CID-078

CID-078 is an oral macrocycle (macrocyclic peptide) from Circle Pharma. An orally bioavailable macrocycle that blocks the RxL-mediated interactions of cyclins A and B, aimed at tumour cells whose cell cycle control is broken (for example high E2F activity). Its furthest stage is phase 1, for advanced solid tumours, small cell lung cancer, triple-negative breast cancer and ER-positive HER2-negative breast cancer after CDK4/6 inhibitors. ClinicalTrials.gov registers it in one study linked below. Phase 1 NCT06577987 is active, not recruiting (ClinicalTrials.gov). FDA orphan drug designation for small cell lung cancer, June 2025. Whether it works in people has not been established unless a trial below reports it.