What's Happening?
Circle Pharma, a clinical-stage biopharmaceutical company, has successfully closed an oversubscribed $92.5 million Series E financing round. The funding was led by The Column Group, with additional participation from Nextech Invest, RA Capital Management,
Euclidean Capital, and a strategic investment from Eli Lilly and Company. The proceeds from this financing will primarily be used to advance CID-165, Circle Pharma's first-in-class oral macrocyclic cyclin D1 RxL inhibitor, into early clinical development for patients with ER-positive breast cancer. The company anticipates CID-165 will enter clinical trials in the first quarter of 2027. This funding will also support the continued development of Circle Pharma’s broader pipeline of cyclin-targeted macrocycles.
Why It's Important?
This significant financing round is crucial for Circle Pharma as it moves its lead candidate, CID-165, closer to becoming a potential treatment for ER-positive breast cancer. Cyclin D1 is a well-established driver of cancer, particularly in this type of breast cancer, but directly targeting it has been a long-standing challenge in oncology. CID-165 is designed to selectively disrupt the interaction between cyclin D1 and retinoblastoma protein, offering a novel approach to inhibit tumor growth. The robust anti-tumor activity observed in preclinical models, both as a monotherapy and in combination with existing treatments, suggests CID-165 could become a new foundational therapy. The investment from major players like Eli Lilly and Company also validates the potential of Circle Pharma's proprietary MXMO™ platform and its macrocycle drug development capabilities.
What's Next?
Circle Pharma plans to initiate clinical development for CID-165 in the first quarter of 2027. This will involve human trials to assess the drug's safety, tolerability, and preliminary efficacy in patients with ER-positive breast cancer. The company will also continue to develop its pipeline of other cyclin-targeted macrocycles, leveraging its platform to address historically undruggable targets. Successful progression through clinical trials could lead to a new therapeutic option for patients, potentially improving outcomes in a significant cancer indication. The biopharmaceutical community will closely watch the initial clinical data for CID-165, as it could validate a novel mechanism of action for cancer treatment.
Beyond the Headlines
The success of Circle Pharma's financing and its advancement of CID-165 highlight the growing interest and investment in macrocycle therapeutics. Macrocycles offer unique advantages, such as improved cell permeability and oral bioavailability, which can overcome limitations of traditional small molecule and biologic drugs. This development could signify a broader shift in drug discovery towards more complex molecular structures capable of targeting challenging intracellular proteins. If CID-165 proves effective in clinical trials, it could not only transform the treatment landscape for ER-positive breast cancer but also open new avenues for targeting other cyclin-driven cancers, demonstrating the potential of macrocycle chemistry to unlock previously inaccessible therapeutic targets and address unmet medical needs.













