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

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 (range, 18-72) years 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 (CIR) and non-relapse mortality (NRM) were 2.9% and 3.3%, respectively. Age>=55 was the only predictive factor in multivariable analysis for inferior PFS (HR 3.41, 95% CI: 1.21-9.60; p=0.020) and OS (HR 3.31, 95% CI: 1.08-10.18; p=0.037). Thirteen patients (9%) died in the long-term survivor group, only two of which 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.

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.

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.

Clinical relevance of MYC/BCL2 expression and cell of origin in patients with diffuse large b-cell lymphoma treated with autologous transplant.

Dual expression of MYC and BCL2 proteins (double-expressor lymphoma [DEL]) as well as cell of origin (COO) are important prognostic factors in patients with diffuse large B-cell lymphoma (DLBCL) after conventional chemotherapy. We studied the prognostic impact of DEL and COO in patients with relapsed DLBCL treated with autologous stem cell transplant (ASCT). Three-hundred and three patients with stored tissue samples were identified. Classification was successful in 267 patients: 161 (60%) were DEL/non-double hit (DHL), 98 (37%) were non-DEL/non-DHL, and 8 (3%) were DEL/DHL. Compared to non-DEL/non-DHL, DEL/DHL had worse overall survival while DEL/non-DHL did not significantly differ in overall survival. On multivariable analysis, DEL/DHL, age >60 years, and >2 prior therapies, but not COO, were important prognostic factors for overall survival. When we explored the interaction of COO and BCL2 expression, patients with germinal center B-cell (GCB)/BCL2 (+) had inferior progression-free survival (PFS) compared to GCB/BCL2 (-) patients (HR, 4.97; P = 0.027). We conclude that the DEL/non-DHL and non-DEL/non-DHL subtypes of DLBCL have similar survival after ASCT. The negative impact of GCB/BCL2 (+) on PFS warrants future trials targeting BCL2 after ASCT. The inferior outcomes in DEL/DHL need to be verified in a larger number of patients.

Enhanced Recovery Stem-Cell Transplantation: Multidisciplinary Efforts to Improve Outcomes in Older Adults Undergoing Hematopoietic Stem-Cell Transplant.

PURPOSE: Older adults have unique risk factors for poor outcomes after hematopoietic stem-cell transplant (HSCT). We sought to determine the impact of our multidisciplinary supportive care program, Enhanced Recovery after stem-cell transplant (ER-SCT), on survival outcomes in patients age 65 years and older who underwent HSCT. PATIENTS AND METHODS: In this retrospective study, clinicodemographic data, nonrelapse mortality (NRM), overall survival (OS), and relapse were compared between 64 patients age 65 years and older who underwent allogeneic stem-cell transplant during ER-SCT program's first year, October 2017 through September 2018, and 140 historical controls age 65 years and older who underwent allogeneic HSCT, January 2015 through September 2017. RESULTS: In the ER-SCT cohort, 41% (26 of 64) of patients were women, and the median (range) age was 68 (65-74) years; in the control cohort, 38% (53 of 140) of patients were women, and the median (range) age was 67 (65-79) years. Hematopoietic cell transplant comorbidity index and donor type/cell source were similar between cohorts. The ER-SCT cohort had a lower 1-year NRM rate (13% v 26%, P = .03) and higher 1-year OS rate (74% v 53%, P = .007). Relapse rate did not differ significantly between cohorts. In multivariate analyses, ER-SCT was associated with improved 1-year NRM (hazard ratio, 0.4; 95% CI, 0.2 to 0.9; P = .02) and improved 1-year OS (hazard ratio, 0.5; 95% CI, 0.3 to 0.9; P = .03). CONCLUSION: A multidisciplinary supportive care program may improve NRM and OS in older patients undergoing allogeneic HSCT. Randomized studies are warranted to confirm this benefit and explore which program components most contribute to the improved outcomes.

Sleeping beauty generated CD19 CAR T-Cell therapy for advanced B-Cell hematological malignancies.

Chimeric antigen receptor (CAR) T-cell therapy has emerged recently as a standard of care treatment for patients with relapsed or refractory acute lymphoblastic leukemia (ALL) and several subtypes of B-cell non-Hodgkin lymphoma (NHL). However, its use remains limited to highly specialized centers, given the complexity of its administration and its associated toxicities. We previously reported our experience in using a novel Sleeping Beauty (SB) CD19-specific CAR T-cell therapy in the peri-transplant setting, where it exhibited an excellent safety profile with encouraging survival outcomes. We have since modified the SB CD19 CAR construct to improve its efficacy and shorten its manufacturing time. We report here the phase 1 clinical trial safety results. Fourteen heavily treated patients with relapsed/refractory ALL and NHL were infused. Overall, no serious adverse events were directly attributed to the study treatment. Three patients developed grades 1-2 cytokine release syndrome and none of the study patients experienced neurotoxicity. All dose levels were well tolerated and no dose-limiting toxicities were reported. For efficacy, 3 of 8 (38%) patients with ALL achieved CR/CRi (complete remission with incomplete count recovery) and 1 (13%) patient had sustained molecular disease positivity. Of the 4 patients with DLBCL, 2 (50%) achieved CR. The SB-based CAR constructs allow manufacturing of targeted CAR T-cell therapies that are safe, cost-effective and with encouraging antitumor activity.

Allogeneic hematopoietic cell transplantation for patients with blastic plasmacytoid dendritic cell neoplasm (BPDCN).

Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) is an aggressive hematological malignancy; however, some patients achieve durable remission with allogeneic hematopoietic cell transplantation (allo-HCT). We report on all 17 patients with BPDCN who underwent allo-HCT at our center between 2000 and 2020. The median age was 39 (18-67) years. All (n = 16, 94%), except one patient, had systemic disease involving bone marrow and/or other organs. Ten patients (59%) were in first complete remission (CR1) at allo-HCT. The donor source was matched related or unrelated in ten (59%) and alternate donor in seven (41%) patients. Five (31%) patients developed acute graft-versus-host disease (GVHD), all grade I-II. The cumulative incidence (CI) of chronic GVHD at five-year was 34%. The CI of non-relapse mortality at one-year was 29%. Progression-free survival (PFS) rates at two-year and five-year were 49% (95% CI = 22-71%) and 39% (95% CI = 14-64%), respectively. The two-year and five-year overall survival (OS) rates were 65% (95% CI = 38-82%) and 40% (95% CI = 12-68%), respectively. The five-year rate for both PFS and OS was 80% in CR1 patients versus 0% in patients not in CR1. In conclusion, allo-HCT provides long-lasting remissions in BPDCN patients, particularly when performed in CR1.

Nine-Year Follow-up of Patients with Relapsed Follicular Lymphoma after Nonmyeloablative Allogeneic Stem Cell Transplant and Autologous Transplant.

PURPOSE: To compare outcomes between patients with relapsed follicular lymphoma who received a nonmyeloablative allogeneic stem cell transplant (alloSCT) and those who received an autologous transplant (autoSCT). PATIENTS AND METHODS: We evaluated 194 patients with follicular lymphoma who received an alloSCT (n = 98) or autoSCT (n = 96) at MD Anderson Cancer Center (Houston, TX). The transplant type used was based on donor availability and by Medicare reimbursement guidelines. Patients who received an alloSCT were enrolled in four consecutive trials in which they received fludarabine, cyclophosphamide (or bendamustine), and rituximab conditioning. autoSCT patients received R-BEAM (rituximab, carmustine, etoposide, cytarabine, and melphalan). RESULTS: The median follow-up of survivors was 108 months for the alloSCT group and 102 months for the autoSCT group. Overall survival was significantly better for patients who received an alloSCT compared with those who received an autoSCT (62% vs. 46%; P = 0.048). Similarly, progression-free survival rates were 52% in patients who received an alloSCT and 31% in those who received an autoSCT (P < 0.001), and the 8-year relapse rates were 11% and 43%, respectively (P < 0.0001). Only three patients in the alloSCT group relapsed beyond 3.5 years. In the alloSCT group, the rates for grade 2 to 4 acute graft-versus-host disease (GVHD), grade 3 to 4 acute GVHD, and extensive chronic GVHD were 22%, 9%, and 38%, respectively. In the autoSCT group, the 8-year incidence of secondary myelodysplasia was 11%. Nonrelapse mortality was similar between the two groups (15% vs. 11% at 8 years; P = 0.27). CONCLUSIONS: This study shows that alloSCT is curative and confers superior survival compared with autoSCT in patients with follicular lymphoma.

Guidelines for Infection Prophylaxis, Monitoring and Therapy in Cord Blood Transplantation.

As an alternative stem cell source, cord blood (CB) has many advantages. However, delayed engraftment, lack of transferred immunity, and a significant incidence of acute graft-versus-host disease renders CB transplant (CBT) recipients at high risk of infectious complications. This guidance written by CBT and infectious disease experts outlines evidence-based recommendations for the prevention and treatment of opportunistic infections in adult patients undergoing CBT. Topics addressed include bacterial, fungal, viral, pneumocystis jirovcii and toxoplasmosis prophylaxis, suggested PCR monitoring for viruses, therapy for the most commonly encountered infections after CBT. We review key concepts including the recent important role of letermovir in the prevention of CMV reactivation. In instances where there is a paucity of data, practice recommendations are provided, including the duration of antimicrobial prophylaxis.

Acute graft-versus-host disease is the foremost cause of late nonrelapse mortality.

Despite low nonrelapse mortality (NRM) at day 100 after allogeneic hematopoietic cell transplantation (HCT), NRM at 1 year remains substantial. In this study, we retrospectively analyzed 199 patients who were treated on a phase II clinical trial assessing safety and efficacy of myeloablative fractionated busulfan and fludarabine conditioning regimen for hematologic malignancies. The goal of the study was to identify factors associated with NRM occurring between days 101 and 365 post-HCT and generate a hypothesis for future studies to reduce the risk of NRM at 1 year. We found that a vast majority (83%) of patients who experienced NRM between days 101 and 365 had prior grade II-IV acute graft-versus-host disease (GVHD), which was the leading cause of death either by itself (33.3%) or complicated by infections (37.5%). In multivariate analysis, grade II-IV acute GVHD (hazard ratio (HR) 2.9, 95% confidence interval (CI) 1.3-6.6, p = 0.01) was the only significant predictor of NRM between days 101 and 365. Measures to reduce the risk of acute GVHD could lower the risk of NRM at 1 year and improve overall survival.

Fractionated busulfan myeloablative conditioning improves survival in older patients with acute myeloid leukemia and myelodysplastic syndrome.

BACKGROUND: A myeloablative conditioning regimen can be safely given to older patients and those with comorbidities without increasing nonrelapse mortality (NRM) by fractionating the dose of intravenous busulfan. How this approach compares in efficacy with traditional, nonfractionated, lower dose regimens is unknown. METHODS: Outcomes were compared in patients with acute myeloid leukemia (AML) or myelodysplastic syndrome who received either myeloablative, fractionated busulfan (f-Bu) dosed to achieve an area under the curve of 20,000 µmol per minute (f-Bu20K) over 2 weeks (n = 84) or a standard, nonfractionated, lower busulfan dose regimen of 16,000 µmol per minute (Bu16K) over 4 days (n = 78). Both groups also received fludarabine 40 mg/m2 intravenously for 4 days. Graft-versus-host disease prophylaxis was tacrolimus and methotrexate. Patients in the Bu16K group who had unrelated donors also received antithymocyte globulin. The primary endpoint was progression-free survival. RESULTS: Roughly one-half of the patients were aged >65 years, approximately 40% had poor-risk cytogenetics, approximately 40% of those with AML were not in complete remission, and approximately 40% had a comorbidity index >3. At 2 years, progression-free survival was significantly improved in the f-Bu20K group compared with the Bu16K group (45% vs 24%, respectively; hazard ratio [HR], 0.6; 95% CI, 0.4-0.8; P = .004). This was because of a significant reduction in progression (34% vs 59%, respectively; HR, 0.5; 95% CI, 0.3-0.8; P = .003) without any increase in NRM (21% vs 15%, respectively; HR, 1.4; 95% CI, 0.7-3; P = .3), which resulted in improved overall survival (51% vs 31%, respectively; HR, 0.6; 95% CI, 0.3-0.9; P = .01). CONCLUSIONS: A myeloablative, fractionated busulfan regimen reduces relapse and improves survival without increasing NRM in older patients with AML and myelodysplastic syndrome.

Cytogenetics and Blast Count Determine Transplant Outcomes in Patients with Active Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) patients not in remission and beyond first or second complete remission are considered allogeneic stem cell transplant (SCT) candidates. We present 361 patients who underwent SCT from matched related or unrelated donors between 2005 and 2013. The purpose was to identify a subgroup of patients with active disease at the time of transplant that benefit. Cox proportional hazards regression analysis was used for univariate and multivariate analyses to predict overall survival (OS). Variables considered were age, sex, SWOG cytogenetic risk group, bone marrow (BM) and peripheral blood (PB) blast percentage, regimen intensity, and type of AML. At a median of 26 months after transplantation, OS, progression-free survival (PFS), non-relapse mortality, and relapse rates were 26, 24, 23, and 48%, respectively. In a univariate analysis, risk cytogenetics (p < 0.001) and BM blasts >4% (p = 0.006) or any blasts in PB (p < 0.001) indicated worse OS. In a multivariate analysis, patients with <5% BM blasts or absence of circulating blasts and good or intermediate risk cytogenetics had significantly superior OS (46%), PFS (44%), and disease progression at 3 years. Based on these findings, patients not in remission with good or intermediate risk cytogenetics and low blast counts should be considered for SCT.

Allogeneic Transplantation after Myeloablative Rituximab/BEAM ± Bortezomib for Patients with Relapsed/Refractory Lymphoid Malignancies: 5-Year Follow-Up Results.

Although bortezomib and rituximab have synergistic activity in patients with lymphoma and both can attenuate graft-versus-host disease (GVHD), the drugs have not been used together in patients undergoing allogeneic stem cell transplantation (alloSCT). In this phase I/II trial, we assessed the safety and activity of bortezomib added to the rituximab (R) plus BEAM (carmustine, etoposide, cytarabine, melphalan) regimen in patients with relapsed lymphoma undergoing alloSCT. Primary GVHD prophylaxis consisted of tacrolimus and methotrexate. Bortezomib (1 to 1.3 mg/m2 per dose) was administered i.v. on days -13, -6, -1, and +2. We performed inverse probability weighting analysis to compare GVHD and survival results with an historical control group that received R-BEAM without bortezomib. Thirty-nine patients were assessable for toxic effects and response. The median age was 54 years. The most common diagnosis was diffuse large B cell lymphoma (41%). Twenty-two patients (56%) and 17 patients (44%) received their transplants from matched related and matched unrelated donors, respectively. The maximum tolerated bortezomib dose was 1 mg/m2. The weighted cumulative incidences of grades II to IV and III or IV acute GVHD were 50% and 34%, respectively; these incidences and survival rates were not significantly different from those of the control group. Median survival was not reached in patients age ≤ 50 years and with a long follow-up time of 60.7 months. The R-BEAM regimen has a survival benefit in lymphoma patients age ≤ 50 years undergoing alloSCT. The addition of bortezomib has no impact on survival or incidence of GVHD.

The role of mesenchymal stem cells in oncology and regenerative medicine.

Mesenchymal stem cells (MSCs) have long been used as therapeutic agents in disease affecting various organ systems. However, MSCs are fast emerging as promising anticancer agents which have the potential to treat a number of different cancer types, including glioblastoma and metastatic breast, ovarian and hepatic carcinoma. The ability of MSC to migrate directly into the tumor microenvironment and to produce IFN-α and -ß makes this possible. However, the possibility of MSC undergoing either malignant transformation or transformation into protumorigenic fibroblasts currently limits their role in clinical use. It is hoped that future research can overcome these limitations and facilitate the use of MSC clinically.

Novel clinical uses for cord blood derived mesenchymal stromal cells.

Regenerative medicine offers new hope for many debilitating diseases that result in damage to tissues and organs. The concept is straightforward with replacement of damaged cells with new functional cells. However, most tissues and organs are complex structures involving multiple cell types, supportive structures, a microenvironment producing cytokines and growth factors and a vascular system to supply oxygen and other nutrients. Therefore repair, particularly in the setting of ischemic damage, may require delivery of multiple cell types providing new vessel formation, a new microenvironment and functional cells. The field of stem cell biology has identified a number of stem cell sources including embryonic stem cells and adult stem cells that offer the potential to replace virtually all functional cells of the body. The focus of this article is a discussion of the potential of mesenchymal stromal cells (MSCs) from cord blood (CB) for regenerative medicine approaches.

Frequent human herpesvirus-6 viremia but low incidence of encephalitis in double-unit cord blood recipients transplanted without antithymocyte globulin.

Cord blood transplantation (CBT) is a known risk factor for human herpesvirus-6 (HHV-6) infection. We analyzed the nature of HHV-6 infections in 125 double-unit CBT recipients (median age, 42 years) transplanted for hematologic malignancies with calcineurin inhibitor/mycophenolate mofetil prophylaxis and no antithymocyte globulin. One hundred seventeen patients (94%) reactivated HHV-6 by quantitative plasma PCR (median peak, 7600 copies/mL; range, 100 to 160,000) at a median of 20 days (range, 10 to 59) after transplantation. HHV-6 encephalitis occurred in 2 patients (1.6%), of whom 1 died and 1 recovered with therapy. No association was found between high-level HHV-6 viremia (≥10,000 or ≥25,000 copies/mL) and age, diagnosis, conditioning intensity, or dominant unit characteristics or between high-level viremia and transplant outcomes (engraftment, cytomegalovirus reactivation, day 100 grades II to IV acute graft-versus-host disease, day 100 transplant-related mortality, or 1-year disease-free survival). HHV-6 therapy delayed the onset of cytomegalovirus reactivation. Interestingly, HHV-6 resolution was observed in untreated patients, and resolution of viremia correlated with absolute lymphocyte count recovery. We observed a low incidence of encephalitis and no association with CBT outcomes. Our data suggest therapy in uncomplicated viremia may not be warranted. However, further investigation of the risk-to-benefit of HHV-6 viremia treatment and standardization of PCR testing is required.