Rintodestrant (G1T48) is an orally active, non-steroidal, selective estrogen receptor degrader (SERD) that also functions as a CDK4/6 inhibitor.

Rintodestrant (G1T48) is a potent and efficacious inhibitor of estrogen-mediated transcription and proliferation in ER-positive breast cancer cells, similar to the pure antiestrogen fulvestrant[1]. Rintodestrant (G1T48) selectively inhibits the growth of ER-positive, but not ER-negative, breast cancer cells[1]. Cell Viability Assay[1]Cell Line: MCF7 cells. Concentration: 1 pM-1 μM. Incubation Time: 18 h. Result: Downregulates the estrogen receptor in breast cancer cells. Significantly inhibited estrogen-mediated growth of MCF7 cells demonstrating approximately threefold higher potency when compared to Fulvestrant. Does not impact apoptosis in MCF7 breast cancer cells.

Rintodestrant (G1T48, 30 or 100 mg/kg) inhibits estrogen signaling in endocrine-resistant breast cancer models[1]. Animal Model: MCF7 xenograft tumors[1]. Dosage: 30 or 100 mg/kg. Administration: P.O. daily for 28 days. Result: Demonstrated dose-dependent inhibition of TamR tumor growth.