US FDA approves expanded use of Amgen's bone drug denosumab, which could boost potential sales to $2.4 billion

The US Food and Drug Administration yesterday approved global biotech leader Amgen’s (Nasdaq: AMGN) Xgeva (denosumab), the first and only RANK Ligand inhibitor for the prevention of skeletal-related events (SREs) in patients with bone metastases from solid tumors, an indication that could increase the drug’s sales potential to as much as $2.4 billion. Amgen’s shares rose 2.4% to $55.14 on the news.

Xgeva was approved following a six-month priority review by the FDA, a designation reserved for drugs that offer major advances in treatment or provide a treatment where no adequate therapy exists. The drug is not indicated for the prevention of SREs in patients with multiple myeloma.

So far denosumab, which is already cleared for the treatment of osteoporosis and sold under the trade name Prolia, has generated disappointing sales in the first reporting period since its launch. Third-quarter 2010 revenues from the drug came in at just $10 million, well down on analysts’ forecasts of $31 million (The Pharma Letter October 26).