Osteoporosis is a disease characterized by low bone mass and structural deterioration of bone tissue, which leads to greater fragility of bones and an increase in fracture risk. Osteoporosis is a progressive bone disease that occurs when the total bone loss exceeds the total bone formation. Osteoporosis is most associated with menopause in women, aging in both women and men and prolonged glucocorticoid steroid use. The bone remodeling cycle can be separated into two distinct processes: (i) bone resorption, where cells called
osteoclasts function in the resorption of mineralized tissue and (ii) bone formation, where cells called osteoblasts are responsible for bone matrix synthesis and subsequent mineralization of the bone. Current osteoporosis pharmacologic treatment is segmented into anti-resorptive agents that suppress osteoclast-mediated bone resorption and anabolic agents that promote new bone formation by activating osteoblasts. There are currently no oral anabolic treatments for osteoporosis.
Osteoporosis is a global public health problem currently affecting more than 200 million people worldwide. Of the estimated 15 million patients diagnosed with osteoporosis in the United States, 13 million are women. According to recent statistics from the International Osteoporosis Foundation, worldwide, 1 in 3 women over the age of 50 years and 1 in 5 men will experience osteoporotic fractures in their lifetime.
Osteoporosis results in a decreased quality of life, increased disability-adjusted life span, and a tremendous financial burden to health insurance system. In the United States, for women aged 55 years and older, the hospitalization burden of osteoporotic fractures and population facility-related hospital cost is greater than that of heart attack, stroke, or breast cancer.
It is estimated that approximately 3.2 million patients are treated with osteoporosis medication in the U.S. alone, however, less than 10% of osteoporosis patients use current anabolic drugs. Despite the validated mechanism of action of these treatments, patients are deterred by their high cost and
injectable mode of administration. Furthermore, healthcare providers indicated that they would support the use of an oral PTH anabolic therapy earlier in the treatment paradigm due to its efficacy and patients’ preference for an oral route of administration.