@article { , title = {A Randomized, Open-label, Presurgical, Window-of-Opportunity Study Comparing the Pharmacodynamic Effects of the Novel Oral SERD AZD9496 with Fulvestrant in Patients with Newly Diagnosed ER+ HER2- Primary Breast Cancer}, abstract = {©2020 American Association for Cancer Research. PURPOSE: Fulvestrant, the first-in-class selective estrogen receptor (ER) degrader (SERD), is clinically effective in patients with ER+ breast cancer, but it has administration and pharmacokinetic limitations. Pharmacodynamic data suggest complete ER degradation is not achieved at fulvestrant's clinically feasible dose. This presurgical study (NCT03236974) compared the pharmacodynamic effects of fulvestrant with AZD9496, a novel, orally bioavailable, nonsteroidal, potent SERD, in treatment-naïve patients with ER+ HER2- primary breast cancer awaiting curative intent surgery. PATIENTS AND METHODS: Patients were randomized 1:1 to receive AZD9496 250 mg twice daily from day 1 for 5-14 days, or fulvestrant 500 mg on day 1. On-treatment imaging-guided core tumor biopsies were taken between day 5 and 14 and compared with pretreatment diagnostic biopsies. The primary objective was to compare the effects of AZD9496 and fulvestrant on ER expression. Secondary objectives included changes in progesterone receptor (PR) and Ki-67 pharmacokinetic/pharmacodynamic relationships and safety. RESULTS: Forty-six women received treatment (AZD9496 n = 22; fulvestrant n = 24); 35 paired biopsies were evaluable (AZD9496 n = 15; fulvestrant n = 20). The least square mean estimate for ER H-score reduction was 24\% after AZD9496 versus 36\% after fulvestrant treatment (P = 0.86). AZD9496 also reduced PR H-scores (-33.3\%) and Ki-67 levels (-39.9\%) from baseline, but was also not superior to fulvestrant (PR: -68.7\%, P = 0.97; Ki-67: -75.4\%, P = 0.98). No new safety findings were identified. CONCLUSIONS: This was the first presurgical study to demonstrate that an oral SERD affects its key biological targets. However, AZD9496 was not superior to fulvestrant at the dose tested.}, doi = {10.1158/1078-0432.CCR-19-3387}, eissn = {1557-3265}, issn = {1078-0432}, issue = {16}, journal = {Clinical cancer research : an official journal of the American Association for Cancer Research}, pages = {4242-4249}, publicationstatus = {Published}, publisher = {American Association for Cancer Research}, url = {https://nottingham-repository.worktribe.com/output/4248891}, volume = {26}, keyword = {Cancer Research, Oncology}, year = {2020}, author = {Robertson, John F.R. and Evans, Abigail and Henschen, Stephan and Kirwan, Cliona C. and Jahan, Ali and Kenny, Laura M. and Dixon, J. Michael and Schmid, Peter and Kothari, Ashutosh and Mohamed, Omar and Fasching, Peter A. and Cheung, Kwok Leung and Wuerstlein, Rachel and Carroll, Danielle and Klinowska, Teresa and Lindemann, Justin P.O. and MacDonald, Alexander and Mather, Richard and Maudsley, Rhiannon and Moschetta, Michele and Nikolaou, Myria and Roudier, Martine P. and Sarvotham, Tinnu and Schiavon, Gaia and Zhou, Diansong and Zhou, Li and Harbeck, Nadia} }