A 12-month study to compare the efficacy and safety of abaloparatide-solid microstructured transdermal system (sMTS) with abaloparatide-subcutaneous (SC).

This study aims to evaluate the non-inferiority of abaloparatide-sMTS 300 micrograms (mcg) compared to abaloparatide-SC 80 mcg based on lumbar spine bone mineral density (BMD) at 12 months and to evaluate the safety and tolerability of abaloparatide-sMTS in the treatment of postmenopausal women with osteoporosis.

Inclusion Criteria:

• Healthy ambulatory female from 50 to 85 years of age (inclusive) with postmenopausal osteoporosis
• Participants who are 50 to 65 years old with BMD T-score ≤ -2.5 and > -5.0 at the lumbar spine or hip (femoral neck or total hip) by dual energy x-ray absorptiometry (DXA) and meet one of the following: 1) radiological evidence of 2 or more mild or one or more moderate lumbar or thoracic vertebral fractures or 2) history of fragility fracture to the forearm, humerus, sacrum, pelvis, hip, femur, or tibia within the past 5 years.
• Participants older than 65 years with BMD T score ≤ -2.0 and > -5.0 who meet the fracture criteria may be enrolled
• Participants older than 65 years with BMD T score ≤ -3.0 and > -5.0 at the lumbar spine or hip (femoral neck or total hip) by DXA
• Body mass index of 18.5 to 33 kilograms (kg)/square meters (m^2), inclusive
• serum calcium (albumin-corrected), parathyroid hormone (1-84), serum phosphorus, alkaline phosphatase, and thyroid stimulating hormone within the normal reference range
• Serum 25-hydroxyvitamin D values must be ≥ 20 nanograms (ng)/milliliters (mL)

Exclusion Criteria:

• History of more than 4 mild or moderate spine fractures or any severe fracture
• Abnormality of the spine or hip that would prohibit assessment of BMD
• History of bone disorders other than postmenopausal osteoporosis or a diagnosis of cancer within the last 5 years
• History of Cushing's disease, thyroid, parathyroid, or malabsorptive syndromes or any chronic or recurrent diseases or disturbances that would interfere with the interpretation of study data or compromise the safety of the patient
• Prior treatment with parathyroid hormone, parathyroid hormone-related peptide-derived drugs, or bone anabolic steroids, including abaloparatide, teriparatide, or parathyroid hormone (1-84)
• Prior treatment with intravenous (IV) bisphosphonates at any time or oral bisphosphonates within the past 3 years; fluoride or strontium within the past 5 years; treatment with corticosteroids within the past 12 months; or selective estrogen receptor modulators within the past 6 months (except hormone replacement therapy)
• Prior treatment with an investigational drug or device within the past 90 days or 5 half-lives of the investigational drug, whichever is longer
• History of nephrolithiasis or urolithiasis within the past 5 years or hereditary disorders predisposing to osteosarcoma