Recently, it has been described that CD36 plays a key role in the metastatic spread of cancer. The main objective of this project is to develop human anti-CD36 antibodies to study their effect as inhibitors of metastasis formation in preclinical models. As a discovery platform we will use a semi-synthetic library of variable fragments of single-chain human antibodies (scFv) expressed in bacteriophages. We will select the CD36-specific scFvs by screening cycles of the library using human recombinant CD36 (hCD36) as selector. Enrichment of the library with human anti-CD36 antibodies will be assessed by hCD36 binding assays. In a second phase we will study the affinity of the selected scFvs and characterize their CD36 blocking activity in relevant cell culture models. Blocker scFvs with higher affinity will be cloned into IgG format and the constructs will be expressed in mammalian cells for characterization. Finally, we will select the best antibodies based on physicochemical and biological activity evaluations in an in vivo model of metastasis. At the end of the project we will have a panel of antibodies that inhibit the growth of secondary tumors and can serve as a basis for developing new anti-metastatic therapies.