Novartis is currently recruiting participants for studies evaluating the safety and effectiveness of a once-yearly infusion of drug zoledronic acid for the treatment of osteoporosis in the United States. These studies are part of an overall clinical program known as HORIZON (Health Outcomes and Reduced Incidence with Zoledronic Acid ONce Yearly).

The HORIZON program is the first to study a once-yearly dosing regimen for treating osteoporosis. HORIZON is the first program to, in a single study, prospectively evaluate both spine and hip fracture benefits as primary endpoints in women with postmenopausal osteoporosis. The program will also evaluate a single dose of zoledronic acid given once for the treatment of Paget's disease, a rare but debilitating bone disease. Worldwide, approximately 11,000 patients in 400 trial centers on four continents will be enrolled in the HORIZON program, which is one of the most comprehensive drug evaluation programs ever undertaken in the area of metabolic bone diseases.

"We urge women and men who have osteoporosis to speak with their doctor about the condition and consider participating in one of the HORIZON clinical trials," said Meryl S. Leboff, director of the skeletal health and osteoporosis in the Endocrine, Diabetes, and Hypertension Division at Brigham and Women's Hospital, Boston, Massachusetts. "If the HORIZON clinical studies show zoledronic acid to be safe and effective, the convenience of a once-yearly therapy may offer an important new treatment option for osteoporosis."

The HORIZON Pivotal Fracture Trial is a multi-national, multi-center, double-blind, randomized, placebo-controlled, Phase III study to evaluate the safety and efficacy of zoledronic acid in the treatment of osteoporosis in postmenopausal women taking calcium and vitamin D. The three-year study will measure fractures at both the hip and the spine. Participants will be women between the ages of 65 and 89 who have documented osteoporosis. They will be given a once-yearly 5 mg dose of either zoledronic acid diluted in 100 ml saline infused intravenously over 15 minutes, or a placebo infusion. There are 70 participating centers in the U.S., enrolling approximately 2,000 patients.

In a separate study, the HORIZON Recurrent Fracture Trial, investigators are recruiting men and women to evaluate the efficacy of once-yearly administration of zoledronic acid in preventing recurrent osteoporosis-related fractures after a recent hip fracture. This study is a multi-national, multi-center, double-blind, randomized, placebo controlled, parallel group study. It is enrolling men and postmenopausal women aged 50 years or older, who have a history of a low trauma hip fracture but were ambulatory prior to the fracture. Participants in this trial will receive a once-yearly 5 mg dose of zoledronic acid in 100 ml saline infused intravenously over a 15-minute period, or a placebo infusion. Eighty centers in the U.S. are participating, recruiting approximately 2,500 patients.

The HORIZON clinical trial program features significant trial design innovations. It is the first trial in osteoporosis to allow participants to simultaneously take other osteoporosis medications (e.g., calcitonin, estrogen replacement and raloxifene) other than the study drug or placebo, and the first to allow previous use of bisphosphonate therapy.

Additionally, it is the first time that a therapy will be studied for the prevention of recurrent osteoporosis-related hip fractures -- a population that has long been recognized to be at very high risk for subsequent fractures.

According to the National Osteoporosis Foundation, the condition affects 10 million U.S. women and men, aged 50 and older. In particular, a woman's risk of osteoporosis hip fracture is equal to her risk of breast, uterine and ovarian cancer combined. An estimated $17 billion in direct expenditures (by hospitals and nursing homes) in the U.S. alone was associated with osteoporosis fractures in 2001.