An Open-label Study to Evaluate the Effect of Treatment With Romosozumab or Teriparatide in Postmenopausal Women

Inclusion Criteria:

- Postmenopausal women, aged ≥ 55 to ≤ 90.

- Received oral bisphosphonate therapy for at least 3 years immediately prior to
screening

- BMD T-score ≤ -2.50 at the lumbar spine, total hip or femoral neck

- History of nonvertebral fracture after age 50, or vertebral fracture.

Exclusion Criteria:

- Use of other agents affecting bone metabolism including Strontium ranelate, fluoride
(for osteoporosis), odanacatib (MK-0822) or any other cathepsin K inhibitor, IV
bisphosphonates, denosumab, teriparatide (TPTD) or any parathyroid hormone (PTH)
analogs, Systemic oral or transdermal estrogen, selective estrogen receptor modulators
(SERMs), activated vitamin D3, vitamin K2, calcitonin, tibolone, cinacalcet, systemic
glucocorticosteroids:

- History of metabolic or bone disease (except osteoporosis) that may interfere with the
interpretation of study results, such as sclerosteosis, Paget's disease, rheumatoid
arthritis, osteomalacia, osteogenesis imperfecta, osteopetrosis, ankylosing
spondylitis, Cushing's disease, hyperprolactinemia, and malabsorption syndrome.

- Vitamin D insufficiency, defined as 25 (OH) vitamin D levels < 20 ng/mL, as determined
by the central laboratory.

- Current hyper- or hypocalcemia

- Current, uncontrolled hyper- or hypothyroidism