RGT-587

RGT-587 is a next‑generation, selective cyclin‑dependent kinase 4 (CDK4) inhibitor being developed for oncology, with an emphasis on potential use in breast cancer and brain metastases settings. It originated at Regor Therapeutics and was acquired by Genentech/Roche, where it is referenced as GDC‑0587. Public reports describe it as preclinical/Phase‑I–ready, small‑molecule CDK4 inhibitor intended to address resistance and central nervous system involvement in hormone receptor–positive breast cancer. Mechanistically, it inhibits CDK4, a key driver of G1‑S cell‑cycle transition via Rb phosphorylation, aligning it with targeted antineoplastic therapy.[7][9][1][10][8]