Biologics-device combinations: Enabling prolonged therapies in the posterior segment ocular disease

Posterior segment ocular diseases (e.g., age-related macular degeneration and diabetic retinopathy, etc.) often necessitate frequent intravitreal (IVT) injections of biologics, due to the rapid drug clearance and formidable ocular barriers. While molecular engineering strategies and high-concentration protein formulations could extend the administration intervals to a certain extent, they are confronted with critical challenges, protein aggregation, high viscosity, and limited duration. This has spurred the development of innovative biologics-device combination products, which represent a paradigm shift towards prolonged therapy. This comprehensive review examines the latest advancements of these combination platforms, including refillable implants (e.g., SUSVIMO®), encapsulated cell technology (e.g., ENCELTO™), and recombinant adeno-associated virus (rAAV) vectors (e.g., LUXTURNA®). The progress in biologics - device combination technologies has significantly reduced the frequency of ocular injections. However, substantial hurdles, such as instability caused by material-biologics interactions, potential risks during the sterilization and manufacturing processes, safety risks, and the evolving regulatory landscape, still need to be addressed. Achieving a balance between the stability of biologics and advanced device design, enhancing long-term safety, and developing responsive smart systems with real-time monitoring and feedback capabilities remain crucial for the advancement of next-generation ophthalmic therapies.