PVP-037

PVP-037 is a novel imidazopyrimidine (IMP) scaffold and a TLR7/8 agonist, demonstrating broad innate immune activation in primary human leukocytes at concentrations ≥1 µM, including NF-κB activation and Th1-polarizing cytokine production, notably TNF, IFN-γ and IL-1β comparable to R848 at concentrations ≥ 11 µM; it exhibits limited activity in THP-1 cells and murine/porcine primary leukocytes. In vivo, PVP-037, administered via intramuscular injection, enhances influenza and SARS-CoV-2 antigen-specific humoral responses in mice at 100 nmol doses and increases antibody titers co-administered with recombinant hemagglutinin (rHA) protein, compared to rHA alone or with alum, notably inducing a higher IgG response when formulated with rHA + PVP-037.