Pharmacists aim to close denosumab dosing gaps

Researchers at the University of Toronto are working with three community pharmacies on a quality improvement project to help patients with osteoporosis stay on schedule with their denosumab injections. As well, the Canadian Foundation for Pharmacy-funded initiative is testing the waters for pharmacists to inject the medication.

Osteoporosis affects more than 2.3 million Canadians and osteoporotic fractures cost the Canadian healthcare system $4.6 billion annually, according to Osteoporosis Canada. Denosumab, injected every six months, is widely used as a second-line therapy. However, 22% to 35% of older community-dwelling adults in Ontario miss their dose by more than a month, according to recent research¹—and the risk of fracture increases as early as two months after a missed dose.

This work was replicated in the U.S. Medicare data and updated in Ontario,² demonstrating that a significant proportion of community-dwelling adults are not receiving their denosumab on time, putting them at risk for rebound fracture.

The three pharmacies in Ontario, part of the Wholehealth Pharmacy Partners banner, began working with the research team in June 2025 to identify and follow up with patients who have missed their dose by more than a month in the past year, and to create automated alerts for all patients to refill their denosumab prescription by the six-month due date. The project is targeting patients receiving coverage from the Ontario Drug Benefit (ODB) plan to enable comparison to provincial data from Ontario’s ICES (healthcare administrative) databases.

As well, participating pharmacists are documenting their interventions to support patients transitioning from the originator biologic, Prolia, to a biosimilar. As of August 2025, Prolia is no longer covered under ODB and thus patients need to transition to the biosimilar at their next refill. The government’s fee to pharmacies to support the patient’s transition to a biosimilar ends in August 2026.

Pharmacists will also advise patients of their ability to administer drugs by injection, including denosumab.

Suzanne Cadarette

“This is a quality improvement project to create a workflow for pharmacists to help transition patients to a biosimilar and remove gaps in dosing. The dispensing of the medication also becomes an opportunity to broach the conversation that pharmacists can administer this injection in the pharmacy,” says principal investigator Suzanne Cadarette, Associate Professor of Pharmacy and Epidemiology, University of Toronto.

Funding from the Nashat Family Community Pharmacy Fund, part of CFP’s Innovation Fund, is enabling the three pharmacies to participate and add an alert to follow up for a refill 170 days after the dispensing of denosumab. Automated alerts typically do not occur beyond 100 days, since they are based on the days-supply value, which is capped at 100 under ODB. Manually creating scheduled reminders is not top of mind and likely contributes to the gaps in denosumab dosing. The grant will also be used for educational material and to remunerate pharmacies $15 for each administered injection.

“The grant takes away the financial barrier for administration in the pharmacy,” says Cadarette.

Participating pharmacies are using two pseudo-DINs to track whether patients receive their injection in the pharmacy. If not, the pharmacist documents the reasons why.

“Anecdotally in the past, patients have told us about the challenges of remembering about denosumab every six months. Many patients are receptive to the option of being trained on self-injection or having denosumab administered in the pharmacy. Others mention that they want to talk to their doctor first, or they may already be going to see their physician for a booked appointment. We anticipate that there will be a bit of resistance, yet if we don’t start somewhere, we will never know,” says Cadarette.

She adds that conversations so far with specialists have been positive. “They love the idea because they know it can be hard to book visits with short notice. And if a patient needs to rebook, they may not be able to get back in for several months.”

Data collection will continue until the end of November 2026 with results analysed and knowledge translation beginning in 2027.

References

1. Rzepka AM, Cheung AM, Kim S, Gomes T, Cadarette SM. On-time denosumab dosing recovered rapidly during the COVID-19 pandemic, yet remains suboptimal. J Bone Min Res Plus 2024; 8:ziae027.
2. Hayes KH, Sendhil SR, Aggarwal S, Zullo AR Berry SD, Oganisian A, Abedboye M, Cadarette SM. Real-world differences in denosumab persistence, reinitiation and switching among older adults in Canada and the United States. J Bone Min Res Plus 2025; 9:ziaf061.