Treatment of EPOR-rearranged acute lymphoblastic leukemia with ruxolitinib: case reports and review of the literature.

Acute lymphoblastic leukemia (ALL) with erythropoietin receptor (EPOR) gene rearrangement is rarely reported. These patients test negative for the Philadelphia chromosome but exhibit a gene expression profile similar to that of Philadelphia chromosome-positive acute lymphoblastic leukemia, leading to their designation as Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL). EPOR-rearranged ALL exhibits aggressive clinical course and dismal prognosis with a short remission duration and high level of minimal residual disease (MRD). The addition of tyrosine kinase inhibitors or Janus kinases inhibitors to conventional chemotherapy is an effective treatment approach for patients with Ph-like ALL. Here, we present two pediatric cases of Ph-like ALL with EPOR rearrangement that were treated with ruxolitinib and provide a literature review to assess the effectiveness of this treatment.