CMV reactivation after allogeneic HCT is associated with a reduced risk of relapse in acute lymphoblastic leukemia

IFN-γ and donor leukocyte infusions for relapsed myeloblastic malignancies after allogeneic hematopoietic stem cell transplantation

BACKGROUNDThe graft-versus-leukemia (GVL) effect contributes to the efficacy of allogeneic stem cell transplantation (alloSCT). However, relapse, indicative of GVL failure, is the greatest single cause of treatment failure. Based on preclinical data showing that IFN-γ is important to sensitize myeloblasts to alloreactive T cells, we performed a phase I trial of IFN-γ combined with donor leukocyte infusions (DLIs) in myeloblastic malignancies that relapsed after HLA-matched alloSCT.METHODSPatients with relapsed acute myeloid leukemia or myelodysplastic syndrome after alloSCT were eligible. Patients self-administered IFN-γ for 4 weeks (cohort 1) or 1 week (cohort 2), followed by DLI and concurrent IFN-γ for a total of 12 weeks. Bone marrow samples were analyzed by single-cell RNA sequencing (scRNA-Seq) to assess in vivo responses to IFN-γ by malignant myeloblasts.RESULTSIFN-γ monotherapy was well tolerated by all participants (n = 7). Treatment-related toxicities after DLI included grade I-II graft-versus-host disease (n = 5), immune effector cell-associated neurotoxicity syndrome (n = 2), and idiopathic pulmonary syndrome (n = 1), all of which resolved with corticosteroids. Four of 6 DLI recipients achieved minimal residual disease-negative complete remissions and full donor hematopoietic recovery. Median overall survival was 579 days (range, 97-906) in responders. scRNA-Seq validated in vivo activation of the IFN-γ response pathway in hematopoietic stem cell-like or myeloid progenitor cells after IFN-γ in analyzed samples.CONCLUSIONIFN-γ was safe and well tolerated in this phase I study of IFN-γ for relapsed acute myeloid leukemia and myelodysplastic syndrome after alloSCT, with a promising efficacy signal when combined with DLI. Larger studies are needed to formally test the efficacy of this approach.TRIAL REGISTRATIONClinicalTrials.gov NCT04628338.FUNDINGUPMC Hillman Cancer Center Cancer Immunology and Immunotherapy Program Pilot Award and Cure Within Reach: Drug Repurposing Clinical Trials to Impact Blood Cancers.

Allogeneic Hematopoietic Stem Cell Transplantation for Elderly Acute Lymphoblastic Leukemia Patients: A Registry Study From the Société Francophone de Greffe de Moelle et Thérapie Cellulaire (SFGM-TC)

There are very limited data regarding the outcomes of elderly patients with acute lymphoblastic leukemia (ALL) who undergo allogeneic hematopoietic stem cell transplantation (alloHSCT). A total of 316 ALL patients aged ≥ 60 years who underwent alloHSCT between 2010 to 2022 were identified in the SFGM-TC registry. The primary objective was to evaluate progression-free survival (PFS), non-relapse mortality (NRM), relapse incidence (RI), and graft-versus-host disease (GvHD)-free relapse-free survival (GRFS), as well as their risk factors. The median age was 63.8 years (range 60-75.8), 49.8% of patients had Philadelphia-positive B-ALL (Ph + ALL), and 70.9% were in first complete remission (CR1) at transplantation. The donor was an unrelated donor in 52.1%, a matched related donor (MRD) in 26.3%, and a haplo-identical donor in 17.7%. Reduced-intensity conditioning (RIC) was administered to 64.6% of patients, while total body irradiation (TBI) was used in 35.8%. The 3-year overall survival (OS) was 46% (95% CI 40%-53%). The 3-year PFS, NRM, RI, and GRFS were 41% (95% CI 35%-48%), 23% (95% CI 18%-28%), 36% (95% CI 31%-42%), and 30% (95% CI 25%-37%), respectively. Multivariable analyses confirmed poorer OS and PFS in patients with advanced disease, with an HR of 1.79 (95% CI 1.22-2.64), p = 0.0032. Additionally, the ALL subtype significantly impacted outcomes, with an HR of 1.99 (95% CI 1.42-2.79) for non-Ph + ALL. This study suggests that alloHSCT is a viable option for elderly ALL patients, as age itself did not impact outcomes. However, advanced disease and non-Ph + ALL were associated with significantly worse survival.

Impact of Cytomegalovirus Reactivation Following Allogeneic Hematopoietic Cell Transplantation on the Relapse of Acute Leukemia

BACKGROUND

Cytomegalovirus (CMV) reactivation following allogeneic hematopoietic cell transplantation (HCT) is a significant complication; however, its impact on relapse remains controversial.

OBJECTIVES

This study aimed to evaluate the clinical impact of CMV reactivation on relapse and survival after HCT in patients with acute leukemia.

STUDY DESIGN

We conducted a retrospective analysis of 1258 patients diagnosed with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) who underwent their first HCT between 2000 and 2020.

RESULTS

Our cohort included 871 patients with AML and 387 patients with ALL. Among all patients, 751 (61.6%) experienced CMV reactivation within one year post-HCT. CMV reactivation was associated with HCT from unrelated donors, anti-thymocyte globulin use, and the occurrence of acute graft-versus-host disease. Notably, CMV reactivation was associated with a lower risk of relapse (HR, 0.713; P = .001) and improved event-free survival (HR, 0.743; P = .001) in both AML and ALL patients. However, there was no significant difference in non-relapse mortality or overall survival according to CMV reactivation.

CONCLUSION

These results suggest that CMV reactivation may prevent post-HCT relapse and enhance event-free survival in AML and ALL patients. Therefore, a CMV prophylaxis strategy is warranted to establish a safe range of CMV reactivation titers that can yield beneficial effects.

Heterogeneity of Survival Benefit Conferred By Letermovir

Variation in treatment effects based on individual patient characteristics-known as treatment effect heterogeneity or effect modification-has recently gained significant attention. A previous clinical trial and its post hoc analysis suggested that letermovir (LTV) may reduce mortality more in some patients than in others. We hypothesized that the survival benefit of LTV differs according to each patient's specific characteristics. This study aimed to identify patient characteristics that are associated with significant survival benefits from LTV. Patients who underwent transplantation between 2018 and 2022 were randomly divided into training (n = 5779) and validation groups (n = 2865). We developed two models: one using a proportional hazards model with interaction terms (PI), and another using a modern machine learning (ML) approach to detect heterogeneity in the survival benefit-specifically, to identify patient characteristics associated with greater benefit from LTV. In our cohort, 60% of patients received LTV as prophylaxis. In the training cohort, the final PI model, using additive interactions, identified advanced age (≥60), high comorbidities (HCT-CI ≥3), umbilical cord blood (UCB), and haploidentical HCT with post cyclophosphamide (PTCy Haplo) as highly beneficial factors. Meanwhile, the ML model, using a causal forest algorithm, classified the top 60% of patients based on the estimated individual treatment effect as the high benefit group. In the validation group, 67.1% and 59.9% of patients were considered to be high benefit by the PI and ML models, respectively. The absolute difference in 6-month NRM (LTV versus no LTV) in the high benefit group (PI model: 9.8% versus 16.3%; ML model: 11.3% versus 16.3%) was greater than that in the low benefit group (PI model: 4.3% versus 6.9%; ML model: 4.1% versus 6.2%). Most patients (>80%) with advanced age, high comorbidities, or UCB were classified as high benefit by the ML model, supporting the robustness of the PI model. Our models successfully identified patients who could be expected to experience lower NRM with LTV prophylaxis, underscoring the importance of personalized medicine.

Role of cytomegalovirus reactivation on relapse after allogeneic hematopoietic stem cell transplantation in acute lymphoblastic leukemia

Cytomegalovirus reactivation (CMV-R) is a frequent complication post-allogeneic hematopoietic stem cell transplantation (allo-HSCT), associated with poor outcomes. Previous studies have demonstrated the protective effect of CMV-R against relapse after allo-HSCT for acute myeloblastic leukemia (AML). However, this impact remains unclear in acute lymphoblastic leukemia (ALL). We conducted a retrospective study on 81 patients with ALL who received allo-HSCT after myeloablative conditioning regimen from matched sibling donors between 2016 and 2022. All patients underwent weekly monitoring for CMV-R by quantitative polymerase chain reaction assay from engraftment until day +100 post allo-HSCT, and received antiviral prophylaxis with acyclovir from day +1 to 6 months after allo-HSCT. Preemptive treatment was initiated when a viremia was higher than 150 copies/mL. The median age was 20 years (range, 5-50 years). After allo-HSCT, 35% of patients developed CMV-R after a median of 39 days (range, 19-100 days). After a median follow-up of 30 months (range, 1-93 months), CMV-R was an independent factor associated with lower cumulative incidence of relapse (CIR) (OR: 0.17; 95% CI [0.03 - 0.98], p = 0.04) without survival benefit. Further studies are needed to validate the protective effect of CMV-R on ALL relapse.

Cytomegalovirus in haematopoietic cell transplantation - The troll is still there

Patients undergoing allogeneic haematopoietic cell transplantation are prone to complications caused by viral infections. Cytomegalovirus (CMV) considerably impacts transplantation as it frequently requires antiviral intervention that evokes substantial side effects depending on the antiviral drug. Intermittent antiviral treatment may become necessary if CMV DNAemia cannot be permanently suppressed, and drug resistance may emerge that hampers and prolongs treatment. Despite sedulous endeavours, vaccination against CMV is not yet available. This review concisely summarises current approaches in managing CMV infection comprising risk factors, diagnostics including indications for resistance testing, and therapeutic options from antiviral drugs to virus-specific T cells.

Impact of Early Cytomegalovirus Reactivation After Allogeneic Hematopoietic Stem Cell Transplantation on Relapse in Patients With Myelodysplastic Syndrome: A Nationwide Retrospective Study From Adult Myelodysplastic Syndrome Working Group of the JSTCT

Cytomegalovirus (CMV) reactivation is a prominent complication associated with adverse outcomes in allogeneic hematopoietic stem cell transplantation (HSCT). However, CMV reactivation after allogeneic HSCT may be associated with a lower incidence of relapse in some hematological malignancies. This study analyzed the Japanese registry data from 1082 patients with myelodysplastic syndrome (MDS) who underwent their first allogeneic HSCT and survived for 100 days after transplantation without graft failure or disease relapse to investigate this association. Patients who received cord blood transplants, demonstrated in vivo T cell depletion, underwent prophylactic anti-CMV treatment, or diagnosed with secondary MDS were excluded. CMV reactivation measured by pp65 antigenemia within 100 days after allogeneic HSCT was observed in 57.5% of patients, with a median time of 46 days from transplant. The 5-yr overall survival and cumulative incidence of relapse (CIR) in the cohort were 60.5% and 15.6%, respectively. The 5-yr CIR showed no significant difference between patients with and without CMV reactivation (14.4% versus 17.2%; P = .185). Interestingly, CMV reactivation within 100 days was significantly associated with a lower 5-yr CIR (7.6% versus 16.4%; P = .002) in patients with <5% myeloblasts in the bone marrow (BM) just before HSCT. Furthermore, this relevancy confirmed even when excluding patients with Grade II to IV acute GVHD (Hazard ratio: 0.38; 95% confidential intervals: 0.18-0.801; P = .011). Our findings indicate a correlation between early CMV reactivation and MDS relapse, based on the proportion of myeloblasts in the BM. These results may contribute to the development of effective CMV prophylaxis post-HSCT.

Flares of acute graft-versus-host disease: a Mount Sinai Acute GVHD International Consortium analysis

ABSTRACT

The absence of a standardized definition for graft-versus-host disease (GVHD) flares and data on its clinical course are significant concerns. We retrospectively evaluated 968 patients across 23 Mount Sinai Acute GVHD International Consortium (MAGIC) transplant centers who achieved complete response (CR) or very good partial response (VGPR) within 4 weeks of treatment. The cumulative incidence of flares within 6 months was 22%, and flares were associated with a higher risk of nonrelapse mortality (NRM; adjusted hazard ratio [aHR], 4.84; 95% confidence interval [CI], 3.19-7.36; P < .001). Flares were more severe (grades 3/4, 41% vs 16%; P < .001) and had more frequent lower gastrointestinal (LGI) involvement (55% vs 32%; P < .001) than the initial GVHD. At CR/VGPR, elevated MAGIC biomarkers predicted the future occurrence of a flare, along with its severity and LGI involvement. In multivariate analyses, higher Ann Arbor (AA) biomarker scores at CR/VGPR were significant risk factors for flares (AA2 vs AA1: aHR, 1.81 [95% CI, 1.32-2.48; P = .001]; AA3 vs AA1: aHR, 3.14 [95% CI, 1.98-4.98; P < .001]), as were early response to initial treatment (aHR, 1.84; 95% CI, 1.21-2.80; P = .004) and HLA-mismatched unrelated donor (aHR, 1.74; 95% CI, 1.00-3.02; P = .049). MAGIC biomarkers also stratified the risk of NRM both at CR/VGPR and at the time of flare. We conclude that GVHD flares are common and carry a significant mortality risk. The occurrence of future flares can be predicted by serum biomarkers that may serve to guide adjustment and discontinuation of immunosuppression.

Differential clinical impact of letermovir prophylaxis according to graft sources: a KSGCT multicenter retrospective analysis

ABSTRACT

Clinically significant cytomegalovirus infection (csCMVi) is frequently observed after allogeneic hematopoietic stem cell transplantation (HSCT) and prophylaxis with letermovir is commonly adopted. However, the clinical benefit of letermovir prophylaxis according to graft sources has not been sufficiently elucidated. We retrospectively analyzed 2194 recipients of HSCT who were CMV-seropositive (236 with letermovir prophylaxis and 1958 without prophylaxis against CMV). csCMVi was significantly less frequent in patients with letermovir prophylaxis than in those without (23.7% vs 58.7% at 100 days after HSCT, P < .001) and the same trend was seen when recipients of bone marrow (BM), peripheral blood stem cell (PBSC), or cord blood (CB) transplantation were separately analyzed. In recipients of BM, nonrelapse mortality (NRM) was significantly lower in the letermovir group at 6 months after HSCT (5.0% vs 14.9%, P = .018), and the same trend was observed in recipients of PBSCs (14.7% vs 24.8%, P = .062); however, there was no statistical significance at 1 year (BM, 21.1% vs 30.4%, P = .67; PBSCs, 21.2% vs 30.4%, P = .096). In contrast, NRM was comparable between recipients of CB with and without letermovir prophylaxis throughout the clinical course (6 months, 23.6% vs 24.3%, P =.92; 1 year, 29.3% vs 31.0%, P = .77), which was confirmed by multivariate analyses. In conclusion, the impact of letermovir prophylaxis on NRM and csCMVi should be separately considered according to graft sources.

Early Allogeneic Transplantation Favorably Influences the Outcome of Pediatric Acute Myeloid Leukemia-A Retrospective Study in a Single Center Over 2 Decades

BACKGROUND

Transplantation advancements offer the potential for improving the prognosis of patients with acute myeloid leukemia (AML). Controversies surrounding indications and timing persist. We focused on identifying prognostic factors and exploring the advantages of early transplantation.

PATIENTS AND METHODS

We studied 102 pediatric patients with AML (February 1999-August 2022), using Cox regression to analyze survival and hematopoietic cell transplantation (HCT) outcomes and Kaplan-Meier curves to assess HCT timing's impact on prognosis.

RESULTS

"Treatment in First Complete Remission [CR1]: Chemotherapy" showed increased risk in multivariate and univariate Cox regression analyses, whereas "HCT during the study period" displayed divergent outcomes. Focusing on transplanted patients, "Treatment in CR1: Chemotherapy" still correlated with higher mortality risk. These findings emphasize the pivotal role of the treatment strategy adopted in CR1 on overall survival rather than HCT alone. Donor cytomegalovirus (CMV) positivity is also related to reduced mortality risk. Kaplan-Meier analysis supported superior 5-year survival rates with "HCT" compared with "chemotherapy" in CR1. In the 3-arm analysis, "HCT in CR1" demonstrated better 5-year overall survival (OS) and 5-year disease-free survival (DFS) compared with "Never HCT," whereas "HCT in CR2" had the least favorable prognosis (5-year OS: 79.2% vs 57.1% vs 50%, P = .056; 5-year DFS: 73.6% vs 55.2% vs 0%, P = .000).

CONCLUSION

Our study highlights the benefits of transplantation during CR1 on prognosis. However, when contemplating CR1 transplantation recommendations, evaluation of various factors, such as the patient's clinical state, relapse risk, transplant-related mortality, CMV status, and other pertinent considerations, is vital. Comprehensive case discussions with patients and families are demanded in optimizing treatment.

Incidence, clinical presentation, risk factors, outcomes, and biomarkers in de novo late acute GVHD

Late acute graft-versus-host disease (GVHD) is defined as de novo acute GVHD presenting beyond 100 days after allogeneic hematopoietic cell transplantation (HCT) without manifestations of chronic GVHD. Data are limited regarding its characteristics, clinical course, and risk factors because of underrecognition and changes in classification. We evaluated 3542 consecutive adult recipients of first HCTs at 24 Mount Sinai Acute GVHD International Consortium (MAGIC) centers between January 2014 and August 2021 to better describe the clinical evolution and outcomes of late acute GVHD. The cumulative incidence of classic acute GVHD that required systemic treatment was 35.2%, and an additional 5.7% of patients required treatment for late acute GVHD. At the onset of symptoms, late acute GVHD was more severe than classic acute GVHD based on both clinical and MAGIC algorithm probability biomarker parameters and showed a lower overall response rate on day 28. Both clinical and biomarker grading at the time of treatment stratified the risk of nonrelapse mortality (NRM) in patients with classic and late acute GVHD, respectively, but long-term NRM and overall survival did not differ between patients with classic and late acute GVHD. Advanced age, female-to-male sex mismatch, and the use of reduced intensity conditioning were associated with the development of late acute GVHD, whereas the use of posttransplant cyclophosphamide-based GVHD prevention was protective mainly because of shifts in GVHD timing. Because overall outcomes were comparable, our findings, although not definitive, suggest that similar treatment strategies, including eligibility for clinical trials, based solely on clinical presentation at onset are appropriate.