Combining blinatumomab and donor lymphocyte infusion in B-ALL patients relapsing after allogeneic hematopoietic cell transplantation: a study of the SFGM-TC

Efficacy and safety of blinatumomab for the treatment of patients relapsing after allogeneic hematopoietic cell transplantation: a systemic review and meta-analysis

OBJECTIVE

We aim to evaluate the efficacy and safety of blinatumomab for the treatment of post-transplant relapse patients with acute lymphoblastic leukemia (ALL).

METHODS

The search was conducted using several databases including the PubMed, Cochrane Library, Embase, Chinese National Knowledge Infrastructure (CNKI) and Wanfang Data Knowledge Service Platform to collect clinical studies related to blinatumomab. The primary outcome measures were complete remission (CR), 1-year overall survival (OS), 2-year OS, median OS and adverse events (AEs). Grade ≥3 AEs were mainly analyzed for safety, including anemia, thrombocytopenia, neutropenia, encephalopathy, peripheral paresthesia, tremor and cytokine release syndrome (CRS).

RESULTS

A total of 7 studies, involving a total of 292 patients were included in the analysis. The analysis results showed CR rate of 48%, 1-year OS rate of 40% 2-year OS rate of 21%, median OS 7.47. For safety analysis, the incidence of grade ≥3 AEs, including the incidence of grade ≥3 anemic toxicity was 13% , the incidence of grade ≥3 thrombocytopenia toxicity was 7% , the incidence of grade ≥3 neutropenia toxicity 24%, the incidence of grade ≥3 encephalopathic toxicity was 4% , the incidence of grade ≥3 peripheral paresthesia toxicity 4%, the incidence of grade ≥3 tremor toxicity 8% , the incidence of grade ≥3 CRS toxicity was 4%.

CONCLUSION

Blinatumomab may be a safe and an effective treatment approach for post-transplant relapse patients with ALL, but its long-term efficacy is still a big challenge. In regard to Regarding AEs, serious CRS and neurological events were infrequent and manageable.

Consensus on the monitoring, treatment, and prevention of leukaemia relapse after allogeneic haematopoietic stem cell transplantation in China: 2024 update

The consensus in 2018 from The Chinese Society of Haematology (CSH) on the monitoring, treatment, and prevention of leukaemia relapse after allogeneic haematopoietic stem cell transplantation (HSCT) facilitated the standardization of clinical practices in China and progressive integration with the world. To integrate recent developments and further improve the consensus, a panel of experts from the CSH recently updated the following consensus: (1) integrate risk-adapted, measurable residual disease (MRD)-guided strategy on modified donor lymphocyte infusion (DLI) and interferon-α into total therapy, which was pioneered and refined by Chinese researchers; (2) provide additional evidence of the superiority of haploidentical HSCT (the dominant donor source in China) to matched HSCT for high-risk populations, especially for pre-HSCT MRD-positive patients; (3) support the rapid progress of techniques for MRD detection, such as next-generation sequencing (NGS) and leukaemia stem cell-based MRD detection; and (4) address the role of new targeted options in transplant settings. In conclusion, the establishment of a "total therapy" strategy represents a great step forward. We hope that the consensus updated by Chinese scholars will include the latest cutting-edge developments and inspire progress in post-HSCT relapse management.

A case of posttransplant isolated extramedullary relapse of acute lymphoblastic leukemia achieving durable treatment-free remission with blinatumomab and donor lymphocyte infusion

Acute lymphoblastic leukemia (ALL) relapsed after allogeneic hematopoietic cell transplantation (allo-HCT) has a catastrophic prognosis. Blinatumomab, a CD3/CD19-directed bispecific T cell engager, is reportedly effective for advanced B-cell ALL (B-ALL), even after allo-HCT. However, the efficacy of blinatumomab in extramedullary relapse (EMR) is controversial. Donor lymphocyte infusion (DLI) is another immunological treatment worth considering for ALL relapsed after allo-HCT. We report the case of a 56-year-old woman with B-ALL. Allo-HCT was performed during the second complete remission (CR). Thirteen months after allo-HCT, isolated EMR (iEMR) of B-ALL developed without bone marrow lesions. A third CR was achieved with 2 cycles of blinatumomab. An additional four cycles each of blinatumomab and DLI were then administered. The patient did not develop graft-versus-host disease and has confirmed 2-year treatment-free remission without a second allo-HCT. Therefore, blinatumomab was considered an effective salvage therapy for iEMR of B-ALL after allo-HCT, because iEMR could have a lower tumor burden than that seen in systemic relapse, and low tumor burden was a prognostic factor for response to blinatumomab. Furthermore, immunological consolidation therapies could only provoke graft-versus-leukemia effects if the imbalanced effector/target ratio was restored and the tumor burden was lowered through immunosurveillance.

Impact of minimal residual disease response and of status of disease on survival after blinatumomab in B-cell acute lymphoblastic leukemia: results from a real-life study

Blinatumomab is a bispecific T-cell engager approved for relapsed/refractory and minimal residual disease positive B-cell Acute Lymphoblastic Leukemia. We conducted a retrospective study evaluating the outcome of Blinatumomab. The impact of clinical and treatment-related variables on cumulative incidence of relapse/progression (CIRP), event-free (EFS) and overall survival (OS) was analyzed. From January 2016 to December 2022 50 Ph'- (37) and Ph+ (13) B-ALL patients received Blinatumomab. The median age was 37. Indications to blinatumomab were relapsed/refractory B-ALL in 29 and MRD-positive in 21 patients. Blinatumomab was the 2nd and 3rd line in 40 and in 10 patients, respectively. Twenty patients were treated pre-transplantation, ten were treated for relapse after transplant, twenty were not eligible for transplant. Out of 29 patients treated for relapsed/refractory disease, 16 (55%) achieved complete response and 12 achieved MRD-negativity. Out of 21 patients treated for MRD, 16 (76%) achieved MRD-negativity. At a median follow-up of 46 months the median EFS and OS were 11.5 and 16.2 months. The CIRP was 50%. In univariate analysis age, disease-status (overt vs. minimal disease) at blinatumomab, bridging to transplant after blinatumomab and MRD-response resulted significant for EFS and OS. In multivariate analysis only disease-status and MRD-response retained significance both for EFS and OS. Disease-status and MRD-response resulted significant for EFS and OS also after censoring at HSCT. This retrospective study on B-ALL patients treated with blinatumomab confirms a superior outcome for MRD-responsive over MRD non-responsive patients. Survival depends also on the disease-status prior treatment.

Blinatumomab in Children with MRD-Positive B-Cell Precursor Acute Lymphoblastic Leukemia: A Report of 11 Cases

Background/Objectives: Relapsed B-cell acute lymphoblastic leukemia (B-ALL) remains an unresolved matter of concern regarding adverse outcomes. This case study aimed to evaluate the effectiveness of blinatumomab, with or without door lymphocyte infusion (DLI), in treating measurable residual disease (MRD)-positive B-ALL. Methods: All patients who received blinatumomab salvage therapy were included in this study. Eleven patients were included in the study. All patients were evaluated for MRD-negativity. Results: Before starting blinatumomab therapy, seven patients tested positive for MRD, three tested negative, and one had refractory disease. Hematopoietic cell transplantation (HCT) was reserved for five patients with persistent MRD. Six patients became MRD-negative and subsequent HCT was not performed. Only two patients relapsed; one patient died of relapse, and the other one received carfilzomib-based therapy and was MRD-negative thereafter. Nine patients were MRD-negative at a median follow-up of 28 months (15-52 months). Two of three MRD-positive post-transplant patients remained in complete molecular remission after preemptive DLI at the last follow-up date. In the first salvage, blinatumomab may achieve complete remission and bridging to HCT in pediatric patients with end-of-induction MRD-positive B-cell precursor ALL. Conclusions: The decision on how to treat post-transplant relapse continues to affect survival outcomes. Blinatumomab combined with DLI may extend the armamentarium of release options for high-risk pediatric patients. This approach is encouraging for high-risk ALL patients who are MRD-positive post-transplantation.

Prophylactic versus Preemptive modified donor lymphocyte infusion for high-risk acute leukemia after allogeneic hematopoietic stem cell transplantation: a multicenter retrospective study

Donor lymphocyte infusion (DLI) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been widely used in preventing post-transplant relapse. We conducted this study to compare the superiority of prophylactic modified DLI (pro-DLI) and preemptive modified DLI (pre-DLI) in patients with high-risk relapse features acute leukemia. Pro-DLI was performed in 95 patients, whereas the pre-DLI cohort included 176 patients. In the pre-DLI cohort, 42 patients relapsed without chance for pre-DLI while 95 patients remained CR without detectable minimal residual disease (MRD). Thirty-nine patients in the pre-DLI cohort became minimal MRD positive/mixed chimerism and received pre-DLI. Pro-DLI cohort had higher 3-year progression-free-survival (PFS) (63.4%vs.53.0%, P = 0.026) and overall survival (OS) (65.2% vs. 57.0%, P = 0.14) compared to the pre-DLI cohort. The 3-year cumulative incidence of relapse (CIR) was 25.3% in the pro-DLI cohort which was significantly lower than 36.7% in the pre-DLI cohort (P = 0.02). The cumulative incidence of grade III-IV aGVHD, cGVHD and non-relapse mortality were comparable between cohorts. Multivariable analysis demonstrated strong protective effect of pro-DLI on OS (hazard ratio (HR) = 0.63, P = 0.04), PFS (HR = 0.54, P = 0.005) and CIR (HR = 0.50, P = 0.005). In high-risk patients with acute leukemia, early scheduled pro-DLI rather than pre-DLI after detectable MRD would reduce post-transplant relapse and improve long-term survival.

Blinatumomab Redirects Donor Lymphocytes against CD19+ Acute Lymphoblastic Leukemia without Relevant Bystander Alloreactivity after Haploidentical Hematopoietic Stem Cell Transplantation

Blinatumomab alone or with donor leukocyte infusions (DLI) has been used after allogeneic hematopoietic stem cell transplantation (HSCT) as a salvage therapy in relapsing patients with CD19+ hematological malignancies. It was effective in a fraction of them, with low incidence of Graft-versus-Host Disease (GvHD). Immunosuppressive drugs used as GvHD prophylaxis hinder T cell function and reduce the efficacy of the treatment. Because T cell-depleted haploidentical HSCT with donor regulatory and conventional T cells (Treg/Tcon haploidentical HSCT) does not require post-transplant immunosuppression, it is an ideal platform for the concomitant use of blinatumomab and DLI. However, the risk of GvHD is high because the donor is haploidentical. We treated two patients with CD19+ acute lymphoblastic leukemia (ALL) who had relapsed after Treg/Tcon haploidentical HSCT with blinatumomab and DLI. Despite the mismatch for one HLA haplotype, they did not develop GvHD and achieved complete remission with negative minimal residual disease. Consistently, we found that blinatumomab did not enhance T cell alloreactivity in vitro. Eventually, the two patients relapsed again because of their high disease risk. This study suggests that treatment with blinatumomab and DLI can be feasible to treat relapse after haploidentical transplantation, and its pre-emptive use should be considered to improve efficacy.

Novel strategies to prevent and overcome relapse after allogeneic hematopoietic cell transplantation in acute lymphoblastic leukemia

The outcome of B-cell acute lymphoblastic leukemia (B-ALL) has improved over time with the incorporation of multi-agent chemotherapy in the treatment landscape as well as the recent approval of immunotherapeutic agents allowing a larger proportion of patients to undergo allogeneic hematopoietic cell transplantation (allo-HCT) which is still considered a potential curative approach. However, relapse post-transplant is still occurring and constitutes a common cause of treatment failure in B-ALL. The present review aims to discuss the novel strategies and therapies used to prevent and overcome relapse post allo-HCT in patients with ALL, focusing on the role of tyrosine kinase inhibitors in Philadelphia chromosome positive B-ALL, the role of innovative agents such as blinatumomab and inotuzumab ozogamicin, and finally the role of cellular therapy.