Definition

A lipid nanoparticle (LNP) encapsulating nucleoside-modified messenger RNA (mRNA) encoding for bispecific antibody directed against the tumor-associated antigen (TAA) Claudin 6 (CLDN6; CLDN-6) and the human T-cell surface antigen CD3, with potential immunostimulating and antineoplastic activities. Upon administration, mRNA-encoded anti-CD3/anti-CLDN6 bispecific antibody BNT142 binds to the plasma membrane of cells and releases the mRNA into the cells. The mRNA is translated and the anti-CD3/anti-CLDN6 bispecific antibody binds to both CD3-expressing T cells and CLDN6-expressing cancer cells, thereby crosslinking CLDN6-expressing tumor cells and cytotoxic T lymphocytes (CTLs). This results in the activation and proliferation of T cells and causes CTL-mediated cell lysis of CLDN6-expressing tumor cells. CLDN6, a transmembrane tight-junction protein and embryonic antigen, is overexpressed on a variety of tumor cells but is not expressed on normal, healthy adult cells.