Blinatumomab-induced donor T-cell activation for post-stem cell transplant-relapsed acute CD19-positive biphenotypic leukemia

[Update on acute leukemia of ambiguous lineage in 2023 - Recommendations of the French Society for Childhood and Adolescent Cancer and Leukemia (SFCE)]

Acute leukemias of ambiguous lineage (ALAL) represent between 3 and 5% of childhood AL. This term encompasses many subtypes of AL that have been defined according to the immunophenotypic profile based on the expression of various lineage markers. This classification has been modified and enriched during the last decade thanks to the improvement of molecular biology techniques, which have led to reconsider the ontogenic proximity existing between certain forms of ALAL. This increasing diagnostic complexity justifies the establishment of a close communication between clinicians and biologists in the management of these rare forms of AL. Indeed, the initial classification remains the cornerstone of their management since it conditions the future choice of therapeutic protocol. Thus, with the notable exception of undifferentiated forms of AL or AUL (for acute undetermined leukemia), it is now accepted that ALAL benefit from a lymphoid-based therapy approach. As with the management of "classic" acute lymphoblastic leukemias (ALL), the evaluation of response to treatment will determine the modalities of therapeutic intensification. The objective of improving the prognosis of ALAL justifies, in the long term, their future inclusion in the international ALLTogether protocol while continuing in-depth molecular exploration of these patients to identify targeted therapies.

Concomitant use of blinatumomab and donor lymphocyte infusion for mixed-phenotype acute leukemia: a case report with literature review

Blinatumomab and donor lymphocyte infusion (DLI) combination is a promising cancer therapy, whereby blinatumomab might achieve an initial reduction in leukemic-cell burden using T cells, and after tumor clearance, DLI can potentially stimulate the donor immune system to achieve longer lasting remission. Here, we present a 51-year-old female with mixed phenotype acute leukemia who had a hematologic relapse 3 months after she received total body irradiation-based myeloablative allogeneic hematopoietic stem cell transplantation from an unrelated human leukocyte antigen matched (10/10) donor and achieved complete remission with minimal residual disease negativity by multi-parameter flow cytometry using the combination of blinatumomab and DLI. To the best of our knowledge, this is the first report to describe the use of blinatumomab and DLI combination therapy in the treatment of B/myeloid mixed phenotype acute leukemia.

Correlates of resistance and relapse during blinatumomab therapy for relapsed/refractory acute lymphoblastic leukemia

We retrospectively analyzed 65 patients with refractory/relapsed (r/r) ALL who were treated with blinatumomab for predictors of leukemia response as well as clinical patterns of relapse and resistance with particular focus on downregulation of CD19 expression and extramedullary disease (EM-ALL). The complete remission (CR) rate was 51%, and 15 (45%) responders underwent allogeneic hematopoietic cell transplantation (HCT) in CR. High leukemia burden (bone marrow blasts >50%) (P = .02), history of prior EM-ALL (P = .005), and active EM-ALL at the time of initiating blinatumomab (P = .05) predicted lower CR rate. Among refractory cases, 13 (41%) had evidence of EM-ALL progression, and CD19 expression was negative or dim in 18% and 23%, respectively. Among responders, 20 (61%) subsequently relapsed among whom EM-ALL relapse occurred in 8 (40%) patients, and CD19 expression was negative or dim in 35 and 6% of evaluable cases, respectively. Pretreatment moderate/strong CD19 expression (P = .01) and history of prior EM-ALL during ALL course (P = .04) were risk factors for developing EM-ALL at progression/relapse. However, no pretreatment factors predicted progression/relapse with CD19-negative ALL. Overall-survival (OS) and even-free survival were improved for patients underwent allogeneic HCT compared to responders who did not. Furthermore, OS was superior for patients responded to blinatumomab compared to those who did not. Extramedullary and CD19-negative disease are common during blinatumomab failure in r/r ALL. In addition to high leukemia burden, concurrent or prior history EM-ALL were associated with lower response to blinatumomab. Higher CD19 expression as well as prior history of EM-ALL were associated with EM-ALL at the time of blinatumomab failure.

Allogeneic hematopoietic cell transplantation for primary refractory acute lymphoblastic leukemia: A report from the Acute Leukemia Working Party of the EBMT

BACKGROUND

Patients with primary refractory acute lymphoblastic leukemia (PREF ALL) who fail to achieve a complete remission (CR) after ≥2 courses of chemotherapy have a dismal prognosis without undergoing allogeneic hematopoietic cell transplantation (HCT). To the authors' knowledge, there currently are no data regarding factors influencing transplantation outcomes.

METHODS

The authors retrospectively studied outcomes of transplantation for cases of PREF ALL reported to European Society for Blood and Marrow Transplantation registry. Eligibility criteria for the current analysis included adult patients who underwent their first HCT for PREF ALL between 2000 and 2012. PREF disease was defined as the failure to achieve a morphological CR after ≥2 courses of induction chemotherapy.

RESULTS

Data regarding 86 adult patients were analyzed. With a median follow-up of 106 months, the probability of survival was 36% at 2 years and 23% at 5 years. The probability of leukemia-free survival was 28% and 17%, respectively, and the probability of nonrecurrence mortality was 20% and 29%, respectively, at 2 years and 5 years. For 66 patients who achieved a CR (77%), the survival at 2 years and 5 years was 36% and 29%, respectively. In multivariate analysis, use of total body irradiation was found to be associated with improved survival. Total body irradiation and infusion of female hematopoietic cells into male recipients was associated with improved leukemia-free survival. These findings were incorporated into a scoring system that identified 3 groups (those with 2, 1, or no prognostic factors) with survival rates of 57%, 22%, and 8%, respectively.

CONCLUSIONS

Although overall these patients would clearly benefit from the introduction of novel antileukemic therapies, the data from the current study support the use of allogeneic HCT in selected patients with PREF ALL. Cancer 2017;123:1965-1970. © 2017 American Cancer Society.

Donor origin CAR T cells: graft versus malignancy effect without GVHD, a systematic review

CD19, CD20 chimeric antigen receptor T (CAR T) cell therapy has shown promising results for the treatment of relapsed or refractory hematological malignancies. Best results have been reported in acute lymphoblastic leukemia patients with a complete response rate above 80%. Patients who received donor-derived CAR T cells for the relapsed malignancy after stem cell transplantation (allogenic hematopoietic stem cell transplant) were identified from the published trials. A total of 72 patients from seven studies were treated with donor-derived CAR T cells. Only five out of 72 patients (6.9%) developed graft versus host disease. Use of donor-derived CAR T cell for relapse prophylaxis, minimal residual disease clearance or salvage from relapse is therefore highly effective, and risk of graft versus host disease flare is very low. Side effects include cytokine release syndrome, tumor lysis syndrome, B-cell aplasia along with CNS toxicity.