Natural Killer Cell Killing of Acute Myelogenous Leukemia and Acute Lymphoblastic Leukemia Blasts by Killer Cell Immunoglobulin-Like Receptor–Negative Natural Killer Cells after NKG2A and LIR-1 Blockade

Although the study of natural killer (NK) cell alloreactivity has been dominated by studies of killer cell immunoglobulin-like receptors (KIRs), we hypothesized that NKG2A and LIR-1, present on 53% ± 13% and 36% ± 18% of normal NK cells, respectively, play roles in the NK cell killing of primary leukemia targets. KIR- cells, which compose nearly half of the circulating NK cell population, exhibit tolerance to primary leukemia targets, suggesting signaling through other inhibitory receptors. Both acute myelogenous leukemia and acute lymphoblastic leukemia targets were rendered susceptible to lysis by fresh resting KIR- NK cells when inhibitory receptor–major histocompatibility class I interactions were blocked by pan-HLA antibodies, demonstrating that these cells are functionally competent. Blockade of a single inhibitory receptor resulted in slightly increased killing, whereas combined LIR-1 and NKG2A blockade consistently resulted in increased NK cell cytotoxicity. Dual blockade of NKG2A and LIR-1 led to significant killing of targets by resting KIR- NK cells, demonstrating that this population is not hyporesponsive. Together these results suggest that alloreactivity of a significant fraction of KIR- NK cells is mediated by NKG2A and LIR-1. Thus strategies to interrupt NKG2A and LIR-1 in combination with anti-KIR blockade hold promise for exploiting NK cell therapy in acute leukemias

Donor KIR B Genotype Improves Progression-Free Survival of Non-Hodgkin Lymphoma Patients Receiving Unrelated Donor Transplantation

Donor killer immunoglobulin-like receptor (KIR) genotypes are associated with relapse protection and survival after allotransplantation for acute myelogenous leukemia. We examined the possibility of a similar effect in a cohort of 614 non-Hodgkin lymphoma (NHL) patients receiving unrelated donor (URD) T cell-replete marrow or peripheral blood grafts. Sixty-four percent (n = 396) of donor-recipient pairs were 10/10 allele HLA matched and 26% were 9/10 allele matched. Seventy percent of donors had KIR B/x genotype; the others had KIR A/A genotype. NHL patients receiving 10/10 HLA-matched URD grafts with KIR B/x donors experienced significantly lower relapse at 5 years (26%; 95% confidence interval [CI], 21% to 32% versus 37%; 95% CI, 27% to 46%; P = .05) compared with KIR A/A donors, resulting in improved 5-year progression-free survival (PFS) (35%; 95% CI, 26% to 44% versus 22%; 95% CI, 11% to 35%; P = .007). In multivariate analysis, use of KIR B/x donors was associated with significantly reduced relapse risk (relative risk [RR], .63, P = .02) and improved PFS (RR, .71, P = .008). The relapse protection afforded by KIR B/x donors was not observed in HLA-mismatched transplantations and was not specific to any particular KIR-B gene. Selecting 10/10 HLA-matched and KIR B/x donors should benefit patients with NHL receiving URD allogeneic transplantation

Updated Efficacy and Safety Data from the AETHERA Trial of Consolidation with Brentuximab Vedotin after Autologous Stem Cell Transplant (ASCT) in Hodgkin Lymphoma Patients at High Risk of Relapse

Abstract Introduction The AETHERA trial is a phase 3, randomized, placebo-controlled trial (ClinicalTrials.gov #NCT01100502), which evaluated whether post-ASCT consolidation treatment with brentuximab vedotin (BV) could prevent disease progression in Hodgkin lymphoma (HL) patients at high risk for relapse. The study met its primary endpoint: significant improvement in progression-free survival (PFS) per independent review with BV versus placebo (hazard ratio [HR]=0.57, P=0.001) (Moskowitz, 2015). The 2 most common adverse events (AEs) in the BV- treatment group were peripheral sensory neuropathy (56%) and neutropenia (35%). We are presenting updated efficacy and safety data after approximately 1 additional year of follow-up after the primary analysis. Methods Patients were randomized to receive BV 1.8 mg/kg q3wk or placebo for 16 cycles (approximately 12 months), 30-45 days after transplantation. Randomization was stratified by response to frontline therapy and by best clinical response to pre-ASCT salvage therapy. Patients whose disease had progressed after salvage treatment were not eligible. Patients received CT scans quarterly for the first year and then at 18 and 24 months during long-term follow-up (LTFU). Clinical lymphoma assessments were performed at each cycle of treatment, quarterly during the first year of LTFU, and every 6 months thereafter. AEs were collected for 30 days after the end of treatment, except for peripheral neuropathies and secondary malignancies, which were followed throughout LTFU. Clinical responses to subsequent BV treatment received after progression were also recorded. Results A total of 329 patients were randomized to the BV- (n=165) or placebo- (n=164) treatment arms. Median PFS per investigator assessment was not reached (95% CI not estimable [NE]-NE) in the BV arm and was 15.8 months (95% CI 8.5-44.0) in the placebo arm (HR=0.52, 95% CI 0.37-0.71). A sustained plateau with substantial separation is evident between both treatment groups, with improved PFS at 3-years post-randomization with BV consolidation versus placebo (Figure). The 3-year PFS rate was 61% (95% CI 52-68) for the BV arm and 43% (95% CI 36-51) for the placebo arm. Six PFS events (2 progressions and 4 deaths) were recorded after the 24-month evaluation period in the BV arm and 3 in the placebo arm (2 progressions and 1 death). The HR for PFS per independent review was 0.58 (95% CI 0.41-0.82). No new secondary malignancies have been observed since the primary analysis. The number of cases were comparable between the 2 treatment arms (n=4 BV, n=2 placebo). Malignancies on the BV arm included bladder cancer, lung cancer, pancreatic cancer, and myelodysplastic syndrome (n=1 each). In the placebo arm, secondary malignancies included mantle cell lymphoma and myelodysplastic syndrome (n=1 each). Among the 112 patients on the BV arm who experienced treatment-emergent peripheral neuropathy based on a Standardised Medical Dictionary for Regulatory Activities (MedDRA) Query (SMQ) analysis, 99 patients (88%) experienced some improvement (23%) or complete resolution (65%) of neuropathy symptoms at the time of analysis. Discontinuation of treatment due to an AE occurred in 54 patients (33%) on the BV arm, most commonly due to peripheral sensory and motor neuropathies (14% and 7%, respectively). Patients who discontinued treatment as a result of an AE received a median of 9.5 cycles (range, 1 to 15) on the BV arm. The 2-year PFS rate in these patients was 69% (95% CI 54-79) versus 82% (95% CI 71-89) for patients who completed all 16 treatment cycles. Conclusions Consolidation treatment with BV in HL patients at high risk of relapse after ASCT showed an improvement in PFS versus placebo, approximately 3 years since the last patient was randomized. Kaplan-Meier analysis of PFS per investigator assessment showed a continued benefit of BV consolidation. No additional secondary malignancies have been observed in either treatment arm and most patients experienced resolution of peripheral neuropathy symptoms. We are currently analyzing clinical responses to BV treatment after disease progression. Figure 1. Progression-Free Survival per Investigator Assessment Figure 1. Progression-Free Survival per Investigator Assessment Disclosures Sweetenham: Seattle Genetics Inc.: Honoraria, Research Funding, Speakers Bureau. Off Label Use: Brentuximab vedotin is indicated in the US for treatment of patients with Hodgkin lymphoma after failure of autologous stem cell transplant or after failure of at least two prior multi-agent chemotherapy regimens in patients who are not ASCT candidates and for the treatment of patients with systemic anaplastic large cell lymphoma after failure of at least one prior multi-agent chemotherapy regimen. This study investigates the use of brentuximab vedotin for consolidation therapy soon after ASCT. . Walewski:Mundipharma; Roche; Takeda: Honoraria, Other: Travel expenses; Amgen; Boehringer Ingelheim; Celgene; Janssen-Cilag; Mundipharma; Roche; Takeda; Teva: Consultancy; Bayer (Inst); Bayer/Onyx (Inst); Boehringer Ingelheim (Inst); Celgene (Inst); Celltrion (Inst); Gilead Sciences (Inst); GlaxoSmithKline (Inst); GlaxoSmithKline (Inst); Mundipharma (Inst); Pfizer (Inst); Roche (Inst); Roche/Genentech (Inst); Seattle Geneti: Research Funding. Nademanee:Celgene: Consultancy; Seattle Genetics Inc.: Research Funding; Spectrum: Research Funding; Gilead: Consultancy. Masszi:Novartis Pharmaceuticals Corporation: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Agura:Seattle Genetics Inc.: Research Funding. Holowiecki:Seattle Genetics Inc.: Research Funding; Takeda: Other: Travel expenses. Abidi:Seattle Genetics Inc.: Research Funding. Chen:Gilead: Consultancy, Other: Advisory Board; Janssen: Consultancy, Other: Advisory Board; Seattle Genetics: Consultancy, Other: Advisory Board; Genentech, Inc.: Consultancy, Other: Advisory Board. Stiff:Seattle Genetics Inc.: Consultancy, Honoraria, Research Funding. Viviani:Italfarmaco SpA: Consultancy; Teva Italia SpA: Consultancy; Takeda Italia SpA: Consultancy; Takeda International: Consultancy. Carella:Seattle Genetics Inc.: Research Funding. Osmanov:Seattle Genetics Inc.: Research Funding. Bachanova:Seattle Genetics Inc.: Consultancy, Research Funding. Sureda:Seattle Genetics Inc.: Research Funding; Takeda: Consultancy, Honoraria, Speakers Bureau. Huebner:Takeda Pharmaceuticals International Co.: Employment, Equity Ownership. Larsen:Seattle Genetics Inc.: Employment, Equity Ownership. Hunder:Seattle Genetics Inc.: Employment, Equity Ownership

Reduced-Intensity Conditioning with Fludarabine, Cyclophosphamide, and High-Dose Rituximab for Allogeneic Hematopoietic Cell Transplantation for Follicular Lymphoma: A Phase Two Multicenter Trial from the Blood and Marrow Transplant Clinical Trials Network

Allogeneic hematopoietic cell transplantation (alloHCT) can induce long term remissions in chemosensitive relapsed follicular lymphoma (FL). The BMT CTN conducted a multicenter phase 2 trial to examine the efficacy of alloHCT using reduced intensity conditioning (RIC) with rituximab (RTX) in multiply relapsed, chemosensitive FL. The primary endpoint was 2 year progression-free survival (PFS). The conditioning regimen consisted of fludarabine, cyclophosphamide and high-dose RTX (FCR) in which 3 of the 4 doses of RTX were administered at a dose of 1 gm/m2. Graft vs host disease (GvHD) prophylaxis was with tacrolimus and methotrexate. Sixty five patients were enrolled and 62 were evaluable. Median age was 55 years (range, 29-74). This group was heavily pre-treated: 77% had received ≥ 3 prior regimens, 32% had received ≥ 5 prior regimens and 11% had received prior autologous HCT. Donors were HLA-matched siblings (n=33) or HLA-matched unrelated adults (n=29). No graft failures occurred. The overall response rate after HCT was 94% with 90% in complete remission (CR), including 24 patients not in CR before alloHCT. With a median follow-up of 47 months (range, 30-73), 3 year PFS and overall survival rates were 71% (95% confidence interval: 58%-81%) and 82% (70%-90%) respectively. Three year cumulative incidences of relapse/progression and non-relapse mortality were 13% and 16%, respectively. Two year cumulative incidences of grade 2-4 and grade 3-4 acute GvHD were 27% and 10%, respectively and extensive chronic GvHD incidence was 55%. Serum RTX concentrations peaked at day +28 and remained detectable as late as 1 year in 59% of patients with available data. In conclusion, alloHCT with FCR conditioning confers high CR rates, a low incidence of relapse/progression and excellent survival probabilities in heavily pretreated FL patients

Reduced-intensity Transplantation For Lymphomas Using Haploidentical Related Donors Versus Hla-matched Sibling Donors: A Center For International Blood And Marrow Transplant Research Analysis

Purpose: Related donor haploidentical hematopoietic cell transplantation (Haplo-HCT) using post-transplantation cyclophosphamide (PT-Cy) is increasingly used in patients lacking HLA-matched sibling donors (MSD). We compared outcomes after Haplo-HCT using PT-Cy with MSD-HCT in patients with lymphoma, using the Center for International Blood and Marrow Transplant Research registry. Materials and Methods: We evaluated 987 adult patients undergoing either Haplo-HCT (n = 180) or MSD-HCT (n = 807) following reduced-intensity conditioning regimens. The haploidentical group received graft-versus-host disease (GVHD) prophylaxis with PT-Cy with or without a calcineurin inhibitor and mycophenolate. The MSD group received calcineurin inhibitor-based GVHD prophylaxis. Results: Median follow-up of survivors was 3 years. The 28-day neutrophil recovery was similar in the two groups (95% v 97%; P = .31). The 28-day platelet recovery was delayed in the haploidentical group compared with the MSD group (63% v 91%; P = .001). Cumulative incidence of grade II to IV acute GVHD at day 100 was similar between the two groups (27% v 25%; P = .84). Cumulative incidence of chronic GVHD at 1 year was significantly lower after Haplo-HCT (12% v 45%; P < .001), and this benefit was confirmed on multivariate analysis (relative risk, 0.21; 95% CI, 0.14 to 0.31; P < .001). For Haplo-HCT v MSD-HCT, 3-year rates of nonrelapse mortality (15% v 13%; P = .41), relapse/progression (37% v 40%; P = .51), progression-free survival (48% v 48%; P = .96), and overall survival (61% v 62%; P = .82) were similar. Multivariate analysis showed no significant difference between Haplo-HCT and MSD-HCT in terms of nonrelapse mortality (P = .06), progression/relapse (P = .10), progression-free survival (P = .83), and overall survival (P = .34). Conclusion: Haplo-HCT with PT-Cy provides survival outcomes comparable to MSD-HCT, with a significantly lower risk of chronic GVHD

American Society of Transplantation and Cellular Therapy, Center of International Blood and Marrow Transplant Research, and European Society for Blood and Marrow Transplantation Clinical Practice Recommendations for Transplantation and Cellular Therapies in Mantle Cell Lymphoma

Autologous (auto-) and allogeneic (allo-) hematopoietic cell transplantation (HCT) are accepted treatment modalities in contemporary treatment algorithms for mantle cell lymphoma (MCL). Chimeric antigen receptor (CAR) T cell therapy recently received approval for MCL; however, its exact place and sequence in relation to HCT remain unclear. The American Society of Transplantation and Cellular Therapy, Center of International Blood and Marrow Transplant Research, and the European Society for Blood and Marrow Transplantation jointly convened an expert panel to formulate consensus recommendations for role, timing, and sequencing of auto-HCT, allo-HCT, and CAR T cell therapy for patients with newly diagnosed and relapsed/refractory (R/R) MCL. The RAND-modified Delphi method was used to generate consensus statements. Seventeen consensus statements were generated, with a few key statements as follows: in the first line setting, auto-HCT consolidation represents standard of care in eligible patients, whereas there is no clear role of allo-HCT or CAR T cell therapy outside of clinical trials. In the R/R setting, the preferential option is CAR T cell therapy, especially in patients with MCL failing or intolerant to at least one Bruton's tyrosine kinase inhibitor, while allo-HCT is recommended if CAR T cell therapy fails or is infeasible. Several recommendations were based on expert opinion, where the panel developed consensus statements for important real-world clinical scenarios to guide clinical practice. In the absence of contemporary evidence-based data, the panel found RAND-modified Delphi methodology effective in providing a formal framework for developing consensus recommendations for the timing and sequence of cellular therapies for MCL

Outcomes of Medicare-age eligible NHL patients receiving RIC allogeneic transplantation: a CIBMTR analysis

The application of allogeneic hematopoietic cell transplantation (allo-HCT) in non-Hodgkin lymphoma (NHL) patients ≥65 years in the United States is limited by lack of Medicare coverage for this indication. Using the Center for International Blood and Marrow Transplant Research (CIBMTR) database, we report allo-HCT outcomes of NHL patients aged ≥65 years (older cohort; n = 446) compared with a cohort of younger NHL patients aged 55-64 years (n = 1183). We identified 1629 NHL patients undergoing a first reduced-intensity conditioning (RIC) or nonmyeloablative conditioning allo-HCT from 2008 to 2015 in the United States. Cord blood or haploidentical transplants were excluded. The median age was 68 years (range 65-77) for the older cohort vs 60 years (range 55-64) in the younger cohort. The 4-year adjusted probabilities of nonrelapse mortality (NRM), relapse/progression (R/P), progression-free survival (PFS), and overall survival (OS) of the younger and older groups were 24% vs 30% (P = .03), 41% vs 42% (P = .82), 37% vs 31% (P = .03), and 51% vs 46% (P = .07), respectively. Using multivariate analysis, compared with the younger group, the older cohort was associated with increased NRM, but there was no difference between the 2 cohorts in terms of R/P, PFS, or OS. The most common cause of death was disease relapse in both groups. In NHL patients eligible for allo-HCT, there was no difference in OS between the 2 cohorts. Age alone should not determine allo-HCT eligibility in NHL, and Medicare should expand allo-HCT coverage to older adults

Integrative Analysis of Clinicopathological Features Defines Novel Prognostic Models for Mantle Cell Lymphoma in the Immunochemotherapy Era: A Report from The North American Mantle Cell Lymphoma Consortium

BACKGROUND: Patients with mantle cell lymphoma (MCL) exhibit a wide variation in clinical presentation and outcome. However, the commonly used prognostic models are outdated and inadequate to address the needs of the current multidisciplinary management of this disease. This study aims to investigate the clinical and pathological features of MCL in the immunochemotherapy era and improve the prognostic models for a more accurate prediction of patient outcomes. METHODS: The North American Mantle Cell Lymphoma Project is a multi-institutional collaboration of 23 institutions across North America to evaluate and refine prognosticators for front-line therapy. A total of 586 MCL cases diagnosed between 2000 and 2012 are included in this study. A comprehensive retrospective analysis was performed on the clinicopathological features, treatment approaches, and outcomes of these cases. The establishment of novel prognostic models was based on in-depth examination of baseline parameters, and subsequent validation in an independent cohort of MCL cases. RESULTS: In front-line strategies, the use of hematopoietic stem cell transplantation was the most significant parameter affecting outcomes, for both overall survival (OS, p \u3c 0.0001) and progression-free survival (PFS, p \u3c 0.0001). P53 positive expression was the most significant pathological parameter correlating with inferior outcomes (p \u3c 0.0001 for OS and p = 0.0021 for PFS). Based on the baseline risk factor profile, we developed a set of prognostic models incorporating clinical, laboratory, and pathological parameters that are specifically tailored for various applications. These models, when tested in the validation cohort, exhibited strong predictive power for survival and showed a stratification resembling the training cohort. CONCLUSIONS: The outcome of patients with MCL has markedly improved over the past two decades, and further enhancement is anticipated with the evolution of clinical management. The innovative prognostic models developed in this study would serve as a valuable tool to guide the selection of more suitable treatment strategies for patients with MCL

Reduced-Intensity Allografting as First Transplantation Approach in Relapsed/Refractory Grades One and Two Follicular Lymphoma Provides Improved Outcomes in Long-Term Survivors

Comparison of long-term outcomes in patients with refractory/relapsed grade 1-2 follicular lymphoma (FL) after allogeneic (allo-HCT) vs. autologous hematopoietic cell transplantation (auto-HCT) in the rituximab-era