Amgen's much-anticipated osteoporosis drug Prolia has been given the green light in Europe, the first approval of the product worldwide.

The European Commission has granted marketing authorisation for Prolia (denosumab) for the treatment of osteoporosis in postmenopausal women at increased risk of fractures, and for bone loss associated with hormone ablation in men with prostate cancer at increased risk of fractures. The treatment has been approved in all 27 European Union member states plus Norway, Iceland and Liechtenstein and it will be co-marketed by GlaxoSmithKline.

The approval is based on data from six Phase III trials, including two studies with fracture endpoints in the osteoporosis and prostate cancer settings. These demonstrated that Prolia administered as a 60mg subcutaneous injection every six months reduces the incidence of fractures and Amgen notes that all six studies showed denosumab’s ability to increase bone mineral density at all skeletal sites measured. In one Phase IIII involving 7,800 patients, denosumab reduced the relative risk of new vertebral (spine) fractures by 68%, non-vertebral fractures by 20% and hip fractures by 40%.

"The European approval “is a significant medical advance for patients with bone loss conditions,” said Will Dere, international chief medical officer at Amgen. He claimed that Prolia will offer “an important alternative to current treatments” as it reduces the risk of fracture through a convenient injection given every six months.

Prolia is a first-in-class, fully human monoclonal antibody designed to target RANK ligand, which regulates osteoclast formation, function and survival. It will compete against bisphosphonates such as Novartis’ Reclast/Zometa (zoledronic acid) and Merck & Co’s Fosamax (alendronate), which is now available generically. It will also up against Warner Chilcott's Actonel (risedronate) and GSK’s own Boniva/Bonviva (ibandronic acid), which is marketed with with Roche.

The US Food and Drug Administration is scheduled to decide by the end of July whether to approve Prolia in osteoporosis and Amgen recently made a second submission to the agency for denosumab, this time for bone loss in cancer patients.