Amgen Inc. (AMGN) said its two-year Phase III study showed that twice-yearly injections of its drug denosumab increased bone mineral density.
Denosumab is considered the most promising product in the biotech giant's pipeline.
In January, Amgen reported that a trial pitting Denosumab against Merck & Co.'s (MRK) Fosamax showed that Denosumab improved bone mineral density better than Fosamax.
The latest study involved 332 patients with early- and late-stage postmenopausal osteoporosis. Its results were published in the Journal of Clinical Endocrinology and Metabolism.
Amgen said the study showed significant increases in bone mineral density in the lumbar spine as well as in the hip, wrist and total body.
"The effect of denosumab on wrist BMD (bone mineral density), reinforced by the BMD increases at the total body and hip regions, suggests denosumab has a positive effect on highly cortical sites," said Javier San Martin, global development lead for the denosumab osteoporosis program.
The number of adverse effects was similar in patients taking the drug and those taking a placebo. The most common adverse events were joint pain, inflammation of the nose and pharynx, and back pain.
The drug maker expects the results of its large Phase III study, evaluating denosumab's impact on fracture risk reduction in women with postmenopausal osteoporosis, in the second half of this year.
Amgen's shares were at $41.95, down 50 cents, or 1.2%, in after-hours trading.