Context Therapeutics Inc. announced a clinical trial collaboration and supply agreement for Menarini's oral selective estrogen receptor degrader (SERD), elacestrant. This agreement will support the upcoming Phase 1b/2 ELONA clinical proof-of-concept trial evaluating onapristone extended release (ONA-XR), an oral progesterone receptor (PR) antagonist, in combination with elacestrant in estrogen receptor positive (ER+), PR+ HER2- metastatic breast cancer (mBC) patients who have previously been treated with a CDK4/6 inhibitor. Context will sponsor the clinical trial and Menarini will supply elacestrant at no cost.

According to the American Cancer Society, breast cancer is the second most common cancer among women occurring in 1 in 8 women (13%) over the course of a woman's lifetime, with 280,000 new cases of invasive breast cancer and 51,400 cases of non-invasive breast cancer expected in 2022. Elacestrant is the first oral SERD to demonstrate a statistically significant and clinically meaningful improvement in progression-free survival (PFS) versus standard-of-care (SOC) endocrine therapy in a Phase 3 trial in patients with ER+, HER2- mBC, with 30% reduction in the risk of progression or death in all patients. Data also showed that 22% of patients were alive and progression-free at 12 months after elacestrant treatment initiation vs.

9% with SOC in the overall population. Therefore, elacestrant may become the new backbone endocrine therapy for ER+, HER2- mBC. Preliminary data from preclinical studies suggest that a dual ER and PR blockade may be associated with enhanced tumor control.

The ELONA clinical trial will be evaluating this important hypothesis.