Cyclic peptides in modern drug discovery: trends and therapeutic directions

Peptide therapeutics have emerged as an important drug modality, driven by their high target specificity, favorable safety profiles, and expanding chemical design space. Within this landscape, cyclic peptides occupy a unique position between small molecules and large biologics, offering enhanced conformational rigidity, proteolytic stability, and improved target engagement. In this report, we analyze trends in cyclic peptide research using data extracted from the CAS Content Collection over the past two decades. Our analysis reveals a sustained increase in both academic publications and patents related to cyclic peptides, reflecting growing interest across discovery and development stages. Notably, the oral route of administration is gaining increased attention, suggesting progress toward overcoming long-standing bioavailability challenges associated with peptide-based therapeutics. Beyond delivery considerations, we examine how peptide types, cyclization types, and specific chemical modifications co-occur with routes of administration, therapeutic indications, and potential molecular targets. Together, these data-driven insights provide a comprehensive overview of the evolving cyclic peptide landscape and highlight emerging design principles that are shaping the future development of cyclic peptide therapeutics.