On Monday, Amgen released results from its Phase 3 clinical trial that compared denosumab ^[1] with Zometa ^[2] (zoledronic acid) in multiple myeloma patients and advanced cancer patients whose tumors have spread to the bone. The results indicated that denosumab delayed skeletal related events in this group of cancer patients.

Bone tumors often weaken and destroy the bone surrounding the tumor, resulting in serious complications that include bone fractures, spinal cord compression, the need for radiation, and the need for bone surgery. These complications are collectively named “skeletal related events,” or SREs for short. Nearly 100 percent of myeloma patients experience SREs.

Denosumab specifically targets RANK Ligand, which regulates the cells that break down bone. The Phase 3 trial evaluated the efficacy of denosumab in the treatment of bone disease by comparing it to Zometa, a current standard treatment for bone disease in cancer patients. Zometa is a bisphosphonate that is used to prevent skeletal fractures in myeloma patients and to treat pain related to bone tumors.

The trial enrolled 1,776 advanced cancer patients in a randomized, double-blind study. Half of the patients were randomly selected to receive 120 mg of denosumab subcutaneously every four weeks, while the other half received Zometa administered intravenously at a dose of 4 mg delivered as a single, 15-minute infusion every four weeks.

Patients receiving denosumab had a median time of 20.6 months until the occurrence of their first SRE, whereas patients receiving Zometa had a median time of 16.3 months. Despite being numerically greater, the average time until the first SRE was not statistically greater for denosumab compared to Zometa. The rate of adverse events (96 percent denosumab, 96 percent Zometa) and rate of serious adverse events (63 percent denosumab, 66 percent Zometa) were similar for the two treatment groups, which is consistent with previous reports for these two drugs.

"The positive results of this study, combined with the convenience of a monthly subcutaneous injection and without the flu-like symptoms associated with Zometa administration, make this an exciting potential treatment option for advanced cancer patients," said Dr. David Henry of Pennsylvania Hospital in Philadelphia.

For more information, please read the Amgen ^[3] press release.