CID-078 is Circle Pharma's first-in-class orally bioavailable macrocyclic peptide cyclin A/B RxL inhibitor, targeting advanced solid tumors that harbor RB1 alterations. The drug is in a Phase 1 multicenter trial (NCT06577987).
Circle secured an oral plenary slot at AACR 2026 (Sunday, April 19, Clinical Trials Plenary) to present early Phase 1 clinical activity data — a notable signal of the field's interest in macrocyclic peptides for previously undruggable cell-cycle targets.
Stories here cover the AACR readouts, the Phase 1 progression, and the broader Circle Pharma pipeline. See #circle-pharma, #cyclin, #rb1, and #macrocyclic-peptide.
Circle Pharma presents early clinical data for CID-078 in the AACR 2026 Clinical Trials Plenary (Sunday, April 19, 1:00-3:00 PT). CID-078 is a first-in-class orally bioavailable macrocyclic peptide cyclin A/B RxL inhibitor evaluated in a Phase 1 multicenter trial (NCT06577987) for advanced solid tumors with RB1 alterations. The plenary slot — a coveted showcase for private biotechs — tests whether macrocyclic peptides can establish themselves as a third modality alongside small molecules and biologics.
Circle Pharma presents "Orally Bioavailable Peptide Macrocycles Disrupting Intracellular Protein-Protein Interactions: Selective Inhibitors of the RxL-binding Site of Cyclin Family Proteins" at AACR's Chemistry to the Clinic Part 3 session on Saturday, April 18, 12:30-2:00 p.m. PST. The presentation covers CID-078, an orally bioavailable macrocycle with dual activity blocking cyclin A/B protein-protein interactions, selectively targeting tumor cells with RB1 alterations.
Circle Pharma secured a coveted oral plenary slot at AACR 2026 to present early Phase 1 clinical activity data for CID-078, a first-in-class orally bioavailable macrocyclic peptide cyclin A/B RxL inhibitor for patients with advanced solid tumors harboring RB1 alterations. The plenary (Sunday, April 19) validates macrocyclic peptides as viable oral oncology drugs — a major milestone for the modality.