Allogeneic transplantation after immunotherapy for relapsed/refractory non-Hodgkin lymphoma: a comparison with a historical cohort.

BACKGROUND AIMS: New immunotherapy drugs, such as bispecific T-cell engager antibodies, checkpoint inhibitors and antibody-drug conjugates, are commonly used as salvage therapy for patients with non-Hodgkin lymphoma relapsing after chimeric antigen receptor (CAR) T-cell therapy. Nevertheless, their potential long-term effects on the outcome of allogeneic stem cell transplantation (Allo-SCT) are not well known. METHODS: We retrospectively analyzed the outcomes of 27 relapsed/refractory non-Hodgkin lymphoma patients receiving Allo-SCT after immunotherapy in the pre-CAR T-cell therapy era and compared them with a historical cohort of 28 subjects undergoing Allo-SCT after conventional therapy. RESULTS: The two cohorts had similar outcomes in terms of graft-versus-host disease/relapse-free survival (4 years, 59% versus 46%), overall survival (4 years, 77% versus 44%), non-relapse mortality (4 years, 19% versus 22%) and acute (6 months, 15% versus 21%) and chronic (4 years, 18% versus 24%) graft-versus-host disease. Of note, the cumulative incidence of relapse was lower after immunotherapy (4 years, 4% versus 14%), although significance was not reached. The cumulative incidence of cytomegalovirus and fungal infection did not differ among the two cohorts. CONCLUSIONS: Consolidation with Allo-SCT is a safe and curative option for patients achieving disease response after new immunotherapy drugs that could represent a desirable salvage strategy for patients relapsing after CAR T-cell therapy.

Outcome of High-Dose Chemotherapy Followed by Autologous Stem Cell Transplantation in Relapsed/Refractory Hodgkin Lymphoma after Different Numbers of Salvage Regimens.

The introduction of novel drugs (PD-1 inhibitors and/or brentuximab vedotin) into salvage regimens has improved the response rate and the outcome of patients with relapsed/refractory Hodgkin lymphoma. However, the impact of new drugs on the outcome has not been adequately investigated so far. We retrospectively analyzed 42 consecutive patients treated at our institution with high-dose chemotherapy/autologous stem cell transplantation after either one standard chemotherapy represented by BEGEV (n = 28) or >1 salvage therapy (ST) comprising novel drugs (n = 14). With a median follow-up of 24 months, the 2-year cumulative incidence of relapse was similar between the two cohorts: 26% for 1 ST and 18% for >1 ST (p = 0.822). Consistently, overall survival and progression-free survival did not differ among the two groups: 3-year overall survival was 91% and 89% (p = 0.731), respectively, and 3-year progression-free survival was 74% and 83% (p = 0.822) for only one and more than one salvage regimens, respectively. Of note, the post-transplant side effects and engraftment rates were similar between the 1 ST and >1 ST cohorts. In conclusion, consolidation with high-dose chemotherapy/autologous stem cell transplantation is a safe and curative option, even for patients achieving disease response after more than one rescue line of therapy.

Impact of Preemptive Use of Tocilizumab on Chimeric Antigen Receptor T Cell Outcomes in Non-Hodgkin Lymphoma.

Despite the impressive results of chimeric antigen receptor (CAR) T cell treatment for lymphomas, adverse events such as cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and infections are major issues that can lead to intensive care unit (ICU) admission and death. Current guidelines recommend tocilizumab for treating patients with CRS grade (G) ≥2; however, the optimal timing of intervention has yet to be determined. Our institution adopted the preemptive use of tocilizumab in cases of persistent G1 CRS, defined as fever (≥38 °C) for >24 hours. This preemptive tocilizumab treatment aimed to reduce evolution to severe (G≥3) CRS, ICU admission, or death. We report on 48 prospectively collected consecutive patients with non-Hodgkin lymphoma treated with autologous CD19-targeted CAR T cells. In total, 39 patients (81%) developed CRS. CRS started as G1 in 28 patients, as G2 in patients, and as G3 in 1 patient. Tocilizumab was administered in 34 patients, including 23 patients who received "preemptive" tocilizumab and 11 patients who received tocilizumab for G2 or G3 CRS from the onset of symptoms. CRS resolved without worsening severity in 19 patients out of 23 (83%) who received preemptive tocilizumab; 4 patients (17%) progressed from G1 to G2 for the development of hypotension and quickly responded to the introduction of steroids. No patients treated with a preemptive approach developed G3 or G4 CRS. Ten out of 48 patients (21%) were diagnosed with ICANS, including 5 patients with G3 or G4. Six infectious events occurred. The overall ICU admission rate was 19%. ICANS management was the most relevant reason for ICU admission (7 patients), and no patient required ICU to manage CRS. No deaths from CAR-T toxicity were observed. Our data indicate that preemptive tocilizumab use is feasible and useful in reducing severe CRS and CRS-related ICU admission, with no impact on neurotoxicity or infection rate. Therefore, early use of tocilizumab can be considered, especially for patients at high risk of CRS.

Selected memory T cells infused post-haploidentical hematopoietic stem cell transplantation persist and hyperexpand.

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with post-transplant cyclophosphamide is a curative treatment for many hematological malignancies, yet a majority of patients still suffers from recurrent infections. Post-transplant infusion of memory T-cells could potentially enhance immunological protection without increasing the risk of eliciting acute graft-versus-host disease, which is mainly induced by naïve T-cells. Here, we performed longitudinal analysis of the lymphocyte compartment in 19 patients who underwent haplo-HSCT previously enrolled in a phase II prospective clinical trial (www.clinicaltrials.gov as #NCT04687982), in which they received post-transplant CD45RA-depleted donor lymphocyte infusions (DLI). T-cell receptor sequencing analysis showed that, surprisingly, CD45RA-depleted DLI do not increase T-cell clonal diversity, but lead to prominent expansion of a selected number of infused memory T-cell clones, suggesting recruitment of these cells in the immune response. Pathogen-specific memory T-cells, including cytomegalovirus (CMV)-specific cells, were engrafted and were able to persist for at least 1 month. Deep immunophenotyping revealed strong polyfunctional effector CMV-specific T-cell responses in the majority of patients, with their expansion correlating with the frequency of CMV-specific cells in the donor. These findings provide a rationale behind the suggested improved protection against viral infections in patients receiving CD45RA-depleted DLI.

EASIX predicts non-relapse mortality after haploidentical transplantation with post-transplant cyclophosphamide.

Endothelial Activation and Stress Index (EASIX) is a prognostic score reflecting endothelial damage. It can identify cohorts of patients at higher risk of non-relapse mortality (NRM) after allogeneic stem cell transplantation (SCT) from a matched-related or -unrelated donor. No data are available in the setting of haploidentical-SCT with post-transplant cyclophosphamide (PT-Cy). We retrospectively analyzed the role of EASIX score in a cohort of 266 patients receiving Haplo-SCT with PT-Cy at our center. By a decision-tree model, 1-year NRM was 16% vs. 29% and overall survival was 59% vs. 32%, respectively, for patients with a pre-transplant EASIX (EASIX-PRE) <0.8 vs. ≥0.8 (p < 0.001). By multivariable analysis, EASIX-PRE was an independent predictor of NRM (hazard ratio [HR] 2.43, p < 0.001) and overall survival (HR: 1.64, p = 0.011). EASIX-PRE did not predict patients at higher risk of developing acute graft-versus-host disease (GVHD) but was an independent predictor of 1-year NRM (3.2 cutoff, HR 6.61, p = 0.002; <3.2 vs. ≥3.2: 10% vs. 56%, p < 0.001) in patients developing acute GVHD. EASIX score can also represent an important tool to predict mortality in the setting of Haplo-SCT with PT-Cy. It may help to make therapeutic decisions both before the transplant and at the onset of acute GVHD.

Persistence of KIRneg NK cells after haploidentical hematopoietic stem cell transplantation protects from human cytomegalovirus infection/reactivation.

Haploidentical hematopoietic stem cell transplantation (h-HSCT) is a therapeutic option to cure patients affected by hematologic malignancies. The kinetics and the quality of immune-reconstitution (IR) impact the clinical outcome of h-HSCT and limit the onset of life-threatening Human Cytomegalovirus (HCMV) infection/reactivation. Natural Killer (NK) cells are the first lymphocytes that recover after h-HSCT and they can provide rapid innate immune responses against opportunistic pathogens. By performing a longitudinal single-cell analysis of multiparametric flow-cytometry data, we show here that the persistence at high frequencies of CD158b1b2jneg/NKG2Apos/NKG2Cneg/NKp30pos/NKp46pos (KIRneg) NK cells is associated with HCMV infection/reactivation control. These KIRneg NK cells are "unlicensed", and are not terminal-differentiated lymphocytes appearing early during IR and mainly belonging to CD56bright/CD16neg and CD56bright/CD16pos subsets. KIRneg NK cells are enriched in oxidative and glucose metabolism pathways, produce interferon-γ, and are endowed with potent antiviral activity against HCMV ex vivo. Decreased frequencies of KIRneg NK cells early during IR are associated with clinically relevant HCMV replication. Taken together, our findings indicate that the prolonged persistence of KIRneg NK cells after h-HSCT could serve as a biomarker to better predict HCMV infection/reactivation. This phenomenon also paves the way to optimize anti-viral immune responses by enriching post-transplant donor lymphocyte infusions with KIRneg NK cells.

Risk Factors for Early Cytomegalovirus Reactivation and Impact of Early Cytomegalovirus Reactivation on Clinical Outcomes after T Cell-Replete Haploidentical Transplantation with Post-Transplantation Cyclophosphamide.

Risk factors for cytomegalovirus (CMV) reactivation and the impact of CMV reactivation on patient outcomes have been extensively investigated after matched related or unrelated donor transplantation, but little is known in the setting of haploidentical stem cell transplantation (Haplo-SCT) with post-transplantation cyclophosphamide (PT-Cy), in which recipients are considered more severely immunocompromised. We retrospectively analyzed a cohort of 554 consecutive patients undergoing Haplo-SCT with PT-Cy at 3 different centers. Early CMV reactivation (occurring within the first 120 days post-transplantation) occurred in 242 patients, for an estimated cumulative incidence of 44%. Among those patients, 74 (30%) had recurrent CMV and 20 (8%) had CMV disease. On multivariable analysis, positive recipient CMV serostatus (hazard ratio [HR] >2.5; P < .001), disease histology (lymphoid versus myeloid: HR, 0.66; P = .003) and increasing recipient age (HR, 1.01; P = .015) were independent predictors of CMV reactivation. At a 4-month landmark analysis, CMV reactivation was associated with higher 1-year and 5-year cumulative incidence of nonrelapse mortality (NRM) relative to patients without reactivation: 13% versus 5% and 22% versus 9%, respectively (P < .001). On multivariable analysis, CMV reactivation was an independent negative predictor of NRM (HR, 2.69; P < .001) and was close to statistically significant for overall survival (HR, 1.38; P = .062). Our results suggest that CMV reactivation plays an important role at determining NRM. Because patient CMV serostatus is the main predictor of CMV reactivation, it should be considered when evaluating strategies for preventing CMV reactivation. 2022 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Feasibility and Efficacy of a Pharmacokinetics-Guided Busulfan Conditioning Regimen for Allogeneic Stem Cell Transplantation with Post-Transplantation Cyclophosphamide as Graft-versus-Host Disease Prophylaxis in Adult Patients with Hematologic Malignancies.

Busulfan (Bu) is an alkylating agent routinely used for conditioning regimens before allogeneic stem cell transplantation (allo-SCT). Bu shows wide pharmacokinetic (PK) variability among patients. Patients can have a higher systemic exposure (expressed as area under the curve [AUC]) with an increased risk of toxicity or a lower AUC with a higher probability of graft rejection and/or disease relapse. After i.v. administration, an optimal Bu therapeutic window (AUC target of 16,000 to 24,000 µM·minute) has been identified. The use of PK-guided Bu dosing leads to improved overall survival (OS) and progression-free survival (PFS) compared with fixed-dose administration in a variety of hematologic diseases. The aim of this study was to evaluate the outcomes and feasibility of a reduced-toxicity conditioning (RTC) regimen comprising thiotepa, Bu, and fludarabine (TBF) with therapeutic drug monitoring of Bu in patients with hematologic disorders. We report on 41 adult patients with myeloid or lymphoid malignancies who underwent an allo-SCT with a PK-guided Bu-based RTC regimen between January 2019 and October 2020. Patients received a total Bu dose to achieve a target AUC of 16,000 µM·minute in combination with Flu and thiotepa. The median time to absolute neutrophil count recovery and transfusion-independent platelet count recovery was 23 days (range, 15 to 42 days) and 29 days (range, 14 to 97 days), respectively. The cumulative incidence (CI) of nonrelapse mortality was 7% at 100 days and 13% at 1 year. Grade 3 liver toxicity was observed in 6 patients. One patient developed sinusoidal obstruction syndrome at day +27. Grade 3 mucositis occurred in 18 patients. Looking at grade ≥3 infections, the CI was 29% at 30 days, 34% at 60 days, 44% at 100 days, and 56% at 1 year. The 180-day CI of grade II-IV acute graft-versus-host disease (GVHD) was 15%, and the 1-year CI of overall chronic GVHD was 20%. With a median follow-up of alive patients of 14.4 months (range, 3.2 to 24 months), the CI of relapse at 1 year was 6%. The 1-year PFS was 81%, and 1-year OS was 84%. In conclusion, these data support the efficacy of PK-guided Bu dose in the context of a TBF conditioning regimen and the feasibility of therapeutic dosage monitoring of i.v. Bu for patients with hematologic diseases. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Single-cell profiling identifies impaired adaptive NK cells expanded after HCMV reactivation in haploidentical HSCT.

Haploidentical hematopoietic stem cell transplantation (h-HSCT) represents an efficient curative approach for patients affected by hematologic malignancies in which the reduced intensity conditioning induces a state of immunologic tolerance between donor and recipient. However, opportunistic viral infections greatly affect h-HSCT clinical outcomes. NK cells are the first lymphocytes that recover after transplant and provide a prompt defense against human cytomegalovirus (HCMV) infection/reactivation. By undertaking a longitudinal single-cell computational profiling of multiparametric flow cytometry, we show that HCMV accelerates NK cell immune reconstitution together with the expansion of CD158b1b2jpos/NKG2Aneg/NKG2Cpos/NKp30lo NK cells. The frequency of this subset correlates with HCMV viremia, further increases in recipients experiencing multiple episodes of viral reactivations, and persists for months after the infection. The transcriptional profile of FACS-sorted CD158b1b2jpos NK cells confirmed the ability of HCMV to deregulate NKG2C, NKG2A, and NKp30 gene expression, thus inducing the expansion of NK cells with adaptive traits. These NK cells are characterized by the downmodulation of several gene pathways associated with cell migration, the cell cycle, and effector-functions, as well as by a state of metabolic/cellular exhaustion. This profile reflects the functional impairments of adaptive NK cells to produce IFN-γ, a phenomenon also due to the viral-induced expression of lymphocyte-activation gene 3 (LAG-3) and programmed cell death protein 1 (PD-1) checkpoint inhibitors.

Nonmyeloablative Conditioning Regimen Including Low-Dose Total Marrow/Lymphoid Irradiation Before Haploidentical Transplantation with Post-Transplantation Cyclophosphamide in Patients with Advanced Lymphoproliferative Diseases.

Low-dose total body irradiation (TBI) has long been used in nonmyeloablative conditioning (NMAC) regimens before allogeneic stem cell transplantation from haploidentical donors (haplo-SCT). More recently, the use of total marrow lymphoid irradiation (TMLI) instead of TBI in conditioning is increasing. This study aimed to evaluate outcomes in a cohort of patients treated with low-dose TMLI in terms of engraftment, full donor chimerism status, graft-versus-host disease (GVHD), and extrahematologic toxicities, and to compare these outcomes with those in a cohort of patients receiving conventional TBI-containing conditioning. This retrospective single-center study included 100 patients with advanced hematologic malignancies who underwent haplo-SCT. Between 2009 and 2011, the NMAC regimen consisted of cyclophosphamide, fludarabine, and low-dose TBI (2 Gy), and after 2011, TBI was replaced with TMLI (2 Gy). Patients received post-transplantation cyclophosphamide, calcineurin inhibitor, and mycophenolate mofetil as GVHD prophylaxis. For all patients, the median time to absolute neutrophil count (ANC) recovery to >0.5 × 109/L was 21 days (range, 15 to 49 days), the 30-day incidence of ANC recovery was 97% (95% confidence interval [CI], 89% to 99%), the median time to achieve an unsupported platelet count >20 × 109/L was 26 days (range, 12 to 67 days), and the 60-day rate of platelet engraftment was 99% (95% CI, 89% to 100%). Cumulative incidence of full donor chimerism by day 100 was 88% (95% CI 79-90). Grade II-IV acute GVHD occurred in 35% of the patients (95% CI, 26% to 45%) at a median of 40 days (range, 23 to 166 days). The incidence of moderate to severe chronic GVHD was 5% (95% CI, 2% to 10%). No differences between the TBI and TMLI cohorts were seen in terms of engraftment, full donor chimerism, and GVHD. No organ toxicity was observed in the first months after transplantation in either cohort. The overall 2-year OS and PFS rates were 63%, and 54%, respectively, and were comparable in the 2 groups (P = .548). The strongest finding was that TBI can be safely replaced by TMLI in terms of engraftment, achievement of full donor chimerism status, GVHD incidence, and extrahematologic toxicities.

Multicenter Phase II Study on Haploidentical Bone Marrow Transplantation Using a Reduced-Intensity Conditioning Regimen and Posttransplantation Cyclophosphamide in Patients with Poor-Prognosis Lymphomas.

Allogeneic stem cell transplantation from haploidentical donors using unmanipulated bone marrow and posttransplantation cyclophosphamide has been largely employed to cure high-risk lymphomas. However, the increased incidence of relapse associated with the use of a nonmyeloablative conditioning regimen is still considered a concerning issue. The aim of our study was to prospectively evaluate the efficacy and feasibility of a reduced-intensity conditioning regimen, including thiotepa, cyclophosphamide, and fludarabine, in high-risk lymphoma patients. This was a prospective multicenter study. We enrolled 49 patients, of whom 47 were evaluable. Graft source (bone marrow) and graft-versus-host disease (GVHD) prophylaxis were the same for all patients. The primary endpoint was the proportion of patients free of disease progression at 1 year. The primary endpoint was met, as 29 out of 47 patients were alive and free of disease at 1 year (1-year progression-free survival, 60%). Forty-five recipients engrafted and achieved full donor chimerism at day 100. The cumulative incidences (CIs) of ANC engraftment at 30 days and platelet engraftment at 60 days were 89% and 83%, respectively. Two patients experienced graft failure. The CIs of day 100 grades 2 to 4 acute GVHD and 2-year moderate-to-severe chronic GVHD were 26% and 16%, respectively. With a median follow-up of 47.5 months (range, 22 to 74), the 4-year progression-free survival and overall survival were 54% and 64%, respectively. The 4-year CI of relapse was 28%, and the 4-year nonrelapse mortality was 15%. Thiotepa-based reduced-intensity conditioning was well tolerated with encouraging survival in a cohort of patients with poor-prognosis lymphoma. Both the incidence of relapse and nonrelapse mortality were acceptable.

Feasibility and Efficacy of CD45RA+ Depleted Donor Lymphocytes Infusion After Haploidentical Transplantation With Post-Transplantation Cyclophosphamide in Patients With Hematological Malignancies.

Allogeneic stem cell transplantation from haploidentical donor using post-transplantation cyclophosphamide has been used to cure hematological diseases. Because of slow immunological reconstitution, there is an increased incidence of viral infection. The aim of our study was to prospectively evaluate the efficacy and the feasibility of a CD45RA+ depleted donor lymphocytes infusion (DLI) in terms of reduction of viral infection early after haploidentical transplantation. This a prospective single-center study. We enrolled 23 patients, of whom 19 were evaluable. Graft-versus-host disease (GVHD) prophylaxis was the same for all patients. The primary endpoint was 100-day cumulative incidence of viral infections. The primary endpoint was met, because the 100-day cumulative incidence of viral infection was 32%. The median time from transplantation to first CD45RA+ depleted DLI was 55 days (range, 46-63). 28% of patients had cytomegalovirus reactivation, no patients reactivated human herpesvirus-6; 1 patient developed BK virus related hemorrhagic cystitis. Most of the patients received the planned 3 infusions. Only 1 patient had development of grade 2 acute GVHD, and 2 patients had moderate chronic GVHD. All evaluable patients were off immunosuppressive therapy at last follow-up. The median follow-up was 12 months (range, 3-23), the 1-year overall survival and progression-free survival were 79% and 75%, respectively; the 100-day and 1-year non-relapse mortality were 5% and 12%, respectively. CD45RA+ depleted DLI are feasible in patients treated with haploidentical transplantation. The toxic profile is good with a low risk for development of both acute and chronic GVHD.

Development of an Immobilization Device for Total Marrow Irradiation.

PURPOSE: A body frame dedicated to total marrow (lymph node) irradiation (TMI/TMLI) could minimize patient motion during the potentially extended beam-on time with this technique. We present the development of a dedicated immobilization system for TMI/TMLI using volumetric modulated arc therapy. METHODS AND MATERIALS: Since 2010, 59 adult patients were treated with TMI/TMLI using a multi-isocenter volumetric modulated arc therapy technique. Two computed tomographies (CTs) were required (1 head-first supine and 1 feet-first supine) to cover the whole volume. For the first 10 patients, 2 standard commercial frames with personalized masks (with/without personalized vacuum cushion for the lower extremities) were used without specific interfixation (frame A). For the next 49 patients a homemade 3-frame immobilization system was adopted (frame B), where each frame was interlocked with the next one and thermoplastic masks used to fix the patient. The effectiveness of the 2 immobilization systems was assessed by offline/online matching between daily cone beam CT of each isocenter and the simulation CTs. RESULTS: Mean offline shifts for frame A were 3 to 12 mm in anterior-posterior, 2 to 5 mm in cranilal-caudal, and 2 to 6 mm in left-right directions. Larger shifts were found for feet-first supine series (shifts up to 23 mm). In frame B, mean offline shifts were 1 to 4 mm in anterior-posterior, 1 to 4 mm in cranial-caudal, and 1 to 4 mm in left-right directions. Mean online adjustments were -1 ± 4 mm in anterior-posterior, 0 ± 2 mm in cranial-caudal, and 0 ± 4 mm in left-right directions. CONCLUSIONS: The patient positioning shifts for TMI/TMLI irradiation were mitigated by a homemade immobilization system and the use of individualized masks.

Allogeneic stem cell transplantation in poor prognosis peripheral T-cell lymphoma: the impact of different donor type on outcome.

We report the outcome of 68 patients with advanced peripheral T-cell lymphoma receiving transplantation from haploidentical or from conventional donors. The 4-year OS, PFS, 2-year cumulative incidence of relapse and 2-year GRFS was 75%, 70%, 21%, and 51%, respectively. Survival was not affected by donor type. The 2-year NRM was 9%, lower after related or haploidentical donor (21% vs 0% vs 7%; p = 0.06). Grade 2-4 aGVHD cumulative incidence was significantly different after transplantation from haploidentical vs matched sibling vs unrelated donor, and (24% vs 35% vs 58%, p = 0.024). The familial donor cohort was compared to the unrelated cohort. Familial donor induced less grade 2-4 aGVHD, with a trend to less grade 3-4 aGVHD or moderate-severe cGVHD. The OS and PFS were not different, while the relapse risk and NRM were reduced. Allo-SCT is highly effective in T-cell lymphoma, with low NRM and low relapse rate. The incidence of aGVHD was lower after haploidentical transplantation. Related donor may challenge unrelated transplant reducing the risk of relapse and NRM.

Haploidentical related donor compared to HLA-identical donor transplantation for chemosensitive Hodgkin lymphoma patients.

BACKGROUND: Allogeneic stem cell transplantation from haploidentical donor using an unmanipulated graft and post-transplantation cyclophosphamide (PT-Cy) is growing. Haploidentical transplantation with PT-Cy showed a major activity in Hodgkin lymphoma (HL), reducing the relapse incidence. The most important predictive factor of survival and toxicity was disease status before transplantation, which was better in patients with well controlled disease. METHODS: We included 198 HL in complete (CR) or partial remission (PR) before transplantation. Sixty-five patients were transplanted from haploidentical donor and 133 from a HLA identical donor (both sibling and unrelated donors). Survival analysis was defined according to the EBMT criteria. Survival curves were generated by using Kaplan-Meier method and differences between groups were compared by the log rank test or by the log rank test for trend when appropriated. RESULTS: The PFS, OS, and RI were significantly better in patients in CR compared to PR (55% vs 29% p = 0.001, 74% vs 55% p = 0.03, 27% vs 55% p <  0.001, respectively). The 2-year PFS was significantly better for HAPLO than HLA-id (63% vs 37%, p = 0.03), without difference in OS. The 1-year NRM was not different. The 2-year relapse incidence (RI) was lower in the HAPLO group (24% vs 44%, p = 0.008). Patients in CR receiving haplo HSCT showed higher 2-year PFS and lower 2-year RI than those allografted with HLA-id donor (75% vs 47%, p <  0.001 and 11% vs 34%, p < 0.001, respectively). In multivariate analysis, donor type and disease status before transplantation were independent predictors of PFS as well as they predict the risk of relapse. Disease status at transplantation and age were independently associated to OS. CONCLUSIONS: Nonetheless this is a retrospective study, limiting the wide applicability of results, data from this analysis suggest that HLA mismatch can induce a strong graft versus lymphoma effect leading to an enhanced PFS.

Checkpoint inhibition before haploidentical transplantation with posttransplant cyclophosphamide in Hodgkin lymphoma.

We report on 59 Hodgkin lymphoma patients undergoing haploidentical stem cell transplantation (SCT; haplo-SCT) with posttransplant cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis, comparing outcomes based on pretransplant exposure to checkpoint inhibitors (CPIs). Considering pretransplant characteristics, the 2 cohorts (CPI = 29 patients vs no-CPI = 30 patients) were similar, except for the number of prior lines of therapy (6 vs 4; P < .001). With a median follow-up of 26 months (range, 7.5-55 months), by univariate analysis, the 100-day cumulative incidence of grade 2-4 acute GVHD was 41% in the CPI group vs 33% in the no-CPI group (P = .456), whereas the 1-year cumulative incidence of moderate to severe chronic GVHD was 7% vs 8%, respectively (P = .673). In the CPI cohort, the 2-year cumulative incidence of relapse appeared lower compared with the no-CPI cohort (0 vs 20%; P = .054). No differences were observed in terms of overall survival (OS), progression-free survival (PFS), and nonrelapse mortality (NRM) (at 2 years, 77% vs 71% [P = .599], 78% vs 53% [P = .066], and 15% vs 21% [P = .578], respectively). By multivariable analysis, CPI before SCT was an independent protective factor for PFS (hazard ratio [HR], 0.32; P = .037). Stable disease (SD)/progressive disease (PD) was an independent negative prognostic factor for both OS and PFS (HR, 14.3; P < .001 and HR, 14.1; P < .001, respectively) . In conclusion, CPI as a bridge to haplo-SCT seems to improve PFS, with no impact on toxicity profile.

Pretransplant active disease status and HLA class II mismatching are associated with increased incidence and severity of cytokine release syndrome after haploidentical transplantation with posttransplant cyclophosphamide.

Cytokine release syndrome (CRS) represents a life-threatening side effect after haploidentical stem cell transplantation (Haplo-SCT) with posttransplant cyclophosphamide (PT-Cy). Factors predictive of CRS development is still a matter of debate. We retrospectively analyzed 102 consecutive patients receiving a bone marrow (BM) (n = 42) or peripheral blood stem cells (PBSC) (n = 60) Haplo-SCT with PT-Cy. The two cohorts were similar in main patients' characteristics besides disease type (P = .02). Cumulative incidence of grades 1, 2, and ≥3 CRS was 80%, 52%, and 15% at a median of 2, 4, and 7 days, respectively. Moderate/High-grade fever (39°-41°), grade 1 and grade ≥3 CRS occurred more frequently after PBSC relative to BM grafts (68% vs 33%, P = .0005; 87% vs 71%, P = .009; 20% vs 7%, P = .07). Only patients experiencing grade ≥3 CRS had a worse outcome in terms of 1-year overall survival (OS) and nonrelapse mortality (NRM): 39% vs 80% (P = .002) and 40% vs 8% (P = .005), respectively. By univariate analysis the only factors associated with the increased risk of ≥3 CRS were pretransplant disease status (8% for complete remission, 11% for partial remission, and 38% for active disease, P = .002), HLA-DRB1 mismatching (57% vs 14%, P = .007), and PBSC graft (P = .07). By multivariable analysis, only pretransplant disease status (hazard ratio, HR: 6.84, P = .005) and HLA-DRB1 mismatching (HR: 17.19, P = .003) remained independent predictors of grade ≥3 CRS. Only grade ≥3 CRS is clinically relevant for the final outcome of patients receiving Haplo-SCT with PT-Cy, is more frequent after a PBSC graft and is associated with pretransplant active disease and HLA-DRB1 mismatching.

Peripheral Blood Stem Cells versus Bone Marrow for T Cell-Replete Haploidentical Transplantation with Post-Transplant Cyclophosphamide in Hodgkin Lymphoma.

Haploidentical stem cell transplantation (haplo-SCT) with post-transplant cyclophosphamide (PT-Cy) represents a potential curative strategy for patients with Hodgkin lymphoma (HL) when a matched related or unrelated donor is not available. The role of graft source, either bone marrow (BM) or peripheral blood stem cells (PBSCs), in this setting has not been fully elucidated. We performed a retrospective study on 91 patients with HL to compare the outcome after BM (n = 53) or PBSC (n = 38) transplant. Eighty-nine patients engrafted with no difference between BM and PBSCs in terms of median time for neutrophil (20 versus 20 days, P = .405) and platelet (26 versus 26.5 days, P = .994) engraftment. With a median follow-up of 40.2 months, 100-day cumulative incidences of grades II to IV acute graft-versus host disease (GVHD) and grades II to IV acute GVHD were 24% and 4%, respectively. Graft source was not associated with a different risk of acute GVHD both by univariate and multivariate analyses. Consistently, 1-year cumulative incidence of chronic GVHD was 7% with no differences between the 2 graft types (P = .761). Two-year rates of overall survival (OS), progression-free survival (PFS), nonrelapse mortality, and GVHD/relapse-free survival (GRFS) were 67%, 58%, 20%, and 52%, respectively. By univariate analysis, pretransplant disease status was the main variable affecting all outcomes. By multivariate analysis, PBSCs resulted in a protective factor for OS (hazard ratio [HR], .29; P = .006), PFS (HR, .38; P = .001), and GRFS (HR, .44; P = .020). The other independent variables affecting the final outcome were pretransplant disease status and hematopoietic cell transplant-specific comorbidity index. In conclusion, when planning a haplo-SCT with PT-Cy for patients with poor-risk HL, graft type is an important variable to take into account when selecting the best available donor.