Denosumab is a human monoclonal IgG2 antibody available as two proprietary products, Prolia and Xgeva.

Prolia (60mg/ml pre-filled syringe) is licensed for the treatment of osteoporosis in post-menopausal women, and men at an increased risk of fractures. Prolia is also licensed for the treatment of bone loss as a consequence of hormone ablation in men with prostate cancer at increased risk of fractures.

Xgeva (120mg solution for injection) is indicated for the prevention of skeletal related events (pathological fractures, radiation to bone, spinal cord compression or surgery to bone) in adults with bone metastases from solid tumours, and for treatment of adults and skeletally mature adolescents with giant cell tumour of bone that cannot be surgically removed or where surgical resection is likely to result in severe morbidity.

Osteonecrosis of the jaw is a recognised side effect of denosumab. Cases of osteonecrosis of the external auditory canal have also been reported. Worldwide 5 reports of osteonecrosis of the external auditory canal have been received for patients treated with 60mg Denosumab for osteoporosis¹.

The product information for all Denosumab containing products has now been revised to include a warning on the risk of osteonecrosis of the external auditory canal.

Like bisphosphonates, which are also associated with osteonecrosis of the jaw, osteonecrosis at sites other than the jaw associated with Denosumab are being kept under review.

The June 2017 Drug Safety Update[1] provides the following advice for healthcare professionals:

• The possibility of osteonecrosis of the external auditory canal should be considered in patients receiving Denosumab who present with ear symptoms including chronic ear infections or in those with suspected cholesteatoma (abnormal collection of skin cells in the ear)
• Possible risk factors include steroid use and chemotherapy, with or without local risk factors such as infection or trauma.
• Advise patients to report any ear pain, discharge from the ear, or an ear infection during denosumab treatment
• Report cases of osteonecrosis of any bone suspected to be associated with denosumab or any other medicine on a Yellow  Card. yellowcard.mhra.gov.uk/