An experimental drug being developed by Amgen (NASDAQ:AMGN) to treat osteoporosis significantly increased bone mineral density (BMD) in postmenopausal women, according to research published in the New England Journal of Medicine.
In a Phase II clinical study of over 400 women, aged 55 to 85, romosozumab was found to be up to three times more effective than current osteoporosis drugs in rebuilding bone density in the lumbar spine and hip. The drug uses an antibody to block the chemical signals of sclerostin, a protein the body naturally produces to inhibit bone growth.
Osteoporosis is caused by a decline in mineral bone density, which makes bones weaker and more likely to fracture. Postmenopausal women are especially vulnerable to osteoporosis because they are more likely to experience rapid bone loss.
“The results of the study demonstrate significantly increased BMD and stimulation of bone formation with romosozumab treatment in women with postmenopausal osteoporosis,” said Michael McClung, MD, director of the Oregon Osteoporosis Center and lead study investigator.
“Additionally, romosozumab treatment resulted in greater increases in bone mineral density than those seen with both placebo and the active comparators. These data provide important insight into this medicine being developed for women with postmenopausal osteoporosis at high risk for fractures.”
About 200 million women worldwide suffer from osteoporosis and about one in three over age 50 will suffer a fracture due to it. In the U.S. alone, the disease is responsible for 1.5 million fractures annually at a cost of $14 billion.
Romosozumab is now in a Phase III clinical study for the treatment of osteoporosis in postmenopausal women. It is not currently approved by any regulatory authority. Researchers must still prove that romosozumab helps reduce fractures.
In the Phase II study, BMD gains were 11.3% higher in the lumbar spine after 12 months of romosozumab treatment, compared to BMD increases of 7.1% with Forteo and 4.1% with Fosamax, two osteoporosis drugs already on the market.
“There remains a significant need for additional treatment options that form new bone. Romosozumab is designed to stimulate bone formation, which makes it different from most available treatments that reduce bone resorption,” said Dr. Iris Loew-Friedrich, chief medical officer of UCB, a Belgium based biopharmaceutical company that is developing romosozumab with Amgen.
“Broken bones due to osteoporosis are common and can have a significant impact on the patient, her family and the healthcare system, yet the seriousness of this health event remains underappreciated, with only two-in-10 women receiving follow-up testing or treatment after they have broken a bone,” said Sean Harper, MD, executive vice president of Research and Development at Amgen. “With its bone-forming ability, romosozumab may result in new treatment strategies to help manage this disease.”