Rintodestrant is an oral selective estrogen receptor degrader (“SERD”) for the treatment of estrogen receptor-positive (“ER+”) breast cancer. Rintodestrant, an oral SERD, is a Phase 2 compound being developed as a monotherapy and in combination with CDK4/6 inhibitors, initially Ibrance® (palbociclib), for the treatment of ER+ breast cancer. In 2018, the Company initiated a Phase 1/2a (dose escalation/dose expansion) clinical trial in ER+, HER2- breast cancer. Preliminary data from the Phase 1 portion of this trial were presented at the 2019 ESMO Congress, showing that rintodestrant was well tolerated and demonstrated evidence of anti-tumor activity in heavily pre-treated patients. Mature data were presented at the 2020 San Antonio Breast Cancer Symposium, confirming the safety and efficacy results of the preliminary analysis. Based on these findings the Company advanced an 800 mg dose of rintodestrant into a 40-patient Phase 1b combination arm with palbociclib, a CDK4/6 inhibitor, positive safety and antitumor activity data from which were presented at the 2021 American Society of Clinical Oncology (ASCO) annual virtual meeting. The Company is in the process of evaluating partnering options for rintodestrant.