anti-CD16/IL-15/anti-CD33 trispecific natural Killer cell engager GTB-3650

A trispecific natural killer (NK) cell engager comprised of an anti-cluster of differentiation 16 (CD16; FcgammaRIII) camelid nanobody, human interleukin-15 (IL-15), and an anti-CD33 single-chain variable fragment (scFv), with potential immunomodulating and antineoplastic activities. Upon administration, anti-CD16/IL-15/anti-CD33 trispecific NK cell engager GTB-3650 targets and binds to CD33 expressed on tumor cells and simultaneously binds to the activating CD16 Fc receptor expressed on NK cells, thereby bringing CD33-expressing tumor cells and NK cells together. This induces NK cell cytotoxicity specifically against CD33-expressing tumor cells. The cytokine IL-15 promotes NK cell proliferation, activity, survival and expansion. CD33 is expressed on normal non-pluripotent hematopoietic stem cells and is overexpressed on myeloid leukemia cells.