T-sphaera Drug Conjugate (TSDC) is a next-generation platform that enables the efficient conjugation of therapeutic payloads to T-sphaera for targeted delivery to cancer cells. Each T-sphaera can carry 24 payload molecules, offering a significantly higher drug-to-ferritin ratio (DFR) compared to conventional ADCs. Moreover, the inherent structural stability of ferritin resulted in the conjugation of insoluble payloads in a stable manner. These features collectively contribute to the potential for enhanced antitumor efficacy over existing ADCs. Furthermore, in line with recent trends in ADC development, we are pursuing research on bispecific TSDCs designed to simultaneously engage two distinct targets.