Over 40 cyclic peptide drugs are already in clinical use, with new rational design and evolution techniques enabling de novo development of cyclic peptide therapeutics beyond what nature provides.
40+ cyclic peptide drugs approvedWith approximately one new cyclic peptide drug entering the market each year, and de novo design techniques opening entirely new target space
What the researchers found
Over 40 cyclic peptide drugs are currently in clinical use, with approximately one new cyclic peptide drug entering the market annually. While the vast majority of approved cyclic peptides derive from natural products (antimicrobials, human peptide hormones), new techniques based on rational design and in vitro evolution now enable de novo development of cyclic peptide ligands for previously untargetable proteins. Several de novo-designed cyclic peptides are already under clinical evaluation.
Why it matters
Cyclic peptides occupy a unique therapeutic space between small molecule drugs and large biologics, combining the best properties of both. The ability to now design them from scratch — rather than relying solely on natural products — dramatically expands their potential to address diseases where no natural peptide solution exists.
How the study worked
This is a review article surveying the landscape of cyclic peptide therapeutics, examining approved drugs, those in clinical trials, and emerging development techniques including rational design and in vitro evolution approaches.
What this study cannot tell us
As a review published in 2017, it does not cover developments from the past several years, a period of rapid advancement in peptide therapeutics. The review focuses on the overview landscape rather than providing detailed clinical efficacy data for individual drugs. The projection of continued growth relies on trends that may be affected by regulatory, manufacturing, or economic factors.
How to read the evidence
This is a narrative review article providing a field overview rather than new experimental data. It offers valuable context for understanding the cyclic peptide drug landscape but does not constitute primary evidence.
When this study was published
Published in 2017, this review is now several years old. The cyclic peptide field has advanced considerably since, with new approvals and techniques. However, the foundational overview and historical perspective remain valuable.
The bigger picture
The pharmaceutical industry is increasingly looking beyond traditional small molecules and antibodies. Cyclic peptides represent a growing middle ground — they're large enough to bind challenging protein-protein interaction targets but small enough to potentially be orally bioavailable. The shift from natural product discovery to rational design marks a new era for this drug class.
Questions still open
- Which de novo-designed cyclic peptides mentioned as being in clinical trials have since reached approval?
- Can cyclic peptides achieve reliable oral bioavailability, or are they limited to injection-based delivery?
- How do manufacturing costs of de novo cyclic peptides compare to conventional small molecule drugs?
Common questions
What makes cyclic peptides good drug candidates?
How are new cyclic peptide drugs being developed?
Read the original research
Cyclic peptide therapeutics: past, present and future.
Current opinion in chemical biology, 38, 24-29
Citation
Zorzi, Alessandro; Deyle, Kaycie; Heinis, Christian. (2017). Cyclic peptide therapeutics: past, present and future.. Current opinion in chemical biology, 38, 24-29. https://doi.org/10.1016/j.cbpa.2017.02.006