Amgen's Osteoporosis Drug Aims at Merck

According to 12-month data included in a research abstract for the American College of Rheumatology meeting (and posted on the group's Web site), post-menopausal women taking escalating doses of AMG 162 exhibited increases in bone mineral density in the range of 4% to 7% (measured in the lumbar spine), compared with a 5% increase in bone mineral density for women taking Merck's Fosamax. When similar bone mineral density measurements were taken from patients' hips, AMG 162 caused a 2% to 4% increase compared with 2% for Fosamax. AMG 162 was able to affect bone mineral density one month after dosing.

Increased bone mineral density is generally believed reduce the risk of bone fracture, one of the common and potentially serious ailments that affect women with osteoporosis.

"The prospects for AMG 162, which has the potential to generate sales exceeding $1 billion, is paramount for [Amgen's] pipeline to progress," writes Susquehanna Financial Group biotech analyst Soham Pandya, adding that "AMG 162 could represent the first novel anti-resorptive agent for osteoporosis in a long time period." Pandya initiated coverage of Amgen Tuesday with a net positive rating; Pandya's firm doesn't have a banking relationship with Amgen.

The one knock on AMG 162 to date has been that the clinical road for osteoporosis drugs is a long one, generally encompassing studies that require three years of patient data in order to seek regulatory approval. In August, Amgen announced that patient enrollment had begun for two pivotal phase III studies of AMG-162 in osteoporosis and treatment-induced bone loss, which is bone loss that results when patients are treated with certain immune- or hormone-suppressing drugs. This could push completion of these studies out to 2008 and beyond.

But Amgen may be able to accelerate AMG 162's timeline, perhaps seeking approval based on two-year data, if those data are especially strong and convincing, said Sanford Bernstein analyst Geoffrey Porges in a recent research note, which he wrote after spending the day with Amgen executives.

"Two-year data could be available as early as 2007, potentially permitting a filing that year," writes Porges, adding that Amgen executives told him that patient enrollment in the phase III AMG 162 studies was moving along at a "stupendous rate." Porges has a market perform rating on Amgen; his firm doesn't do banking.

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