Long-Term Remission in T315I+ Relapsed Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia with Blinatumomab and Allogeneic Stem Cell Transplantation: Two Case Studies

Am J Case Rep. 2024 Aug 5:25:e944956. doi: 10.12659/AJCR.944956.

Abstract

BACKGROUND Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) in adults has a poor prognosis with conventional chemotherapy. Treatment with tyrosine kinase inhibitors (TKIs) followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT) has improved clinical outcomes; however, the relapse rate is still high. Therapeutic options for patients with relapsed/refractory (R/R) Ph+ ALL are scarce, with very few studies focusing on these patients. Blinatumomab is a novel bispecific T-cell engager antibody construct showing promising efficacy in R/R Ph+ ALL. CASE REPORT Here, we present 2 cases of relapsed Ph+ ALL with T315I mutation refractory to multiple TKIs and chemotherapy. Patient 1 was a 48-year-old woman who had increased leukocytes in her peripheral blood cells, with 90% abnormal cells and decreased platelets. Bone marrow (BM) smear showed 95% blasts. Patient 2 was a 20-year-old man who had leukocytosis with thrombocytopenia, while all other parameters were normal. BM aspirate showed 98% immature granulocytes/blasts. The immunophenotypic observations of both the patients on BM were consistent with the presence of ALL. Both patients were effectively treated with a combination of blinatumomab and allo-HSCT and achieved complete remission in 1 month with minimal residual disease negativity and remained in remission for a long period. CONCLUSIONS The findings suggest, that for patients with R/R Ph+ ALL with T315I mutation who respond poorly to TKIs, salvage therapy with blinatumomab is a potentially effective treatment for improving clinical outcomes. The treatment with blinatumomab can further act as a bridge to HSCT in these patients, helping them to attain deeper remission.

Publication types

  • Case Reports

MeSH terms

  • Antibodies, Bispecific* / therapeutic use
  • Antineoplastic Agents / therapeutic use
  • Female
  • Hematopoietic Stem Cell Transplantation*
  • Humans
  • Male
  • Middle Aged
  • Philadelphia Chromosome
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma* / drug therapy
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma* / therapy
  • Remission Induction
  • Transplantation, Homologous
  • Young Adult

Substances

  • Antibodies, Bispecific
  • blinatumomab
  • Antineoplastic Agents