(55g) Implantable Optical Fibers for Delivering Immunotherapies and Tumor Impedance Measurement

Immune checkpoint blockade antibodies have promising clinical applications but suffer from disadvantages such as severe systemic toxicities and moderate patient-response rate. None of the current delivery strategies, including local administration, which aims to avoid systemic toxicities, can sustainably supply the drugs over the course of weeks; and adjustment of the drug dose, either to lower systemic toxicities or to augment therapeutic response, is not possible. In addition, most of the reported delivery devices do not have a mechanism for timely presentation of treatment outcomes. Herein, we develop an implantable miniaturized device using electrode-embedded optical fibers with both local delivery and measurement capabilities over the course of a few weeks. This device uses tumor impedance measurement for timely presentation of treatment outcomes. The combination of local delivery of immune checkpoint blockade antibodies via this device with photodynamic therapy elicits a sustained anti-tumor immune response in multiple tumor models: specifically, the combination either cured tumor-bearing mice or delayed tumor growth. Our local drug delivery device integrated with means to quickly determine efficacy exhibits versatility in allowing changes to the delivered drugs and their concentrations, therefore rendering our device potentially useful for on-demand delivery of potent immunotherapeutics without exacerbating toxicities.