Circle Pharma Secures $66 Million in Oversubscribed Series C Financing to Advance Macrocyclic Therapeutics for Intractable Cancers

Circle Pharma, a macrocyclic drug R&D company invested in by United Capital Investment Group, recently completed a $66 million Series C financing round.

Circle Pharma, Inc. is a macrocyclic drug development company focused on researching therapeutic targets for refractory cancers. The company recently announced the completion of an oversubscribed Series C financing round totaling $66 million.

This round of financing was co-led by The Column Group and Nextech Invest. All investors from the company’s previous round participated in this follow-on investment, including Pandect Bioventures. Additionally, several new investors joined this round, such as Euclidean Capital, Pavillion Capital, Hartford HealthCare Endowment, and Eli Lilly and Company.

The current round of funding will be used to advance the company’s proprietary cyclin-targeting system into the clinical market. This technology will enable the treatment of cancers associated with Rb (retinoblastoma) gene dysfunction, such as small cell lung cancer, as well as cyclin E–based malignancies including ovarian cancer. Furthermore, the company will leverage its macrocyclic technology platform to target other precision oncology targets with well-defined therapeutic mechanisms that are difficult to address using small-molecule drugs.

Peter Svennilson, Managing Partner of The Column Group“Circle has made significant progress since its Series B financing round last year, and we are delighted to co-lead this investment round alongside Nextech Invest. We look forward to Circle’s pioneering macrocyclic platform delivering breakthrough, best-in-class therapies to patients.”

Dr. David J. Earp, Chairman and CEO of Circlestated, “We are deeply grateful for the unwavering support from our existing investors and welcome the trust placed in us by the new investors in this round. This financing will further help us expand into the clinic market and accelerate the preparation of additional new projects.”

Circle is establishing a new paradigm for macrocyclic drug discovery through rational structural design and synthetic chemistry. Circle’s technology facilitates the design and synthesis of cell-intrinsically permeable macrocyclic compounds that can simultaneously target intracellular and extracellular therapeutic targets and be administered via various routes, including oral delivery. Circle’s macrocyclic drug development platform has broad applicability in the development of therapeutics for numerous serious diseases. The company’s current primary research focus is on oncogenic intracellular protein–protein interactions. Its lead programs center on cyclins, proteins that regulate the cell growth and division cycle. Inhibition of cyclin A can kill cancer cells harboring mutations that lead to Rb gene dysfunction, a type of alteration highly prevalent in small cell lung cancer. Cyclin E upregulation is also common in many tumor types, such as uterine and ovarian cancers, which often exhibit strong resistance to conventional cancer therapies, including trastuzumab and CDK4/6 inhibitors.