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What is the new drug for bone loss? An update on Romosozumab, biosimilars, and other treatments

4 min read

Affecting over 10 million Americans, osteoporosis and subsequent bone loss is a serious health concern that can lead to debilitating fractures. While numerous treatments exist, the question, "What is the new drug for bone loss?" points to recent advancements like Romosozumab (Evenity) and the 2025 introduction of biosimilars for Prolia.

Quick Summary

The newest available drug with a novel mechanism for bone loss is Romosozumab (Evenity), approved in 2019 for postmenopausal women at high fracture risk. In 2025, interchangeable biosimilars for denosumab (Prolia), such as Jubbonti and Stoboclo, also became available.

Key Points

  • Romosozumab (Evenity) is a relatively new drug: Approved by the FDA in 2019, it works differently from most osteoporosis medications by both building bone and slowing bone breakdown.

  • Romosozumab requires a follow-up drug: The 12-month course of monthly injections must be followed by an antiresorptive therapy (like a bisphosphonate or denosumab) to maintain bone density gains.

  • New denosumab biosimilars are now available: As of 2025, interchangeable biosimilars like Jubbonti and Stoboclo reference the brand-name drug Prolia, offering more affordable and accessible options.

  • The Osteoboost wearable is a non-drug option: FDA-approved in 2025 for osteopenia, this device uses targeted vibrations to slow bone loss in postmenopausal women.

  • Cardiovascular risks are associated with Romosozumab: The drug carries a boxed warning and is not recommended for patients with a recent history of heart attack or stroke.

  • Emerging research on CCN3 shows promise: Scientists have identified a molecule that stimulates new bone growth, suggesting future therapies for bone regeneration.

In This Article

Romosozumab (Evenity): The Newest Dual-Action Drug for Bone Formation

Romosozumab (brand name Evenity) was approved by the U.S. Food and Drug Administration (FDA) in April 2019 for the treatment of osteoporosis in postmenopausal women who are at a very high risk of fracture. Its mechanism of action is unique because it works in two ways: it increases new bone formation while simultaneously decreasing bone resorption. This dual effect is achieved by targeting and blocking a protein called sclerostin, which naturally inhibits bone creation.

How Romosozumab is Administered

  • Treatment course: The medication is given as two separate subcutaneous (under the skin) injections once a month for a limited duration of 12 months.
  • Combination therapy: The bone-building effects of Romosozumab wane after 12 months. To maintain the gains in bone mineral density and reduce fracture risk, patients must transition to a different class of osteoporosis medication, such as an antiresorptive agent like a bisphosphonate or denosumab.
  • Supervised injection: The two monthly injections are typically administered by a healthcare professional at a clinic visit.

Important Safety Considerations

Romosozumab has a boxed warning due to an increased risk of serious cardiovascular events, including heart attack and stroke. Therefore, it is generally not recommended for women who have had a heart attack or stroke within the previous year. Other, rare but serious side effects include osteonecrosis of the jaw and atypical femur fractures.

Recent Developments: Interchangeable Denosumab Biosimilars in 2025

While not a new class of drug, the introduction of biosimilars is a major recent development in the treatment of bone loss. In 2025, several biosimilars for denosumab (the active ingredient in the brand-name drugs Prolia and Xgeva) received FDA approval. These interchangeable biosimilars are designed to have the same safety and effectiveness as the original reference product, offering potentially more affordable treatment options.

Examples of New Biosimilars

  • Jubbonti (denosumab-bbdz): An interchangeable biosimilar for Prolia, approved in March 2024, with major insurers recognizing its interchangeability starting in September 2025.
  • Stoboclo (denosumab-bmwo): Approved in early 2025, this biosimilar also references Prolia and is commercially available in the U.S..
  • Bildyos (denosumab-nxxp): Another biosimilar for denosumab that was approved by the FDA in September 2025.

Comparison of Osteoporosis Medications

Feature Romosozumab (Evenity) Denosumab (Prolia/Biosimilars) Alendronate (Fosamax)
Drug Class Anabolic (sclerostin inhibitor) Antiresorptive (monoclonal antibody) Antiresorptive (bisphosphonate)
Mechanism Increases bone formation & decreases resorption Decreases bone resorption Decreases bone resorption
Administration Subcutaneous injection Subcutaneous injection Oral tablet
Frequency Monthly for 12 months Every 6 months Weekly or daily
Follow-up Therapy Required (antiresorptive) Often indefinite or requires transition May have 'drug holiday' period
Dual-Action Yes No No
Cost High (initial list price), manufacturer programs available Moderate to High (biosimilars reduce cost) Low (generic available)
Cardiovascular Risk Boxed warning for increased risk No boxed warning Low risk

Experimental and Non-Drug Treatments

Beyond new drug approvals, the field of bone health is seeing other innovations:

  • Osteoboost Wearable Device: Approved by the FDA in May 2025, Osteoboost is a non-drug, prescription wearable device for postmenopausal women with osteopenia. It delivers calibrated vibrations to the hips and spine, helping to slow bone density loss through mechanical stimulation. This creates a new, non-pharmacological treatment category.
  • Maternal Brain Hormone (CCN3): In November 2024, researchers identified a molecule called CCN3 that increases bone density. This discovery, stemming from studies in mice, has the potential for future therapies that actively regenerate bone, offering a promising new research path for osteoporosis and other bone conditions.
  • Eladynos: An experimental oral medication that is still in clinical trial stages, aiming to offer another alternative therapy for osteoporosis.

Weighing Your Options

With the expansion of treatment options for bone loss, patients have more choices than ever before. Romosozumab provides a powerful, initial anabolic therapy for those at highest risk, particularly with recent fractures. The arrival of biosimilars for denosumab makes another effective option more accessible and potentially more affordable. For patients seeking non-drug alternatives, the Osteoboost device offers a novel approach, while ongoing research hints at future breakthroughs. Selecting the most suitable treatment depends on an individual's specific fracture risk, medical history, lifestyle factors, and budget.

Conclusion

For those asking "What is the new drug for bone loss?", the answer includes Romosozumab (Evenity), an innovative monthly injectable approved in 2019 that builds new bone and reduces resorption. Additionally, several interchangeable biosimilars for Prolia (denosumab) were approved and launched in 2025, offering more accessible options. Other novel therapies like the Osteoboost wearable and research into molecules such as CCN3 further diversify the treatment landscape. Given the complexities and potential side effects associated with different therapies, a thorough discussion with a healthcare provider is essential to create a personalized treatment plan for managing bone loss effectively.

Frequently Asked Questions

The newest injectable drug for bone loss with a dual mechanism is Romosozumab, sold under the brand name Evenity. It was approved in 2019 and works by blocking sclerostin to both build new bone and prevent bone resorption.

Yes, in 2025, several interchangeable biosimilars for denosumab (Prolia) were launched in the US, including Jubbonti and Stoboclo. Biosimilars are highly similar and equally effective versions of a reference product, typically at a lower cost.

Romosozumab treatment is limited to a 12-month course of monthly injections. After this period, patients must transition to an antiresorptive medication, such as a bisphosphonate or denosumab, to sustain the bone density improvements.

Romosozumab is approved for postmenopausal women who are at a very high risk of fracture. This includes those who have a history of fracture, multiple risk factors, or have not responded well to other therapies.

The Osteoboost device is an FDA-approved wearable belt that delivers targeted, low-level vibrations to the hips and spine. It is a non-drug prescription treatment for postmenopausal women with osteopenia, a condition of low bone density.

Romosozumab carries a boxed warning for an increased risk of heart attack, stroke, and cardiovascular death. Other potential side effects include headache, joint pain, and, rarely, osteonecrosis of the jaw or atypical thigh bone fractures.

Due to the potential increased risk of cardiovascular events, Romosozumab is not recommended for people who have had a heart attack or stroke within the previous year. Individuals with other cardiovascular risk factors should discuss the risks and benefits with their doctor before starting treatment.

Similar to the reference drug Prolia, stopping denosumab biosimilars can lead to a rapid loss of the bone density gains. It is important to discuss a follow-up treatment plan with your doctor before discontinuation to prevent a high risk of fractures, especially in the spine.

References

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Medical Disclaimer

This content is for informational purposes only and should not replace professional medical advice. Always consult a qualified healthcare provider regarding personal health decisions.