Osteoporosis is a disease characterized by low bone mass and structural deterioration of bone tissue, which leads to greater fragility and an increase in fracture risk. Osteoporosis is also a silent disease, often displaying no signs or symptoms until a fracture occurs, leaving the majority of patients undiagnosed and untreated, representing a high unmet medical need. Osteoporosis is a progressive bone disease that is characterized by a decrease in bone mass and density. It occurs when the total bone lose exceeds the total bone formation. As a result, the bones become weak and have an increased chance of breaking or fracturing. The debilitating effects of osteoporosis have substantial costs and osteoporotic fractures create a significant healthcare burden.

There are two categories of osteoporosis medications: antiresorptive medications that slow bone loss and anabolic drugs that increase the rate of bone formation.
Antiresorptive medications include bisphosphonates which interfere with bone resorption while PTH is an anabolic (bone forming) drug.

Although PTH (teriparatide) would be the drug of choice for this disease, the high cost, low dosing flexibility and inconvenience of a daily injection, make it less desirable for patients. Entera’s platform technology has taken PTH and enabled it to be delivered orally which should lead to higher compliance rates. Additionally, physicians would potentially prescribe the oral PTH 1-34 to a wider population of osteoporosis patients and at an earlier stage of the disease.


Osteoporosis is a global public health problem currently affecting more than 200 million people worldwide. The National Osteoporosis Foundation, or NOF, has estimated that eight million women in the United States already have osteoporosis, and another approximately 44 million may have low bone mass placing them at increased risk for osteoporosis. In US women 55 years of age and older, the hospitalization burden of osteoporotic fractures and population facility-related hospital cost is greater than that of myocardial infarction, stroke, or breast cancer. Furthermore, the NOF expects that the number of fractures in the U.S. due to osteoporosis will rise to three million by 2025, resulting in an estimated $25.3 billion in costs each year. Worldwide, osteoporosis affects an estimated 200 million women according to the International Osteoporosis Foundation, or IOF, and causes more than 8.9 million fractures annually, which is equivalent to an osteoporotic fracture occurring approximately every three seconds. The IOF has estimated that 1.6 million hip fractures occur worldwide each year, and by 2050 this number could reach between 4.5 million and 6.3 million. The IOF estimates that in Europe alone, the annual cost of osteoporotic fractures could surpass €76 billion by 2050.

Current Status

We have successfully completed a dose ranging Phase 2 study in postmenopausal women with low bone mass. This study met primary and key secondary endpoints and was presented in a late-breaker oral presentation at the ASBMR 2021 conference (See presentation slides here). We have subsequently held an End of Phase 2 meeting with the FDA at which guidance was provided and implemented in a Phase 3 study design. The registrational Phase 3 is designed as an 18-month randomized, double-blind, multicenter study comparing the effects of oral PTH (1-34, teriparatide) EB613 vs. placebo on BMD in post-menopausal women with osteoporosis at high risk of fracture, followed by a 6-month open-label extension where all patients will be transitioned to alendronate, a standard of care anti-resorptive therapy.