NCIt definition : A human bispecific antibody composed of a single-chain variable fragment (scFv) domain
targeting the immune co-stimulatory receptor 4-1BB (CD137; tumor necrosis factor receptor
superfamily member 9; TNFRSF9) and a scFv domain targeting the tumor associated antigen
(TAA) 5T4 (trophoblast glycoprotein; TPBG), that are linked through a mutated and
silenced immunoglobulin G (IgG)-Fc domain, with potential immunomodulatory and antineoplastic
activities. Upon administration of anti-4-1BB/5T4 bispecific antibody ALG.APV-527,
the anti-5T4-specific scFv domain of ALG.APV-527 targets and binds to 5T4 expressed
on tumor cells and the anti-4-1BB-specific scFv domain targets and binds to 4-1BB
expressed on certain immune cells, such as T-cells and natural killer cells (NK) cells
within the tumor microenvironment (TME). This crosslinks T-cells and tumor cells and
allows for conditional 4-1BB activation, which stimulates the activation and proliferation
of NKs and cytotoxic T-lymphocytes (CTLs) in the TME leading to an anti-tumor immune
response against the 5T4-expressing tumor cells. 5T4 is expressed on many different
tumor cell types, including tumor-initiating cells, but expressed at low levels or
not at all in normal tissue. ALG.APV-527 minimizes systemic immune activation and
allows for tumor-specific responses that are localized to 5T4-positive tumors.;
Semantic type(s)