Denosumab's BMD gain greater than Fosamax

US biotechnology major Amgen's denosumab provided superior gain in bone mineral density than Merck & Co's blockbuster Fosamax (alendronate), according to results presented at the annual European Symposium on Calcified Tissues meeting, held in Barcelona, Spain. In the non-pivotal Phase III study, administration of denosumab resulted in significantly greater BMD gains at all sites measured in postmenopausal women with low BMD.

"This study is the first of any investigational or approved therapy to show greater BMD gains compared with alendronate at all skeletal sites measured," said Jacques Brown, lead study investigator. "We may be seeing a greater effect with denosumab at all sites measured because, as a RANK Ligand inhibitor, denosumab may be able to target all osteoclasts - wherever they are found in bone tissue throughout the skeleton - and at all stages of their formation and function," he added.

For the primary endpoint, denosumab resulted in significant increases in BMD at the total hip compared with alendronate (3.5% vs 2.5%, p<0.0001), as well as significant increases in BMD compared with alendronate at the trochanter (4.5% vs 3.5%), 1/3 radius (1.1% vs 0.6%), lumbar spine (5.3% vs 4.2%) and femoral neck (2.2% vs 1.6%) (p less than or equal 0.0003 at all sites). The incidence and types of adverse events and serious AEs observed in this study were similar between the two treatment groups, Amgen noted.