Lower intensity therapy with cladribine/low dose cytarabine/venetoclax in older patients with acute myeloid leukemia compares favorably with intensive chemotherapy among patients undergoing allogeneic stem cell transplantation.

BACKGROUND: Allogeneic stem cell transplantation (SCT) remains the best consolidative modality in most patients with acute myeloid leukemia (AML). Along with factors directly pertaining to SCT, pretransplantation disease control, performance status, and prior treatment-related complications are important factors that affect posttransplantation survival outcomes. METHODS: The authors compared the survival outcomes of patients ≥60 years of age treated on the phase 2 clinical trial of venetoclax (Ven) added to cladribine (CLAD) and low dose cytarabine (LDAC) alternating with azacitidine (CLAD/LDAC/Ven arm) (NCT03586609) who underwent allogeneic SCT in first remission to a retrospective cohort of patients ≥60 years of age who underwent SCT after intensive chemotherapy. Intensive chemotherapy was defined as the use of cytarabine >1 g/m2 and anthracyclines during induction/consolidation. RESULTS: Thirty-five patients at median age of 68 years in the CLAD/LDAC/Ven arm were compared to 42 patients at a median age of 62 years in the intensive therapy arm. The 2-year relapse-free survival was superior with CLAD/LDAC/Ven versus intensive chemotherapy (88% vs. 65%; p = .03) whereas the 2-year overall survival (OS) was comparable (84% vs. 70%; p = .14). On a competing event analysis, the 2-year cumulative incidence of relapse (CIR) was significantly lower with CLAD/LDAC/Ven versus intensive chemotherapy (2.9% vs. 17.2%, Gray's p = .049) whereas nonrelapse mortality was comparable (16.2% vs. 17.1%; p = .486). CONCLUSION: In conclusion, treatment with CLAD/LDAC/Ven was associated with favorable outcomes in older patients who underwent subsequent allogeneic SCT. The OS was comparable to that with intensive chemotherapy followed by allogeneic SCT, but the CIR rate was significantly lower.

Long-term outcomes after haploidentical stem cell transplantation for hematologic malignancies.

ABSTRACT: The introduction of posttransplant cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis lead to significant improvements in haploidentical stem cell transplantation (haplo-SCT) outcomes over the past decade. We retrospectively assessed long-term outcomes of patients who had their first haplo-SCT between February 2009 and March 2019. Long-term survivors were defined as patients who were alive and disease-free at 2 years after transplant. Three hundred thirty-five patients with a median age of 48 years (range, 18-72) were identified. Of these, 142 patients were disease-free and alive at 2 years after transplant. The 4-year progression-free survival (PFS) and overall survival (OS) for all study patients were 42% and 47%, respectively. With a median follow-up of 52 months for the long-term survivor group, the 4-year PFS and OS were 94% and 96%, respectively. The 4-year cumulative incidence of relapse and non-relapse mortality (NRM) were 2.9% and 3.3%, respectively. Age ≥55 years was the only predictive factor in multivariate analysis for inferior PFS (hazard ratio [HR], 3.41; 95% confidence interval [CI], 1.21-9.60; P = .020) and OS (HR, 3.31; 95% CI, 1.08-10.18; P = .037). Thirteen patients (9%) died in the long-term survivor group, only 2 of whom died of relapsed disease. Secondary primary malignancy was the most frequent cause of NRM (n = 4), followed by infection (n = 2). For haplo-SCT with PTCy-based GVHD prophylaxis, our findings suggest an excellent long-term survival for patients who were disease-free and alive at 2 years after transplant. Late relapses were rare, and age was the only predictive factor for long-term outcomes.

ABT199/venetoclax synergism with thiotepa enhances the cytotoxicity of fludarabine, cladribine and busulfan in AML cells.

ABT199/venetoclax, an inhibitor of the pro-survival BCL-2 protein, has improved AML treatment. Its efficacy in hematopoietic stem cell transplantation (HSCT), when combined with other chemotherapeutic drugs, has not been thoroughly investigated. The present study demonstrates the synergistic cytotoxicity of ABT199/venetoclax with the DNA alkylator thiotepa (Thio) in AML cells. Cleavage of Caspase 3, PARP1 and HSP90, as well as increased Annexin V positivity, suggest potent activation of apoptosis by this two-drug combination; increased levels of γ-H2AX, P-CHK1 (S317), P-CHK2 (S19) and P-SMC1 (S957) indicate an enhanced DNA damage response. Likewise, the increased level of P-SAPK/JNK (T183/Y185) and decreased P-PI3Kp85 (Y458) suggest enhanced activation of stress signaling pathways. These molecular readouts were synergistically enhanced when ABT199/venetoclax and Thio were combined with fludarabine, cladribine and busulfan. The five-drug combination decreased the levels of BCL-2, BCL-xL and MCL-1, suggesting its potential clinical relevance in overcoming ABT199/venetoclax resistance. Moreover, this combination is active against P53-negative and FLT3-ITD-positive cell lines. Enhanced activation of apoptosis was observed in leukemia patient-derived cell samples exposed to the five-drug combination, suggesting a clinical relevance. The results provide a rationale for clinical trials using these two- and five-drug combinations as part of a conditioning regimen for AML patients undergoing HSCT.

Harmonizing definitions for hematopoietic recovery, graft rejection, graft failure, poor graft function, and donor chimerism in allogeneic hematopoietic cell transplantation: a report on behalf of the EBMT, ASTCT, CIBMTR, and APBMT.

Despite emergence of novel therapies to treat hematologic malignancies, allogeneic hematopoietic cell transplantation (allo-HCT) remains an essential treatment modality capable of curing these diseases. Allo-HCT has been also shown to be curative in benign hematologic disorders such as aplastic anemia, sickle cell disease, and thalassemia, among others. Recently, the American Society for Transplantation and Cellular Therapy (ASTCT) published standardized definitions for hematopoietic recovery, graft rejection, graft failure, poor graft function, and donor chimerism. To attempt broader international consensus, a panel of adult and pediatric physician transplant experts was assembled from European Society for Blood and Marrow Transplantation (EBMT), ASTCT, the Center for International Blood and Marrow Transplant Research (CIBMTR), and Asia-Pacific Blood and Marrow Transplantation (APBMT). Consensus was defined as ≥70% of voting members strongly agreeing or somewhat agreeing with a definition. With few exceptions, there was a consensus to endorse the prior ASTCT definitions. Importantly, we revised existing EBMT and CIBMTR data collection forms to align with these harmonized definitions that will facilitate research and international collaboration among transplant researchers and across transplant registries.

Safety and long-term survival results of the addition of inotuzumab ozogamicin to the conditioning regimen of allogeneic stem cell transplantation: A single-center phase 1,2 trial.

Here we report on the first prospective study evaluating the safety and long-term survival when an escalating dose of inotuzumab ozogamicin (INO) (0.6, 1.2, or 1.8 mg/m2 on day 13) was added to one alkylator-containing conditioning regimen in patients with relapsed CD22 (+) lymphoid malignancies who were candidates for hematopoietic stem cell transplantation (HSCT). Twenty-six patients were enrolled. Six (23%) of these patients entered the phase 1 study: four were treated at an INO dose of 0.6 mg/m2 and two at dose of 1.2 mg/m2. None of these patients experienced dose-limiting toxicities. The remaining 20 (77%) patients entered the phase 2 part of the study at the maximum dose of 1.8 mg/m2. One patient developed VOD; this patient had received nivolumab immediately before HSCT while simultaneously experiencing hyperacute graft-vs-host disease (GVHD). Treatment-related mortality (TRM) at 5 years was 12%. With a median follow-up of 48.7 months, the 5-year overall survival (OS) and progression-free survival (PFS) rates were 84% and 80%, respectively. Compared with a historical cohort who received same conditioning for HSCT but without INO (n = 56), the INO group showed no significant differences in incidence of liver toxicity, engraftment time, TRM, or risk of acute GVHD. Patients with lymphoma who received INO had a trend for a better 5-year OS (93% versus 68%) and PFS (93% versus 58%) than those in the control group. In conclusion, our results showed that INO is safe with no increased risk of VOD when combined with one alkylator-containing regimen of HSCT.

Azacitidine Post-transplant Maintenance Improves Disease Progression in High-Risk Acute Myeloid Leukemia and Myelodysplastic Syndrome.

BACKGROUND: Maintenance after allogeneic hematopoietic cell transplantation (alloHCT) with hypomethylating agents has yielded conflicting results. MATERIALS AND METHODS: We conducted a single center retrospective matched-control analysis with the study group (5-azacitidine [AZA] group) including adults with FLT3-negative acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) who received post-transplant AZA maintenance off clinical trial (n = 93). A matched control group was comprised of contemporaneous AML/MDS patients who did not receive any maintenance (n = 357). Primary endpoint was disease progression. RESULTS: The AZA and control groups had comparable patient and disease characteristics except for older age (median: 61 vs. 57 years, P = .01) and lower hematopoietic comorbidity index (median: 2 vs. 3, P = .04) in the AZA group. The 3-year cumulative incidence of progression in the AZA and control groups was 29% vs. 33% (P = .09). The protective effect of AZA on progression was limited to patients with high-risk AML/MDS (HR = 0.4, 95% CI = 0.2-0.8, P = .009). This led to improved progression-free survival both in high-risk AML and MDS patients with maintenance (HR = 0.2, 95% CI = 0.1-0.6, P = .004 and HR = 0.4, 95% CI = 0.2-0.9, P = .04). CONCLUSION: AZA maintenance was associated with a lower progression rate in patients with high-risk FLT3-negative AML or MDS, and AZA maintenance should be considered for post-alloHCT maintenance in this subset.

Eltrombopag improves platelet engraftment after haploidentical bone marrow transplantation: Results of a Phase II study.

Slow platelet recovery frequently occurs after haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with bone marrow graft and post-transplant cyclophosphamide (PCy)-based graft-versus-host disease (GVHD) prophylaxis. Improved platelet recovery may reduce the need for transfusions and improve outcomes. We investigated the safety and efficacy of eltrombopag, a thrombopoietin receptor agonist, at enhancing platelet recovery post-haplo-HSCT. The prospective study included patients ≥18 years of age who received haplo-HSCT with bone marrow graft and PCy. Patients received eltrombopag 300 mg/day starting on Day +5. The primary objective was to estimate platelet engraftment (>50 000/µL by Day 60). In a post hoc analysis, they were compared to a contemporary matched control group who did not receive eltrombopag. One hundred ten patients were included in the analysis (30 eltrombopag and 80 control). Seventy-three percent and 50% of patients in the eltrombopag group and control group, respectively, attained >50 000/µL platelet count by Day 60 (p = .043). No eltrombopag-related grade ≥4 adverse events were observed. Median time to platelet recovery (>20 000/µL) was 29 days with eltrombopag and 31 days for controls (p = .022), while its cumulative incidence was 90% (95% confidence interval [CI]: 78%-100%) with eltrombopag versus 67.5% (95% CI: 57%-78%) for controls (p = .014). Number of platelet transfusions received, overall survival, progression-free survival, GVHD rate, relapse rate, and non-relapse mortality were similar between groups. Overall, eltrombopag is safe and improves platelet recovery in patients undergoing haplo-HSCT with bone marrow graft and PCy.

Safety, efficacy and determinants of response of allogeneic CD19-specific CAR-NK cells in CD19+ B cell tumors: a phase 1/2 trial.

There is a pressing need for allogeneic chimeric antigen receptor (CAR)-immune cell therapies that are safe, effective and affordable. We conducted a phase 1/2 trial of cord blood-derived natural killer (NK) cells expressing anti-CD19 chimeric antigen receptor and interleukin-15 (CAR19/IL-15) in 37 patients with CD19+ B cell malignancies. The primary objectives were safety and efficacy, defined as day 30 overall response (OR). Secondary objectives included day 100 response, progression-free survival, overall survival and CAR19/IL-15 NK cell persistence. No notable toxicities such as cytokine release syndrome, neurotoxicity or graft-versus-host disease were observed. The day 30 and day 100 OR rates were 48.6% for both. The 1-year overall survival and progression-free survival were 68% and 32%, respectively. Patients who achieved OR had higher levels and longer persistence of CAR-NK cells. Receiving CAR-NK cells from a cord blood unit (CBU) with nucleated red blood cells ≤ 8 × 107 and a collection-to-cryopreservation time ≤ 24 h was the most significant predictor for superior outcome. NK cells from these optimal CBUs were highly functional and enriched in effector-related genes. In contrast, NK cells from suboptimal CBUs had upregulation of inflammation, hypoxia and cellular stress programs. Finally, using multiple mouse models, we confirmed the superior antitumor activity of CAR/IL-15 NK cells from optimal CBUs in vivo. These findings uncover new features of CAR-NK cell biology and underscore the importance of donor selection for allogeneic cell therapies. ClinicalTrials.gov identifier: NCT03056339 .

Incidence and risk factors of early onset VOD/SOS differ in younger vs older adults after stem cell transplantation.

ABSTRACT: Veno-occlusive disease (VOD) is a rare but potentially life-threatening complication after allogeneic hematopoietic stem cell transplantation (allo-SCT). Although increasing awareness and modern transplant techniques have mitigated risk, the interaction of historic risk factors in the current era with posttransplant cyclophosphamide (PTCy) is unknown. We performed a retrospective single-center analysis of adult patients aged ≥18 years undergoing allo-SCT (N = 1561) using predominately PTCy as graft-versus-host disease (GVHD) prophylaxis (72%). We found a higher rate of VOD at 16.8% (20 of 119) in those aged ≤25 years compared with 3.8% (55 of 1442) in those aged >25 years, with unique predictors of VOD within each cohort. Multivariate classification and regression tree (CART) analysis confirmed age as the primary independent determinant of the rate of VOD. Among patients aged 18 to 25 years, disease risk index (DRI; 31% with high/very high DRI vs 12% low/intermediate DRI; P = .03) and prior lines of chemotherapy (24% with >1 vs 6% with ≤1; P = .03) were the strongest predictors of VOD. Incidence of VOD in patients aged >25 years of age consistently ranged between 3% and 5% across most risk factors evaluated, with only hepatic factors (baseline elevation of bilirubin, aspartate transferase, alanine aminotransferase) or gemtuzumab exposure associated with increased rates of VOD. There was no significant difference in rates of VOD in those receiving PTCy compared with those receiving alternate GVHD prophylaxis. Our data highlight the differences in incidence and predictors of VOD between younger (≤25) and older (>25) adults undergoing allo-SCT.

The Role of Outpatient Physical Medicine and Rehabilitation in a Multidisciplinary Prehabilitation Program for Older Adults before Allogeneic Hematopoietic Stem Cell Transplant.

INTRODUCTION: Physical rehabilitation is increasingly incorporated throughout the allogeneic hematopoietic stem cell transplant (allo-HSCT) journey for older adults. OBJECTIVE: This study aimed to describe physical medicine and rehabilitation (PM&R)-related diagnoses, exercise barriers, and management recommendations for older adults before allo-HSCT. DESIGN: Fifty PM&R consults as part of the Enhanced Recovery-Stem Cell Transplant (ER-SCT) multidisciplinary prehabilitation program at a comprehensive cancer center were retrospectively reviewed. RESULTS: Many PM&R-related diagnoses (173), exercise barriers (55), and management recommendations (112) were found. Common diagnoses were musculoskeletal dysfunction (more commonly back, shoulder, then knee) (n = 39, 23%) and fatigue (n = 36, 21%). Common exercise barriers were also musculoskeletal dysfunction (more commonly back, knee, then shoulder) (total n = 20, 36%) and fatigue (n = 20, 36%). Most patients (n = 32, 64%) had 1 or more exercise barriers. Common PM&R management recommendations were personalized exercise counseling (n = 37, 33%), personalized nutrition management (n = 19, 17%), body composition recommendations (n = 17, 15%), medications (n = 15, 13%), and orthotics and durable medical equipment (n = 8, 7%). CONCLUSION: Routine PM&R referral of older allo-HSCT patients for prehabilitation resulted in the identification of many rehabilitative needs and substantial additional management recommendations. Increased early, collaborative prehabilitation efforts between PM&R and allo-HSCT teams to optimize care for these patients is recommended.

Characteristics and Outcomes of Patients With Multiple Myeloma Who Developed Therapy-Related Acute Myeloid Leukemia and Myelodysplastic Syndrome After Autologous Cell Transplantation.

Patients with multiple myeloma (MM) who undergo high-dose chemotherapy and autologous hematopoietic cell transplantation (Auto-HCT) have an increased risk of developing therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML). We retrospectively reviewed the medical records of all MM patients who underwent an Auto-HCT at our institution between 1 January and 31 December 2018 and later developed t-MDS/AML. Among the 2982 patients who underwent at least 1 Auto-HCT, 55 (2%) developed t-MDS/AML (MDS, n = 52; AML, n = 3). The median age at t-MDS/AML diagnosis was 66 years (range 43-83 years), and the median time from Auto-HCT to t-MDS/AML diagnosis was 58.5 months (range 6-206 months). At diagnosis, all 3 patients with tAML and 65% of those with therapy-related myelodysplastic syndrome (tMDS) had high-risk disease, per 2022 European LeukemiaNet and R-IPSS, respectively, and 62% had TP53 gene mutations. Patients who developed tMDS/AML were older at MM diagnosis (median 61 versus 59 years; P = .06), more often were male (73% versus 58%; P = .029), received more than 2 years of lenalidomide maintenance (57% versus 39%; P = .014), and experienced complete remission more frequently after Auto-HCT compared to those who did not develop t-MDS/AML (56% versus 40%; P = .012). In a multivariable model, male gender, advanced age at MM diagnosis, experiencing complete remission after Auto-HCT, and lenalidomide maintenance were independent predictors of developing t-MDS/AML. Among the patients who developed t-MDS/AML, 14 (25%) underwent allogeneic hematopoietic stem transplantation (Allo-HCT). After a median follow-up of 9.9 months from t-MDS/AML diagnosis, the median overall survival (OS) after t-MDS/AML diagnosis was 11.8 months for all patients, and 18.2 months versus 11.1 months for Allo-HCT recipients versus nonrecipients, respectively (P = .25). On univariate analysis, receiving an alkylator as induction for MM (hazard ratio [95% confidence interval]: 2.9 [1.3-6.3]; P = .009), age > 60 years (3.1 [1.2-8.2]; P = .025), and higher-risk R-IPSS (2.7 [1.3-6.0]; P=0.011) predicted worse OS after t-MDS/AML diagnosis. None of these retained significance in the multivariable analysis. T-MDS/AML after Auto-HCT for MM is associated with aggressive disease characteristics, including high-risk cytogenetics and TP53 mutations. The outcomes of patients remain poor, even with Allo-HCT. A better understanding of disease biology and novel therapeutic approaches is warranted.

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.

Synergistic cytotoxicity of fludarabine, clofarabine, busulfan, vorinostat and olaparib in AML cells.

Combinations of nucleoside analog(s) and DNA alkylating agent(s) are used for cancer treatment as components of pre-transplant regimens used in hematopoietic stem cell transplantation. Their efficacies are enhanced by combining drugs with different mechanisms of action, which also allows a reduction in the individual drug dosages and thus potentially in toxicity to the patient. We hypothesized that addition of SAHA and olaparib, an HDAC- and a PARP-inhibitor, respectively, to the established combination of fludarabine, clofarabine and busulfan would enhance AML cell cytotoxicity. Exposure of the AML cell lines KBM3/Bu2506, MV4-11, MOLM14 and OCI-AML3 to the 5-drug combination resulted in synergistic cytotoxicity with combination indexes < 1. Increased protein acetylation and decreased poly(ADP-ribosyl)ation were observed, as expected. Activation of apoptosis was suggested by cleavage of Caspase 3 and PARP1, DNA fragmentation, increased reactive oxygen species, and decreased mitochondrial membrane potential. The reduction in poly(ADP-ribosyl)ation was independent of caspase activation. Several proteins involved in DNA damage response and repair were downregulated, which may be contributing factors for the observed synergism. The increased phosphorylation of DNAPKcs suggests inhibition of its kinase activity and diminution of its role in DNA repair. A similar synergism was observed in patient-derived cell samples. These findings will be important in designing clinical trials using these drug combinations as pre-transplant conditioning regimens for AML patients.

Characteristics and outcomes of children, adolescents and young adults with relapsed/refractory non-hodgkin lymphoma undergoing autologous stem cell transplant.

BACKGROUND: There is paucity of data regarding outcomes of children, adolescents and young adults (CAYA) patients with non-Hodgkin lymphoma (NHL) undergoing autologous stem cell transplantation (ASCT). METHODS: Patients aged 0-39 years undergoing first ASCT for NHL at MD Anderson Cancer Center between 2000 and 2020 were analyzed. RESULTS: Two hundred twenty-one patients were included in the analysis, 129 (58%) were male and the median age was 32 (range 6-39) years. The most common histological subtypes were diffuse large B cell lymphoma (DLBCL) (44%), T-NHL (19%) and primary mediastinal B-Cell lymphoma (PMBCL) (19%). Younger patients (age ≤ 25) had lower incidence of DLBCL and higher incidence of PMBCL and T-NHL compared to older patients (age > 25) (P = 0.02). None of the younger patients had double hit (DH)/double expressor (DE) DLBCL, compared to 14 patients in the older age group (18%, P = 0.07). Considering the three main aggressive NHL subtypes (DLBCL, PMBCL and T-NHL), younger patients had numerically better 15-year post-transplant progression free survival (PFS) (67% vs. 54%) and overall survival (OS) (71% vs. 62%) compared to older patients, yet these differences did not reach statistical significance (P = 0.19 and P = 0.24, respectively). In multivariate analysis, not achieving a CR prior to ASCT was independently predictive of worse PFS [partial remission (PR) (HR, 3.9); stable disease (SD) (HR, 18.0), P = 0.03] and of worse OS [PR (HR, 4.2), SD (HR, 6.5) and progressive disease (HR, 4.7), P < 0.0001]. DH/DE status was an independent adverse predictor of PFS in multivariate analysis (HR 5.8, p = 0.03). Ten patients (4.5%) (all aged > 25 years) developed second primary malignancies (SPM), at a median of 34.4 (range, 1.0-196.6) months after ASCT, and SPM was the cause of death in five (50%) of them. CONCLUSIONS: CAYA NHL patients aged ≤ 25 years who received ASCT presented a distinct NHL histology as compared to older CAYA patients, and none in this younger age group had DH/DE DLBCL. We observed a trend towards improved PFS and OS in younger patients. Disease status at ASCT was predictive of both PFS and OS. DH/DE status was an adverse predictor of PFS.

Transplantation Outcomes of Myelofibrosis with Busulfan and Fludarabine Myeloablative Conditioning.

Outcomes of myelofibrosis (MF) with allogeneic stem cell transplantation (allo-SCT) have improved over the past decade, related in part to advances in supportive treatments and conditioning regimens. Several factors are known to predict transplantation outcomes. However, most studies lack homogeneity in conditioning regimens used, limiting their ability to assess prognostic factors on transplantation outcomes. We aimed to identify the risk factors that predict transplantation outcomes in patients with MF who underwent matched or mismatched allo-SCT using a uniform myeloablative conditioning regimen consisting of busulfan and fludarabine with tacrolimus and methotrexate-based graft-versus-host disease prophylaxis. This single-center study included patients with MF who underwent allo-SCT with a matched unrelated donor (MUD), matched related donor (MRD), or mismatched unrelated donor (MMUD) and received busulfan and fludarabine conditioning with methotrexate/tacrolimus-based GVHD prophylaxis. Sixty-five patients with MF met the study criteria and were included in our analysis. At a median follow-up of 35.6 months, the 3-year cumulative incidence of relapse (CIR), nonrelapse mortality (NRM), and overall survival (OS) for all study patients were 27%, 20%, and 65%, respectively. In a multivariable analysis for CIR, prior use of JAK inhibitors was significantly associated with a decreased risk of relapse (hazard ratio [HR], .33; 95% confidence interval [CI], .11 to .99; P = .048). For NRM, Hematopoietic Cell Transplantation Comorbidity Index (≥3 versus <3; HR, 10.09; 95% CI, 2.09 to 48.76; P = .004) and donor type (MUD versus MRD: HR, 5.38; 95% CI, 1.14 to 25.30; P = .033; MMUD versus MRD: HR, 10.73; 95% CI, 1.05 to 109.4; P = .045) were associated with an increased risk of mortality. Likewise for OS, HCT-CI (≥3 versus <3; HR, 3.31; 95% CI, 1.22 to 8.99; P = .019) and donor type (MMUD versus MRD: HR, 5.20; 95% CI, 1.35 to 19.98; P = .016) were significantly associated with inferior survival. Longer time from diagnosis to allo-SCT seemed to confer worse survival, but the difference did not reach statistical significance (>12 months versus ≤12 months: NRM: HR, 7.20; 95% CI, .96 to 53.94; P = .055; OS: HR, 2.60; 95% CI, .95 to 7.14; P = .06). In a homogenous cohort of MF patients uniformly treated with busulfan/fludarabine myeloablative conditioning and methotrexate-based GVHD prophylaxis, we show that donor choice and HCT-CI are the 2 strongest predictors for improved survival after allo-SCT.

High-Dose Chemotherapy and Autologous Stem Cell Transplantation for Relapsed or Refractory Primary Mediastinal Large B-Cell Lymphoma.

Primary mediastinal large B-cell lymphoma (PMBCL) is an uncommon, aggressive type of non-Hodgkin lymphoma. Rituximab-containing chemoimmunotherapy with or without radiation therapy (RT) is standard first-line treatment. Relapsed or refractory (R/R) disease has long been treated with salvage chemotherapy followed by high-dose chemotherapy (HDC), with autologous stem cell transplantation (ASCT) in appropriate patients. We retrospectively analyzed all patients with R/R PMBCL treated with HDC/ASCT at our center between January 2000 and August 2022. The 60 study patients received either rituximab-BEAM (n = 37) or rituximab-gemcitabine/busulfan/melphalan (R-GemBuMel) with or without vorinostat (n = 23), followed by ASCT. Forty-six patients received mediastinal RT, either as prior consolidation of frontline therapy or following ASCT. At median follow-up of 6 years (range, .3 to 21 years), the 5-year progression-free survival (PFS) and overall survival (OS) rates of the whole group were 58% and 77%, respectively, for the entire cohort, 51% and 65% for the R-BEAM recipients, and 69% and 82% for R-vorinostat/GemBuMel recipients. Multivariable analyses showed that a negative positron emission tomography scan at ASCT (hazard ratio [HR], .28) and involvement of only 1 organ (HR, .33) were independently associated with improved PFS. In addition, receipt of R-vorinostat/GemBuMel (HR, .23) was an independent favorable predictor of OS. Our data indicate that HDC/ASCT is effective in R/R PMBCL, with improved outcomes in patients receiving R-vorinostat/GemBuMel.

Myeloablative fractionated busulfan for allogeneic stem cell transplant in older patients or patients with comorbidities.

Traditional conditioning regimens for patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) provide suboptimal outcomes, especially for older patients and those with comorbidities. We hypothesized that a fractionated myeloablative busulfan dose delivered over an extended period would reduce nonrelapse mortality (NRM) while retaining antileukemic effects. Here, we performed a phase 2 trial for adults with hematological malignancies receiving matched related or unrelated allo-HCT. Participants received busulfan 80 mg/m2 as outpatients on days -20 and -13 before transplant. Fludarabine 40 mg/m2 was administered on days -6 to -3, followed by busulfan dosed to achieve a target area under the curve of 20 000 mol/min for the whole course. The primary end point was day-100 NRM. Seventy-eight patients were included, with a median age of 61 years (range, 39-70 years), who received transplantation for acute leukemia (24%), myelodysplastic syndrome (27%), or myeloproliferative disease/chronic myeloid leukemia (44%). HCT-specific comorbidity index (HCT-CI) was ≥3 in 34 (44%). With a median follow-up of 36.4 months (range, 2.9-51.5), the 100-day, 1-year, and 3-year NRM rates were 3.8%, 8%, and 9.3%, respectively, without a significant difference in age or HCT-CI score. The 1-year and 3-year relapse incidence was 10% and 18%, respectively. The 3-year overall survival was 80%, without a significant difference in age or HCT-CI score and was similar for patients aged >60 years and those aged <60 years as well as for those with HCT-CI ≥3 and HCT-CI <3. Overall, a myeloablative fractionated busulfan regimen has low NRM without an increase in relapse rate, resulting in promising survival, even in older patients or in patients with comorbidities. This trial was registered at www.clinicaltrials.gov as #NCT02861417.