STIMULON cpcQS-21

STIMULON cpcQS-21 is a proprietary vaccine adjuvant consisting of the saponin QS-21 produced via cultured plant cells rather than traditional extraction from Quillaja saponaria tree bark. Developed by SaponiQx (a subsidiary of Agenus), this formulation offers a sustainable and scalable alternative to conventional sources, ensuring consistent quality and supply. As an adjuvant, it is designed to enhance both humoral and cellular immune responses when combined with antigens in vaccines. Mechanistically, QS-21 acts primarily on antigen-presenting cells—facilitating antigen uptake by dendritic cells and activating the NLRP3 inflammasome pathway to promote pro-inflammatory cytokine release (IL‑1β, IL‑18). It is a key component in several leading vaccine adjuvant systems such as AS01 (used in GSK’s Shingrix and Arexvy vaccines) and has demonstrated robust immunostimulatory activity across numerous clinical trials[3][6][8][10]. The cultured plant cell production method enables large-scale manufacturing for research or commercial use.

Brand names

STIMULON cpcQS-21

Other names

cultured plant cell QS-21QS-21 (cultured plant cell)STIMULON QS-21 (cultured plant cell)