Programmed death 1 antibody drug conjugates (PD 1 ADCs): Innovations in overcoming resistance and enhancing immune...

Programmed death-1 (PD-1) antibody-drug conjugates (ADCs) are a new generation of immune checkpoint blockers, which incorporate the delivery of cytotoxic drug targets. The objectives of these ADCs are to selectively target cells in the tumor microenvironment expressing PD-1, causing tumor cells to die, rejuvenating T cell exhaustion, and destroying immunosuppressive cells. PD-1 ADCs aim to address the shortcomings of conventional PD-1 inhibitors, which may be resistant in certain cancers, by harnessing a two-pronged mechanism. This method can also be used to boost antitumor immunity by stimulating the activation and expansion of immune effector cells. Despite promising preclinical and early clinical outcomes, multiple issues remain in the development of PD-1 ADCs, including heterogeneity in tumor antigens, the development of resistance mechanisms, and instability of the ADC linker. Current studies are trying to overcome these challenges by improving ADC engineering, cytotoxic payload optimization, and investigating combination therapy. PD-1 ADCs, with their capacity to specifically regulate immunity and deliver potent cytotoxic drugs directly to tumor cells, have the potential to provide a valuable treatment modality. This would be beneficial for clinical outcomes, especially in cancers resistant to traditional treatment methods, and it represents a great step forward in cancer immunotherapy.