Circle has developed a new paradigm for macrocycle drug discovery, combining structure-based rational design and advanced synthetic chemistry. Our platform facilitates the design and synthesis of intrinsically cell-permeable macrocycles that can address both intra- and extra-cellular therapeutic targets, and can be delivered by multiple routes, including oral administration. While the platform can be applied to challenging targets across a wide range of serious diseases, our pipeline is focused on developing macrocycles against intracellular protein-protein interactions that are key drivers in cancer.

Our lead programs target cyclin proteins, including cyclins A and E, which are part of the regulatory machinery that controls progression of cells through the cell cycle. Inhibition of cyclin A has been reported to be synthetic lethal to cancer cells that carry mutations causing dysregulation of the Retinoblastoma (Rb) pathway; we are researching the potential of macrocycles that inhibit cyclin A in a broad range of cancer types including small cell lung cancer (SCLC) where mutations in the Rb gene occur at a high frequency. Cyclin E is upregulated in many tumor types including uterine and ovarian cancer and is often associated with resistance to widely used cancer therapies, including trastuzumab and cdk4/6 inhibitors. Cyclin E is also implicated in diseases beyond cancer.

Our Pipeline

Cell Cycle

Cyclin Expression Cycle

Board of Directors

The Column Group

Managing Director of Pandect Bioventures

Board of Directors

Scientific Advisory Board

Scientific Advisory Board Chair

Scientific Advisory Board member

Scientific Advisory Board member