From the Guidelines
Yes, a male patient with osteoporosis secondary to hyperparathyroidism can continue taking Prolia (denosumab) beyond 2 years.
Rationale
- The evidence-based guidelines for the management of osteoporosis in men recommend denosumab as a second-line treatment for men at a high risk of fracture 1.
- Denosumab has been shown to provide benefits in BMD accrual compared with placebo in randomized controlled trials of men with osteoporosis over 2 years of follow-up 2.
- A 2023 meta-analysis demonstrated the benefits of denosumab for BMD at the lumbar spine, femoral neck, and total hip 2.
- While the guidelines do not specifically address the duration of denosumab treatment, they do recommend monitoring adherence to anti-resorptive therapy using biochemical markers of bone turnover 1.
- It is essential to continue treatment with denosumab beyond 2 years if the patient is responding well to the therapy and has a high risk of fracture, as the benefits of treatment outweigh the risks.
Key Considerations
- Ensure the patient's vitamin D and calcium levels are replete, as recommended by the guidelines 1.
- Monitor the patient's bone turnover markers to assess adherence to denosumab therapy 1, 2.
- Consider the patient's overall risk of fracture and adjust the treatment plan accordingly, using tools such as FRAX to adjudicate the type of anti-osteoporosis treatment used 1.
From the Research
Denosumab Treatment for Osteoporosis
- Denosumab is a potent antiresorptive medication used to treat osteoporosis, and its efficacy in reducing fracture risk has been demonstrated in various studies 3.
- However, rebound effects after denosumab cessation, including loss of bone mineral density and increased risk of osteoporotic fractures, have been reported 4, 5.
Rebound Hypercalcemia
- Rebound hypercalcemia is a less frequently reported phenomenon after denosumab discontinuation, which may pose a diagnostic challenge to physicians 5.
- This condition has been observed in patients with parathyroid carcinoma and may be associated with autonomous tertiary hyperparathyroidism 5.
- Treatment approaches for rebound hypercalcemia include bisphosphonates or re-administration of denosumab, while a watch and wait strategy may be sufficient in asymptomatic cases 5.
Denosumab Treatment Beyond 2 Years
- There is limited evidence on the long-term use of denosumab beyond 2 years, but some studies suggest that it may be safe and effective in reducing fracture risk in patients with osteoporosis 3, 6.
- A study on men with osteoporosis found that denosumab reduced the risk of hip fractures by 36% compared to those who stopped treatment after one administration 3.
- Another study on patients with glucocorticoid-induced osteoporosis refractory to previous treatment found that denosumab significantly increased bone mineral density and reduced serum levels of bone turnover markers over a 24-month period 6.
Elevated Parathyroid Hormone Levels
- Elevated parathyroid hormone (PTH) levels have been observed in older women treated with denosumab for osteoporosis, and increasing age is associated with PTH elevations in these patients 7.
- However, in the absence of any pathology, continuation of denosumab may be safe in lowering fracture risk, but a larger study may be required to confirm this 7.