Intensity Conditioning Allogeneic Transplantation Research Articles

Ovarian Function Following Reduced Intensity Conditioning (RIC) Allogeneic Hematopoietic Cell Transplantation (HCT): How Fertile Is the Future?

Ovarian Function Following Reduced Intensity Conditioning (RIC) Allogeneic Hematopoietic Cell Transplantation (HCT): How Fertile Is the Future?

Maintenance Therapy with Venetoclax/Azacitidine Can be Safely Given after Venetoclax/FluBu2 RIC Allogeneic Transplantation for the Treatment of High Risk MDS/AML: Results of a Phase 1 Study

Background: Relapse is the main cause of transplant failure. We previously reported safety and durable remissions with venetoclax (Ven) added to fludarabine/busulfan (FluBu2) reduced intensity conditioning allogeneic hematopoietic cell transplantation (HCT) without planned maintenance therapy in patients (pts) with high risk myelodysplastic syndromes (MDS)/acute myeloid leukemia (AML) (Garcia, Blood Advances, 2021). Detectable measurable residual disease (MRD) at day +100 frequently resulted in relapse after transplant. To address relapse risk after VenFluBu2 transplant in this high risk population, we assessed the safety and activity of Ven/Azacitidine (VenAza) maintenance therapy. Methods: In a Phase 1 trial (NCT03613532), pts with an 8/8 HLA-matched donor and diagnosis of AML with <5% blasts (ELN adverse, secondary, or flow MRD positive) or MDS/MPN or MDS with ≥10% blasts (secondary, IPSS higher risk, or TP53mut or RAS pathway mutations) received VenFluBu2 (Ven 400 mg on D-8 to D-2; fludarabine 30 mg/m2/d on D-5 to D-2; IV busulfan 0.8 mg/kg bid on D-5 to D-2), followed by PBSC infusion (D0) and tacrolimus/methotrexate GVHD prophylaxis. Between D42-D90, VenAza maintenance therapy (Ven 400 mg on D1-D14 and Aza 36 mg/m2 IV on D1-D5) was initiated in pts who engrafted and had no evidence of morphologic relapse or uncontrolled GVHD in 42-day (dose level 1) or 28-day (dose level 2) cycles for up to 1 year. DLT was defined as Gr 4 neutropenia/thrombocytopenia >2 wks. Clinical NGS (sensitivity 1-3%) was performed before and after HCT (+28, +100). BH3 profiling analysis was performed on 11 paired blood samples before/after cycle 1 of VenAza. Results: As of 6/2022, 27 pts were enrolled and had the following disease status at time of HCT: 10 AML pts (8 CR, 2 CRi); 16 MDS pts (1 CR, 5 marrow CR (mCR) with hematologic improvement (HI), 5 mCR without HI, 1 HI-erythroid alone, and 4 active disease (5-10% blasts)); and 1 MDS/MPN pt in CR. Pts had a median age of 67y (range 47,78), co-morbidities (52% HCT-CI≥4), 44% were flow MRD negative, and 56% had Ven exposure prior to HCT. Baseline TP53mut was present in 59% (16/27). After VenFluBu2 RIC HCT, 22 of 27 pts received VenAza maintenance therapy (n=11 per dose level); remaining 5 of 27 pts did not (3 relapsed early, 2 withdrew). No DLTs were observed. The most common grade 3-4 treatment emergent adverse events (AE) during maintenance were anemia (45%), neutropenia (95%) and thrombocytopenia (91%), which were mainly transient. Cycle 1 nadir occurred on D29 for ANC (median 1.2 K/µL, range 0,3.7) and on D15 for platelet (median 119 K/µL, range 70,169). Infection during maintenance was reported in only 1 pt (n=1 BK viruria). Serious AEs were reported in 2 (1 rash; 1 BK case). Median of 4 VenAza cycles were received in DL1 (range 1,8); DL2 on-going. Cumulative incidence of grade ≥2 acute GVHD at 6 mo was 22% (95% CI: 9,39) and chronic GVHD at 1y was 23% (95% CI: 8,42). With a median 12 mo follow up (range 4-21), regardless of maintenance status, 1y OS, PFS, NRM and relapse were 70% (95% CI: 46,85), 57% (95% CI: 36,74), 0% and 43% (95% CI: 28,57), respectively. To date, 12 of 27 pts have relapsed (4 before, 7 during, and 1 after maintenance on D523). Ven use prior to HCT did not impact outcome. Pre-transplant flow MRD negativity was associated with improved 1y OS (88% vs 50%, p=0.03) and 1y PFS (81% vs 39%, p=0.08). Flow MRD was positive in 17% (4/24) at D28 and in 44% (11/25) at D100. At time of HCT, NGS was positive in 89% (24/27), but this reduced to 42% (10/24) at D28 and 58% (14/24) at D100 (Figure 1). PFS was similar for those with or without TP53mut at HCT (p=0.14). Among 22 pts that received VenAza maintenance therapy, 1y PFS and 1y OS were 65% (95% CI: 40,82) and 79% (95% CI: 52,92), respectively. BH3 profiling did not reveal any significant changes in baseline apoptotic priming in CD3+, CD3+CD4+, CD3+CD8+ T cells, and CD3+CD4+CD127-CD25+ Treg cells, suggesting VenAza was not cytotoxic to T cells. Flow cytometry to assess for immune recovery is in process. Conclusions: VenAza maintenance therapy after VenFluBu2 RIC alloHCT appears to be safe with low infection rate and no excessive GVHD. This Ven-based peri-transplant strategy for high risk MDS/AML pts has encouraging activity though relapses still occurred. A cohort assessing all oral maintenance (Ven plus decitabine/cedazuridine) is enrolling. A randomized trial will be required to evaluate the benefit of Ven with conditioning chemotherapy or with maintenance therapy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

A Novel Dual-Antigen Targeting Approach Enables Off-the-Shelf CAR NK Cells to Effectively Recognize and Eliminate the Heterogenous Population Associated with AML

While acute myeloid leukemia (AML) treatment has improved, relapse is still common, even after reduced intensity conditioning allogeneic transplantation. Natural killer (NK) cells are a promising allogeneic cell immunotherapy without the risk of graft-versus-host disease or cytokine release syndrome. We and others have reported that haploidentical NK cells can safely result in 30-50% complete remissions in advanced AML patients when given with high-dose lymphodepleting chemotherapy and exogenous cytokine support. However, while NK cell natural cytotoxicity has a clinical signal in AML, increased specificity and multi-dosing are likely to enhance the efficacy and durability of this treatment strategy. A number of stress ligands, including the MHC-I polypeptide-related sequence A and B (MICA/B), bind to the NK cell activating receptor NKG2D and initiate NK cell killing of transformed and infected cells, and several groups have shown promising results in clinical trials by developing NK cells that carry a NKG2D chimeric antigen receptor (CAR). However, the distal α1 and α2 domains of MICA/B that are recognized by NKG2D can be proteolytically cleaved from the surface of the tumor by metalloproteases, allowing for escape from NK cell-mediated detection and elimination. Wucherpfennig and colleagues have described that the membrane proximal α3 domain remains on the cell surface and may be a potential target for immunotherapy across many cancers, including AML. However, since AML is heterogenous, we hypothesized that clinical success would require dual-targeting and selected CD33 as the ideal complementary targeting approach since CD33 is a validated marker expressed on greater than 80% of AML blasts. To this end, our lab has developed a Tri-specific Killer Engager (TriKE) capable of agonistically ligating the CD16 Fc receptor to CD33 found on AML along with IL-15 co-stimulation to further activate the NK cell response. Here, we demonstrate the efficacy of a multiplexed-gene edited induced pluripotent stem-cell (iPSC) derived NK cell (iNK) product that expresses a high-affinity, non-cleavable version of CD16 (hnCD16), a membrane-bound IL-15 fusion receptor, CD38 knockout to enhance metabolic fitness, and a CAR against the α3 domain of MICA/B (α3 MICA/B) to drive a potent response against AML alone and when combined with anti-CD33 TriKE. In the initial study, the iNK cell backbone (iNK cells without the α3 MICA/B CAR) induced potent activity against the AML cell line HL60, and displayed further enhancement of activity with the addition of anti-CD33 TriKE (GTB-3650), representing combined effects of natural cytotoxicity and antibody-dependent cellular cytotoxicity. To show specificity for α3 MICA/B targeting, the AML cell line THP-1 was stained for the presence of MICA/B by flow cytometry using the 6D4 clone that recognizes the α1/2 domains of MICA/B or the 7C6 clone that uniquely recognizes the α3 domain +/- proteolytic cleavage with trypsin (Fig. 1A-B). Significant expression of the α3 domain was observed on THP-1 cells using the 7C6 antibody, which was highly expressed even after protease treatment. On the other hand, the α1/2 domains of MICA/B were detectable at lower levels using the 6D4 antibody and were undetectable after protease treatment (Fig. 1A-B). To assess a dual targeting approach, THP-1 cells were used as targets in live imaging functional assays under standard conditions (Effector:Target [E:T] 2:1). The iNK cell backbone had modest natural cytotoxicity at 3 hours that was significantly enhanced by the addition of α3 MICA/B CAR. The effect was further improved with more rapid killing kinetics when combined with the anti-CD33 TriKE (Fig. 1C). To evaluate the efficacy of dual-targeting in a more stringent physiologic manner, we mimicked "stress” conditions by minimizing the E:T ratio to 0.25:1. While all effector conditions induced immediate killing in 4 hours at the low E:T ratio, sustained tumor control was only observed with dual-antigen targeting (Fig. 1D). Studies with primary AML targets, +/- preincubation of decitabine and all-trans retinoic acid, known to upregulate NKG2D ligands in AML, are in progress and will be discussed. In summary, dual-targeting strategies using off-the-shelf CAR NK cells targeting α3 MICA/B in combination with antigen-specific TriKE targeting CD33 represent an ideal clinical strategy to enhance efficacy and durability of treatment in advanced AML. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Life expectancy and burden of late complications after reduced intensity conditioning allogeneic transplantation.

Reduced intensity conditionings (RIC) before after allogeneic hematopoietic stem cell transplantation (HSCT) allow older or unfit patients of being transplanted, but survival expectancy and burden of late complications are poorly described in this setting. All patients (N = 456) who were alive and relapse-free 2 years after HSCT following RIC were included. Cumulative incidences (CI), standardized incidence, or mortality, ratio (SIR or SMR), and competing risk models were used. The 10-year CIs of relapse and non-relapse mortality incidences were 13.9 and 13.4%, respectively. Seventy-eight patients died, late relapse being the most frequent cause of death leading to a SMR of 6.38 (95% CI, 5.1-8.0; p < 0.001). Among non-relapsing patients (n = 412), 30 died (SMR 4.38; 95% CI, 3.3-5.8: p < 0.001). A total of 37 patients developed 41 SM leading to a 10-year cumulative incidence of 12.9%, and a significant SIR relative to the general population (1.4). Finally, we found high CI of cardiovascular (CVC) and venous thromboembolic complications (VTE) (10-year CI; 15.1% and 11.7%, respectively). Older age was the only significant risk factor for CVC and VTE in multivariable analysis. In conclusion, with life expectancy rate of 70%, late survivors after RIC warrants long-term follow-up and active intervention on averting cardiovascular disease and screening cancers.

Reduced Intensity Conditioning for Allogeneic Transplantation: Modified Fludarabine Dose Plus Cyclophosphamide/Total Body Irradiation Yields Promising Outcomes

Reduced intensity conditioning (RIC) extends the curative potential of allogeneic hematopoietic cell transplantation (HCT) to patients with hematologic malignancies unsuitable for myeloablative conditioning. We prospectively studied a RIC HCT approach for patients with hematologic malignancies and sibling or unrelated donors (URD) from 2001-2016. Patients received cyclophosphamide (Cy) 50mg/kg/day IV day -6, fludarabine (Flu) 40mg/m2/d IV days -6 to -2 and TBI 200cGy on day -1 +/- anti-thymocyte globulin (ATG) on days -6 to -4 for those without prior autografting or recent multidrug chemotherapy. After identifying potential increased non-relapse mortality from excess fludarabine metabolite (F-ara-A) exposure we reduced the fludarabine dosing to 30 mg/m2/d IV days -6 to -2 in late 2009.The 292 patients (median age 58: range 19-75); median follow-up 8 years (IQR range 4-12) included 127 with acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS), 40 aggressive non-Hodgkin lymphoma (NHL), 11 indolent NHL, 21 Hodgkin Lymphoma (HL), 26 multiple myeloma, 14 chronic myeloid leukemia (CML), 23 chronic lymphocytic leukemia (CLL), 17 acute lymphocytic leukemia (ALL), 13 myeloproliferative neoplasms (MPN). Five year overall survival (OS) was 73% (95% CL, 37-90%) for patients with indolent NHL, 53% (95% CL, 36-67%) for aggressive NHL, 55% (95% CL, 31-74%) for HL, 39% (95% CL, 30-48%) for AML/MDS, 32% (95% CL, 15-50%) for myeloma, 50% (95% CL, 23-72%) for CML, 45% (95% CL, 24-46%) for CLL, 15% (95% CL, 2-39%) for MPN and 34% (95% CL, 12-59%) for those with ALL. By donor source, 5 year OS was 46% (95% CL, 40-53%), 25% (95% CL, 6-50%), 38% (95% CL, 22-54%), and 11% (95% CL, 1-35%) using matched sibling donors (n=225), mismatched (MM) sibling PBSC (n=12), matched marrow unrelated donor (URD) (n=37), and matched peripheral blood URD (n=18) (p<0.01) (Figure 1). Fludarabine dosing (30 vs. 40 mg/m2/day x 5) had no significant influence on OS (45 vs. 40%, p=0.42) or 2 year NRM (25% vs. 26%, p=0.86). NRM (overall 26%; 95% CI 21-31%) was significantly worse with MM sibling or URD (either BM or PBSC) compared to matched sibling BM/PBSC. Relapse at 5 years was significantly worse in patients with myeloma (76%) and Hodgkins (53%), intermediate in AML/MDS (37%), but lowest in aggressive (25%) and particularly indolent NHL (0%).These results suggest that: 1) this Cy/Flu/TBI RIC conditioning was well tolerated by an older population; 2) indolent and aggressive NHLs responded best to RIC conditioning highlighting the importance of the graft versus lymphoma (GVL) effect; and 3) reduction in fludarabine dosing did not compromise disease control or survival but did not appear to diminish NRM. Diagnosis, donor source, and HCT-CI remain the dominant factors influencing outcomes. Targeted disease treatments or maintenance therapy to limit relapse might be the best approach to improve overall survival. [Display omitted] DisclosuresBrunstein:Novartis: Research Funding; Magenta Therapeutics: Research Funding. MacMillan:Magenta Therapeutics: Research Funding.

RIC Allogeneic Stem Cell Transplantation for High Risk CLL Followed By Preemptive MRD-Based Immunointervention - Final Results from the Phase II ICLL03 Ricac-Pmm Trial (FILO - SFGM-TC French intergroup)

RIC Allogeneic Stem Cell Transplantation for High Risk CLL Followed By Preemptive MRD-Based Immunointervention - Final Results from the Phase II ICLL03 Ricac-Pmm Trial (FILO - SFGM-TC French intergroup)

Frontline Azacitidine As a Bridge to Allogeneic Transplantation in Acute Myeloid Leukemia

Introduction: Treatment with the hypomethylating agent (HMA) azacitidine (AZA) has become a standard treatment option for older acute myeloid leukemia (AML) patients thought unfit for standard induction chemotherapy with infusional cytarabine and an anthracycline. AZA is generally well-tolerated, and carefully selected AML patients who achieve complete remission (CR) with frontline HMA therapy may subsequently improve to become suitable candidates for reduced intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (HCT) (Lübbert 2009). However, there are very limited data available regarding the use of AZA as a bridge to HCT in AML. The purpose of this study was to evaluate remission status and survival outcomes in patients treated with upfront AZA who undergo HCT.Methods: All AML patients at our institution diagnosed between December 2015 and October 2016 who were initially deemed unfit for intensive chemotherapy and received frontline AZA as a direct bridge to HCT were included in this analysis. Remission statuses after AZA therapy, immediately before transplant, and following transplant were evaluated and categorized as CR, CR with incomplete platelet recovery (CRp), CR with incomplete hematologic recovery (CRi), refractory, or relapsed. Descriptive statistics were used for categorical and continuous variables. The Kaplan-Meier method estimated overall survival (OS) and leukemia-free survival (LFS).Results: Ten patients treated with frontline AZA proceeded directly to HCT; by comparison, during the same period, 17 patients in this age range who received upfront AZA at our institution did not undergo HCT. Of those patients proceeding directly to HCT, there was a male predominance (80%), and median age at diagnosis was 70.5 years (range 60-77; Table 1). Of the 10 patients bridged to HCT, 3 were favorable risk by NCCN guidelines, 3 were intermediate risk, 3 were poor risk, and 1 had an unknown risk status. All patients received 75 mg/m2 of AZA administered daily intravenously on days 1-7 of a 28-day cycle, for a median of 6 cycles (range 4-11), without delays or dose reductions. Four patients received other chemotherapeutic agents concomitantly with azacitidine.During AZA therapy, 5 patients achieved CR, 4 obtained CRi, and 1 was refractory (despite exhibiting a reduction in bone marrow blasts). All patients maintained their respective remission statuses following AZA therapy until immediately prior to HCT. Nine patients underwent haploidentical peripheral blood HCT, and 1 underwent matched related peripheral blood HCT. All patients received a RIC regimen consisting of fludarabine, cyclophosphamide, and total body irradiation as well as post-transplant cyclophosphamide. One patient died from septic shock early during his transplant admission and was included in survival analyses but did not undergo post-HCT disease assessment. At their first disease assessment following HCT, 3 patients achieved CR, 3 obtained CRp, 2 exhibited CRi, and 1 had relapsed. For the aggregate patient cohort, Kaplan-Meier analyses revealed a 1-year OS rate of 86% and a 1-year LFS rate of 75% (Figure 1). Median OS was 19.2 months (95% CI [12.0, N/A]), and median LFS was not reached during the study. Median follow-up time from diagnosis was 14.5 months (range 9.6-19.7).Conclusions: Treatment with AZA was well-tolerated and adequately effective to yield remissions in an older patient population that typically experiences poor outcomes with intensive chemotherapy. Such patients may sufficiently improve while in remission to then proceed with HCT. Frontline AZA can thus be used as a successful bridge to HCT in selected elderly AML patients who were originally considered unfit for standard induction. These results require validation in a larger cohort. [Display omitted] DisclosuresGrunwald:Incyte: Consultancy, Research Funding; Genentech: Research Funding; Alexion: Consultancy; Pfizer: Consultancy; Amgen: Consultancy, Research Funding; Forma Therapeutics: Research Funding; Celgene: Consultancy; ARIAD: Consultancy; Cardinal Health: Consultancy; Janssen: Research Funding. Trivedi:Pharmacyclics: Consultancy, Honoraria.

Test-dose pharmacokinetics guided melphalan dose adjustment in reduced intensity conditioning allogeneic transplant for non-malignant disorders.

We studied melphalan pharmacokinetics (PK) and feasibility of melphalan full-dose adjustment based on test-dose PK in children and young adults with non-malignant disorders (NMD) undergoing allogeneic hematopoietic cell transplantation (HCT) using reduced intensity conditioning (RIC) containing alemtuzumab, fludarabine and melphalan. Patients received test-dose melphalan (10% of planned full-dose) prior to conditioning. Blood samples for PK were obtained around test and full-dose melphalan (140 mg/m2 or 4.7mg/kg in patients <10kg). Melphalan concentration was measured by liquid chromatography electrospray ionization tandem mass-spectrometry assay and data were analysed using a population-PK model and Bayesian estimation. Test and full-dose melphalan clearance estimates were evaluated by pairwise Wilcoxon test and Bland-Altman plot. Twenty-four patients undergoing 25 transplants were included in the final analysis. Patients received standard full-dose melphalan in 17 transplants, with median area under the concentration-time curve (AUC) of 5.5mg*h/L (range, 3.0-9.5mg*h/L). Patients received test-dose melphalan in 23 transplants with a test-dose PK predicted full-dose AUC range of 2.9-16.8mg*h/L. In seven transplants where patients had baseline organ impairment, test-dose PK predicted higher exposure for standard full-dose (median AUC 13.8mg*h/L). Melphalan full-dose was adjusted in these patients, with achievement of desired target AUC (3.6-5.4mg*h/L) and no excess toxicity. Mean ratio of test-dose clearance to full-dose clearance was 1.03. Twenty of 22 patients (91%) were within the 95% confidence intervals of the clearance ratio. Melphalan test-dose PK reliably predicts full-dose PK and allows for accurate adjustment of full-dose melphalan in RIC-HCT for NMD. This approach can avoid excess toxicity from increased systemic exposure, especially in patients with organ impairment.

Don't Let the HCT-CI Fool You: Similar Outcomes with Myeloablative CD34+ Selected Allo-HCT Compared to Unmodified RIC Allo-HCT in Patients with AML or MDS and High Comorbidity Scores.

Introduction The BMT CTN 0901 phase 3 trial showed improved relapse-free survival (RFS) in patients with AML or MDS with myeloablative-conditioning (MAC) vs. Reduced intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (allo-HCT). However, overall survival (OS) increase was not statistically significant because of higher non-relapse mortality (NRM) compared to RIC allo-HCT. HCT-CI ≥ 3 also predicts for poor OS related to high NRM in patients undergoing MAC CD34+ selected allo-HCT. Objectives We aimed to evaluate impact on OS, NRM and RFS of MAC CD34+ selected vs. RIC allo-HCT in patients with high comorbidity burden. Methods We retrospectively compared the outcomes of 221 patients with AML or MDS with HCT-CI ≥ 3 who underwent MAC CD34+ selected (n=157) vs. RIC allo-HCT (n=64) at our institution from 2009 to 2017. The indication for MAC CD34+ vs. RIC allo-HCT was based on multidisciplinary consensus and primary physician's choice. Results Patients in the RIC group were older, had a higher proportion of high disease risk index (DRI), and higher use of matched unrelated donors compared to the MAC CD34+ group. HCTCI grades were balanced between the two cohorts, but the RIC group had a higher though non-significant proportion of patients with HCTCI > 5 (Figure 1). When comparing the MAC CD34+ vs. unmodified RIC cohorts, respectively, no difference was seen in OS [43% (95% CI 32-59) vs. 53% (95% CI 46-52), p=0.37], NRM [31% (95% CI 19-44) vs. 30% (95% CI 23-38), p=0.74], and relapse-free survival (RFS) [34% (95% CI 23-49) vs. 48% (95% CI 41-57) p=0.1], even when adjusting for age, DRI, and donor differences (Figure 2). However, incidence of acute and chronic graft versus host disease (GVHD) was lower for MAC CD34+ allo-HCT. When evaluating outcomes by HCT-CI subgroups (3, 4-5 and >5), MAC CD34+ allo-HCT resulted in higher 3-year estimated RFS [54% (95% CI 44-68) vs. 28% (95% CI 14-58), p=0.03] in patients with HCT-CI = 3, though this did not translate into an OS advantage [44% (95% CI 27-73) vs 59% (95% CI 48-72), p=0.26], possibly related to higher though non-significant NRM [16% (95% CI 4-35) vs. 28% (95% CI 18-39), p=0.26] (figure 3). When adjusting for differences in age, DRI, and donor, the difference in RFS was no longer statistically significant (p=0.13). Conclusions Though limited by their retrospective nature, our data suggest that CD34+ selected allografts after myeloablative conditioning can be feasible in selected patients with comorbidity scores over 3 with low rates of acute and chronic GVHD. However, further prospective studies are needed to reduce NRM and optimize this treatment platform in older patients with comorbidities.

Prognostic Score and Cytogenetic Risk Classification for Chronic Lymphocytic Leukemia Patients: Center for International Blood and Marrow Transplant Research Report.

To develop a prognostic model and cytogenetic risk classification for previously treated patients with chronic lymphocytic leukemia (CLL) undergoing reduced intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (HCT). We performed a retrospective analysis of outcomes of 606 patients with CLL who underwent RIC allogeneic HCT between 2008 and 2014 reported to the Center for International Blood and Marrow Transplant Research. On the basis of multivariable models, disease status, comorbidity index, lymphocyte count, and white blood cell count at HCT were selected for the development of prognostic model. Using the prognostic score, we stratified patients into low-, intermediate-, high-, and very-high-risk [4-year progression-free survival (PFS) 58%, 42%, 33%, and 25%, respectively, P < 0.0001; 4-year overall survival (OS) 70%, 57%, 54%, and 38%, respectively, P < 0.0001]. We also evaluated karyotypic abnormalities together with del(17p) and found that del(17p) or ≥5 abnormalities showed inferior PFS. Using a multivariable model, we classified cytogenetic risk into low, intermediate, and high (P < 0.0001). When the prognostic score and cytogenetic risk were combined, patients with low prognostic score and low cytogenetic risk had prolonged PFS (61% at 4 years) and OS (75% at 4 years). In this large cohort of patients with previously treated CLL who underwent RIC HCT, we developed a robust prognostic scoring system of HCT outcomes and a novel cytogenetic-based risk stratification system. These prognostic models can be used for counseling patients, comparing data across studies, and providing a benchmark for future interventions. For future study, we will further validate these models for patients receiving targeted therapies prior to HCT.

PTCy-based haploidentical vs matched related or unrelated donor reduced-intensity conditioning transplant for DLBCL

AbstractThis study retrospectively compared long-term outcomes of nonmyeloablative/reduced intensity conditioning (NMC/RIC) allogeneic hematopoietic cell transplantation (allo-HCT) from a haploidentical family donor (haplo-HCT) using posttransplant cyclophosphamide (PTCy) with those of matched sibling donor (MSD) and matched unrelated donor (MUD) with or without T-cell depletion (TCD+/TCD−) in patients with relapsed diffuse large B-cell lymphoma (DLBCL). Adult patients with DLBCL who had undergone their first NMC/RIC allo-HCT between 2008 and 2015 were included. Recipients of haplo-HCT were limited to those receiving graft-versus-host disease (GVHD) prophylaxis with PTCy. GVHD prophylaxis in MSD was limited to calcineurin inhibitor (CNI)–based approaches without in vivo TCD, while MUD recipients received CNI-based prophylaxis with or without TCD. Outcome analyses for overall survival (OS) and progression-free survival (PFS), nonrelapse mortality (NRM), and disease relapse/progression were calculated. A total of 1438 patients (haplo, 132; MSD, 525; MUD TCD+, 403; and MUD TCD−, 378) were included. Patients with haplo donors were significantly older, had a better performance status and had more frequently received total body irradiation-based conditioning regimens and bone marrow grafts than MSD and MUD TCD+ or TCD−. 3-year OS, PFS, NRM and relapse/progression incidence after haplo-HCT was 46%, 38%, 22%, and 41%, respectively, and not significantly different from outcomes of matched donor transplants on multivariate analyses. Haplo-HCT was associated with a lower cumulative incidence of chronic GVHD compared with MSD, MUD TCD+/TCD−. NMC/RIC haplo-HCT with PTCy seems to be a valuable alternative for patients with DLBCL considered for allo-HCT but lacking a matched donor.

Safety and Efficacy of Myeloablative Conditioning Autologous Stem Cell Transplantation, Targeted Immunotherapy, and Reduced Intensity Conditioning Allogeneic Stem Cell Transplantation in Children, Adolescents, and Young Adults with Relapsed/Refractory Mature B-Cell Non-Hodgkin Lymphoma

Background Despite high cure rates for children, adolescents and young adults (CAYA) with mature B-cell non-Hodgkin lymphoma (B-NHL) (Cairo, JCO, 2012), the results are dismal in those with relapsed/refractory (r/r) disease following reinduction therapy with myeloablative conditioning (MAC) and autologous stem cell transplantation (AutoSCT) (Cairo, BBMT, 2013). Sequential MAC AutoSCT and reduced intensity conditioning (RIC) allogeneic stem cell transplantation (AlloSCT) has achieved 59% 10-year event-free survival (EFS) in CAYA with Hodgkin (Satwani/Cairo, Leukemia, 2015). The addition of Y-ibritumomab tiuxetan to an RIC based regimen prior to AlloSCT in a cohort of adults with high risk B-NHL was proven to be safe and efficacious (Boubdallah, Annals of Oncology, 2015) and may further improve outcomes. Objective To investigate the safety and efficacy in CAYA with poor risk r/r B-NHL of sequential MAC AutoSCT followed by RIC AlloSCT with or without targeted radioimmunotherapy. Design/Methods CAYA patients with poor risk r/r mature B-NHL who underwent MAC AutoSCT followed by RIC AlloSCT ± targeted radioimmunotherapy are included in this study. Twelve of thirteen patients with chemo-sensitive disease underwent sequential MAC AutoSCT followed by RIC AlloSCT (Fig 1). Six patients received radioimmunotherapy with Yttrium-90 ibritumomab tiuxetan prior to MAC. In addition to EFS, patients were assessed for time to hematological recovery, graft failure, whole blood chimerism, aGVHD ≥ Gr 2 and extensive chronic GVHD. Results Thirteen patients with a mean age of 15.3 years and mean follow-up of 48 months were analyzed. Median time to neutrophil and platelet engraftment is 18.8 and 36.4 days, respectively (Fig. 2). Whole blood chimerism at D+100 is 98.4 ± 1.5 %. Eleven patients are in complete remission with an EFS of 91% (Fig. 3). The transplant-related mortality was 0% and no graft failures developed. Conclusions CAYA with r/r B-NHL receiving MAC AutoSCT, targeted radioimmunotherapy, and RIC AlloSCT can achieve long-term EFS. The combination of radioimmunotherapy comprised of Yttrium-90 ibritumomab tiuxetan with MAC AutoSCT was safe and effective in our cohort. A potential graft versus lymphoma effect may explain the favorable outcomes in this cohort of patients with otherwise dismal outcomes.

Reduced Intensity Conditioning for Allogeneic Hematopoietic Cell Transplantation Utilizing Cladribine and Melphalan

Introduction Reduced intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (HCT) has been shown to be successful; however, the ideal RIC regimen is not known. In this study, we report the pooled results of three separate prospective studies utilizing cladribine (2CdA) and melphalan (Mel) based conditioning in patients undergoing allogeneic HCT. Objectives To determine the feasibility, toxicity, and efficacy of a 2Cda/Mel based regimen in patients requiring RIC HCT. Methods 63 adult patients were treated with 2Cda/Mel and included for analysis (84% greater than 50 years of age). 40 men and 23 women received HCT between 1999 and 2014 at Scripps Clinic. 17 patients had previously undergone autologous HCT. All patients received 2CdA 0.14 mg/kg/day for either 4 or 5 days and Mel at either 100 mg/m2 or 180mg/m2 total dose. All patients received rabbit-derived anti-thymocyte globulin (ATG). 22 unrelated recipients received Methotrexate. 41 related recipients received oral cyclosporine as GVHD prophylaxis. 22 patients received tacrolimus as GVHD prophylaxis. Donor lymphocyte infusions (DLI) were allowed but not scheduled. Results Two patients expired prior to neutrophil engraftment; for the remaining 61 the median time to recovery of absolute neutrophil count > 0.5 × 109/L was 12 days (range 9-21). 7 patients expired prior to platelet engraftment; for the remaining 56 the median time to platelets >20 × 109/L without transfusion support was 19 days (12-55). Median overall survival for all 63 patients was 17 months (11 days to 16 years). 10 patients expired prior to day 100, 19 between day 101 and 365, and 14 greater than one year. Diseases included AML (18), Lymphoma (15), MDS (8), Multiple Myeloma (5) and others (17). Non-relapse mortality (NRM) at 100 days, NRM at 365 days, and 1 year OS were 18%, 53%, and 26% for AML, 0%, 37%, and 63% for MDS, and 13%, 27%, and 73% for Lymphoma. In evaluable patients, Grade 2-4 acute GVHD was seen in 47%. Grade 3-4 acute GVHD was seen in 34%. Chronic GVHD was seen in 45% of patients. For 2 patients, acute GVHD was the primary cause of death. 18 patients received DLI; reasons for DLI were relapse (11), mixed chimerism (5), post-transplant lymphoproliferative disorder (PTLD) (1), and idiopathic hemolytic anemia (1). Several patients developed second malignancies after HCT including non-melanoma skin cancers (8), melanoma (1), PTLD (4), myeloproliferative disorder (1), breast cancer (1), cervical cancer (1), and tonsillar squamous cell carcinoma (1). Conclusion 2CdA and Mel are effective agents for RIC HCT. This is the largest study of this regimen published to date. Though it is difficult to fully compare the results from different non-randomized trials, rates of NRM, OS, and GVHD appear similar to other published RIC regimens.

T Prolymphocytic Leukemia, a rare disease, case presentation with typical pathological findings and review of management

Background: Prolymphocytic leukemia (PLL) is a rare disease, accounting for < 2% of lymphoid leukemias [1].There are 2 quite different entities with distinct pathologic features and different therapeutic strategies, T-cell and B-cell [2]. T-PLL is more common [3]. Although termed ‘prolymphocytic,’ T-PLL is characterized by the proliferation of post-thymic T-lymphocytes. It is estimated that physicians will see a case of T-PLL every five to ten years [4]. Over the last 15 years, 3 cases of T-PLL were diagnosed in our center. We present here the latest case, with typical pathological findings. Case Report: A 63-year-old British gentleman, previously healthy with good performance, presented with fatigue for 6 – 8 weeks with puffiness of face and eyelids and weight loss of 5 kilograms. Physical exam showed periorbital edema and conjunctival injection (Figure 1), cervical lymphadenopathy, and hepatosplenomegaly. Initial complete blood count (CBC): white blood cells (WBCs) 331.9 x109/L (4.0 – 10.0), with 94% lymphocytes, hemoglobin (Hb) 119 gm/L (130 – 170), platelets (Plts) 128 x109/L (150 – 400). Lactate dehydrogenase 10.4 µkat/L (2.1 – 3.7), uric acid 537 µmol/L (210 – 420). Abdomen ultrasound showed markedly enlarged spleen (20.3 cm). The peripheral blood smear showed profound leukocytosis with 94% abnormal lymphoid cells. The cells were small to medium in size with high nucleo-cytoplasmic ratio, moderately condensed chromatin and almost all with prominent nucleolus. Substantial number of the cells show irregular nuclear contour with short indentation. The cytoplasm was basophilic agranular and many cells show irregular cytoplasmic protrusions (Figure 2). Flow cytometry on peripheral blood revealed one homogenous abnormal population positive for cluster of differentiation 45 (CD45) and express the pan T-cell markers (CD3, CD2, CD5 and CD7). All were positive for CD4, T-cell receptor (TCR) alpha/beta, CD43 and BCl2 with partial expression of CD38. These cells were negative for CD56, CD57, CD16, CD25, CD103, CD10, CD117, Terminal deoxynucleotidyl transferase (TdT), CD1a and CD34. (Figure3A) TCRVb region analysis by flow cytometry using IO Test Beta Mark TCR Repertoire kit (Beckman Coulter, Brea, CA, USA) using the panel of 24 monoclonal antibodies to TCR Vb families showed restricted expansion of region 13.1 in 99%. (Figure 3B) Bone marrow aspirate was remarkably hypercellular and extensively infiltrated with abnormal lymphoid cells comprising approximately 75% of total nucleated cells, morphologically similar to those seen in peripheral blood. The biopsy showed extensive diffuse infiltration with small to moderately sized lymphoid cells with prominent nuclear irregularity (Figure 4A&B). The immunophenotype was confirmed by immunohistochemistry and the cells were positive for CD3, CD5, CD7, CD2, CD4, BCL2 as well as for Zap70. BCL6 was uniformly negative. Based on the morphology and the immunophenotypic profile, a diagnosis of CD4+/CD8− T-prolymphocytic leukemia was made. FISH analysis revealed ATM deletion at 11q22 and TRA/D rearrangement in 93% of the cells analyzed and karyotype was complex with multiple numeric and structural abnormalities including inv(14)(q11.2q32); Karyotype: 43,XY,del(11)(q14),add(11)(p15),-13,inv(14)(q11.2q32),der(19)t(13;19)(q11;q13.4),-20,-22[7]/42,idem,-9,add(14)(p11.1),add(17)(p13)[23] After confirming the diagnosis of T-PLL the patient travelled back to his home country. He was started on treatment with alemtuzumab, then pentostatin was added in week 4, after 10 weeks of treatment he achieved complete remission. After that he received reduced intensity conditioned allogeneic stem cell transplant from a matched brother, complicated by mild acute graft versus host disease. Until the time of writing this report he was doing fine.

Current and emerging treatment options for mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma with typically aggressive behavior. The genetic signature is the chromosomal translocation t(11;14)(q13;q32) resulting in overexpression of cyclin D1. Asymptomatic newly diagnosed MCL patients with low tumor burden can be closely observed, deferring therapy to the time of disease progression. Although MCL classically responds to upfront chemotherapy, it remains incurable with standard approaches. For patients in need of frontline therapy, the initial decision is whether to proceed with an intensive treatment strategy or a non-intensive treatment strategy. In general, given the unfavorable risk-benefit profile, older MCL patients should be spared intensive strategies, while younger and fit patients can be considered for intensive strategies. The bendamustine and rituximab (BR) regimen is becoming an increasingly popular treatment option among the elderly population, with improved progression-free survival (PFS) and acceptable side-effect profile. Although rituximab maintenance after R-CHOP improves survival outcomes in elderly patients, no clinical trial to date has shown statistical significance to support the use of rituximab maintenance after BR induction in older patients. In young and fit patients with MCL, an intensive strategy to maximize the length of first remission has emerged as a worldwide standard of care. With current high-dose cytarabine-containing immunochemotherapy regimens followed by autologous stem cell transplantation, the median PFS has exceeded 7 years. In the relapsed or refractory (R/R) setting, reduced intensity conditioning allogeneic hematopoietic stem cell transplantation may offer the highest likelihood of long-term survival in young R/R MCL patients, at the cost of increased risk of non-relapse mortality and chronic graft versus host disease. Novel agents targeting activated pathways in MCL cells, such as bortezomib, lenalidamide, ibrutinib and temsirolimus are now available for the management of R/R disease.

Hematopoietic Stem Cell Transplant in Adolescent and Young Adults With Fanconi Anemia Is Feasible With Acceptable Toxicity, With Those Surviving 100 Days Posttransplant Having Excellent Outcomes.

Fanconi anemia is a congenital bone marrow failure syndrome that is associated with congenital anomalies and increased risk of cancer. Hematopoietic stem cell transplant is a potentially curative modality for bone marrow failure in Fanconi anemia patients. Here, we report our center's experience regarding adolescent and young adult patients with Fanconi anemia and hematopoietic stem cell transplant. We conducted a retrospective patient record analyses of patients who presented at our center from 1988 to 2014. We included patients greater than 14 years old with confirmed Fanconi anemia based on positive chromosome breakage study and who underwent hematopoietic stem cell transplant at our institution. Our study group comprised 12 patients with Fanconi anemia who underwent hematopoietic stem cell transplant at our institution. The median age was 20 years (range, 14-31 y) with a female predominance of 83%. Low-dose cyclophosphamide (20-80 mg/kg)-based conditioning regimens were used with different combinations that included fludarabine, antithymocyte globulin, or total body irradiation. All patients had HLA-matched sibling grafts. In all patients, stem cell source was the bone marrow. All patients showed engraftment. Four patients (33%) developed acute graft-versus-host disease. Three patients (25%) died early before day 100 after hematopoietic stem cell transplant due to infectious complications, with 1 patient having steroid refractory acute graft-versus-host disease. Overall survival was 75% at a median follow-up of 43 months. All patients who survived are well and remained transfusion independent without evidence of secondary malignancy. Our findings support the feasibility of reduced intensity conditioning allogeneic hematopoietic stem cell transplant in older and more heavily pretreated patients with Fanconi anemia, especially for those who are engrafted.

Reduced intensity conditioning allogeneic hematopoietic stem cell transplantation in chronic lymphocytic leukemia (CLL) patients with the aberration of p53 gene

目的探讨减低强度预处理的异基因造血干细胞移植（RIC-allo-HSCT）治疗伴p53缺失的超高危慢性淋巴细胞白血病（CLL）的疗效及安全性，并提高allo-HSCT在CLL治疗中的认识。方法回顾性分析2012年7月至2014年1月进行同胞全相合供者RIC-allo-HSCT且伴p53缺失的4例超高危CLL患者资料，移植方式采用RIC方案，观察造血重建、移植相关并发症、总体生存（OS）、无进展生存（PFS）等临床指标。结果4例CLL患者中男3例，女1例，中位年龄56（49~61）岁。输注的中位单个核细胞（MNC）数为6.54（2.85~14.70）×108/kg，中位CD34+细胞数为5.81（2.85~7.79）×106/kg。4例患者移植后均获得快速而持久的造血重建，中性粒细胞和血小板植入时间分别为11（9~12）和5.5（0~11）d。造血重建后植活细胞嵌合鉴定证实3例为供者完全植入，1例为供受者混合植入。2例发生Ⅰ度急性移植物抗宿主病（GVHD），2例出现CMV感染，1例发生带状疱疹病毒及EB病毒血症，对症支持治疗后均好转；无移植相关死亡。中位随访时间为26.5（21~39）个月，3例完全缓解期行RIC-allo-HSCT的患者均无病生存，1例部分缓解期行移植的患者于移植后5个月发生疾病进展。结论伴p53缺失的超高危CLL患者对临床常规化疗敏感性差，生存期短；RIC-allo-HSCT对此类患者不良反应小并耐受性良好，临床缓解期长，值得进一步观察、推广。

Research progress of reduced-intensity conditioning allogeneic hematopoietic stem cell transplantation in treatment of myelodysplastic syndrome

Allogeneic hematopoietic stem cell transplantation(allo-HSCT) is likely to be the optimum method to cure international prognostic scoring system (IPSS) intermediate and high-risk patients with myelodysplastic syndrome(MDS). However, patients suffered with MDS are usually too old to undergo myeloablative conditioning allogeneic stem cell transplantation(MAC-HSCT). On account of its advantages of higher efficiency and lower toxicity, reduced intensity conditioning allogeneic stem cell transplantation(RIC-HSCT) is widely applied in the treatment of MDS patients. Currently, fludarabine plus alkylating regimens are widely applied, but the clinical outcomes are different from each regimen. Although RIC-HSCT has unique advantages in treating intermediate and high-risk elder MDS compared with MAC-HSCT and non-HSCT therapy, whether the outcome is influenced by factors such as tumor burden, recipient age, IPSS risk stratification, type of allo-HSCT, and comorbidity before transplantation is still unclear. In this article, we review literatures on RIC-HSCT in treatment of MDS. Key words: Myelodysplastic syndrome; Transplantation conditioning; Hematopoietic stem cell transplantation

Antithymocyte Globulin (ATG) 4.5 Vs. 6.0 Mg/Kg in Reduced Intensity Conditioning (RIC) Allogeneic Hematopoietic Stem Cell Transplant (alloHSCT)

Antithymocyte Globulin (ATG) 4.5 Vs. 6.0 Mg/Kg in Reduced Intensity Conditioning (RIC) Allogeneic Hematopoietic Stem Cell Transplant (alloHSCT)

Alemtuzumab levels impact acute GVHD, mixed chimerism, and lymphocyte recovery following alemtuzumab, fludarabine, and melphalan RIC HCT

AbstractReduced intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (HCT) with alemtuzumab, fludarabine, and melphalan is an effective approach for patients with nonmalignant disorders. Mixed chimerism and graft-versus-host-disease (GVHD) remain limitations on success. We hypothesized that higher levels of alemtuzumab at day 0 would result in a low risk of acute GVHD, a higher risk of mixed chimerism, and delayed early lymphocyte recovery and that alemtuzumab level thresholds for increased risks of these outcomes would be definable. We collected data from 105 patients to examine the influence of peritransplant alemtuzumab levels on acute GVHD, mixed chimerism, and lymphocyte recovery. The cumulative incidences of initial grades I-IV, II-IV, and III-IV acute GVHD in patients with alemtuzumab levels ≤0.15 vs ≥0.16 μg/mL were 68% vs 18% (P < .0001), 47% vs 13% (P = .0002), and 32% vs 8%, respectively (P = .005). The cumulative incidence of mixed chimerism in patients with an alemtuzumab level ≤0.15 μg/mL was 21%, vs 42% with levels of 0.16 to 4.35 μg/mL, and 100% with levels >4.35 μg/mL (P = .003). Patients with alemtuzumab levels ≤0.15 or 0.16 to 0.56 μg/mL had higher lymphocyte counts at day +30 and higher T-cell counts at day +100 compared with patients with levels ≥0.57 μg/mL (all P < .05). We conclude that peritransplant alemtuzumab levels impact acute GVHD, mixed chimerism, and lymphocyte recovery following RIC HCT with alemtuzumab, fludarabine, and melphalan. Precision dosing trials are warranted. We recommend a day 0 therapeutic range of 0.2 to 0.4 μg/mL.