly, these HLH-like toxicities are often not as directly associated with CRS and/or its severity as initially described. This emergent toxicity, however ill-defined, is associated with life-threatening complications, creating an urgent need for improved identification and optimal management. With the goal of improving patient outcomes and formulating a framework to characterize and study this HLH-like syndrome, we established an American Society for Transplantation and Cellular Therapy panel composed of experts in primary and secondary HLH, pediatric and adult HLH, infectious disease, rheumatology and hematology, oncology, and cellular therapy. Through this effort, we provide an overview of the underlying biology of classical primary and secondary HLH, explore its relationship with similar manifestations following CAR T cell infusions, and propose the term "immune effector cell-associated HLH-like syndrome (IEC-HS)" to describe this emergent toxicity. We also delineate a framework for identifying IEC-HS and put forward a grading schema that can be used to assess severity and facilitate cross-trial comparisons. Additionally, given the critical need to optimize outcomes for patients experiencing IEC-HS, we provide insight into potential treatment approaches and strategies to optimize supportive care and delineate alternate etiologies that should be considered in a patient presenting with IEC-HS. By collectively defining IEC-HS as a hyperinflammatory toxicity, we can now embark on further study of the pathophysiology underlying this toxicity profile and make strides toward a more comprehensive assessment and treatment approach.

Alternative donor BMT with posttransplant cyclophosphamide as initial therapy for acquired severe aplastic anemia

Severe aplastic anemia (SAA) is a marrow failure disorder with high morbidity and mortality. It is treated with bone marrow transplantation (BMT) for those with fully matched donors, or immunosuppressive therapy (IST) for those who lack such a donor, which is often the case for underrepresented minorities. We conducted a prospective phase 2 trial of reduced-intensity conditioning HLA-haploidentical BMT and posttransplantation cyclophosphamide (PTCy)-based graft-versus-host (GVHD) prophylaxis as initial therapy for patients with SAA. The median patient age was 25 years (range, 3-63 years), and the median follow-up time was 40.9 months (95% confidence interval [CI], 29.4-55.7). More than 35% of enrollment was from underrepresented racial/ethnic groups. The cumulative incidence of grade 2 or 4 acute GVHD on day 100 was 7% (95% CI, not applicable [NA]-17), and chronic GVHD at 2 years was 4% (95% CI, NA-11). The overall survival of 27 patients was 92% (95% CI, 83-100) at 1, 2, and 3 years. The first 7 patients received lower dose total body irradiation (200 vs 400 cGy), but these patients were more likely to have graft failure (3 of 7) compared with 0 of 20 patients in the higher dose group (P = .01; Fisher exact test). HLA-haploidentical BMT with PTCy using 400 cGy total body irradiation resulted in 100% overall survival with minimal GVHD in 20 consecutive patients. Not only does this approach avoid any adverse ramifications of IST and its low failure-free survival, but the use of haploidentical donors also expands access to BMT across all populations. This trial was registered at www.clinicaltrials.gov as NCT02833805.

Co-occurring mutations in ASXL1, SRSF2, and SETBP1 define a subset of myelodysplastic/ myeloproliferative neoplasm with neutrophilia

Identification of genomic signatures with consistent clinicopathological features in myelodysplastic/myeloproliferative neoplasm (MDS/MPN) is critical for improved diagnosis, elucidation of biology, inclusion in clinical trials, and development of therapies. We describe clinical and pathological features with co-existence of mutations in ASXL1 (missense or nonsense), SRSF2, and SKI homologous region of SETBP1, in 18 patients. Median age was 68 years with a male predominance (83%). Leukocytosis and neutrophilia were common at presentation. Marrow features included hypercellularity, granulocytic hyperplasia with megakaryocytic atypia, while the majority had myeloid hyperplasia and/or erythroid hypoplasia, myeloid dysplasia, and aberrant CD7 expression on blasts. Mutations in growth signaling pathways (RAS or JAK2) were noted at diagnosis or acquired during the disease course in 83% of patients. Two patients progressed upon acquisition of FLT3-TKD (acute myeloid leukemia) or KIT (aggressive systemic mastocytosis) mutations. The prognosis is poor with only two long-term survivors, thus far, who underwent blood or marrow transplantation. We propose that the presence of co-occurring ASXL1, SRSF2, and SETBP1 mutations can be diagnostic of a subtype of MDS/MPN with neutrophilia if clinical and morphological findings align. Our report underscores the association between genotype and phenotype within MDS/MPN and that genomic signatures should guide categorization of these entities.

How I treat cytopenias after CAR T-cell therapy

Increasing use of chimeric antigen receptor T-cell therapy (CAR-T) has unveiled diverse toxicities warranting specific recognition and management. Cytopenias occurring after CAR-T infusion invariably manifest early (<30 days), commonly are prolonged (30-90 days), and sometimes persist or occur late (>90 days). Variable etiologies of these cytopenias, some of which remain incompletely understood, create clinical conundrums and uncertainties about optimal management strategies. These cytopenias may cause additional sequelae, decreased quality of life, and increased resource use. Early cytopenias are typically attributed to lymphodepletion chemotherapy, however, infections and hyperinflammatory response such as immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome may occur. Early and prolonged cytopenias often correlate with severity of cytokine release syndrome or immune effector cell-associated neurotoxicity syndrome. Bone marrow biopsy in patients with prolonged or late cytopenias is important to evaluate for primary disease and secondary marrow neoplasm in both pediatric and adult patients. Commonly, cytopenias resolve over time and evidence for effective interventions is often anecdotal. Treatment strategies, which are limited and require tailoring based upon likely underlying etiology, include growth factors, thrombopoietin-receptor agonist, stem cell boost, transfusion support, and abrogation of infection risk. Here we provide our approach, including workup and management strategies, for cytopenias after CAR-T.

The E592K variant of SF3B1 creates unique RNA missplicing and associates with high-risk MDS without ring sideroblasts

Among the most common genetic alterations in the myelodysplastic syndromes (MDS) are mutations in the spliceosome gene SF3B1. Such mutations induce specific RNA missplicing events, directly promote ring sideroblast (RS) formation, generally associate with more favorable prognosis, and serve as a predictive biomarker of response to luspatercept. However, not all SF3B1 mutations are the same, and here we report that the E592K variant of SF3B1 associates with high-risk disease features in MDS, including a lack of RS, increased myeloblasts, a distinct co-mutation pattern, and decreased survival. Moreover, in contrast to canonical SF3B1 mutations, E592K induces a unique RNA missplicing pattern, retains an interaction with the splicing factor SUGP1, and preserves normal RNA splicing of the sideroblastic anemia genes TMEM14C and ABCB7. These data expand our knowledge of the functional diversity of spliceosome mutations, and they suggest that patients with E592K should be approached differently from low-risk, luspatercept-responsive MDS patients with ring sideroblasts and canonical SF3B1 mutations.

Allogeneic Blood or Marrow Transplantation with Post-Transplantation Cyclophosphamide for Peripheral T Cell Lymphoma: The Importance of Graft Source

The use of post-transplantation cyclophosphamide (PTCy) for graft-versus host-disease (GVHD) prophylaxis has revolutionized allogeneic blood or marrow transplantation (alloBMT), but there is limited published experience in peripheral T cell lymphoma (PTCL). We sought to assess outcomes in patients with PTCL who underwent alloBMT with PTCy. We reviewed the charts of all adult patients age ≥18 years who underwent alloBMT with nonmyeloablative conditioning and PTCy-based GVHD prophylaxis at the Sidney Kimmel Comprehensive Cancer Center between January 2004 and December 2020. Sixty-five patients were identified. The median age was 59 years (range, 24 to 75 years). Lymphoma histology included PTCL not otherwise specified (n = 24), anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (n = 14), angioimmunoblastic T cell lymphoma (n = 7), enteropathy-associated T cell lymphoma (n = 6), hepatosplenic T cell lymphoma (n = 4), and others (n = 10). Eleven patients were in first complete remission (17%); the remaining patients were in first partial remission or underwent salvage therapy to at least PR prior to transplantation. Forty-eight patients underwent alloBMT from a haploidentical related donor (74%), 10 from a fully matched donor (15%), and 7 from a mismatched unrelated donor (11%). All patients received fludarabine, cyclophosphamide, and total body irradiation (TBI). The graft source was bone marrow (BM) in 46 patients (71%) and peripheral blood (PB) in 19 patients (29%); all patients in the BM cohort received 200 cGy TBI, and most patients in the PB cohort (15 of 19) received 400 cGy TBI. GVHD prophylaxis comprised PTCy, mycophenolate mofetil, and a calcineurin inhibitor or sirolimus. With a median follow-up of 2.8 years (range, 290 days to 14.2 years), the 2-year progression-free survival (PFS) for the entire cohort was 49% (95% confidence interval [CI], 38% to 64%), and the 2-year overall survival (OS) was 55% (95% CI, 44% to 69%). Outcomes were significantly improved in those receiving PB compared to those receiving BM, including a 2-year PFS of 79% (95% CI 63% to 100%) versus 39% (95% CI, 27% to 56%), 2-year OS of 84% (95% CI, 69% to 100%) versus 46% (95% CI, 33% to 63%), and 1-year cumulative incidence of relapse of 5% (95% CI, 0 to 16%) versus 33% (95% CI, 19% to 46%), with no difference in GVHD and nonrelapse mortality. AlloBMT with PTCy is safe and well-tolerated in patients with PTCL. Our data suggest that increasing the TBI dose to 400 cGy and using PB allografts may offer improved disease control and better survival outcomes, though additional studies are needed to confirm these findings.

Haploidentical Donor Blood or Marrow Transplantation for Myelodysplastic/Myeloproliferative Overlap Neoplasms: Results from a North American Collaboration

Haploidentical donors offer a potentially readily available donor, especially for non-White patients, for blood or marrow transplantation (BMT). In this collaboration across North America, we retrospectively analyzed outcomes of first BMT using haploidentical donor and posttransplantation cyclophosphamide (PTCy) in MDS/MPN-overlap neoplasms (MDS/MPN), an otherwise incurable hematological neoplasm. We included 120 patients, 38% of non-White/Caucasian ethnicity, across 15 centers with median age at BMT 62.5 years. The median follow-up is 2.4 years. Graft failure was reported in 6% patients. At 3-years, nonrelapse mortality (NRM) was 25%, relapse 27%, grade 3-4 acute graft versus host disease (GVHD) 12%, chronic GVHD requiring systemic immunosuppression 14%, progression-free survival (PFS) 48% and overall survival (OS) 56%. On multivariable analysis, statistically significant associations included older age at BMT (per decade increment) with NRM (sdHR 3.28, 95%CI 1.30-8.25), PFS (HR 1.98, 95% 1.13-3.45) and OS (HR 2.01, 95% CI 1.11-3.63), presence of mutation in EZH2/RUNX1/SETBP1 with relapse (sdHR 2.61, 95%CI 1.06-6.44), and splenomegaly at BMT/prior splenectomy with OS (HR 2.20, 95%CI 1.04-4.65). Haploidentical donors are a viable option for BMT in MDS/MPN, especially for those disproportionately represented in the unrelated donor registry. Disease-related factors including splenomegaly and high-risk mutations dominate outcomes following BMT.

Survival trends in young patients with Waldenström macroglobulinemia: Over five decades of experience

Waldenström macroglobulinemia (WM) is a rare, indolent lymphoma, that predominately affects the elderly. We report the outcomes of young WM patients, evaluated over five decades, compared to their older counterparts, matched for the time of diagnosis. Between January 1, 1960 and October 31, 2013, 140 (11.8%) WM patients were ≤50 years of age at diagnosis in our database, and their estimated 10-year overall survival (OS) was 74%, with death attributable to WM in a higher proportion of patients compared to their older (≥65 years) counterparts (91% vs. 58%, p = .0001). Young patients were grouped into three cohorts based on the timing of the initiation of therapy: Group 1 (1960-1977, n = 12), Group 2 (1978-1995, n = 48), and Group 3 (1996-2013, n = 74). Among young patients, there was no disease-specific survival (DSS) difference across the three periods, [median DSS at 13 years (95% CI 5-23), 16 years (95% CI 14-22), and 15 years (95% CI 10-NR; p = .41), respectively]. However, DSS for the older cohort incrementally improved (Group 1, median 5.2 years, Group 2: 9.6 years, Group 3: 12 years; p = .05) over these periods. The estimated average years-of-life lost for the young cohort was 11.2 years from diagnosis, based on the expected survival for a normal age- and sex-matched population. Despite a protracted disease course, nearly all young patients succumb to their disease. In contrast to the improved survival of the elderly patient population, the evolving treatment strategies in WM have not impacted the outcome of young patients; however, the impact of Bruton tyrosine kinase inhibitors on this unique patient population remains to be determined.

Allogeneic Blood or Marrow Transplantation with High-Dose Post-Transplantation Cyclophosphamide for Acute Lymphoblastic Leukemia in Patients Age ≥55 Years

Patients age ≥55 years with acute lymphoblastic leukemia (ALL) fare poorly with conventional chemotherapy, with a 5-year overall survival (OS) of ∼20%. Tyrosine kinase inhibitors and novel B cell-targeted therapies can improve outcomes, but rates of relapse and death in remission remain high. Allogeneic blood or marrow transplantation (alloBMT) provides an alternative consolidation strategy, and post-transplantation cyclophosphamide (PTCy) facilitates HLA-mismatched transplantations with low rates of nonrelapse mortality (NRM) and graft-versus-host disease (GVHD). The transplantation database at Johns Hopkins was queried for patients age ≥55 years who underwent alloBMT for ALL using PTCy. The database included 77 such patients. Most received reduced-intensity conditioning (RIC) (88.3%), were in first complete remission (CR1) (85.7%), and had B-lineage disease (90.9%). For the entire cohort, 5-year relapse-free survival (RFS) and overall survival (OS) were 46% (95% confidence interval [CI], 34% to 57%) and 49% (95% CI, 37% to 60%), respectively. Grade III-IV acute GVHD occurred in only 3% of patients, and chronic GVHD occurred in 13%. In multivariable analysis, myeloablative conditioning led to worse RFS (hazard ratio [HR], 4.65; P = .001), whereas transplantation in CR1 (HR, .30; P = .004) and transplantation for Philadelphia chromosome-positive (Ph+) ALL versus T-ALL (HR, .29; P = .03) were associated with improved RFS. Of the 54 patients who underwent RIC alloBMT in CR1 for B-ALL, the 5-year RFS and OS were 62% (95% CI, 47% to 74%) and 65% (95% CI, 51% to 77%), respectively, with a 5-year relapse incidence of 16% (95% CI, 7% to 27%) and an NRM of 24% (95% CI, 13% to 36%). RIC alloBMT with PTCy in CR1 represents a promising consolidation strategy for B-ALL patients age ≥55 years.

Chronic myeloid leukemia (CML) evolves from Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) with unexpected frequency

Myeloproliferative neoplasms (MPN) are chronic clonal disorders characterized by overproduction of myeloid-lineage blood cells and potential risk of evolution to acute myeloid leukemia (AML). Chronic myeloid leukemia (CML) is distinct from other MPNs in that its pathophysiology stems from the BCR-ABL fusion protein of the Philadelphia chromosome (Ph +). Though there are known cases of Ph- and Ph + MPNs coexisting in a single patient, overall prevalence has never been quantified in a prospective cohort. Here, we review our center's MPN registry, which shows 0.6% of Ph- MPN patients later developed CML. This development occurred no less than 10 and up to 36 years after Ph- MPN diagnosis. This rate of chronic transformation exceeds what is expected, as the incidence of CML in the United States is 2 per 100,000 people-years. The probability of this CML case rate in an average-risk population is less than 0.001%, suggesting there are shared risk factors between Ph- and Ph + MPNs. We speculate that these risk factors may include exposures, genetic predispositions, or be inherent to disease biology. Abrupt-onset leukocytosis heralded post-MPN CML in all cases here and suggests this salient clinical feature should trigger hematologists to consider this diagnosis and perform appropriate testing.

Venetoclax in combination with hypomethylating agent for the treatment of advanced myeloproliferative neoplasms and acute myeloid leukemia with extramedullary disease

The combination of venetoclax and hypomethylating agent (HMA/venetoclax) has emerged as a treatment option for patients with de novo acute myeloid leukemia (AML) who are unfit to receive intensive chemotherapy. In this single-center retrospective study, we evaluated clinical outcomes following treatment with HMA/venetoclax in 35 patients with advanced myeloproliferative neoplasms, myelodysplastic syndrome/myeloproliferative neoplasm overlap syndromes or AML with extramedullary disease. The composite complete remission (CR) rate (including confirmed/presumed complete cytogenetic response, acute leukemia response-complete, CR and CR with incomplete hematologic recovery) was 42.9% with median overall survival (OS) of 9.7 months. Complex karyotype was associated with inferior median OS (3.7 versus 12.2 months; p = 0.0002) and composite CR rate (22% versus 50.0%; p = 0.2444). Although SRSF2 mutations were associated with higher composite CR rate (80.0% versus 28.0%; p = 0.0082), this was not associated with longer median OS (10.9 versus 8.0 months; p = 0.2269). Future studies should include these patient subgroups.

Characterization of myeloproliferative neoplasms in the paediatric and young adult population

The aim of this study was to compare the genomic features and clinical outcomes between paediatric and young adult patients (PAYA, <40 years) and older adults (OA, ≥40 years) with myeloproliferative neoplasms (MPN) to gain insight into pathogenesis, disease prognosis and management. Of 630 MPN patients, 171 (27%) were PAYA with an average age at diagnosis of 31 years. Females were more prevalent in PAYA than OA (71% vs 58%; p = 0.002), and PAYA more frequently presented with essential thrombocytosis (ET) at diagnosis (67% vs 39%; p < 0.001). The presence of a JAK2 somatic mutation was higher in OA (80.4% vs 64.3%; p < 0.001), while a CALR mutation or lack of any traditional driver mutation was more common in PAYA (20.5% vs 10.5%; p = 0.001, 8.8% vs 3.7%; p = 0.01 respectively). Venous thrombosis was more common in PAYA compared to OA (19.8% vs 10.7%; p = 0.002). PAYA had a higher prevalence of familial MPN and familial cancer predisposition, and two PAYA patients harboured pathogenic germline JAK2 lesions. PAYA demonstrated longer survival from diagnosis than OA (median not reached vs 13 years), while disease transformation was less frequent (19.3% vs 37.9%).

CCRL2 affects the sensitivity of myelodysplastic syndrome and secondary acute myeloid leukemia cells to azacitidine

Better understanding of the biology of resistance to DNA methyltransferase (DNMT) inhibitors (DNMTi) is required to identify therapies that can improve their efficacy for patients with highrisk myelodysplastic syndrome (MDS). CCRL2 is an atypical chemokine receptor that is upregulated in CD34+ cells from MDS patients and induces MDS and secondary AML (sAML) cell proliferation. In this study, we evaluated any role CCRL2 may have in the regulation of pathways associated with poor response or resistance to DNMTi. We found that CCRL2 KD in TF-1 cells downregulates DNA methylation and PRC2 activity pathways and increases DNA methyltransferases (DNMT) suppression by azacitidine in MDS/sAML vell lines (MDS92, MDS-L and TF-1). Consistently, CCRL2 deletion increased the sensitivity of these cells to azacitidine in vitro and the efficacy of azacitidine in an MDS-L xenograft model. Consistently, CCRL2 overexpression in MDS-L and TF-1 cells decreased their sensitivity to azacitidine. Finally, CCRL2 levels were higher in CD34+ cells from MDS and MDS/myeloproliferative neoplasm patients with poor response to DNMTi. In conclusion, we demonstrate that CCRL2 modulates epigenetic regulatory pathways, particularly DNMT levels, and affects MDS/sAML azacitidine sensitivity. These results support CCRL2 targeting as having MDS/sAML therapeutic potential.

Hyperinflammatory syndrome resembling haemophagocytic lymphohistiocytosis following axicabtagene ciloleucel and brexucabtagene autoleucel

Haemophagocytic lymphohistiocytosis-like toxicity following chimeric antigen receptor T cells (CAR-HLH) is being increasingly recognized, while published data are limited and criteria for recognition are elusive. We describe three patients who developed CAR-HLH after infusion of brexucabtagene autoleucel (n = 2) or axicabtagene ciloleucel (n = 1). All three patients presented following cytokine release syndrome, with fever, recurrent or worsening cytopenias, hyperferritinaemia, elevated soluble interleukin (IL)-2 receptor, hypofibrinogenaemia, hypertriglyceridaemia, elevated liver transaminases, and decreasing C-reactive protein and IL-6. Clinical improvement following treatment with anakinra (n = 2) and ruxolitinib (n = 1) was observed. Our report offers an opportunity for prompt recognition and initiation of potentially life-saving treatment for CAR-HLH.

Disseminated Tuberculosis With an Atypical Cutaneous Manifestation in a Hematopoietic Cell Transplant Patient in the Early Posttransplant Period: Case Report and Review of the Literature

We describe an unusual case of posttransplant tuberculosis reactivation in a man who underwent allogeneic hematopoietic cell transplant. Concomitant with disseminated adenovirus infection, reactivation of tuberculosis manifested as disseminated, nonfollicular pustules on day +49. Skin biopsy was obtained on day +50. Initial histopathologic evaluation did not suggest mycobacterial infection, but tissue stain showed acid-fast organisms, which were subsequently identified as Mycobacterium tuberculosis. Shortly after the cutaneous presentation of tuberculosis, the patient died on day +52. Our case is among a paucity of reports describing tuberculosis reactivation in hematopoietic cell transplant patients in the early posttransplant period. It highlights the difficulty of diagnosing contemporaneous systemic infections, and it presents a rare and atypical cutaneous manifestation of tuberculosis in a hematopoietic cell transplant patient. Our case and review of the literature emphasize the need for further research to elucidate risk factors associated with early posttransplant reactivation of tuberculosis, and the importance of remaining vigilant for active tuberculosis in hematopoietic cell transplant patients with epidemiologic risk factors.

Chimeric Antigen Receptor T Cell Therapy versus Hematopoietic Stem Cell Transplantation: An Evolving Perspective

Cellular therapy modalities, including autologous (auto-) hematopoietic cell transplantation (HCT), allogeneic (allo-) HCT, and now chimeric antigen receptor (CAR) T cell therapy, have demonstrated long-term remission in advanced hematologic malignancies. Auto-HCT and allo-HCT, through hematopoietic rescue, have permitted the use of higher doses of chemotherapy. Allo-HCT also introduced a nonspecific immune-mediated targeting of malignancy resulting in protection from relapse, although at the expense of similar targeting of normal host cells. In contrast, CAR T therapy, through genetically engineered immunotherapeutic precision, allows for redirection of autologous immune effector cells against malignancy in an antigen-specific and MHC-independent fashion, with demonstrated efficacy in patients who are refractory to cytotoxic chemotherapy. It too has unique toxicities and challenges, however. Non-Hodgkin lymphoma (including large B cell lymphoma, mantle cell lymphoma, and follicular lymphoma), B cell acute lymphoblastic leukemia, and multiple myeloma are the 3 main diseases associated with the use of fully developed CAR T products with widespread deployment. Recent and ongoing clinical trials have been examining the interface among the 3 cellular therapy modalities (auto-HCT, allo-HCT, and CAR T) to determine whether they should be "complementary" or "competitive" therapies. In this review, we examine the current state of this interface with respect to the most recent data and delve into the controversies and conclusions that may inform clinical decision making.

Myeloproliferative Neoplasms, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology

The classic Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) consist of myelofibrosis, polycythemia vera, and essential thrombocythemia and are a heterogeneous group of clonal blood disorders characterized by an overproduction of blood cells. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for MPN were developed as a result of meetings convened by a multidisciplinary panel with expertise in MPN, with the goal of providing recommendations for the management of MPN in adults. The Guidelines include recommendations for the diagnostic workup, risk stratification, treatment, and supportive care strategies for the management of myelofibrosis, polycythemia vera, and essential thrombocythemia. Assessment of symptoms at baseline and monitoring of symptom status during the course of treatment is recommended for all patients. This article focuses on the recommendations as outlined in the NCCN Guidelines for the diagnosis of MPN and the risk stratification, management, and supportive care relevant to MF.

Role of CD19 Chimeric Antigen Receptor T Cells in Second-Line Large B Cell Lymphoma: Lessons from Phase 3 Trials. An Expert Panel Opinion from the American Society for Transplantation and Cellular Therapy

Since 2017, 3 CD19-directed chimeric antigen receptor (CAR) T cell therapies-axicabtagene ciloleucel, tisagenlecleucel, and lisocabtagene maraleucel-have been approved for relapsed/refractory aggressive diffuse large B cell lymphoma after 2 lines of therapy. Recently, 3 prospective phase 3 randomized clinical trials were conducted to define the optimal second-line treatment by comparing each of the CAR T cell products to the current standard of care: ZUMA-7 for axicabtagene ciloleucel, BELINDA for tisagenlecleucel, and TRANSFORM for lisocabtagene maraleucel. These 3 studies, although largely addressing the same question, had different outcomes, with ZUMA-7 and TRANSFORM demonstrating significant improvement with CD19 CAR T cells in second-line therapy compared with standard of care but BELINDA not showing any benefit. The US Food and Drug Administration has now approved axicabtagene ciloleucel and lisocabtagene maraleucel for LBCL that is refractory to first-line chemoimmunotherapy or relapse occurring within 12 months of first-line chemoimmunotherapy. Following the reporting of these practice changing studies, here a group of experts convened by the American Society for Transplantation and Cellular Therapy provides a comprehensive review of the 3 studies, emphasizing potential differences, and shares perspectives on what these results mean to clinical practice in this new era of treatment of B cell lymphomas.

Genomic landscape of myelodysplastic/myeloproliferative neoplasm can predict response to hypomethylating agent therapy

There are currently no known predictors of myelodysplastic syndrome (MDS)/myeloproliferative overlap neoplasm (MPN) patients' response to hypomethylating agents (HMA). Forty-three patients with MDS/MPN who were treated with HMA during chronic phase and had next-generation sequencing using the established 63-genes panel were identified. Complete and partial remission and marrow response were assessed based on the MDS/MPN International Working Group response criteria. On univariate analysis, younger age, higher number of mutations, and mutations in SETBP1, RUNX1, or EZH2 were associated with no response. Multivariable analysis for modeling response were conducted via least absolute shrinkage and selection operator logistic regression approach, and showed that mutations in SETBP1, RUNX1, or EZH2 predict lack of HMA response. While limited by sample size, our findings suggest that genomic landscape can potentially identify MDS/MPN patients with lower likelihood of response to HMA.

Comparative study of nutritional and functional characteristics of pearl millet, buckwheat, amaranth and unripe banana flours for gluten-free bakery products

Suburbanization and changes in societal habits have led to a paradigm shift towards products that are nutritionally rich and therapeutic. However, the indispensable wheat flour in the bakery industry is also a trigger for gluten-related disorders. The present research focused on the characterization of nutritional and functional properties of glutenfree cereals-pearl millet, buckwheat, amaranth and unripe banana flours in comparison with wheat flour. The data were evaluated using analysis of variance and the difference between specific pair of means was compared using Duncan’s multiple range test at a 95% confidence interval. Pearson correlation analysed the interaction amongst derived parameters. The results were significantly different (p<0.05) except for oil-absorbing capacity. The gluten-free flours reported higher protein (15.55% for amaranth), carbohydrates (82.69% for unripe banana) and energy content (384.72 kcal/g for pearl millet) compared to wheat flour whereas the moisture (6.26% for pearl millet) and fat content (0.98% for unripe banana) were lower. Amaranth had the highest water holding capacity and foam capacity (3.86 mL/g and 26.62% respectively) but the lowest foam stability (89.20%). Pearson correlation showed significant relations among functional properties and food components. Oil-absorbing capacity was found to be positively correlated to protein and negatively to carbohydrates and foam stability. The foam capacity was strongly correlated with different food components. The protein-rich and high energy gluten-free flours along with their functional properties can aid in the development of composite flour and fill the gap in the demand-supply of the therapeutic gluten-free diet.

Abstract 5435: CCRL2 affects the sensitivity of MDS and secondary AML to azacitidine

INTRODUCTION: We recently found that the atypical chemokine receptor, CCRL2 promotes the growth of MDS and secondary AML (sAML) while CCRL2 knockdown inhibits their growth. The aim of the current study is to investigate if CCRL2 regulates pathways associated with the development of resistance to hypomethylating agents (HMA), commonly used drugs in MDS and occasionally sAML.

MATERIALS AND METHODS: We used lentivirus-mediated transduction of MDS92, MDS-L and TF-1 MDS/sAML cells to suppress CCRL2 expression. Two different shRNA constructs were used. We performed RNA sequencing and gene-set enrichment analysis of CCRL2 knocked down (KD) and wild-type (WT) TF-1 cells. We measured DNA methyl-transferases’ expression by western blot, CD11b and CD71 expression was measured in MDS and sAML cells to assess cell differentiation. Apoptosis was measured by Annexin V/PI staining, and clonogenicity by methylcellulose assays. CD34+ cells were sorted from bone marrow aspirates of MDS patients before the initiation of treatment with HMA by using magnetic beads and measurement of CCRL2 was performed by flow cytometry. Response to HMA in MDS patients was assessed by 6 months of treatment based on the International Working Group response criteria.

RESULTS: CCRL2 KD cells demonstrated suppression of pathways associated with PRC2 complex activity, histone modification, and DNA methylation. CCRL2 KD also lead to a more prominent degradation of DNMT1, DNMT3A and DNTM3B under azacitidine treatment. CCRL2 increased apoptosis in response to 0.5 and 1 μM azacitidine (P&lt;0.010) and MDS-L cells (P&lt;0.010 with both sh1 and sh2). Similarly, CCRL2 knockdown increased morphologic differentiation with both 0.5 and 1 μΜ azacitidine (P&lt;0.010) as well as increased the clonogenic inhibition caused by azacitidine (P&lt;0.05). In order to analyze the effect CCRL2 clinically, we analyzed CCRL2 expression in CD34+ cells from patients undergoing HMA treatment. Non-responders to HMA (progressive disease) express higher levels of CCRL2 compared to CD34+ cells from responders (complete remission, partial remission or stable disease) (P=0.020).

DISCUSSION: Our analysis suggests that CCRL2 regulates the expression of genes associated with induction of PRC2-mediated histone modification and DNA methylation in sAML cells. CCRL2 suppression also increased the sensitivity of MDS and sAML cells to azacitidine. In addition, increased CCRL2 expression in MDS cells is associated with worse response to HMA. These data suggest that targeting CCRL2 has therapeutic potential in MDS and sAML.

Citation Format: Theodoros Karantanos, Patric Teodorescu, Brandy Perkins, Marios Arvanitis, Ilias Christodolou, Christopher Esteb, W. Brian Dalton, Tania Jain, Amy E. DeZern, Lukasz P. Gondek, Mark J. Levis, Gabriel Ghiaur, Richard J. Jones. CCRL2 affects the sensitivity of MDS and secondary AML to azacitidine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5435.

Combination Therapy With Casirivimab/Imdevimab and Remdesivir for Protracted SARS-CoV-2 Infection in B-cell-Depleted Patients

Profoundly B-cell-depleted patients can have prolonged severe acute respiratory syndrome coronavirus 2 infections with evidence of active viral replication, due to inability to mount an adequate humoral response to clear the virus. We present 3 B-cell-depleted patients with prolonged coronavirus disease 2019 infection who were successfully treated with a combination of casirivimab/imdevimab and remdesivir.

Nonmyeloablative Allogeneic Transplantation With Post-Transplant Cyclophosphamide for Acute Myeloid Leukemia With IDH Mutations: A Single Center Experience

INTRODUCTION

Mutations in the IDH1 or IDH2 genes are detected in approximately 20% of cases of acute myeloid leukemia (AML). Few studies have examined the impact of IDH mutations in AML on allogeneic bone marrow transplant (alloBMT) outcomes.

PATIENTS AND METHODS

In this single center study, alloBMT outcomes for 61 patients with IDH-mutated (mIDH) AML were compared to those for 146 patients with IDH-wildtype (wtIDH) AML.

RESULTS

Patients with mIDH AML had a 2-year overall survival (OS) of 85% (95% CI 76%-95%), 2-year relapse free survival (RFS) of 71% (95% CI 59%-85%), 1-year cumulative incidence of relapse (CIR) of 14% (95% CI 5%-23%) and a 1-year cumulative incidence of transplant related mortality (CITRM) of 3% (95% CI 0%-8%). Patients with wtIDH had a 2-year OS of 61% (95% CI 53%-70%), 2-year RFS of 58% (95% CI 50%-67%), 1-year CIR of 27% (95% CI 20%-35%), and a 1-year CITRM of 9% (95% CI 5%-14%). In a univariate analysis cox-proportional hazard model, mIDH was associated with significantly better OS (HR 0.52, 95% CI 0.29-0.96) and a trend toward better RFS (HR 0.60, 95% CI 0.35-1.01). After controlling for donor age, diagnosis, and ELN risk category, mIDH was associated with a nonsignificantly improved OS (HR 0.54, 95% CI 0.29-1.01) and RFS (HR 0.67, 95% CI 0.39-1.15).

CONCLUSION

Among patients with mIDH AML, patients who received a peritransplant IDH inhibitor had improved OS (P = .03) compared to those who did not, but there was no detectable difference for RFS (P = .29).

Gut microbiome correlates of response and toxicity following anti-CD19 CAR T cell therapy

Anti-CD19 chimeric antigen receptor (CAR) T cell therapy has led to unprecedented responses in patients with high-risk hematologic malignancies. However, up to 60% of patients still experience disease relapse and up to 80% of patients experience CAR-mediated toxicities, such as cytokine release syndrome or immune effector cell-associated neurotoxicity syndrome. We investigated the role of the intestinal microbiome on these outcomes in a multicenter study of patients with B cell lymphoma and leukemia. We found in a retrospective cohort (n = 228) that exposure to antibiotics, in particular piperacillin/tazobactam, meropenem and imipenem/cilastatin (P-I-M), in the 4 weeks before therapy was associated with worse survival and increased neurotoxicity. In stool samples from a prospective cohort of CAR T cell recipients (n = 48), the fecal microbiome was altered at baseline compared to healthy controls. Stool sample profiling by 16S ribosomal RNA and metagenomic shotgun sequencing revealed that clinical outcomes were associated with differences in specific bacterial taxa and metabolic pathways. Through both untargeted and hypothesis-driven analysis of 16S sequencing data, we identified species within the class Clostridia that were associated with day 100 complete response. We concluded that changes in the intestinal microbiome are associated with clinical outcomes after anti-CD19 CAR T cell therapy in patients with B cell malignancies.

CAR-T-OPENIA: Chimeric antigen receptor T-cell therapy-associated cytopenias

Chimeric antigen receptor (CAR) T-cell is the most recent version in the evolution of cellular therapy with promising responses, which has revolutionized the management of some hematological malignancies in the current times. As the clinical use has progressed rather rapidly since the first approval in 2017, toxicities beyond cytokine release syndrome and immune effector cell-associated neurological syndrome have surfaced. Cytopenias are common in <30 days ("early"), 30-90 days ("short-term") as well as >90 days ("prolonged"); and have clinical implications to patient care as well as resource utilization. We review the details of etiology, factors associated with cytopenias, and management considerations for patients with cytopenias for each of these time-frames. This would potentially serve as a clinical guide for hematological toxicity or CAR-T-OPENIA, which is commonly encountered with the use of CAR T-cell therapy.

Outcomes of SOT Recipients With COVID-19 in Different Eras of COVID-19 Therapeutics

BACKGROUND

Few reports have focused on newer coronavirus disease 2019 (COVID-19) therapies (remdesivir, dexamethasone, and convalescent plasma) in solid organ transplant recipients; concerns had been raised regarding possible adverse impact on allograft function or secondary infections.

METHODS

We studied 77 solid organ transplant inpatients with COVID-19 during 2 therapeutic eras (Era 1: March-May 2020, 21 patients; and Era 2: June-November 2020, 56 patients) and 52 solid organ transplant outpatients.

RESULTS

In Era 1, no patients received remdesivir or dexamethasone, and 4 of 21 (19.4%) received convalescent plasma, whereas in Era 2, remdesivir (24/56, 42.9%), dexamethasone (24/56, 42.9%), and convalescent plasma (40/56, 71.4%) were commonly used. Mortality was low across both eras, 4 of 77 (5.6%), and rejection occurred in only 2 of 77 (2.8%) inpatients; infections were similar in hypoxemic patients with or without dexamethasone. Preexisting graft dysfunction was associated with greater need for hospitalization, higher severity score, and lower survival. Acute kidney injury was present in 37.3% of inpatients; renal function improved more rapidly in patients who received remdesivir and convalescent plasma. Post-COVID-19 renal and liver function were comparable between eras, out to 90 d.

CONCLUSIONS

Newer COVID-19 therapies did not appear to have a deleterious effect on allograft function, and infectious complications were comparable.

American Society for Transplantation and Cellular Therapy Guidelines for Fellowship Training in Hematopoietic Cell Transplantation and Immune Effector Cell Therapy

The rapidly advancing field of hematopoietic cell transplantation (HCT) as well as the advent of immune effector cell therapy (IEC) has resulted in an increasing number of patients undergoing these therapies and a greater level of expertise required to manage them. Previous guidelines for the training of HCT physicians were last published in 2012. In recognition of the expanding knowledge base and increasing skill set essential to the delivery of these treatment modalities, the American Society for Transplantation and Cellular Therapy Committee on Education has updated these guidelines to reflect nearly a decade of new knowledge in the field of HCT, as well as the evolution of IEC from an experimental modality to a widely utilized and mainstream therapy. The resulting document reflects the Committee on Education's recommended educational structure for programs engaged in the training, evaluation, and mentorship of HCT/IEC trainees.

Nonmyeloablative, HLA-Mismatched Unrelated Peripheral Blood Transplantation with High-Dose Post-Transplantation Cyclophosphamide

High-dose post-transplantation cyclophosphamide (PTCy) is an effective platform for prevention of severe graft-versus-host disease (GVHD) after allogeneic bone marrow (BM) transplantation with mismatched unrelated donors (mMUDs). Previous studies evaluating PTCy with mMUDs favored BM allografts over peripheral blood stem cell transplantation (PBSCT) due to concerns that PBSCT may be associated with an increased risk of acute and chronic GVHD. In addition, haploidentical PBSCT is associated with high rates of cytokine release syndrome (CRS), which is another concern with mMUD PBSCT. This study was conducted to determine the feasibility and safety of using mMUD PBSCT with PTCy as GVHD prophylaxis. Patients who received mMUD PBSCT using a PTCy-based GVHD prophylaxis at Johns Hopkins Hospital as part of a prospective clinical trial of mMUD and non-first-degree relative haploidentical transplantation with PTCy (ClinicalTrials.gov identifier NCT01203722) were included. All patients underwent T cell-replete PBSCT between November 2012 and August 2020. Statistical analyses were performed using the Kaplan-Meier method and proportional subdistribution hazard regression model for competing risks. The 29 patients in the study had a median age of 54 years, with 10 patients (34%) age ≥60 years. Nineteen grafts (66%) were matched for 9/10 HLA loci, 6 (21%) were match for 8/10, and 4 (14%) were matched for 7/10. No primary or secondary graft failure occurred. The median time to neutrophil recovery (≥500/µL) was 17 days, and that to platelet recovery (≥20,000/µL) was 28 days. Full donor chimerism was achieved in all patients by day +60. The cumulative incidence (CuI) of grade II-IV acute GVHD at 180 days was 15% (90% confidence interval [CI], 3% to 26%). There were no cases of severe chronic GVHD, 3 cases of mild chronic GVHD, and 1 case of moderate chronic GVHD. The CuI of nonrelapse mortality (NRM) was 7% (90% CI, NA to 18%) at 1 year. Eighteen patients (62%) experienced mild CRS (grade 1-2), and 1 patient (3%) experienced severe CRS (grade 3-5). At 1 year, the CuI of relapse was 29% (90% CI, 8% to 50%), overall survival was 93% (90% CI, 85% to 100%), progression-free survival was 64% (90% CI, 46% to 88%), GVHD-free relapse-free survival was 41% (90% CI, 23% to 73%), and chronic GVHD-free relapse-free survival was 64% (90% CI, 46% to 88%). Our data indicate that mMUD PBSCT using PTCy-based GVHD prophylaxis is safe and feasible. All patients engrafted, and rates of NRM (7%) and acute GVHD (15%) at 1 year were low. There was only 1 case (3%) of severe CRS. Compared with previously published outcomes, mMUD PBSCT using PTCy-based GVHD prophylaxis has a safety and efficacy profile that may not be different from that of PBSCT from matched donors. These results further solidify that all patients who require blood or BM transplantation should be able to find an acceptable donor.

Fludarabine and Melphalan Compared with Reduced Doses of Busulfan and Fludarabine Improve Transplantation Outcomes in Older Patients with Myelodysplastic Syndromes

Reduced-intensity conditioning (RIC) regimens developed to extend the use of allogeneic hematopoietic stem cell transplantation (HSCT) to older patients have resulted in encouraging outcomes. We aimed to compare the 2 most commonly used RIC regimens, i.v. fludarabine with busulfan (FluBu) and fludarabine with melphalan (FluMel), in patients with myelodysplastic syndrome (MDS). Through the Center for International Blood and Marrow Transplant Research (CIBMTR), we identified 1045 MDS patients age ≥60 years who underwent first HSCT with a matched related or matched (8/8) unrelated donor using an RIC regimen. The CIBMTR's definition of RIC was used: a regimen that incorporated an i.v. busulfan total dose ≤7.2 mg/kg or a low-dose melphalan total dose ≤150 mg/m². The 2 groups, recipients of FluBu (n = 697) and recipients of FluMel (n = 448), were comparable in terms of disease- and transplantation-related characteristics except for the more frequent use of antithymocyte globulin or alemtuzumab in the FluBu group (39% versus 31%). The median age was 67 years in both groups. FluMel was associated with a reduced relapse incidence (RI) compared with FluBu, with a 1-year adjusted incidence of 26% versus 44% (P ≤ .0001). Transplantation-related mortality (TRM) was higher in the FluMel group (26% versus 16%; P ≤ .0001). Because the magnitude of improvement with FluMel in RI was greater than the improvement in TRM with FluBu, disease-free survival (DFS) was better at 1 year and beyond with FluMel compared with FluBu (48% versus 40% at 1 year [P = .02] and 35% versus 27% at 3 years [P = .01]). Overall survival (OS) was comparable in the 2 groups at 1 year (63% versus 61%; P = .4) but was significantly improved with FluMel compared with FluBu at 3 years (46% versus 39%; P = .03). Our results suggest that FluMel is associated with superior DFS compared with FluBu owing to reduced RI in older patients with MDS patients. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Examining disease boundaries: Genetics of myelodysplastic/myeloproliferative neoplasms

Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are clonal myeloid malignancies that are characterized by dysplasia resulting in cytopenias as well as proliferative features such as thrombocytosis or splenomegaly. Recent studies have better defined the genetics underlying this diverse group of disorders. Trisomy 8, monosomy 7, and loss of Y chromosome are the most common cytogenetic abnormalities seen. Chronic myelomonocytic leukemia (CMML) likely develops from early clones with TET2 mutations that drive granulomonocytic differentiation. Mutations in SRSF2 are common and those in the RAS-MAPK pathway are typically implicated in disease with a proliferative phenotype. Several prognostic systems have incorporated genetic features, with ASXL1 most consistently demonstrating worse prognosis. Atypical chronic myeloid leukemia (aCML) is most known for granulocytosis with marked dysplasia and often harbors ASXL1 mutations, but SETBP1 and ETNK1 are more specific to this disease. MDS/MPN with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) most commonly involves spliceosome mutations (namely SF3B1) and mutations in the JAK-STAT pathway. Finally, MDS/MPN-unclassifiable (MDS/MPN-U) is least characterized but a significant fraction carries mutations in TP53. The remaining patients have clinical and/or genetic features similar to the other MDS/MPNs, suggesting there is room to better characterize this entity. Evolution from age-related clonal hematopoiesis to MDS/MPN likely depends on the order of mutation acquisition and interactions between various biologic factors. Genetics will continue to play a critical role in our understanding of these illnesses and advancing patient care.