A New Biotin Derivative?DOTA Conjugate as a Candidate for Pretargeted Diagnosis and Therapy of Tumors

The synthesis of a new biotin derivative, the (CO) reduced N-aminohexyl biotinamido derivative, designed to be serum biotinidase resistant, and its conjugation to the chelator DOTA through an amide bond at one of the four carboxymethyl chains are described. The 90Y-labeled conjugate was able to bind avidin at different Av/conjugate molar ratios with good results. The preclinical results indicate that this new biotin–DOTA conjugate is a good candidate for pretargeted diagnosis and therapy of tumors.