Tumor-associated antigens: MAGE-A3, CLDN6, KK-LC-1, PRAME, MAGE-A4

Class

mRNA-lipoplex cancer vaccine (FixVac platform)

Pathway

Primes cytotoxic T cells against shared NSCLC tumor-associated antigens

Notes

original target text: Tumor-associated antigens: MAGE-A3, CLDN6, KK-LC-1, PRAME, MAGE-A4, MAGE-C1 (six-antigen mRNA vaccine)

This mechanism targets a defined panel of tumor-associated antigens (TAAs) — proteins that are largely absent from normal adult tissue but become re-expressed in cancer cells. Several of these, including members of the MAGE family, PRAME, and KK-LC-1, belong to the cancer-testis antigen group, normally confined to immune-privileged germline tissue; CLDN6 is an oncofetal antigen expressed during embryonic development but silenced thereafter. Because tumors reactivate these otherwise dormant genes, the antigens are tumor-selective without being unique to any one patient, unlike mutation-derived neoantigens. The vaccine platform delivers messenger RNA encoding several such antigens simultaneously, packaged in a lipid-based carrier designed to reach antigen-presenting cells. Once translated inside these cells, the antigens are processed and displayed to the immune system, priming cytotoxic T lymphocytes capable of recognizing and killing tumor cells bearing the same antigens on their surface. Encoding multiple antigens rather than one addresses the reality that tumors vary in which antigens they express and can lose individual antigens under immune pressure; a multi-antigen response broadens coverage and reduces the chance that escape at a single antigen abolishes the whole response. This general approach is being explored across cancers, including non-small cell lung cancer, where several of these antigens are commonly expressed.