Article date: February 2013
Denosumab is a human monoclonal IgG2 antibody. Denosumab 60 mg solution for injection (Prolia▼) is given once every 6 months for the treatment of osteoporosis in postmenopausal women at increased risk of fractures, and for the treatment of bone loss associated with hormone ablation in men with prostate cancer at increased risk of fractures.
Denosumab 120 mg solution for injection (Xgeva▼) is given once every 4 weeks for the prevention of skeletal-related events (pathological fracture, radiation to bone, spinal cord compression or surgery to bone) in adults with bone metastases from solid tumours.
Possible risk of atypical femoral fracture
Two cases of atypical femoral fracture have been confirmed in patients receiving denosumab 60 mg for 2.5 or more years participating in the ongoing open-label extension study of the pivotal phase 3 fracture trial in postmenopausal osteoporosis (FREEDOM). These events occurred rarely (in ≥ 1/10 000 to < 10/10 000 patients), based on 8 928 subjects being exposed to denosumab 60 mg in bone loss studies.
The risk of atypical femoral fractures also exists for denosumab 120 mg (Xgeva▼).
The nature of the fractures seen with denosumab 60 mg is similar to the atypical femoral fractures seen with long-term bisphosphonate therapy. For further information on this, and a list of clinical and radiographic features of atypical femoral fractures, seeDrug Safety Update June 2011 .
A letter was sent to healthcare professionals in February 2013, regarding the updated product information for denosumab 60 mg (Prolia▼).
Advice for healthcare professionals:
- during denosumab treatment, patients should be advised to report new or unusual thigh, hip, or groin pain; patients presenting with such symptoms should be evaluated for an incomplete femoral fracture
- atypical femoral fractures may occur with little or no trauma in the subtrochanteric and diaphyseal regions of the femur
- the contralateral femur should be examined in denosumab-treated patients who have sustained a femoral shaft fracture, as atypical femoral fractures are often bilateral (as noted from the bisphosphonates assessment)
- discontinuation of denosumab treatment should be considered if an atypical femur fracture is suspected, while the patient is evaluated; an individual assessment of the benefits and risks should be performed
BNF section 6.6: Drugs affecting bone metabolism
Article citation: Drug Safety Update February 2013, vol 6, issue 7: A1