According to a media release issued by Amgen earlier today, the U.S. Food & Drug Administration (FDA) has approved denosumab (marketed as both Prolia® and Xgeva®) as a treatment to increase bone mass in in men with non-metastatic prostate cancer who are already being treated with androgen deprivation therapy (ADT) and who are at high risk for bone fractures.
In November last year, the FDA originally approved denosumab for the “prevention of skeletal-related events (SREs) in patients with bone metastases from solid tumors.” This indication clearly included men with prostate cancer and evident bone metastasis. The new indication significantly expands the potential clinical applications of denosumab, but still does not specifically include the approval of denosumab for use to delay the onset of evident metastases in men being treated with ADT. A separate supplementary new drug application (sNDA) for that indication is pending at the FDA.
As stated in Amgen’s media release, bone mineral density (BMD) was significantly higher at the lumbar spine in prostate cancer patients treated with denosumab for 2 years compared to men who were treated with a placebo. Furthermore, after 3 years of treatment with denosumab, differences in BMD were 7.9 percent at the lumbar spine, 5.7 percent at the (total) hip, and 4.9 percent at the femoral neck. The incidence of new vertebral fractures was 3.9 percent in the men treated with a placebo compared to 1.5 percent for the men treated with denosumab, which equates to an absolute risk reduction of 2.4 percent and a relative risk reduction of 62 percent (P = 0.0125).