We provide here the preclinical characterization of the fusion protein PRS-352/S095025, a bispecific molecule composed of a PD-L1 blocking moiety and an Anticalin protein agonizing OX40. In vitro, this molecule showed the desired MoA, PD-L1 blocking and potent OX40 agonism driven by binding to PD-L1, with superior activity to a clinical stage OX40 agonist.