DSP-0546LP

DSP-0546LP is a novel vaccine adjuvant developed as part of a universal influenza vaccine candidate. It is a synthetic compound that specifically activates Toll-like receptor 7 (TLR7), which senses virus-derived RNA and induces innate immune responses. As an adjuvant, DSP-0546LP enhances the quantity, quality, and durability of immune responses when combined with antigens such as post-fusion hemagglutinin (fH1). Preclinical studies have shown that formulations containing DSP-0546LP induce cross-reactive antibodies more efficiently than non-adjuvanted formulations, strongly promote Th1-polarized immune responses (evidenced by increased interferon-gamma and IgG2c production), and enhance antibody-dependent cellular cytotoxicity (ADCC) against diverse influenza strains. The mechanism does not primarily rely on neutralizing antibodies but rather on functional antibody induction and Th1-mediated immunity. The universal influenza vaccine candidate fH1/DSP-0546LP is being jointly developed by Sumitomo Pharma and the National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), with clinical development currently in Phase 1 trials for prophylaxis against influenza[1][3][5][8].