Aclasta ( Zoledronic acid 5 mg ) has received European Union approval as the first once-yearly treatment for women with postmenopausal osteoporosis.
Unlike oral bisphosphonate therapies taken daily, weekly or monthly, Aclasta is given as a once-yearly 15-minute intravenous ( IV ) infusion. This means with a single treatment, a patient can receive a full year's protection against the effects of osteoporosis.
Aclasta is the only treatment approved in the EU and US to reduce the risk of fractures in areas of the body typically affected by osteoporosis, including the hip, spine and non-spine ( e.g. wrist and rib ).
Results of the first-ever clinical study in patients with osteoporosis who had suffered a hip fracture, published in the The New England Journal of Medicine ( NEJM ), has shown a once-yearly infusion of Aclasta reduced the risk of any type of subsequent osteoporotic fracture by 35% compared to patients treated with placebo.
The Recurrent Fracture Trial involving more than 2,100 men and women also found the risk of death was significantly reduced by 28% in the Aclasta patient group compared to the placebo group ( 101 vs. 141 deaths ).
The regulatory approvals were based on efficacy and safety data from another study, the three-year Pivotal Fracture Trial involving more than 7,700 women. In this study, Aclasta was shown to increase bone strength and reduce the risk of spine fractures by 70% and hip fractures by 41%. The reduction in spine fractures was sustained over three years, and bone mineral density increased significantly in the spine by 6.7% and in the hip by 6% in women on Aclasta compared to placebo.
The active ingredient in Aclasta is Zoledronic acid, which is also available in a different dosage under the brand name Zometa ( Zoledronic acid 4 mg ) injection for use in certain oncology indications.
Aclasta was found to be generally safe and well tolerated in clinical trials. The most common adverse events associated with Aclasta were transient post-dose symptoms such as fever and muscle pain. Most of these symptoms occurred within the first three days following Aclasta administration and resolved within three days. The incidence of post-dose symptoms can be reduced with the administration of Paracetamol or Ibuprofen shortly following Aclasta infusion.
In the Pivotal Fracture Trial an increased number of cases of atrial fibrillation serious adverse events were observed in women given Aclasta compared to those on placebo ( 1.3% vs. 0.6% respectively ).
However, this finding has not been observed in other clinical studies or in post-marketing experience with over 1.5 million patients treated with Zoledronic acid for oncology indications.
In the Recurrent Fracture Trial, atrial fibrillation serious adverse events occurred in 1.1% of Aclasta-treated patients compared to 1.3% of placebo-treated patients.
No spontaneous reports of osteonecrosis of the jaw ( ONJ ) - a rare occurrence in the osteoporosis population treated with bisphosphonates - were seen in either the Pivotal Fracture Trial or Recurrent Fracture Trial.
Source: Novartis, 2007