Amgen and UCB announced positive top-line results for romosozumab from the pivotal phase 3 placeBo-contRolled study evaluatIng the efficacy anD safety of romosozumab in treatinG mEn with osteoporosis (BRIDGE). These data showed the BRIDGE study met the primary endpoint, demonstrating a statistically significant increase in bone mineral density (BMD) at the lumbar spine (as assessed by dual energy x-ray absorptiometry) in men with osteoporosis treated with romosozumab compared with placebo at 12 months.

"While the focus of managing osteoporosis is often on women, osteoporosis in men is also a serious health issue that poses a significant health risk to millions of men worldwide,"1 said Sean E. Harper, M.D., executive vice president of research and development at Amgen. "We are excited that these data showed romosozumab stimulates bone formation, leading to increases in bone mass, in this often overlooked and undertreated patient population."

All secondary endpoints comparing romosozumab with placebo were also met. Patients receiving romosozumab experienced a statistically significant increase in BMD at the femoral neck and total hip at 12 months and a statistically significant increase in BMD at the lumbar spine, femoral neck, and total hip at six months, compared with those receiving placebo.

"Although there has been considerable progress in the treatment and management of osteoporosis, a large unmet medical need remains. One in three women and one in five men over the age of 50 will experience an osteoporosis-related fracture in their lives,"3,4 said Professor Dr. Iris Loew-Friedrich, chief medical officer and executive vice president, UCB. "These positive results from BRIDGE add to our growing body of phase 3 data demonstrating romosozumab's potential to build bone strength and to decrease fracture risk and thus help fill an unmet need for patients with osteoporosis."

In the BRIDGE study, a total of 245 men were randomized 2:1 to receive either 210 mg romosozumab subcutaneous (SC) every month (QM) or matched placebo SC QM for the duration of the 12-month treatment period.

The overall patient incidence of adverse events and serious adverse events (SAEs) was generally balanced between arms. The most frequently reported adverse events (greater than five percent in the romosozumab arm) were nasopharyngitis, back pain, hypertension, headache and constipation. Injection site reactions were reported in 5.5 per cent of patients in the romosozumab treatment group and 3.7 percent in the placebo group during the 12-month period. Most injection site reactions were reported as mild in severity. The patient incidence of positively adjudicated cardiovascular (CV) SAEs was 4.9 percent (8/163) in the romosozumab group and 2.5 percent (2/81) in the placebo group. The patient incidence of positively adjudicated cardiovascular death was 0.6 percent (1/163) in the romosozumab group and 1.2 percent (1/81) in the placebo group. Amgen and UCB recently reported the results of the FRAME study in 7,180 postmenopausal women with osteoporosis in which the overall patient incidences of adjudicated CV SAEs were balanced.

Further analysis of the phase 3 BRIDGE study data is ongoing and will be submitted to a future medical conference and for publication. UCB and Amgen plan to discuss these results with global regulators.

Romosozumab is an investigational bone-forming monoclonal antibody and is not approved by any regulatory authority for the treatment of osteoporosis. It is designed to work by inhibiting the protein sclerostin, and has a dual effect on bone, both increasing bone formation and decreasing bone breakdown. Romosozumab is being studied for its potential to reduce the risk of fractures in an extensive global phase 3 programme. This programme includes two large fracture trials comparing romosozumab to either placebo or active comparator in more than 10,000 postmenopausal women with osteoporosis. Amgen and UCB are co-developing romosozumab.

BRIDGE is a multi-center, international, randomized, double-blind, placebo-controlled study in men with osteoporosis, defined as low bone mineral density (BMD) at the spine, total hip or femoral neck. The study evaluated the effectiveness of romosozumab treatment for 12 months, compared with placebo, in increasing BMD at the lumbar spine, as well as the effect on BMD at the femoral neck and total hip at 12 months and on BMD at the lumbar spine, femoral neck, and total hip at six months.