ATYPICAL FRACTURES WITH AN OSTEOPOROSIS DRUG

December 21, 2012

If you are taking the drug denosumab [PROLIA] for osteoporosis and you experience any new “dull, unusual aching pain in the thigh, hip, or groin area,” you should contact your health care provider immediately. These may be symptoms of an atypical fracture of the thigh bone.

Amgen, the maker of PROLIA, issued a November 16, 2012, letter to health care professionals and the public in Canada concerning post-marketing cases of atypical thigh bone fractures. PROLIA is a drug administered by injection every six months to postmenopausal women and men who have either low bone mass or osteoporosis and are at high risk of fracture.

(XGEVA is a higher-dosage form of denosumab that is given for prevention of skeletal-related events in patients with bone metastases from solid tumors; no warning has yet been issued for XGEVA.)

Although these fractures are rare, they may occur at any time, with little or no trauma in the thigh bones of one or both legs. Amgen emphasizes the importance of examining both legs, even if the pain appears confined to only one.

The latest version of the PROLIA drug label (September 20, 2012) does list atypical fractures in the Warnings and Precautions section, but it does not appear that health care professionals were alerted to the addition of this information.

Other drugs for osteoporosis, such as the bisphosphonates, can also cause atypical fractures.

Neither the Food and Drug Administration (FDA) nor the European Union has as yet provided similar warnings to health care providers and patients relating to PROLIA.

Be sure to report serious adverse events while taking drugs to the FDA’s MedWatch Adverse Event reporting program at https://www.accessdata.fda.gov/scripts/medwatch/medwatch-online.htm or by calling (800) FDA-1088.

To read the full reports from Health Canada, go to:
Association of Prolia (denosumab) with Risk of Atypical Femoral Fracture
Prolia (denosumab) - Risk of Unusual Thigh Bone Fractures