A Study of Romosozumab in People With Breast Cancer and Osteoporosis

A Phase II Study Evaluating the Efficacy and Safety of Romosozumab as a Bone-Modifying Agent in Patients With Metastatic Breast Cancer to Bones and Osteoporosis With High Fracture Risk (REMOLD-Breast)

The researchers are doing this study to see if romosozumab is effective at helping with bone formation in people with metastatic breast cancer (MBC) that has spread to the bones. All participants will have osteoporosis. The researchers will also look at bone breakdown (resorption) in participants and determine if romosozumab is a safe treatment for osteoporosis in people with MBC that has spread to the bones.

Inclusion Criteria:

• ≥18 years of age at the time of giving informed consent;
• Patients diagnosed with hormone-receptor positive (ER/PR >1%) metastatic breast cancer to bones on any endocrine therapy with or without targeted therapy (i.e. CDK 4/6 inhibitors, PI3K inhibitors, anti-HER2-therapy);
• Evidence of osteoporosis on dual X-ray absorptiometry (DXA) scan; must following:
• osteoporosis on dual X-ray absorptiometry (DXA) scan; or history of fragility fracture of the spine or hip; or of morphometric spine fracture;

Exclusion Criteria:

• Prior therapy with a bone-modifying agent (intraveous bisphosphonates or subcutaneous denosumab) for metastatic bone disease;
• 25 (OH) vitamin D levels < 20 ng/mL; Vitamin D repletion will be permitted and subjects will be be rescreened once 25 (OH) vitamin D level ³ 20 ng/mL;
• History of myocardial infarction or stroke within the preceding year;
• Current hyper- or hypocalcemia, defined as albumin-adjusted serum calcium outside the normal range per institutional standard (<8.5 or >10.5 mg/dL); Calcium repletion will be permitted and subjects will be be rescreened once values are within the institutional standard.
• History of non-healed dental or oral surgery;
• History of osteonecrosis of the jaw