Osteoporosis Trials Just Got Faster, but Most Fracture Patients Still Go Untreated

For three decades, anyone trying to bring a new osteoporosis drug to market faced the same brutal arithmetic: prove that the drug prevents fractures, which meant enrolling thousands of women and following them for years until enough bones broke to show a difference. That math is now changing. Regulators have accepted a faster yardstick, and the first registrational programs built around it are heading into the clinic. But the data that should worry sponsors most is not about trial design at all. It is about what happens to patients after they have already broken a hip, and the answer, across countries and decades, is that most of them never get treated properly.

A Surrogate Endpoint Rewrites the Trial Math

The shift traces to a regulatory milestone that is only now working its way into development plans. According to the University of Sheffield, whose researchers co-led the work, the FDA qualified the treatment-related change in total hip bone mineral density (BMD) as a surrogate endpoint for fractures in trials of drugs for postmenopausal osteoporosis. The evidence behind it came from the SABRE project, which pooled data from 52 randomized clinical trials and more than 160,000 patients, one of the most comprehensive datasets ever assembled in the field.

The practical consequence is that future trials can be "smaller, faster and more affordable," in the university's words, because they no longer need to wait for fractures to accumulate. Professor Richard Eastell called the qualification "a major advance for osteoporosis research." The stakes are large: osteoporosis affects up to 500 million people worldwide, and its fractures bring chronic pain, disability, loss of independence and higher mortality.

The first programs are already being redrawn around the new standard. Entera Bio said in June that the FDA had accepted its plan for a single registrational Phase III of EB613, an oral tablet version of the bone-building peptide PTH(1-34). The randomized, placebo-controlled study will enroll roughly 750 postmenopausal women, use percent change in total hip BMD at 12 months as its primary endpoint, and add a 24-month open-label extension for durability and safety. Initiation is planned for late 2026, with topline results expected in the second half of 2028. Entera says the study is powered to show hip BMD gains comparable to Forteo at 12 months, changes the company associates with a 60% to 80% relative reduction in vertebral fracture risk.

The Burden the Pipeline Is Chasing

The commercial logic is not hard to see. Entera's announcement cites more than 2 million osteoporosis-related fractures a year in the United States, a one-in-three lifetime fracture risk for women over 50, and one-year mortality of up to 20% to 24% after a hip fracture. Total medical costs are projected to climb from $57 billion in 2018 to $95 billion by 2040. "Our goal with EB613 is to democratize anabolic treatment," CEO Miranda Toledano said, a goal that reflects how rarely bone-building agents are used today. In the Italian cohort described below, fewer than 1% of hip fracture patients ever received one.

That last point is where the story turns. A cheaper, faster route to approval matters only if the resulting drugs reach the patients at highest risk. And the real-world evidence on that question is bleak.

The Treatment Gap Nobody Has Closed

A multicenter prospective study published in May in Frontiers in Aging followed 1,012 older adults admitted for hip fracture at Italian orthogeriatric centers. The median patient was 83 and 77.2% were women, precisely the population every osteoporosis drug is designed for. At admission, 85.6% were receiving no osteoporosis treatment at all. Discharge brought the untreated share down to 34.4%, largely because patients were started on vitamin D and calcium, but by one year it had drifted back to about 50%. Antiresorptive drugs never reached more than 5.6% of patients, and anabolic agents stayed below 1% throughout. More than one in five patients, 22%, never received any treatment during follow-up, and men were more than twice as likely to go untreated (odds ratio 2.37).

The U.S. picture is no more reassuring. A study in the Journal of Bone and Mineral Research tracked 96,887 patients hospitalized for hip fracture between 2002 and 2011 and found that the share receiving osteoporosis medication within a year of discharge fell from 40.2% to 20.5%, even as more drug options became available. The strongest predictor of post-fracture treatment was simply having been treated before: prior users were 7.45 times more likely to be treated afterward. The authors concluded that the majority of hip fracture patients do not receive osteoporosis treatment, and that the rates had been declining.

Put those numbers next to the trial reforms and the tension is obvious. The industry has just made it easier to prove a drug works. It has not made it any easier to get a drug to the 83-year-old leaving an orthopedic ward, whose next stop is often a rehabilitation facility, a home health program or a primary care practice with no clear owner of her bone health.

Where the Value Will Actually Be Won

For sponsors, the lesson is that the surrogate endpoint compresses the cost of development but leaves the cost of adoption untouched. The organizations that capture value from the next generation of osteoporosis drugs will be the ones that treat the post-fracture pathway as part of the product, not an afterthought. That means working with the settings where hip fracture patients actually land. Discharge variation shapes outcomes, a point PointClickCare makes in The Same Discharge: Two Very Different Outcomes. Fall prevention protects the high-risk populations that fracture in the first place, the focus of Hinge Health's Fall Prevention: Rising to the Challenge. And pharmacy benefit managers increasingly use outreach and adherence tools to keep members on therapy, as Optum Rx describes in Top 5 Ways Optum Rx Is Putting AI Into Action.

• Design for the 12-month label, plan for the 12-month patient. A shorter trial gets a drug approved sooner, but the GIOG data shows treatment lapses within a year. Build persistence support into launch plans from the start.
• Target the discharge moment. The Italian cohort's untreated share fell by more than half between admission and discharge, then rebounded. The hospital-to-post-acute handoff is where treatment is won or lost.
• Close the gap in men. Male hip fracture patients were more than twice as likely to go untreated. Trial populations built around postmenopausal women will not generate the evidence or awareness that fixes that.
• Use claims data to find the never-treated. Prior treatment was the strongest predictor of post-fracture treatment in the U.S. study, so treatment-naive patients are the ones systems miss. Real-world data can flag them before a second fracture.
• Price for access, not just approval. Oral anabolics promise to widen use beyond injectables, but only if formulary placement and benefit design do not recreate the barriers the new route of administration was meant to remove.

The FDA's decision is a genuine win for osteoporosis research, and programs like EB613 show how quickly development plans can adapt. But a faster trial is only half of the equation. Until the system reliably treats the patients who have already fractured, the most important endpoint in osteoporosis will remain the one no surrogate can measure: whether the drug is actually taken.