Amgen and UCB have announced results from the fourth year of a phase 2 study showing the efficacy and safety of a second course of treatment with Evenity (romosozumab), an investigational agent for postmenopausal women with osteoporosis. The results were presented in an oral session (OR08-1) at ENDO 2017, the Endocrine Society's Annual Meeting in Orlando.
In the study, postmenopausal women with low bone mass (lumbar spine, total hip or femoral neck T score between -2.0 and -3.5) were initially randomized to various doses of Evenity or placebo for 24 months and then re-randomized to receive denosumab (Prolia) or placebo for the next 12 months (24 to 36 months), as previously reported. For months 36 to 48, all of these patients were then treated with Evenity (210 mg) for 12 months.
In patients who initially received 210 mg of Evenity followed by placebo and then a second course of Evenity (n=19), the second course led to significant increases in bone mineral density (BMD) to an extent similar to the initial Evenity treatment: lumbar spine (12.7 percent), total hip (5.8 percent) and femoral neck (6.3 percent) during months 36 to 48. In those patients who received a second course of Evenity after denosumab, Evenity further increased BMD by 2.8 percent at the lumbar spine, while maintaining BMD at the total hip and femoral neck.
"Since osteoporosis is a chronic condition, which may lead to debilitating fractures, the option of providing a second course of bone-building therapy may benefit some patients with severe osteoporosis," said David L. Kendler, M.D., University of British Columbia, Vancouver, Canada and lead study investigator. "This latest study is important as it shows that the safety and efficacy of romosozumab extends from initial use to a second course of treatment."
A similar adverse event (AE) profile was observed in the Evenity groups, regardless of prior treatment group (placebo or denosumab). In patients treated with Evenity for months 36 to 48, serious AEs were reported for five percent of patients who initially received Evenity (n=7/140) and four percent who initially received placebo (n=1/27). The AEs reported by these patients for months 36 to 48 include hypersensitivity (7.4 percent, initial placebo; 7.9 percent, initial Evenity), injection-site reactions (7.4 percent, initial placebo; 7.1 percent, initial Evenity), malignancies (3.7 percent, initial placebo; 3.6 percent, initial Evenity) and osteoarthritis (11.1 percent, initial placebo; 2.1 percent, initial Evenity). There were no reports of osteonecrosis of the jaw or atypical femoral fracture.
In the same oral session, Amgen and UCB presented results from a separate analysis of the phase 2 study (OR08-2) showing BMD gains from prior Evenity treatment were generally maintained for two years (months 48 to 72) when followed by a single dose of zoledronic acid.
The pivotal romosozumab phase 3 studies have all been designed with patients receiving 12 months (single course) of romosozumab followed by treatment with an anti-resorptive therapy such as denosumab.