A Study of LY3295668 Erbumine in Participants With Breast Cancer That Has Spread to Other Parts of the Body

Inclusion Criteria: * Participant must have hormone receptor positive and HER2 negative metastatic breast cancer * Participant must have progressed on at least 1 line of endocrine therapy and 1 cyclin dependent kinase (CDK)4/6 inhibitor * Participant must be able and willing to undergo mandatory tumor biopsy * Participant must have normal organ function * Participant must be able to swallow capsules Exclusion Criteria: * Participant must not have had prior chemotherapy for mBC. Chemotherapy in the adjuvant/neoadjuvant setting is permitted * Participant must not be currently enrolled in a clinical study * Participant must not have another serious medical condition * Participant must not have previously received an aurora kinase inhibitor