Circle Pharma, Inc., a clinical-stage biopharmaceutical company pioneering next-generation targeted macrocycle therapeutics for cancer, today announced an upcoming poster presentation highlighting the potential of CID-078 as a novel therapeutic option in pediatric cancers at the American Association for Cancer Research (AACR) Special Conference on Pediatric Cancer, taking place from September 25-28 in Boston, MA. CID-078 is a first-in-class, orally bioavailable macrocyclic cyclin A/B RxL inhibitor that is currently being evaluated in a Phase 1 clinical trial for patients with advanced solid tumors.

The presentation, based on a collaboration between Circle Pharma and Children’s Cancer Institute (Sydney, Australia), will focus on the novel mechanism of action of CID-078 for cancers driven by high E2F activity including those with alterations in the tumor suppressor genes RB1 or CDKN2A/B, as well as the prevalence of these biomarkers across a diverse range of pediatric cancer types. In addition, the presentation will outline new preclinical data on the correlation between CID-078 sensitivity and RB1 and E2F biomarker status in a database of pediatric tumor samples from The ZERO Childhood Cancer Precision Medicine Program.

“We believe CID-078 may represent a promising new therapeutic option for pediatric cancers with certain defined molecular drivers,” said Michael C. Cox, PharmD, MHSc, BCOP, senior vice president and head of early development at Circle Pharma. “These findings may inform strategies for real-time patient identification and stratification in potential future pediatric studies of CID-078. Presenting these data generated in collaboration with Children’s Cancer Institute during Childhood Cancer Awareness Month reinforces our commitment to advancing the development of our therapies for patients who urgently need new options.”

Details of the presentation are as follows:

Title: Investigating the Cyclin A/B RxL Inhibitor CID-078 in Pediatric Cancers with RB1 Loss and High E2F1

Abstract Number: B021

Session: Poster Session B

Date & Time: Friday, September 26, 5:00-7:00 p.m. ET

Presenting Author: Chelsea Mayoh, Children's Cancer Institute, Lowy Cancer Centre, UNSW Sydney, Kensington, Australia

About CID-078, Circle Pharma’s Oral Cyclin A/B RxL Inhibitor Program

CID-078 is an orally bioavailable macrocycle with dual activity blocking protein-protein interactions between both cyclins A and B and key substrates that bind to them via conserved RxL motifs. CID-078 selectively targets tumor cells with oncogenic alterations that cause cell cycle dysregulation, including alterations in the tumor suppressor RB1. In pre-clinical 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 with advanced solid tumors harboring RB1 alterations.

About Circle Pharma

Circle Pharma is a clinical-stage biopharmaceutical company harnessing the power of macrocycles to develop next-generation targeted 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, including for historically undruggable targets. Circle Pharma’s pipeline is focused on targeting cyclins, key regulators of the cell cycle that drive many cancers. The company’s lead program, CID-078, is a cyclin A/B RxL inhibitor in Phase 1 clinical development for patients with advanced solid tumors. Circle Pharma is based in South San Francisco, CA. For additional information, please visit us at circlepharma.com and follow us on LinkedIn and X.

View source version on businesswire.com: https://www.businesswire.com/news/home/20250924099547/en/