Bisphosphonates Update - The Treatment and Prevention of Bone Metastases in Breast and Prostate Cancer

Introduction

Novartis'  Zometa (zoledronate) is likely to supersede Aredia (pamidronate), also from Novartis, as the gold-standard therapy for the treatment of bone metastases imminently

• What are the advantages of Zometa over Aredia?
• How significant will the results of Z-FAST be to Novartis'  strategy in the breast cancer market?

The skeleton is the most common site of recurrence of metastatic breast cancer, and bone metastases will occur in 65% to 75% of patients with metastatic breast cancer during their lifetime

• What are the risk factors for developing bone metastases?
• What are the different mechanisms of bone metastases?

Despite the dominance of Zometa and Aredia in the bone metastases market, there is significant opportunity for clodronate to enter the US market

• What are the reasons for the potential uptake of clodronate in the US?
• Why is clodronate more commonly used in some countries than Zometa?

Prevention of bone metastases and treatment of osteoporosis will be the key to the expansion of the bisphosphonate market.

• What are the opinion leader views on bisphosphonates'  potential in adjuvant setting?
• How efficacious is the treatment of osteoporosis in prostate cancer?

Action point 1 - The use of bisphosphonates in the adjuvant setting remains controversial due to conflicting results in clinical trials. More studies to determine the efficacy and cost-effectiveness of adjuvant bisphosphonates are needed to gain wider acceptance

Action point 2 - Clodronate remains unavailable in the US despite numerous clinical studies involving the drug for the treatment and prevention of bone metastases. This represents a significant opportunity for Schering AG, the marketer of clodronate in Europe, and generic companies marketing clodronate to enter the US bone metastases market

Action point 3 - Datamonitor believes that there is significant potential of bisphosphonates in the treatment of hormonal therapy-induced osteoporosis, especially in the prostate cancer market. However, cost is expected to be a major issue in the uptake of the drugs in the European markets

Action point 4 - The key to Novartis'  expansion in the breast cancer market for Zometa will be the results of Z-FAST. Although the trial results will not be available for several years, Datamonitor expects the usage of Zometa with Femara (letrozole) to creep into physician prescribing due to Novartis'  marketing