Key Points: Recurrent mutations in chromatin modifiers and cohesin were observed in t(8;21) AML, but not inv(16) AML. t(8;21) AML patients with mutations in kinase signaling plus chromatin modifiers or cohesin members had the highest risk of relapse.

The recently described vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is caused by somatic mutations in UBA1. Patients with VEXAS syndrome display late-onset autoinflammatory symptoms, usually refractory to treatment, and hematologic abnormalities. The identification of an easily-accessible specific marker (UBA1 mutations) is of particular interest as it allows the convergence of various inflammatory and hematological symptoms in a unique clinico-biological entity and gives the opportunity to design specific treatment strategies. Here we retrospectively identified 6 patients with VEXAS syndrome who underwent allogeneic hematopoietic stem cell transplantation (ASCT). To date, no treatment guidelines have been validated. In 4 patients, ASCT was guided by life-threatening autoinflammatory symptoms that were refractory to multiple therapies. Three patients are in durable complete remission 32, 38, and 37 months after ASCT. Two others are in complete remission response after 3 and 5 months. One unfortunately died post-ASCT. This report suggests that ASCT could be a curative option in patients with VEXAS syndrome and severe manifestations. Considering the complications and side effects of the procedure as well as the existence of other potential treatment, clinical trials are needed to define the subgroup of patients who will benefit from this strategy and its place in the therapeutic arsenal against VEXAS syndrome.

Tanasi et al present a prospective strategy for identifying patients with Philadelphia-like acute lymphoblastic leukemia, demonstrating the efficacy of early introduction of tyrosine kinase inhibitors in improving outcomes.

Acute myeloid leukemia (AML) with t(8;21) (q22;q22) is considered to have favorable risk; however, nearly half of t(8;21) patients are not cured, and recent studies have highlighted remarkable genetic heterogeneity in this subset of AML. Here we identify somatic mutations in additional sex combs-like 2 (ASXL2) in 22.7% (25/110) of patients with t(8;21), but not in patients with inv(16)/t(16;16) (0/60) or RUNX1-mutated AML (0/26). ASXL2 mutations were similarly frequent in adults and children t(8;21) and were mutually exclusive with ASXL1 mutations. Although overall survival was similar between ASXL1 and ASXL2 mutant t(8;21) AML patients and their wild-type counterparts, patients with ASXL1 or ASXL2 mutations had a cumulative incidence of relapse of 54.6% and 36.0%, respectively, compared with 25% in ASXL1/2 wild-type counterparts (P = .226). These results identify a high-frequency mutation in t(8;21) AML and identify the need for future studies to investigate the clinical and biological relevance of ASXL2 mutations in this unique subset of AML. Key Points ASXL2 was mutated in 22.7% (25/110) of adult and pediatric t(8;21)/RUNX1-RUNX1T1 acute myeloid leukemia patients. ASXL2 mutations are mutually exclusive with ASXL1 mutations and occur in t(8;21) but not inv(16)/t(16;16) or RUNX1-mutant AML.

Acute myeloid leukemia (AML) was initially subdivided according to morphology (the French-American-British system), which proved helpful in pathologic categorization. Subsequently, clinical and genomic factors were found to correlate with response to chemotherapy and with overall survival. These included a history of antecedent hematologic disease, a history of chemotherapy or radiation therapy, the presence of various recurrent cytogenetic abnormalities, and, more recently, the presence of specific point mutations. This article reviews the biology and responses of one AML subgroup with consistent response and good outcomes following chemotherapy (core-binding factor leukemia), and two subgroups with persistently bad, and even ugly, outcomes (secondary AML and TP53-mutated AML).