NCIt definition : A recombinant form of the endogenous cytokine interleukin-2 (IL-2) conjugated to six
releasable polyethylene glycol (PEG) chains, with potential immunostimulating activity.
Upon administration of bempegaldesleukin, the IL-2 moiety binds to the IL-2 receptor
beta subunit (IL2Rb; IL2Rbeta; CD122). The binding of IL-2 to IL2Rb activates IL2Rb-mediated
signaling, which activates cytotoxic T-lymphocytes (CTLs) and natural killer (NK)
cells, and induces expression of certain cytotoxic cytokines, such as interferon-gamma
(IFNg) and transforming growth factor-beta (TGFb). The specific induction of T-cell-mediated
cytotoxic immune responses against tumor cells primarily causes tumor cell destruction.
IL2Rb plays a key role in the proliferation and activation of effector T-cells. PEG
conjugation prevents IL-2 binding to the IL2Ralpha subunit (IL2Ra) because signaling
through IL2Ra activates CD4-positive regulatory, immunosuppressive T-cells (Tregs),
which would suppress tumor cell killing.;