Ectopic expression of a combination of 5 genes detects high risk forms of T-cell acute lymphoblastic leukemia.

BACKGROUND: T cell acute lymphoblastic leukemia (T-ALL) defines a group of hematological malignancies with heterogeneous aggressiveness and highly variable outcome, making therapeutic decisions a challenging task. We tried to discover new predictive model for T-ALL before treatment by using a specific pipeline designed to discover aberrantly active gene. RESULTS: The expression of 18 genes was significantly associated with shorter survival, including ACTRT2, GOT1L1, SPATA45, TOPAZ1 and ZPBP (5-GEC), which were used as a basis to design a prognostic classifier for T-ALL patients. The molecular characterization of the 5-GEC positive T-ALL unveiled specific characteristics inherent to the most aggressive T leukemic cells, including a drastic shut-down of genes located on the mitochondrial genome and an upregulation of histone genes, the latter characterizing high risk forms in adult patients. These cases fail to respond to the induction treatment, since 5-GEC either predicted positive minimal residual disease (MRD) or a short-term relapse in MRD negative patients. CONCLUSION: Overall, our investigations led to the discovery of a homogenous group of leukemic cells with profound alterations of their biology. It also resulted in an accurate predictive tool that could significantly improve the management of T-ALL patients.

Preclinical characterization and comparison between CD3/CD19 bispecific and novel CD3/CD19/CD20 trispecific antibodies against B-cell acute lymphoblastic leukemia: targeted immunotherapy for acute lymphoblastic leukemia.

The CD19-targeting bispecific T-cell engager blinatumomab has shown remarkable efficacy in patients with relapsed/refractory B-cell precursor acute lymphoblastic leukemia. However, several studies showed that blinatumomab has a short plasma half-life due to its low molecular weight, and thus its clinical use is limited. Furthermore, multiple trials have shown that approximately 30% of blinatumomab-relapsed cases are characterized by CD19 negative leukemic cells. Here, we design and characterize two novel antibodies, A-319 and A-2019. Blinatumomab and A-319 are CD3/CD19 bispecific antibodies with different molecular sizes and structures, and A-2019 is a novel CD3/CD19/CD20 trispecific antibody with an additional anti-CD20 function. Our in vitro, ex vivo, and in vivo experiments demonstrated that A-319 and A-2019 are potent antitumor agents and capable of recruiting CD3 positive T cells, enhancing T-cell function, mediating B-cell depletion, and eventually inhibiting tumor growth in Raji xenograft models. The two molecules are complementary in terms of efficacy and specificity profile. The activity of A-319 demonstrated superior to that of A-2019, whereas A-2019 has an additional capability to target CD20 in cells missing CD19, suggesting its potential function against CD19 weak or negative CD20 positive leukemic cells.