Peptide therapeutics have emerged as a major drug class, with over 80 FDA-approved peptide drugs and hundreds in clinical development.
The Therapeutic "Middle Space"
| Property | Small Molecules | Peptides | Proteins/Antibodies |
|---|---|---|---|
| Size | < 500 Da | 500-5,000 Da | > 10,000 Da |
| Target | Enzyme pockets | PPIs, GPCRs | Cell surfaces |
| Specificity | Moderate | High | Very High |
| Oral availability | Usually yes | Challenging | No |
| Immunogenicity | Low | Low | Moderate-High |
| Manufacturing | Chemical | Chemical/Recombinant | Recombinant |
Major Therapeutic Areas
Metabolic Disorders **Insulin** and its analogs remain the cornerstone of diabetes treatment. The GLP-1 receptor agonists represent the fastest-growing peptide drug class: - **Semaglutide** (Ozempic, Wegovy) — Diabetes, obesity - **Tirzepatide** (Mounjaro) — Dual GIP/GLP-1 agonist - **Liraglutide** (Victoza) — Daily diabetes injection
Oncology Peptides enable targeted cancer therapies: - **GnRH agonists** (Leuprolide) — Hormone-sensitive cancers - **Somatostatin analogs** (Octreotide) — Neuroendocrine tumors - **Peptide Receptor Radionuclide Therapy (PRRT)** — Targeted radiotherapy
Cardiovascular - **Natriuretic peptides** — Heart failure (Nesiritide) - **Vasopressin analogs** — Bleeding disorders (Desmopressin)
Rare Diseases - **Exenatide** — Originally from Gila monster venom - **Ziconotide** — Cone snail venom for severe pain
Overcoming Peptide Limitations
Native peptides suffer from rapid degradation and poor bioavailability. Modern engineering addresses these challenges: