Ph-like acute lymphoblastic leukemia in adults: understanding pathogenesis, improving outcomes, and future directions for therapy

Philadelphia (Ph)-like acute lymphoblastic leukemia (ALL) is a high-risk subgroup of B cell ALL with distinct genotypes, unified by gene expression profile similar to Ph-positive ALL, but lacking the BCR::ABL1 fusion. Ph-like ALL patients respond inadequately to conventional chemotherapy with higher rates of induction failure, persistent measurable residual disease, and lower survival rates compared to other B cell ALL subtypes. Considering Ph-like ALL's chemo-refractory nature, there is an interest in pursuing innovative therapeutic approaches to treat, including the combination of tyrosine kinase inhibitors with frontline regimens, and early introduction of novel antibody-drug conjugates and immunotherapies. Accurate diagnosis and disease-risk stratification are key to increase access for high-risk patients to allogeneic hematopoietic cell transplantation in their first complete remission. In this review, we will discuss our current knowledge of pathogenesis of Ph-like ALL, diagnostic strategies, as well as emerging data on new and current treatment strategies for this disease.