SOUTH SAN FRANCISCO, Calif. – June 16, 2025 – Circle Pharma, a clinical-stage biopharmaceutical company advancing macrocycle therapeutics for difficult-to-treat cancers, today announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) to CID-078 for the treatment of small cell lung cancer (SCLC).
Small-cell lung cancer is a highly aggressive form of lung cancer that accounts for approximately 13–15% of all lung cancer cases1 and is strongly linked to tobacco exposure. Despite existing treatments, SCLC has a high recurrence rate and is associated with poor overall prognosis. While improvements in overall survival are occurring with newer therapies, most patients experience rapid disease progression2.
“The Orphan Drug Designation from the FDA underscores both the seriousness of small cell lung cancer and the lack of effective treatment options,” said Michael C. Cox, PharmD, MHSc, BCOP, SVP, and head of early development Circle Pharma. “We are committed to accelerating the clinical development of CID-078 to offer new hope for patients who face limited therapeutic choices.”
The FDA’s Orphan Drug Designation program is intended to promote the development of drugs for rare diseases or conditions affecting fewer than 200,000 people in the United States3. This designation provides several development incentives, including seven years of market exclusivity upon regulatory approval, tax credits for qualified clinical trial costs, and eligibility to apply for FDA-administered research grants4.
Circle Pharma has initiated a Phase 1 clinical trial (NCT06577987) of CID-078 to evaluate its safety, tolerability, pharmacokinetics, and early signs of anti-tumor activity in patients with advanced solid tumors, including SCLC.
About CID-078, Circle Pharma’s Cyclin A/B RxL Inhibitor Program
CID-078 is an orally bioavailable macrocycle with dual cyclin A and B RxL inhibitory activity that selectively targets tumor cells with oncogenic alterations that cause cell cycle dysregulation. In biochemical and cellular studies, Circle Pharma’s cyclin A/B RxL inhibitors have been shown to potently and selectively disrupt the protein-to-protein interaction between cyclins A and B and their key substrates and modulators, including E2F (a substrate of cyclin A) and Myt1 (a modulator of cyclin B). Preclinical studies have demonstrated the ability of these cyclin A/B RxL inhibitors to cause single-agent tumor regressions in multiple in vivo models. A multi-center phase 1 clinical trial (NCT06577987) is currently enrolling patients.
About Circle Pharma, Inc.
South San Francisco-based Circle Pharma is a clinical-stage biopharmaceutical company harnessing the power of macrocycles to develop therapies for cancer and other serious illnesses. The company’s proprietary MXMO™ platform overcomes key challenges in macrocycle drug development, enabling the creation of intrinsically cell-permeable and orally bioavailable therapies for historically undruggable targets. Circle Pharma’s pipeline is focused on targeting cyclins, key regulators of the cell cycle that drive many cancers. Its lead program, CID-078, a cyclin A/B-RxL inhibitor, is in a Phase 1 clinical trial (NCT06577987) for patients with advanced solid tumors.
Media Contact:
Roslyn Patterson
Phone: 650.825.4099
Email: roslyn.patterson@circlepharma.com
1. American Cancer Society. What is Small Cell Lung Cancer? https://www.cancer.org/cancer/lung-cancer/about/what-is.html
2. National Cancer Institute. Small Cell Lung Cancer Treatment (PDQ®)–Patient Version. https://www.cancer.gov/types/lung/patient/small-cell-lung-treatment-pdq
3. U.S. Food and Drug Administration. Developing Products for Rare Diseases & Conditions. https://www.fda.gov/industry/developing-products-rare-diseases-conditions
4. U.S. Food and Drug Administration. Benefits of Orphan Drug Designation. https://www.fda.gov/industry/medical-products-rare-diseases-and-conditions/designating-orphan-product-drugs-and-biological-products
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SOUTH SAN FRANCISCO, Calif. – May 27, 2025 – Circle Pharma, a clinical-stage biopharmaceutical company advancing macrocycle therapeutics for difficult-to-treat cancers, today announced the presentation of preclinical data on CID-078 at the Advances in Neuroblastoma Research (ANR) Meeting in Washington, D.C., May 25 -28, 2025. The data, which explore the therapeutic potential of CID-078 in neuroblastoma (NB), were presented in a poster entitled:
“Cyclin A/B-RxL Inhibition as a Novel Therapeutic Strategy in Neuroblastoma” Dylan M.M. Jongerius et al. Poster #P010
The poster highlights the work of researchers from the Princess Máxima Center for Pediatric Oncology (Utrecht, the Netherlands), the Hopp Children’s Cancer Center Heidelberg (KiTZ) (Heidelberg, Germany), and Circle Pharma, demonstrating the potent anti-tumor activity of CID-078 in preclinical neuroblastoma (NB) models.
CID-078 is a first-in-class oral macrocycle cyclin A/B RxL inhibitor that selectively disrupts RxL-mediated interactions between cyclin A2/B1 and their substrates, a novel mechanism of action that targets cell cycle dysregulation in cancer. In neuroblastoma, where CDK-RB-E2F axis deregulation and oncogenic E2F activity are common, this mechanism is particularly relevant.
Key Findings Presented:
Potent Single agent CID-078 activity was observed across multiple neuroblastoma cell line models.
Mechanism of action studies confirmed induction of DNA damage, G2/M arrest and the activation of the spindle assembly checkpoint (SAC).
Deletion of CDKN2A sensitized cells to CID-078 suggesting CDKN2A status maybe be used as a potential patient stratification strategy.
“A greater understanding of the biology of neuroblastoma, the most common extra-cranial solid tumor diagnosed in children, has shown specific genomic alterations which deregulate the cell cycle leading to E2F activation,” said Michael C. Cox, PharmD, MHSc, BCOP, SVP and head of early development of Circle Pharma. “Circle’s collaboration with these two premier pediatric oncology research institutions has shown again the potential of our macrocycle platform to develop new therapies for historically challenging targets. The exciting CDKN2A deletion biomarker data, as well as the in vitro data in a pediatric tumor with a need for better treatments support our clinical development plans for CID-078.”
The full poster is available here.
About CID-078, Circle Pharma’s Cyclin A/B RxL Inhibitor Program
CID-078 is an orally bioavailable macrocycle with dual cyclin A and B RxL inhibitory activity that selectively targets tumor cells with oncogenic alterations that cause cell cycle dysregulation. In biochemical and cellular studies, Circle Pharma’s cyclin A/B RxL inhibitors have been shown to potently and selectively disrupt the protein-to-protein interaction between cyclins A and B and their key substrates and modulators, including E2F (a substrate of cyclin A) and Myt1 (a modulator of cyclin B). Preclinical studies have demonstrated the ability of these cyclin A/B RxL inhibitors to cause single-agent tumor regressions in multiple in vivo models. A multi-center phase 1 clinical trial (NCT06577987) is currently enrolling patients.
About Circle Pharma, Inc.
South San Francisco-based Circle Pharma is a clinical-stage biopharmaceutical company harnessing the power of macrocycles to develop therapies for cancer and other serious illnesses. The company’s proprietary MXMO™ platform overcomes key challenges in macrocycle drug development, enabling the creation of intrinsically cell-permeable and orally bioavailable therapies for historically undruggable targets. Circle Pharma’s pipeline is focused on targeting cyclins, key regulators of the cell cycle that drive many cancers. Its lead program, CID-078, a cyclin A/B-RxL inhibitor, is in a Phase (NCT06577987) for patients with advanced solid tumors.
Media Contact:
Roslyn Patterson
Phone: 650.825.4099
Email: roslyn.patterson@circlepharma.com
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SOUTH SAN FRANCISCO, Calif. – May 12, 2025 – Circle Pharma, a clinical-stage biopharmaceutical company advancing macrocycle therapeutics for difficult-to-treat cancers, today announced that its Trials in Progress abstract has been selected for poster presentation at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting taking place May 30 to June 3 in Chicago. The poster will showcase the design and ongoing progress of its Phase 1 study of CID-078 (NCT06577987), a first-in-class, oral macrocycle cyclin A/B RxL inhibitor.
The abstract will be featured in a Poster Session focused on Developmental Therapeutics—Molecularly Targeted Agents and Tumor Biology, under the New Targets and New Technologies (non-IO) subtrack.
Presentation Details
Title:
Abstract Title: A phase 1 study to evaluate the safety, pharmacokinetics, and efficacy of the first-in-class cyclin A/B RxL inhibitor CID-078, an orally bioavailable, cell-permeable macrocycle.
First Author: Nehal Lakhani, MD, PhD, The START Center for Cancer Research, Grand Rapids, MI,
Abstract Number: TPS3175
Poster Board Number: 481a
Session Title: Developmental Therapeutics—Molecularly Targeted Agents and Tumor Biology
Date & Time: June 2, 2025, from 1:30 PM – 4:30 PM CDT
“CID-078 exemplifies Circle Pharma’s commitment to advancing new treatments for patients with cancer,” said Michael C. Cox, PharmD, MHSc, BCOP, SVP, and head of early development of Circle Pharma. “CID-078 has shown strong single-agent activity in tumor models with dysregulated cell cycle pathways, where activity has been linked to specific molecular features such as RB1 mutations and high E2F pathway scores. We believe CID-078 has the potential to be a new treatment option for patients with solid tumors such as small-cell lung cancer or triple-negative breast cancer which are known to harbor these alterations, or solid tumors harboring an RB mutation identified through comprehensive genomic profiling. We are encouraged by the progress of the CID-078 phase 1 study, and we’re excited to share early clinical insights at ASCO 2025.”
Contributing Authors:
William McKean, Ildefonso Rodriguez Rivera, Antonio Giordano, Timothy Yap, Afshin Dowlati, Vivek Subbiah, Judy Wang, Manali Bhave, Kyaw Thein, Jinshu Fang, Eric Connor, Li-Fen Liu, Peadar Cremin, Lukas Makris, Li-Pen Tsao, Lisa Kopp, Michael Cox, and Shivaani Kummar.
About CID-078, Circle Pharma’s Cyclin A/B RxL Inhibitor Program
CID-078 is an orally bioavailable macrocycle with dual cyclin A and B RxL inhibitory activity that selectively targets tumor cells with oncogenic alterations that cause cell cycle dysregulation. In biochemical and cellular studies, Circle Pharma’s cyclin A/B RxL inhibitors have been shown to potently and selectively disrupt the protein-to-protein interaction between cyclins A and B and their key substrates and modulators, including E2F (a substrate of cyclin A) and Myt1 (a modulator of cyclin B). Preclinical studies have demonstrated the ability of these cyclin A/B RxL inhibitors to cause single-agent tumor regressions in multiple in vivo models. A multi-center phase 1 clinical trial (NCT06577987) is currently enrolling patients.
About Circle Pharma, Inc.
South San Francisco-based Circle Pharma is a clinical-stage biopharmaceutical company harnessing the power of macrocycles to develop therapies for cancer and other serious illnesses. The company’s proprietary MXMO™ platform overcomes key challenges in macrocycle drug development, enabling the creation of intrinsically cell-permeable and orally bioavailable therapies for historically undruggable targets. Circle Pharma’s pipeline is focused on targeting cyclins, key regulators of the cell cycle that drive many cancers. Its lead program, CID-078, a cyclin A/B-RxL inhibitor, is in a Phase 1 clinical trial (NCT06577987) for patients with advanced solid tumors.
To learn more about Circle Pharma, please visit www.circlepharma.com.
Media Contact:
Roslyn Patterson
Phone: 650.825.4099
Email: roslyn.patterson@circlepharma.com
Click the poster to download.
SOUTH SAN FRANCISCO, Calif. – April 22, 2025 – Circle Pharma, a clinical-stage biopharmaceutical company focused on developing cell-permeable macrocycle therapeutics, today announced a late-breaking poster presentation at the American Association for Cancer Research (AACR) Annual Meeting 2025 in Chicago, Illinois.
The poster will present new mechanistic insights into the anti-cancer activity of cyclin A/B RxL inhibitors, including their impact on DNA repair pathways and mitotic progression in E2F-high cancers. Circle Pharma’s CID-078, an oral macrocycle Cyclin A/B RxL inhibitor, is being evaluated in a Phase 1 clinical study (NCT06577987).
Presentation Details
Title: Anti-cancer effect of Cyclin A/B RxL inhibitors is mediated in part by disruption
of the ATR/Chk1 DNA repair pathway
Session: Late-Breaking Research: Experimental and Molecular Therapeutics 3
Session Start: 4/29/2025 9:00:00 AM CT
Session End: 4/29/2025 12:00:00 PM CT
Location: Poster Section 52, Poster Board Number: 19, Abstract Number: LB296
The study, led by researchers from Circle Pharma in collaboration with the University of Oxford and Dana-Farber Cancer Institute, highlights the dual mechanism by which Cyclin A/B RxL inhibitors induce tumor regression.
Contributing Authors: Catherine E. Gleason, Ranya Odeh, Frances Hamkins-Indik, Iolanda Vendrell, Roman Fischer, Benedikt Kessler, Shilpa Singh, Matthew Oser, Marie Evangelista, and Pablo D. Garcia, Circle Pharma Inc., South San Francisco, CA, University of Oxford, UK, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
About Circle Pharma, Inc.
South San Francisco-based Circle Pharma is a clinical-stage biopharmaceutical company harnessing the power of macrocycles to develop therapies for cancer and other serious illnesses. The company’s proprietary MXMO™ platform overcomes key challenges in macrocycle drug development, enabling the creation of intrinsically cell-permeable and orally bioavailable therapies for historically undruggable targets. Circle Pharma’s pipeline is focused on targeting cyclins, key regulators of the cell cycle that drive many cancers. Its lead program, CID-078, a cyclin A/B-RxL inhibitor, is in a Phase 1 clinical trial (NCT06577987) for patients with advanced solid tumors.
To learn more about Circle Pharma, please visit www.circlepharma.com.
Media Contact:
Roslyn Patterson
Phone: 650.825.4099
Email: roslyn.patterson@circlepharma.com
SOUTH SAN FRANCISCO, Calif. – March 31, 2025 – Circle Pharma, a clinical-stage biopharmaceutical company focused on developing cell-permeable macrocycle therapeutics, today announced that Chief Executive Officer David Earp, JD, Ph.D., will present at the following investor conferences:
About Circle Pharma, Inc.
South San Francisco-based Circle Pharma is a clinical-stage biopharmaceutical company harnessing the power of macrocycles to develop therapies for cancer and other serious illnesses. The company’s proprietary MXMO™ platform overcomes key challenges in macrocycle drug development, enabling the creation of intrinsically cell-permeable and orally bioavailable therapies for historically undruggable targets. Circle Pharma’s pipeline is focused on targeting cyclins, key regulators of the cell cycle that drive many cancers. Its lead program, CID-078, a Cyclin A/B-RxL inhibitor, is in a Phase 1 clinical trial for patients with advanced solid tumors.
To learn more about Circle Pharma, please visit www.circlepharma.com.
Media Contact:
Roslyn Patterson
Phone: 650.825.4099
Email: roslyn.patterson@circlepharma.com
Click the poster to download.