Updates in the management of relapsed/refractory multiple myeloma

Multiple myeloma, a malignant neoplasm of plasma cells that accumulate in bone marrow, accounts for approximately 18% of hematologic malignancies in the United States. Patients are often treated with triplet therapy and may undergo stem cell transplantation. Despite effective therapies, multiple myeloma remains incurable. Patients often require maintenance therapy, and many will progress or relapsed following upfront treatment. Selection of treatment in the relapse/refractory setting is complex due numerous active therapeutic agents and combinations. Treatment is often tailored to prior exposure and duration. In 2020, three novel pharmacological agents were approved in the relapsed setting. We highlight the clinical safety and efficacy of selinexor, isatuximab-irfc, and belantamab mafodotin for patients with multiple myeloma.

Single-cell transcriptomic analysis reveals disparate effector differentiation pathways in human Treg compartment

Human FOXP3+ regulatory T (Treg) cells are central to immune tolerance. However, their heterogeneity and differentiation remain incompletely understood. Here we use single-cell RNA and T cell receptor sequencing to resolve Treg cells from healthy individuals and patients with or without acute graft-versus-host disease (aGVHD) who undergo stem cell transplantation. These analyses, combined with functional assays, separate Treg cells into naïve, activated, and effector stages, and resolve the HLA-DRhi, LIMS1hi, highly suppressive FOXP3hi, and highly proliferative MKI67hi effector subsets. Trajectory analysis assembles Treg subsets into two differentiation paths (I/II) with distinctive phenotypic and functional programs, ending with the FOXP3hi and MKI67hi subsets, respectively. Transcription factors FOXP3 and SUB1 contribute to some Path I and Path II phenotypes, respectively. These FOXP3hi and MKI67hi subsets and two differentiation pathways are conserved in transplanted patients, despite having functional and migratory impairments under aGVHD. These findings expand the understanding of Treg cell heterogeneity and differentiation and provide a single-cell atlas for the dissection of Treg complexity in health and disease.