(600a) Implantable Optical Fibers for Immunotherapeutics Delivery and Tumor Impedance Measurement

Immune checkpoint blockade antibodies have promising clinical applications but suffer from disadvantages such as severe toxicities and moderate patient-response rates. None of the current delivery strategies, including local administration aiming to avoid systemic toxicities, can sustainably supply drugs over the course of weeks; adjustment of drug dose, either to lower systemic toxicities or to augment therapeutic response, is not possible. 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. 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. Our device uses tumor impedance measurement for timely presentation of treatment outcomes, and allows changes to the delivered drugs and their concentrations, rendering this device potentially useful for on-demand delivery of potent immunotherapeutics without exacerbating toxicities.