Allogeneic hematopoietic cell transplantation with non-myeloablative conditioning for patients with hematologic malignancies: Improved outcomes over two decades.

We have used a non-myeloablative conditioning regimen for allogeneic hematopoietic cell transplantation for the past twenty years. During that period, changes in clinical practice have been aimed at reducing morbidity and mortality from infections, organ toxicity, and graft-versus-host disease. We hypothesized that improvements in clinical practice led to better transplantation outcomes over time. From 1997-2017, 1,720 patients with hematologic malignancies received low-dose total body irradiation +/- fludarabine or clofarabine before transplantation from HLA-matched sibling or unrelated donors, followed by mycophenolate mofetil and a calcineurin inhibitor ± sirolimus. We compared outcomes in three cohorts by year of transplantation: 1997 +/- 2003 (n=562), 2004 +/- 2009 (n=594), and 2010 +/- 2017 (n=564). The proportion of patients ≥60 years old increased from 27% in 1997 +/- 2003 to 56% in 2010-2017, and with scores from the Hematopoietic Cell Transplantation Comborbidity Index of ≥3 increased from 25% in 1997 +/- 2003 to 45% in 2010 +/- 2017. Use of unrelated donors increased from 34% in 1997 +/- 2003 to 65% in 2010-2017. When outcomes from 2004 +/- 2009 and 2010-2017 were compared to 1997 +/- 2003, improvements were noted in overall survival (P=.0001 for 2004-2009 and P <.0001 for 2010-2017), profression-free survival (P=.002 for 2004-2009 and P <.0001 for 2010 +/- 2017), non-relapse mortality (P<.0001 for 2004 +/- 2009 and P <.0001 for 2010 +/- 2017), and in rates of grades 2 +/- 4 acute and chronic graft-vs.-host disease. For patients with hematologic malignancies who underwent transplantation with non-myeloablative conditioning, outcomes have improved during the past two decades. Trials reported are registered under ClinicalTrials.gov identifiers: NCT00003145, NCT00003196, NCT00003954, NCT00005799, NCT00005801, NCT00005803, NCT00006251, NCT00014235, NCT00027820, NCT00031655, NCT00036738, NCT00045435, NCT00052546, NCT00060424, NCT00075478, NCT00078858, NCT00089011, NCT00104858, NCT00105001, NCT00110058, NCT00397813, NCT00793572, NCT01231412, NCT01252667, NCT01527045.

Impact of Rituximab and Host/Donor Fc Receptor Polymorphisms after Allogeneic Hematopoietic Cell Transplantation for CD20+ B Cell Malignancies.

We previously reported a 24% 1-year relapse rate in 93 older or medically unfit patients with CD20+ B cell malignancies after allogeneic hematopoietic cell transplantation (HCT) with low-intensity conditioning. The current prospective study tested the hypothesis that disease relapse could be reduced and overall survival (OS) improved by peritransplantation administration of rituximab (RTX). Sixty-three patients received RTX (375 mg/m2/day) on days -3, +10, +24, and +38 along with 2 to 3 Gy total body irradiation with or without fludarabine (30 mg/m2 for 3 days). Median RTX levels of >25 µg/mL were achieved through day +84 after transplantation, but RTX level was not correlated with relapse or graft-versus-host disease (GVHD). HCT recipients with F/F and V/F FCγRIIIa polymorphisms showed a trend toward a higher relapse rate compared with those with V/V polymorphism (P= .15). No difference in outcome was found based on V/V donor pairing. Five-year relapse rates were similar between RTX-treated patients and historical controls (32% versus 28%; P = .94). RTX-treated patients had greater 5-year OS (47% versus 38%; P = .13) and progression-free survival (41% versus 32%; P = .12) compared with historical controls who underwent HCT without RTX, although the difference was not statistically significant. The incidence of acute GVHD was similar in the 2 groups (grade II-IV, 57% versus 56%; grade III-IV, 13% versus 17%), but the 5-year incidence of chronic GVHD was higher among RTX-treated patients (62% versus 47%). In patients with relapsed or refractory non-Hodgkin lymphoma, peritransplantation RTX neither reduced relapse nor improved GVHD. The role of donor-recipient pairing by FCγRIIIa polymorphisms in outcomes remains to be determined.

History of hematopoietic cell transplantation: challenges and progress.

After more than 60 years of research in allogeneic hematopoietic cell transplantation (HCT), this therapy has advanced from one that was declared dead in the 1960s to a standard treatment of otherwise fatal malignant and non-malignant blood diseases. To date, close to 1.5 million hematopoietic cell transplants have been performed in more than 1,500 transplantation centers worldwide. This review will highlight the enormous efforts by numerous investigators throughout the world who have brought the experimental field of HCT to clinical reality, examine ongoing challenges, and provide insights for the future.

Allogeneic Hematopoietic Cell Transplantation in the Outpatient Setting.

Conditioning with fludarabine and low-dose total-body irradiation before allogeneic hematopoietic cell transplantation (HCT) enabled treating older or medically infirm patients with advanced hematologic malignancies in the outpatient setting. Between December 1997 and June 2017, 1037 patients with hematologic malignancies received peripheral blood stem cell (PBSC) grafts from HLA-matched or 1 HLA antigen/allele-mismatched related or unrelated donors. Median age was 58 (range, 18 to 80) years. Serious comorbidities with Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI) scores ≥3 were present in 52% of patients. We found that 47% of patients were either never hospitalized or only had an overnight hospital stay for infusion of late-arriving PBSCs while 53% were admitted for a median of 6 days. Main reasons for admission were infection, fever, graft-versus-host disease, and regimen-related toxicity. Two thirds of admissions occurred within 3 weeks of HCT. The 5-year risk of nonrelapse mortality (NRM) was 26% among hospitalized patients and 13% among nonhospitalized patients. Significant risk factors for hospitalization included unrelated transplants, 1 HLA antigen-mismatched transplant, high HCT-CI scores, and diagnosis of nonmyeloma malignancies. Significant risk factors for NRM were hospitalization, older age, unrelated transplants, and high HCT-CI scores. Ambulatory allogeneic HCT is feasible and safe.

Syncytial variant of nodular sclerosing Hodgkin lymphoma in children: A prognostic factor?

Nodular sclerosing Hodgkin lymphoma (HL) has an excellent prognosis in children. The syncytial variant (SV) of HL in adults represents a clinic pathologic entity with a worse outcome. We report the clinical features and the course of the disease of three children with refractory HL. The three patients with SV were analyzed in a retrospective multi-institutional study conducted in Israel in 51 children diagnosed with refractory or recurrent HL between 1997 and 2014. All the three children developed multiple recurrences soon after diagnosis. All three received at least three different chemotherapy combinations with autologous bone marrow transplantation for two patients, allogenic bone marrow transplantation in one, and immunotherapy in one. One patient died of disease, one is in complete response of the disease but developed a second metastatic malignancy, and one is alive without disease. This retrospective study shows that SV histology may be a prognostic factor for poor outcome in children diagnosed with HL.

Anti-ICOS mAb Targets Pathogenic IL-17A-expressing Cells in Canine Model of Chronic GVHD.

BACKGROUND: Chronic graft-versus-host disease (GVHD) is a significant cause of morbidity and mortality in transplant patients. We have previously shown that 3 doses of an anti-inducible costimulator (ICOS) mAb transiently ameliorated symptoms and extended survival of dogs affected by chronic GVHD over that of control dogs. The purpose of this study was to specifically correlate changes in T-cell populations in the peripheral blood with anti-ICOS treatment and chronic GVHD progression and regression to reach a better understanding of the mechanism of the disease and prioritize future studies. METHODS: Peripheral blood cells from canines transplanted with DLA-mismatched bone marrow and peripheral blood mononuclear cells to generate chronic GVHD were analyzed by flow cytometry using a panel of antibodies specific to helper and cytolytic T cells. RESULTS: Chronic GVHD was specifically associated with an increase in CD4+ICOS+ cells, ICOS+ cells expressing IL-17A, and CD8+ cells generating granzyme B. Treatment with anti-ICOS mAb at onset of chronic GVHD symptoms specifically targeted IL-17A+-expressing cells, transiently relieved symptoms, and lengthened survival but was unable to reduce the percentage of CD8+ T-cells expressing granzyme B. CONCLUSIONS: These studies suggested a role for both CD4+ and CD8+ T cells in pathogenesis of chronic GVHD in the canine model. We propose that future studies should focus on further extending survival by developing a treatment that would control both CD4+ and CD8+ T cells.

Conditioning Intensity, Pre-Transplant Flow Cytometric Measurable Residual Disease, and Outcome in Adults with Acute Myeloid Leukemia Undergoing Allogeneic Hematopoietic Cell Transplantation.

How conditioning intensity is related to outcomes of AML patients undergoing allografting in morphologic remission is an area of great ongoing interest. We studied 743 patients in morphologic remission and known pre-transplant measurable residual disease (MRD) status determined by multiparameter flow cytometry (MFC) who received a first allograft after myeloablative, reduced intensity, or nonmyeloablative conditioning (MAC, RIC, and NMA). Overall, relapse-free survival (RFS) and overall survival (OS) were longer after MAC than RIC or NMA conditioning, whereas relapse risks were not different. Among MRDpos patients, 3-year estimates of relapse risks and survival were similar across conditioning intensities. In contrast, among MRDneg patients, 3-year RFS and OS were longer for MAC (69% and 71%) than RIC (47% and 55%) and NMA conditioning (47% and 52%). Three-year relapse risks were lowest after MAC (18%) and highest after NMA conditioning (30%). Our data indicate an interaction between conditioning intensity, MFC-based pre-transplant MRD status, and outcome, with benefit of intensive conditioning primarily for patients transplanted in MRDneg remission. Differing from recent findings from other studies that indicated MAC is primarily beneficial for some or all patients with MRDpos pre-HCT status, our data suggest MAC should still be considered for MRDneg AML patients if tolerated.