Amcenestrant (SAR439859, compound 43d) is an orally available and nonsteroidal selective estrogen receptor degrader (SERD) with potential antineoplastic activity. SAR439859 is a potent estrogen receptor (ER) antagonist with EC50 of 0.2 nM for ERα degradation.
SAR439859 is a novel, orally bioavailable SERD with potent antagonist and degradation activities against both wild-type and mutant Y537S ER. Driven by its fluoropropyl pyrrolidinyl side chain, SAR439859 has demonstrated broader and superior ER antagonist and degrader activities across a large panel of ER+ cells, including inhibition of ER signaling and tumor cell growth.[2]
SAR439859 shows promising antitumor activity in breast cancer mice xenograft models.[1] In vivo treatment with SAR439859 demonstrates significant tumor regression in ER+ breast cancer models, including MCF7-ESR1 wild-type and mutant-Y537S mouse tumors, and HCI013, a patient-derived tamoxifen-resistant xenograft tumor.[2]
[1] Youssef El-Ahmad, et al. J Med Chem. 2020 Jan 23;63(2):512-528. [2] Maysoun Shomali, et al. Mol Cancer Ther. 2021 Feb;20(2):250-262.