Cancer cells can evade host immunity by up-regulating enzymes that produce small molecule metabolites capable of blocking T cells in the tumor microenvironment. ImmuSmol S.A.S.'s antibodies target the metabolites to restore the immune response to tumors while sidestepping problems associated with inhibiting the enzymes themselves.

Antibodies against small molecules were first developed in the 1940s, when researchers at the University of Vienna discovered that conjugating a small molecule target to a protein carrier could elicit antibodies against that target in vivo. While such antibodies found use as immunohistochemical research tools, they have not been widely harnessed therapeutically because of technical challenges in constructing the appropriate target-carrier conjugates, ImmuSmol CEO Alban Bessede told BioCentury.