Circle Pharma, Inc., a South San Francisco, Calif.-based macrocycle drug discovery and development company focused on intractable cancer targets, raised $66m in Series C financing.
The round was co-led by The Column Group and Nextech Invest with participation from Pandect Bioventures, together with new investors including Euclidean Capital, Pavillion Capital, Hartford HealthCare Endowment and Eli Lilly and Company.
The company intends to use the funds to advance its wholly owned cyclin-targeted programs towards the clinic, with potential applications in Rb-dysregulated cancers such as small cell lung cancer and cyclin E dependent malignancies, including ovarian cancer. In addition, Circle Pharma will apply its macrocycle platform to other precision oncology targets that have a clear therapeutic rationale but are considered undruggable with small molecules.
Led by David J. Earp, J.D., Ph.D., President and CEO, Circle is developing a technology platform that 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. Its macrocycle drug discovery & development platform is applicable across a wide range of serious diseases and the company is initially focusing its development efforts on intracellular protein-protein interactions that are key drivers in cancer. Its lead programs target cyclin proteins, which are part of the regulatory machinery that controls progression of cells through the growth and division cycle. Inhibition of cyclin A is synthetically lethal to cancer cells that carry mutations causing dysregulation of the Rb pathway – such mutations are frequently found in small cell lung cancer. Cyclin E upregulation is found 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.