CHAPTER 2: Developing Complex Dosage Forms of Long-acting Biologics for the Eye: Current State, Challenges, and Opportunities

Long-acting protein and peptide formulations have long been sought after to shift the treatment paradigm of chronic disease conditions. By extending treatment intervals, long-acting dosage forms can help address patient adherence and compliance challenges, align the treatment schedule with real-world practice and medical capacities, and ultimately improve the overall therapeutic outcome for patients. The eye has been recognized particularly as an opportunity for local and long-acting products for treating chronic eye conditions, due to the restricted physical access and complex anatomical structure. In recent years, biologics have emerged as an effective modality for ocular therapies, but their need for frequent injections imposes a severe treatment burden on both patients and health-care systems and compromises the intended therapeutic effects. Long-acting versions of these biologics are expected to address the treatment burden by reducing administration frequency and represent a trend in the future landscape of ocular treatment. The pursuit of long-acting products for biologics, especially proteins and antibodies, is continuing to be met with significant technical hurdles related to formulation and process conditions that are often incompatible with fragile biomolecules. Recent progress, however, is promising to break new ground. This chapter will review a variety of complex dosage forms for long-acting biologic products for the eye, and discuss the current state, scientific challenges, as well as emerging opportunities for the development of these products.