Design and Synthesis of Basic Selective Estrogen Receptor Degraders for Endocrine Therapy Resistant Breast Cancer
journal contributionposted on 10.12.2019, 15:50 by Yunlong Lu, Lauren M. Gutgesell, Rui Xiong, Jiong Zhao, Yangfeng Li, Carlo I. Rosales, Michael Hollas, Zhengnan Shen, Jesse Gordon-Blake, Katherine Dye, Yueting Wang, Sue Lee, Hu Chen, Donghong He, Oleksii Dubrovyskyii, Huiping Zhao, Fei Huang, Amy W. Lasek, Debra A. Tonetti, Gregory R. J. Thatcher
The clinical steroidal selective estrogen receptor (ER) degrader (SERD), fulvestrant, is effective in metastatic breast cancer, but limited by poor pharmacokinetics, prompting the development of orally bioavailable, nonsteroidal SERDs, currently in clinical trials. These trials address local breast cancer as well as peripheral metastases, but patients with brain metastases are generally excluded because of the lack of blood–brain barrier penetration. A novel family of benzothiophene SERDs with a basic amino side arm (B-SERDs) was synthesized. Proteasomal degradation of ERα was induced by B-SERDs that achieved the objectives of oral and brain bioavailability, while maintaining high affinity binding to ERα and both potency and efficacy comparable to fulvestrant in cell lines resistant to endocrine therapy or bearing ESR1 mutations. A novel 3-oxyazetidine side chain was designed, leading to 37d, a B-SERD that caused endocrine-resistant ER+ tumors to regress in a mouse orthotopic xenograft model.