Amgen has presented new long-term data showing that women with osteoporosis who have been treated with Prolia for up to five years experienced statistically significant, year-to-year increases in lumbar spine and total hip bone mineral density.

The 4,550-patient follow-up data, presented at the European Congress on Osteoporosis and Osteoarthritis in Valencia, Spain, showed treatment with Prolia (denosumab), a first-in-class, fully human monoclonal antibody designed to target RANK ligand, resulted in "robust BMD gains after five continuous years of treatment," i.e. 13.7% for lumbar spine BMD and 7.0% for total hip BMD.

In years four and five, women taking Prolia experienced further 1.9% and 1.7% increases in lumbar spine BMD and extra 0.7% and 0.6% increases in total hip BMD. Amgen also said the incidences of new osteoporotic fractures remained low for women taking Prolia for five years. Also, the women who transitioned from placebo to Prolia in the extension study showed significant BMD increases during the first two years of treatment: 7.9% in lumbar spine BMD and 4.1% in total hip BMD.