A Rollover Protocol of Elacestrant, in Combination With Onapristone, for Patients With ER+, PR+, HER2- Advanced or Metastatic Breast Cancer

A Rollover Protocol of Elacestrant, in Combination With Onapristone, for Patients With Estrogen Receptor-Positive, Progesterone Receptor-Positive, HER2-negative Advanced or Metastatic Breast Cancer

This is a rollover study for patients enrolled in the discontinued ELONA clinical trial (ONA-XR-103) with the primary objective to characterize the safety of elacestrant in combination with onapristone either alone or in combination.

Inclusion Criteria:

• Patient is currently enrolled in the ELONA clinical study (ONA-XR-103) and receiving onapristone or elacestrant, either alone or in combination.
• Patient is currently benefiting from the treatment in the ELONA clinical study, as determined by the investigator.
• Patient currently has no evidence of progressive disease, as determined by the investigator.

Exclusion Criteria:

• Pregnant or nursing (lactating) women.
• Female patients of childbearing potential (e.g., are menstruating) who do not agree to abstinence or, if sexually active, do not agree to the use of highly effective contraception, throughout the study and for up to 30 days after stopping study treatment.