Bicycle Therapeutics

Bicycle Therapeutics is a clinical-stage biopharmaceutical company founded in 2009. It develops bicyclic peptides, a class of fully synthetic medicines, for cancer and other diseases with significant unmet medical needs. The company is headquartered in Cambridge, UK, with operations in Lexington, Massachusetts.

Its technology is built around Bicycle® molecules: short peptides constrained by small-molecule scaffolds to form two stabilising loops. The company states that this geometry confers high affinity and selectivity, combining pharmacological properties of biologics with the manufacturing and pharmacokinetic advantages of small molecules. No immunogenicity has been observed to date. The approach is applied to the targeting of protein-protein interactions involving historically "undruggable" proteins, and has been described as drawing on Nobel Prize-winning science.

The clinical pipeline comprises multiple active programmes directed at solid tumour cancers, including Bicycle Toxin Conjugates, in which Bicycle molecules are conjugated to toxins, and Bicycle Tumor-Targeted Immune Cell Agonists, which engage immune cells in a tumour-targeted manner. Technical work spans bicyclic peptide engineering, synthetic peptide chemistry, targeted drug conjugates, pharmacokinetics optimisation and immunogenicity assessment. The company identifies therapeutic areas including oncology, anti-infectives, cardiovascular health, ophthalmology and central nervous system disorders.