On-body drug delivery systems: State-of-the-art technologies, clinical application, and future perspectives

• OBDSs enable safe subcutaneous delivery of high-dose, high-viscosity drugs. • Smart OBDS platforms support connectivity and personalized drug regimens. • OBDSs face complex EU/US regulations as integral drug–device combinations. • Regulatory bridging studies are key for OBDS approval in new indications. • Economic sustainability of OBDSs can expand their use for chronic therapies. In the context of subcutaneous administration, one of the main obstacles is related to the limited volume that can be administered without causing pain, immunogenicity, and injectability issues. To meet patient-specific needs, administering a highly concentrated drug within a relatively small volume poses several challenges. Recently, on-body drug delivery systems (OBDSs) have emerged as a way to overcome existing limitations in drug delivery, as they can enable the delivery of doses exceeding 2 ml at precisely controlled rates and durations. This article examines recently developed and/or authorized OBDSs, classified as either medical devices or medicinal products; provides an overview of biopharmaceutical requirements and patient compliance; and highlights market concerns and economic sustainability.