IL-15/IL-15Rα-FC Fusion Protein XmAb24306 Potentiates Activity of CD3 Bispecific Antibodies Through Enhancing T Cell Expansion

Researchers hypothesized that XmAb24306, a lymphoproliferative interleukin (IL)-15/IL-15 receptor α Fc-fusion protein, may potentiate the activity of T cell dependent (TDB) antibodies. Activation of human peripheral T cells by cevostamab or anti-HER2/CD3 TDB resulted in upregulation of IL-2/15Rβ receptor subunit in nearly all CD8+ and majority of CD4+ T cells, suggesting that TDB treatment may sensitize T cells to the IL-15.