Amgen Rises on Bone-Drug Data (Update)

In prior studies, Fosamax reduced the relative risk of vertebral and hip fractures by 47% and 51%, respectively. For Reclast, the vertebral and hip fracture reduction rates from previous studies were 70% and 41%, respectively.

None of these bone-fracture studies tested denosumab against Fosamax or Reclast directly, but that doesn't stop doctors and investors from comparing results.

On these efficacy measures, denosumab appears to be comparable to Reclast, although the denosumab patients entering the FREEDOM study had fewer previous fractures, which makes it more difficult for denosumab to lower the risk of fracture rates.

Generally speaking, most analysts and investors were expecting denosumab to reduce hip fractures in the range of 40% to 50% -- in line with its competitors.

On the safety side of FREEDOM's ledger, the rate of serious infections was comparable between denosumab and placebo at 53% vs. 54%.

Denosumab is a monoclonal antibody discovered by Amgen scientists that works against osteoporosis in an entirely new way by blocking a protein called RANK Ligand involved with the breakdown of bone.

In recent trading, Amgen was up $2.49, or 4%, at $64.68.