This chapter takes up the chapter of the same name from the first edition of this handbook with minor changes. It is based on a shortened version of the investigators’ brochures from the EORTC clinical trials 11001 and 11011 concerning the boron compounds sodium borocaptate (BSH) and boronophenylalanine (BPA). It summarizes essential information that might be asked by regulatory authorities. The intention of this chapter is to support and to facilitate the preparation of new clinical trials based on these compounds. However, this compilation cannot offer a complete and final description of all aspects concerning these two compounds necessary to file for drug approval.