- Participants must be at least 2 weeks out from prior endocrine therapy, chemotherapy,radiotherapy, or other cancer-directed therapy (including novel agents), with adequate recovery of toxicity to baseline, or grade ≤1, with the exception of alopecia and hot flashes. Participants may have initiated bisphosphonate/denosumab therapy prior to start of protocol therapy. Biphosphonate/denosumab therapy may continue during protocol treatment. Such participants will have bone lesions considered evaluable for progression. Washout for trastuzumab is not necessary.