Denosumab Significantly Reduced Risk Of Developing Multiple Skeletal Related Events By 23 Percent Versus Zometa(R) In Advanced Breast Cancer Patients

SAN ANTONIO, TX, USA | December 10, 2009 | Amgen (Nasdaq: AMGN) today announced further detailed results from a Phase 3, head-to-head trial of denosumab versus Zometa(R) (zoledronic acid) in the treatment of bone metastases in 2,046 patients with advanced breast cancer. In this trial denosumab met both primary and secondary endpoints and demonstrated superiority for both delaying the time to the first on-study skeletal related events (SRE) (fracture, radiation to bone, surgery to bone, or spinal cord compression) (hazard ratio 0.82, 95 percent CI: 0.71, 0.95), and delaying the time to the first-and subsequent SREs (multiple SREs) (hazard ratio 0.77, 95 percent CI: 0.66, 0.89). Both results were statistically significant. These results will be presented today at the 2009 CTRC-AACR San Antonio Breast Cancer Symposium (SABCS) in San Antonio, Texas and highlighted in the congress press conference.

"In clinical trials testing new medications for bone metastases, treatment success is measured by whether the bone complications, or skeletal related events, caused by the tumor are reduced or delayed," said Alison Stopeck, M.D., associate professor of Medicine, Arizona Cancer Center, University of Arizona Health Sciences Center, Tucson, Ariz. "Skeletal complications from bone metastases are a critical and painful health concern for patients with advanced breast cancer, and can increase the risk of mortality. Patients who have a first skeletal related event are twice as likely to experience a subsequent SRE, so it is imperative to treat these advanced breast cancer patients."

Additional data from this study showed that denosumab significantly reduced the mean annual skeletal morbidity rate (SMR) (the ratio of the number of skeletal complications to the time on trial) compared with Zometa (0.45 vs. 0.58, respectively; p=0.004).

Overall, the incidence of adverse events (96 percent denosumab, 97 percent Zometa) and serious adverse events (44 percent denosumab, 46 percent Zometa) was consistent with what has previously been reported for these two agents. Adverse events potentially associated with acute phase reactions during the first three days of the study were reported in 10.4 percent of the denosumab arm and 27.3 percent of the Zometa arm. Adverse events potentially associated with renal toxicity occurred in 4.9 percent of patients treated with denosumab compared to 8.5 percent in patients treated with Zometa. Osteonecrosis of the jaw (ONJ) was seen infrequently in both treatment groups (20 patients receiving denosumab [2.0 percent] as compared with 14 patients [1.4 percent] receiving Zometa). Rates of new primary malignancies were similar between treatment arms (5 patients receiving denosumab [0.5 percent] and 5 receiving Zometa [0.5 percent]). Time to disease progression or overall survival was balanced between the study arms.

SABCS Denosumab 136 Data Presentation

An oral presentation of the denosumab 136 data by Dr. Alison Stopeck will take place at SABCS on Thursday, December 10 at 3:15 PM (CT) in Exhibit Hall D of the Henry B. Gonzalez Convention Center, San Antonio, Texas.

Study Design

This was an international, Phase 3, randomized, double-blind study comparing denosumab with Zometa in the treatment of bone metastases in patients with advanced breast cancer. Patients enrolled in the study were randomized in a one-to-one ratio to receive either 120 mg of denosumab subcutaneously every four weeks (Q4W) or Zometa administered intravenously at a dose of 4 mg in a 15 minute infusion every four weeks as per the label instructions.

The primary endpoint was to evaluate if denosumab is non-inferior to Zometa with respect to the first, on-study SRE in patients with advanced breast cancer and bone metastases. Secondary endpoints were to evaluate if denosumab was superior to Zometa with respect to the first, on-study SRE, as well as the first-and-subsequent on-study SREs, and to assess the safety and tolerability of denosumab compared with Zometa. Other endpoints included time to first radiation of bone; time to first on-study SRE or hypercalcemia of malignancy (HCM); skeletal morbidity rate (SMR; the number of SREs per year); and the proportion of patients with at least 1 on-study SRE.

About Denosumab and Amgen’s Research in Bone Biology

Denosumab is the first fully human monoclonal antibody in late stage clinical development that specifically targets RANK Ligand, the essential regulator of osteoclasts (the cells that break down bone). With more than 19,000 patients in trials across indications worldwide, the denosumab development program is the largest ever initiated by Amgen. This broad and deep development program demonstrates Amgen’s commitment to researching and delivering pioneering medicines to patients with unmet medical needs. Amgen is studying denosumab in numerous tumor types across the spectrum of cancer-induced bone disease. Over 11,000 patients have been enrolled in the denosumab oncology clinical trials, testing the drug for the reduction of SREs in breast cancer patients, for the amelioration of treatment-induced bone loss in patients with breast or prostate cancers, for the prevention of SREs due to the spread of cancer to the bone in patients with multiple myeloma or those suffering from a variety of solid tumors, and for its potential to delay bone metastases in prostate cancer.

Bone Metastases: Impact and Prevalence

Bone metastases, cancer cells that separate from tumors and migrate to bone tissue where they settle and grow, occur in more than 1.5 million people worldwide.(1) With improvements in cancer care, including earlier diagnosis and new treatment options, leading to increases in survival rates(2), the number of patients developing metastatic disease secondary to a primary cancer is increasing. Bone metastases are a significant problem for patients with certain types of advanced cancer, with incidence rates of nearly 100 percent in myeloma patients and as high as 75 percent in breast and prostate cancer patients.

With bone metastases the growing cancer cells weaken and destroy the bone around the tumor. The damage the tumor has caused to the bone can result in a number of serious complications, collectively called SREs. These include fracture of a bone, the need for radiation to bone, the need for bone surgery, or spinal cord compression. All are serious complications for advanced cancer patients.

The economic burden of United States (U.S.) patients with bone metastases is significant and was estimated to be $12.6 billion last year.(3) Patients with bone metastases who experience an SRE incur significantly higher medical costs compared with those who do not experience an SRE.(4)

About Amgen

Amgen discovers, develops, manufactures, and delivers innovative human therapeutics. A biotechnology pioneer since 1980, Amgen was one of the first companies to realize the new science’s promise by bringing safe and effective medicines from lab, to manufacturing plant, to patient. Amgen therapeutics have changed the practice of medicine, helping millions of people around the world in the fight against cancer, kidney disease, rheumatoid arthritis, and other serious illnesses. With a deep and broad pipeline of potential new medicines, Amgen remains committed to advancing science to dramatically improve people’s lives. To learn more about our pioneering science and our vital medicines, visit http://www.amgen.com/.

ZOMETA is a registered trademark of Novartis Oncology.

*Editors Note: The FDA has provisionally approved the trade name Prolia(TM) for the proposed indications of treatment and prevention of osteoporosis in postmenopausal women, and treatment and prevention of bone loss in patients undergoing hormone ablation for non-metastatic prostate or breast cancer, for which denosumab is administered twice yearly subcutaneously at a 60 mg dose. The Prolia(TM) trade name is only for these indications and may not apply for other indications of denosumab.

1. Coleman, R. Potential use of bisphosphonates in the prevention of metastases in early-stage breast cancer. Clin Breast Cancer. 2007; 7(Suppl 1):S29-35. 2Coleman RE. Metastatic bone disease: clinical features, pathophysiology and treatment strategies. Cancer Treat Rev. 2001;27:165-76.
2. Capanna R, Coia LR, Coleman R. et al. eds. Textbook of Bone Metastases. Hoboken, NJ: Edition: John Wiley and Sons; 2005:105.
3. Mundy GR. Metastasis to bone: causes, consequences and therapeutic opportunities. Nat Rev Cancer. 2002 Aug;2(8):584-93.
4. Schulman K and Kohles J. Cancer. 2007;109:2334-2342

SOURCE Amgen