Impact of donor type on long-term graft-versus-host disease-free/relapse-free survival for adult acute lymphoblastic leukemia in first remission

Comparative analysis of reduced toxicity conditioning regimens between fludarabine plus melphalan and fludarabine plus busulfex in adult patients with acute lymphoblastic leukemia

Reduced-toxicity conditioning (RTC) regimens aim to mitigate regimen-related toxicity while maintaining anti-leukemic efficacy in allogeneic hematopoietic stem cell transplantation (allo-HSCT). We assessed outcomes of RTC regimens utilizing melphalan versus intravenous busulfan combined with fludarabine in adult acute lymphoblastic leukemia (ALL) patients. A retrospective analysis was conducted with 149 consecutive adult ALL patients (median age 51, range 18-60) in remission undergoing allo-HSCT. Patients received either fludarabine 150 mg/BSA plus 2 days of melphalan 70 mg/BSA (FM140, n = 76) from 2009 to 2015 or fludarabine plus 3 days of busulfan 3.2 mg/kg (FB9.6, n = 73) from 2016 to 2021. At 5 years post-HSCT, FM140 demonstrated superior disease-free survival (53.4% vs. 30.5%, p = 0.007) and lower cumulative relapse (27.4% vs. 46.8%, p = 0.026) than FB9.6. Five-year overall survival and non-relapse mortality did not significantly differ. FM140 exhibited a higher incidence of acute graft-versus-host disease (GVHD) grades II-IV (49.3% vs. 30.3%, p = 0.016), though rates of acute GVHD grades III-IV and chronic GVHD were similar. Multivariate analysis identified Philadelphia chromosome and minimal residual disease positive status, and FB9.6 conditioning as predictors of increased relapse and poorer disease-free survival. FM140 RTC regimen displayed significantly reduced relapse and superior disease-free survival compared to FB9.6 in ALL patients undergoing allo-HSCT, highlighting its current clinical utility.

Diagnostic and therapeutic advances in adults with acute lymphoblastic leukemia in the era of gene analysis and targeted immunotherapy

Acute lymphoblastic leukemia (ALL) is one of the most rapidly changing hematological malignancies with advanced understanding of the genetic landscape, detection methods of minimal residual disease (MRD), and the development of immunotherapeutic agents with good clinical outcomes. The annual incidence of adult ALL in Korea is 300-350 patients per year. The WHO classification of ALL was revised in 2022 to reflect the molecular cytogenetic features and suggest new adverse- risk subgroups, such as Ph-like ALL and ETP-ALL. We continue to use traditional adverse-risk features and cytogenetics, with MRD-directed post-remission therapy including allogeneic hematopoietic cell transplantation. However, with the introduction of novel agents, such as ponatinib, blinatumomab, and inotuzumab ozogamicin incorporated into frontline therapy, good MRD responses have been achieved, and overall survival outcomes are improving. Accordingly, some clinical trials have suggested a possible era of chemotherapy-free or transplantation-free approaches in the near future. Nevertheless, relapse of refractory ALL still occurs, and some poor ALL subtypes, such as Ph-like ALL and ETP-ALL, are unsolved problems for which novel agents and treatment strategies are needed. In this review, we summarize the currently applied diagnostic and therapeutic practices in the era of advanced genetic analysis and targeted immunotherapies in United States and Europe and introduce real-world Korean data.

Haploidentical versus Double-Cord Blood Stem Cells as a Second Transplantation for Relapsed Acute Myeloid Leukemia

There are limited data on second stem cell transplantation (SCT2) outcomes with alternative donors for relapsed AML after the first stem cell transplantation (SCT1). We analyzed the outcomes of 52 adult AML patients who received SCT2 from haploidentical donors (HIT, N = 32) and double-cord blood (dCBT, N = 20) between 2008 and 2021. The HIT group received T-cell-replete peripheral blood stem cells after reduced-toxicity conditioning with anti-thymocyte globulin (ATG), while the dCBT group received myeloablative conditioning. For a median follow-up of 64.9 months, the HIT group, compared to the dCBT group, had earlier engraftment, superior 2-year overall survival (OS), disease-free survival (DFS), and non-relapse mortality (NRM) with similar relapse. Multivariate analysis demonstrated that HIT was significantly associated with better OS, DFS, and lower NRM than dCBT. Both longer remission duration after SCT1 and complete remission at SCT2 were significantly associated with a lower relapse rate. In addition, bone marrow WT1 measurable residual disease (MRD) positivity was significantly associated with inferior OS and higher relapse. This study suggests that T-cell-replete HIT with ATG-based GVHD prophylaxis may be preferred over dCBT as SCT2 for relapsed AML and that WT1-MRD negativity may be warranted for better SCT2 outcomes.

Superior survival outcome of blinatumomab compared with conventional chemotherapy for adult patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia: a propensity score-matched cohort analysis

Background

Blinatumomab showed a higher complete remission (CR) rate and a safe bridging to allogeneic hematopoietic cell transplantation (allo-HCT) in adults with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (R/R BCP-ALL).

Objectives

We tried to analyze the outcome of blinatumomab compared with the real-world historical data. We expected superior outcome of blinatumomab compared with historical conventional chemotherapy.

Design

We conducted a retrospective study using real-world data in the Catholic Hematology Hospital.

Methods

Total 197 consecutive cases of R/R BCP-ALL were treated with conventional chemotherapy (n = 113) or blinatumomab, which was available since late 2016 (n = 84). Patients who achieved CR underwent allo-HCT if donor was available. We conducted a propensity score-matched cohort analysis using 5 criteria of age, CR duration, cytogenetics, previous allo-HCT, and salvage lines between historical group and blinatumomab.

Results

Each cohort consisted of 52 patients. In blinatumomab group, CR rate was higher (80.8% versus 53.8%, p = 0.006) and more patients proceeded to allo-HCT (80.8% versus 46.2%, p < 0.001). Among the CR patients with available minimal residual disease (MRD) results, 68.6% in blinatumomab group and 40.0% in conventional chemotherapy group were MRD-negative. Regimen-related mortality during the chemotherapy cycles was significantly higher in the conventional chemotherapy group (40.4% versus 1.9%, p < 0.001). Estimated 3-year overall survival (OS) was 33.2% (median, 26.3 months) after blinatumomab, and 15.4% (median, 8.2 months) after conventional chemotherapy (p < 0.001). Estimated 3-year non-relapse mortality were 30.3% and 51.9% (p = 0.004), respectively. In multivariate analysis, CR duration < 12 months showed more relapses and poor OS, and conventional chemotherapy showed higher non-relapse mortality and poor OS.

Conclusions

Matched cohort analysis showed superior outcomes of blinatumomab compared with conventional chemotherapy. However, large numbers of relapses and non-relapse mortalities continue to occur even after blinatumomab followed by allo-HCT. Novel therapeutic strategies are still needed for R/R BCP-ALL.

Durable outcomes of double cord blood transplantation in adults with acute lymphoblastic leukemia: high-risk features for early and long-term mortality

Background:

Cord blood transplantation (CBT) has been reported as an acceptable option with comparable outcomes to conventional donors in adults with acute lymphoblastic leukemia (ALL). We aimed to analyze the long-term CBT outcomes and risk factors for early and long-term mortalities.

Methods:

Between 2006 and 2020, 112 patients (median age: 35 years; 62 Ph-negative ALL and 50 Ph-positive ALL) were treated with double CBT. Conditioning regimen consisted of total body irradiation (12 Gy) plus cytarabine (9.0 g/m²) plus fludarabine (150 mg/ m²), and graft-versus-host disease (GVHD) prophylaxis was attempted by administering tacrolimus plus mycophenolate mofetil.

Results:

The median time for neutrophil and platelet recovery was 25 days (range: 5–59 days) and 34 days (range: 7–185 days), respectively. The cumulative incidence of acute GVHD at 1 year was 43.8%, and the incidence of acute GVHD with grades III–IV was 8.9%. The overall cumulative incidence of chronic GVHD was 22.0%, and the incidence of moderate to severe chronic GVHD was 8.5%. After a median follow-up of 60.1 months (range: 5.7–181.3 months), the 5-year cumulative incidence of relapse (CIR) and nonrelapse mortality (NRM) were 15.9% and 28.5% (9.7% and 27.2% for CR1), respectively, and the 5-year overall survival (OS) was 57.9% (66.5% for CR1). In multivariate analysis of 88 patients receiving double CBT in CR1, delayed CR1 was related to high CIR, and age older than 40 years was associated with high NRM and early mortality. Unexpectedly, Ph-positive ALL with MRD had a higher NRM and early mortality than Ph-negative ALL and Ph-positive ALL without MRD subgroups, possibly due to delayed neutrophil and platelet recovery.

Conclusion:

Our data suggest that double CBT for adult ALL in CR1 has a greater benefit in younger patients and in patients with Ph-positive ALL without MRD or Ph-negative ALL.

Hepatic venoocclusive disease/sinusoidal obstruction syndrome with normal portal vein flow mimicking aggravated chronic hepatic GVHD following inotuzumab ozogamicin salvage therapy: a case report of pathologic-radiologic discrepancy

Inotuzumab ozogamicin (INO) showed improved treatment outcomes for relapsed or refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL) but can induce hepatotoxic adverse events. Hepatic venoocclusive disease/sinusoidal obstruction syndrome (VOD/SOS) frequently develops after allogeneic hematopoietic cell transplantation (allo-HCT), and INO is a strong pretransplant risk factor. However, VOD/SOS can occur just after INO therapy. Here, we describe a BCP-ALL patient treated with INO for isolated extramedullary relapse after allo-HCT. The patient experienced elevated liver enzymes with ascites at 21 days from the last INO dose. Although she met the criteria for VOD/SOS, the diagnosis was challenging because of her ongoing hepatic graft-versus-host disease (GVHD) and normal portal vein flow on Doppler sonogram. The radiologist suggested liver cirrhosis based on computed tomography, with VOD/SOS, liver cirrhosis, and GVHD assumed to be differential diagnoses. She received supportive care with GVHD management; however, due to progressive hepatic failure, we conducted emergent deceased-donor liver transplantation, and the pathologic findings indicated VOD/SOS. Her leukemia was stable, but she died of sepsis after 3 months. INO use is a high-risk factor for VOD/SOS, but an accurate diagnosis can be challenging due to various hepatic complications. Early diagnosis and proper management for VOD/SOS is important for improved outcomes.

Improved survival after allogeneic transplantation for acute lymphoblastic leukemia in adults: a Danish population-based study

We investigated trends of survival in a population-based cohort study of all 181 adults who received HCT for ALL in Denmark between 2000-2019. Patients had a median (min-max) age of 36 (18-74) years at HCT and were followed for a median of eight years. Overall survival (OS) improved over time with an estimated 2-year OS of 49% (CI 27-66%) in year 2000 versus 77% (CI 59-88%) in year 2019. More patients achieved cure over time (OR for cure per year 1.07, CI 1.00-1.15), while the rate of death in non-cured patients remained stable (HR of excess mortality per year 0.99, CI 0.93-1.06). Relapse decreased over time (HR 0.92 per year, CI 0.87-0.98), whereas non-relapse mortality did not change notably (HR 0.98 per year, CI 0.93-1.04). In conclusion, survival after HCT in adults with ALL has improved over the past two decades, primarily due to more patients achieving cure.