GVHD relapse-free survival after peripheral blood hematopoietic cell transplantation for hematologic malignancies

The preferred choice for hematopoietic cell transplantation (HCT) donors in India is a matched related donor (MRD) followed by a haploidentical (haplo) donor for patients with hematological malignancies. International data in the haplo-HCT setting is mainly using bone marrow as a source. Almost all HCTs in India use peripheral blood stem cells (PBSC), which increases the risk of graft-versus-host disease (GVHD). In this single-center prospective study from 2017 to 2021, we sought to compare these outcomes prospectively in adult patients with hematological malignancies. Patient, disease, donor, and HCT details were prospectively recorded. GVHD prophylaxis included cyclosporine + methotrexate in MRD-HCT and post-transplant cyclophosphamide (PTCy) based in haplo-HCT. The primary endpoint GVHD relapse-free survival (GRFS) was defined as the time post-HCT without any of the following events: grade III-IV acute GVHD, chronic GVHD requiring systemic immunosuppressive treatment, disease relapse, or death from any cause. A total of 41 MRD and 33 haplo-HCT recipients were included in the study. Both cohorts were matched for age, sex, diagnosis, disease risk index, donor age, sex and CMV mismatches, and CD34 counts. A lower proportion of MRD-HCT recipients than haplo-HCT received myeloablative conditioning (39% vs. 76%, p = 0.002). There was no difference in the cumulative incidence of grade III-IV acute GVHD (16% vs. 27%, p = 0.2) or moderate-to-severe chronic GVHD (58% vs. 71%, p = 0.5). The one-year GRFS was not significantly different (53% vs. 38%, p = 0.2), with median GRFS of 420 and 274 days. The relapse incidence (22% vs. 19%, p = 0.6) and non-relapse mortality (25% vs. 35%, p = 0.4) did not differ. There was no difference in overall survival at one year (60% vs. 52%, p = 0.3). Despite a higher proportion of myeloablative conditioning in the haplo-HCT cohort, all outcomes, including GRFS, were comparable to those of the MRD-HCT cohort. This should encourage patients without an MRD to undergo haplo-HCT.

Comprehensive evolutionary analysis of growth-regulating factor gene family revealing the potential molecular basis under multiple hormonal stress in Gramineae crops

Growth-regulating factors (GRFs) are plant-specific transcription factors that contain two highly conserved QLQ and WRC domains, which control a range of biological functions, including leaf growth, floral organ development, and phytohormone signaling. However, knowledge of the evolutionary patterns and driving forces of GRFs in Gramineae crops is limited and poorly characterized. In this study, a total of 96 GRFs were identified from eight crops of Brachypodium distachyon, Hordeum vulgare, Oryza sativa L. ssp. indica, Oryza rufipogon, Oryza sativa L. ssp. japonica, Setaria italic, Sorghum bicolor and Zea mays. Based on their protein sequences, the GRFs were classified into three groups. Evolutionary analysis indicated that the whole-genome or segmental duplication plays an essential role in the GRFs expansion, and the GRFs were negatively selected during the evolution of Gramineae crops. The GRFs protein function as transcriptional activators with distinctive structural motifs in different groups. In addition, the expression of GRFs was induced under multiple hormonal stress, including IAA, BR, GA3, 6BA, ABA, and MeJ treatments. Specifically, OjGRF11 was significantly induced by IAA at 6 h after phytohormone treatment. Transgenic experiments showed that roots overexpressing OjGRF11 were more sensitive to IAA and affect root elongation. This study will broaden our insights into the origin and evolution of the GRF family in Gramineae crops and will facilitate further research on GRF function.

Determinants of refined GvHD-free, relapse-free survival after reduced-intensity allogeneic hematopoietic cell transplantation in older patients with myeloid malignancies

BACKGROUND

Older patients with AML/MDS have a poor prognosis with alloHCT as the only curative option. However alloHCT is challenging given its high TRM. Recently, a composite endpoint of GRFS was proposed to define transplant success. A single centre retrospective analysis was performed to determine the main variables influencing GRFS.

PATIENTS AND METHODSMETHODS

91 consecutive patients≥ 60 years (median 64 years, range 60-74) with AML/MDS who received reduced-intensity alloHCT during 2001-2017 analysed. Disease risk index (DRI) at HCT was low/intermediate in 47pts (52%) and high in 44 pts (48%).

RESULTS

After median follow-up for survivors of 56 months (range 7-144), 37 (40.6%) patients were alive. The OS, LFS and GRFS were 61.4%, 58.1%, 49.1% at 1 year and 35.5%, 32.3% and 23.1% at 5 years, respectively. The 1-year and 5-year incidences of NRM and relapse were 26.9%, 21.3% and 47.9% and 35.4%, respectively. In univariate analysis, high DRI was the strongest factor for worse OS (HR 2.121; p = 0.049), LFS (HR 1.924; p = 0.0123) and GRFS (HR 2.319; p = 0.0005). The donor age ≥ 62 years had a negative impact on OS (HR 2.110; p = 0.0345) and GRFS (HR 2.014; p = 0.0341). High DRI (HR 2.652; p = 0.0003) and donor age (HR 2.304; p = 0.0257) retained its significance in multivariate analysis for GRFS.

CONCLUSION

A significant portion of older patients with myeloid malignancies survive alloHCT without experiencing GRFS event with DRI as the main determinant of outcome. Negative impact of donor age≥ 62 years suggests preference of a young donor, regardless of being related or unrelated.

Inferences for current chronic graft-versus-host-disease free and relapse free survival

This paper provides the methodologies of a new summary curve that measures the dynamic outcome following allogenic hematopoietic cell transplantation. This new summary curve computes the probabilities that a patient is alive in remission and free of severe-to-moderate chronic graft-versus-host disease (GVHD) over time. The probability is called Current chronic GVHD-free, Relapse-Free Survival (CGRFS). Based on a multistate model depicting the possible states that a patient may experience after transplant, CGRFS can be formulated as a linear combination of five survival functions. This method is known as the model-free approach. In this paper we provide the inferences of the model-free approach, including estimation of CGRFS, precision evaluation and comparison of CGRFS between two independent samples.

PTCY and Tacrolimus for GVHD Prevention for Older Adults Undergoing HLA-Matched Sibling and Unrelated Donor AlloHCT

INTRODUCTION

The use of PTCY for graft-versus-host disease (GHVD) prevention is becoming prevalent in the transplant community when HLA-identical sibling (MSD) and 10/10 HLA-matched (MUD) and 9/10 mismatched (MMUD) unrelated donors are selected for alloHSCT. However, reported evidence on outcomes from elderly receiving PTCY-containing GVHD prophylaxis remains limited.

OBJECTIVES

This study aims to compare the outcomes of PTCY-TK prophylaxis and conventional GVHD prophylaxis in patients aged >50 years undergoing peripheral blood alloHSCT from a single institution.

STUDY DESIGN

A total of 161 consecutive patients aged >50 years undergoing alloHSCT between Jan-2014 and Feb-2021 were included. Data was collected retrospectively and updated in December 2021. Patients received grafts from HLA-identical sibling (MSD), and from 10/10 and 9/10 HLA matched and mismatched unrelated donors (UD).

RESULTS

Overall, median age was 60 years and 91 (54.8%) received PTCY-TK for GVHD prevention. Time to neutrophil and platelet engraftment was longer in the PTCY-TK group (20 vs. 16 days and 19 vs. 11 days, P< 0.001). The cumulative incidences of grade II-IV and III-IV aGVHD at day +100 and moderate/severe cGVHD at 2 years were 18.2%, 5.7% and 9.5% for patients receiving PTCY-TK, and 26.0%, 9.6% and 39.5% for those that did not. The multivariate analysis showed that PTCY-TK reduced the probability of grade II-IV aGVHD (HR 0.41, p=0.035), of cGVHD [any grade: HR 0.43 (p=0.014), and of moderate/severe cGVHD (HR 0.15 (p<0.001)]. At 2-years, the overall survival (65.4% vs. 65.6%, p=0.472), non-relapse mortality (17.4% vs. 13.7%, p=0.967), and cumulative incidence of relapse rates (24.2% vs. 27.5%, p=0.712) were comparable between both cohorts; GVHD-Free/Relapse-free survival (GRFS) was higher in the PTCY-TK group (2-years: 50.2% vs. 21.8%; HR 0.42, p=0.001). In patients aged ≥50 years, Conclusion: PTCY-TK was safe and a more effective drug combination than non-PTCY containing GVHD prophylaxis, even with the use of matched and mismatched UD, and resulted in comparable relapse rates and better GRFS.

Acute Lymphoblastic Leukemia in Children: Better Transplant Outcomes After Total Body Irradiation-based Conditioning

BACKGROUND/AIM

Comparison of transplant outcomes in long-term follow-up of children after total body irradiation (TBI)- or chemotherapy-based conditioning allogeneic hematopoietic cell transplantation (allo-HCT).

PATIENTS AND METHODS

Patients undergoing allo-HCT for Acute lymphoblastic leukemia (ALL) conditioned either with TBI (n=55) or chemotherapy (n=84) were compared. The following transplant outcomes were analyzed: overall survival (OS), event-free survival (EFS), relapse incidence (RI), and graft-versus-host-disease (GVHD)-free-relapse-free survival (GRFS).

RESULTS

All analyzed long-term transplant outcomes were significantly better for patients conditioned with TBI at 2 years after transplant. OS at 2 years was 84% after TBI and 60.5% after chemotherapy-conditioning (p=0.005). Risk factor analysis showed that two factors, TBI-based conditioning and transplant in first remission of ALL, significantly improved OS, EFS, GRFS, and decreased RI.

CONCLUSION

TBI-based conditioning before allogeneic HCT in children with acute lymphoblastic leukemia provides significantly better transplant outcomes, when compared to chemotherapy-based conditioning.

Graft-Versus-Host Disease Prophylaxis Using Low-Dose Antithymocyte Globulin in Peripheral Blood Stem Cell Transplantation-A Matched-Pair Analysis

Antithymocyte globulin (ATG) decreases chronic graft-versus-host disease (cGVHD) in peripheral blood stem cell transplantation (PBSCT); however, the optimal ATG dose has not been elucidated. We conducted a matched-pair analysis to evaluate whether low-dose ATG could inhibit cGVHD in HLA-matched PBSCT after myeloablative conditioning. A total of 70 patients who were enrolled in the JSCT-ATG15 study, a multicenter phase II clinical trial of 2 mg/kg of ATG (thymoglobulin) given on days -2 and -1, were compared with 210 patients not receiving ATG, who were matched for age, sex, disease, and calcineurin inhibitor selected from the database in Japan. The primary endpoint, cumulative incidence of extensive cGVHD at 2 years was significantly less in the ATG group than that in the non-ATG group (8.7% [95% CI, 3.5%-16.8%] versus 26.2% [95% CI, 20.3%-32.5%], P = .002). ATG significantly reduced the incidence of overall cGVHD and inhibited multiple organ involvement. The ATG group had favorable outcome compared to the non-ATG group in GVHD-free, and relapse-free survival at 2 years. In conclusion, low-dose ATG effectively inhibits chronic GVHD in PBSCT.

Novel Composite Endpoints after Allogeneic Hematopoietic Cell Transplantation

With the recent development of transplant-specific composite endpoints for evaluation of allogeneic hematopoietic cell transplantation (alloHCT) outcomes, the use of these novel endpoints is growing rapidly. Combining multiple endpoints into a single endpoint, these composite endpoints appear simple and can be used as a summary measure for overall effectiveness of an intervention. However, all component endpoints may not have equal clinical significance, and an intervention may not work proportionally in the same direction for all components of a composite endpoint. This may complicate the interpretation of results, particularly if there are opposing effects of differing component endpoints. We assess the benefits and limitations of various composite endpoints used in alloHCT studies recently and propose guidelines for their use and interpretation. © 2021 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Cyclosporine/methotrexate versus tacrolimus/methotrexate with or without anti-thymocyte globulin as GVHD prophylaxis in adult patients with aplastic anemia

The impact of calcineurin inhibitor types and anti-thymocyte globulin (ATG) in conditioning on overall survival (OS) and GVHD-free, relapse-free survival (GRFS) has not yet been analyzed in detail for aplastic anemia. We herein examined 517 adult patients with aplastic anemia who underwent BMT from HLA-matched sibling donors (MSD, n = 255) and unrelated donors (UD, n = 262) and were treated with cyclosporine A (CSA) + methotrexate (MTX) (n = 258) and tacrolimus (TAC) + MTX (n = 259). In total, 330 patients received ATG in conditioning. CSA + MTX versus TAC + MTX did not have a significant impact on acute and chronic GVHD, OS, or GRFS in each donor type. The use of ATG in conditioning reduced the risk of grade II-IV acute GVHD in the MSD and UD cohorts (HR 0.42, P = 0.014, and HR 0.3, P < 0.001, respectively); however, a differential impact on GRFS was identified, namely, better GRFS in MSD recipients (HR 0.56, P = 0.016), but not in UD recipients (HR 1.1, P = 0.657). In conclusion, CSA + MTX and TAC + MTX were similar as GVHD prophylaxis regardless of the donor type, and ATG in conditioning increased GRFS in MSD transplants, but not in UD transplants.

Dynamic Graft-versus-Host Disease-Free, Relapse-Free Survival: Multistate Modeling of the Morbidity and Mortality of Allotransplantation

Graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) represents complete, ideal recovery after allogeneic hematopoietic cell transplantation (HCT). However, as originally proposed, this composite endpoint does not account for the possibility that HCT complications may improve after treatment. To more accurately estimate survival with response to GVHD and relapse after HCT, we developed a dynamic multistate GRFS (dGRFS) model with outcomes data from 949 patients undergoing their first allogeneic HCT for hematologic malignancy at the University of Minnesota. Because some patients were successfully treated for GVHD and relapse, dGRFS was higher than the originally defined time-to-event GRFS at 1 year (37.0 versus 27.6%) through 4 years (37.4% versus 22.2%). Mean survival without failure events was .52 years (95% confidence interval, .45 to .58 year) greater in dGRFS compared with the originally defined GRFS. Patient age (P< .001), disease risk (P < .001), conditioning intensity (P = .007), and donor type (P = .003) all significantly influenced dGRFS. The multistate model of dGRFS closely estimates the continuing and prevalent severe morbidity and mortality of allogeneic HCT. To serve the greater HCT community in more accurately modeling recovery from transplantation, we provide our R code for determination of dGRFS with annotations in Supplementary Materials.

Fludarabine and Total-Body Irradiation Conditioning before Ablative Haploidentical Transplantation: Long-Term Safety and Efficacy

Although myeloablative conditioning (MAC) before haploidentical donor transplant (HIDT) with post-transplant cyclophosphamide is being increasingly used, the optimal preparative regimen remains unclear. In our initial trial, the feasibility of HIDT following a MAC preparative regimen using fludarabine and 12 Gy of total-body irradiation was demonstrated in 30 patients. We now present long-term outcome results, including an additional 52 patients, now with 47 months (16 to 96) median follow-up. Median patient age was 42 (19 to 61) years. The most common diagnoses were acute myelogenous leukemia (51%) and acute lymphoblastic leukemia (33%), and 39% had a high/very high disease risk index (DRI). Engraftment was universal with no cases of primary or secondary graft failure. Grade 3 to 4 acute graft-versus-host disease (GVHD) and moderate to severe chronic GVHD occurred in 17% and 23%, respectively. Nonrelapse mortality (NRM) was 7% at 1 year and 13% at 4 years. Estimated 4-year overall survival (OS), disease-free survival, and cumulative incidence of relapse (CIR) were 67%, 60%, and 27%, respectively. CIR was significantly higher in patients with high/very high- versus low/intermediate-risk DRI (38% versus 20%, P= .032), which led to inferior 4-year OS (50% versus 77%, P = .001). Median time to systemic immunosuppressive therapy (IST) discontinuation was 7.8 months, with 84% of patients off IST at 2 years post-transplant. Current GHVD-free, relapse-free survival (CGRFS) at 2, 3, and 4 years was 60%, 57%, and 60%, respectively. This approach to MAC HIDT results in universal engraftment; low rates of NRM, infection, and clinically significant GVHD; and relatively rapid IST discontinuation, resulting in high rates of CGRFS and survival.

Challenges in Conducting Studies in Chronic Graft-versus-Host Disease

The lack of standardized criteria for measuring therapeutic response has been a major obstacle to the development of therapeutic trials in chronic graft-versus-host disease (cGvHD). Nevertheless, recent advances have been made in understanding of the biology and pathophysiology of cGvHD, as well as establishing more precise criteria for the diagnosis and classification of disease manifestations. The momentum has shifted, and currently there is a long list of new potential treatment targets being identified for cGvHD. Consequently, new drugs are being implemented for its prophylaxis and treatment. It is crucial to continue that trend and develop better systems to test new drugs in clinical practice that would eventually translate toward seeking regulatory review and approval. We provide a historical perspective and current challenges in conducting cGvHD clinical trials.

Assessment of Individual versus Composite Endpoints of Acute Graft-versus-Host Disease in Determining Long-Term Survival after Allogeneic Transplantation

The overall composite of graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS), defined as survival free of grade III-IV acute GVHD (aGVHD), chronic GVHD (cGVHD) requiring systemic immunosuppressive therapy (IST), or relapse, has emerged as a useful composite in clinical trials and to capture clinically meaningful events that impact quantity and quality of survival after allogeneic hematopoietic cell transplantation (HCT). We reviewed 565 consecutive patients aged ≥18 years undergoing HCT for hematologic malignancy to analyze how baseline incidence, specifics of clinical definitions, and proposed reductions in any one individual event may dynamically alter the overall performance of the composite To determine the relative impact of each GRFS event (excluding death), we accounted for competing risks using Fine and Gray methods, and correlated each event with overall survival (OS) using Kaplan-Meier methods. The consequences of modulating individual or composite endpoints on OS, such as hypothesized reductions of events of an HCT interventional trial, were examined using Monte Carlo simulations. The median age of the cohort was 54 years (range, 18 to 73 years). The majority of patients received HLA-matched unrelated donor HCT (53%), consisting of peripheral blood stem cell grafts (90%) after myeloablative conditioning (68%). Relapse conferred the greatest risk for death (hazard ratio [HR], 7.89; 95% confidence interval [CI], 5.83 to 10.69), followed by grade III-IV aGVHD (HR, 6.16; 95% CI, 4.42 to 8.56) and cGVHD requiring IST (HR, 1.69; 95% CI, 1.16 to 2.46). The overall GRFS composite correlated with an HR of 4.81 (95% CI, 3.61 to 6.41), which was lower compared with either relapse or grade III-IV aGVHD. Statistical simulations found that modulating the combined risk of both relapse and grade III-IV aGVHD predicted the greatest change in 5-year OS. These simulations suggest that GRFS as currently defined may be less optimal for correlating with OS, and further refinement of composite endpoints is needed. Nonetheless, composite endpoints may be particularly helpful in mitigating potential difficulties in interpretation when competing risks are present, most commonly seen in HCT studies.

Impact of in vivo T cell depletion in HLA-identical allogeneic stem cell transplantation for acute myeloid leukemia in first complete remission conditioned with a fludarabine iv-busulfan myeloablative regimen: a report from the EBMT Acute Leukemia Working Party

Background

The impact of the use of anti-thymocyte globulin (ATG) in allogeneic stem cell transplantation performed with HLA-identical sibling donors following fludarabine and 4 days intravenous busulfan myeloablative conditioning regimen has been poorly explored.

Methods

We retrospectively analyzed 566 patients who underwent a first HLA-identical allogeneic stem cell transplantation with this conditioning regimen for acute myeloid leukemia in first complete remission between 2006 and 2013 and compared the outcomes of 145 (25.6%) patients who received ATG (ATG group) to 421 (74.4%) who did not (no-ATG group). The Kaplan-Meier estimator, the cumulative incidence function, and Cox proportional hazards regression models were used where appropriate.

Results

Patients in the ATG group were older, received more frequently peripheral blood stem cell grafts from older donors, and were transplanted more recently. With a median follow-up of 19 months, patients in the ATG group had reduced 2-year cumulative incidence of chronic graft-versus-host disease (GVHD) (31 vs. 52%, p = 0.0002) and of its extensive form (8 vs. 26%, p < 0.0001) but similar relapse incidence (22 vs. 27%, p = 0.23) leading to improved GVHD and relapse-free survival (GRFS) (60 vs. 40%, p = 0.0001). In multivariate analyses, the addition of ATG was independently associated with lower chronic GVHD (HR = 0.46, p = 0.0001), improved leukemia-free survival (HR = 0.67, p = 0.027), overall survival (HR = 0.65, p = 0.027), and GRFS (HR = 0.51, p = 4 × 10⁻⁵). Recipient age above 50 years was the only other factor associated with worse survivals.

Conclusions

These results suggest that the use of ATG with fludarabine and 4 days intravenous busulfan followed by HLA-identical sibling donor allogeneic stem cell transplantation for acute myeloid leukemia improves overall transplant outcomes due to reduced incidence of chronic GVHD without increased relapse risk.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-016-0389-4) contains supplementary material, which is available to authorized users.