Once-yearly Aclasta (zoledronic acid 5 mg) has been approved in the European Union to treat men and postmenopausal women with osteoporosis caused by long-term use of glucocorticoids, commonly known as steroids. Glucocorticoids are widely used to treat inflammatory conditions such as asthma and rheumatoid arthritis, but also cause bone loss and can increase the risk of fracture in up to 50 per cent of patients on long-term glucocorticoid therapy.
The new indication for men and women with glucocorticoid-induced osteoporosis (GIO) is based on study data showing that Aclasta, given once a year as a 15-minute infusion, is more effective at treating bone loss than daily oral risedronate, a current established therapy.
The study results, recently published in The Lancet, show that Aclasta produced a significantly greater increase in bone mineral density (BMD) than risedronate at six months, indicating a faster onset of efficacy.
"Oral bisphosphonates have been used for many years for the treatment of GIO, but they are associated with poor compliance as patients frequently fail to take them as prescribed," said professor David M Reid, head of the Division of Applied Medicine at the University of Aberdeen, UK. "Available data show that patients who remember to take their medicines only half of the time receive little or no protection."
He added, "The approval of Aclasta is a significant step forward, as it is more effective and faster-acting than a current established therapy for the treatment of GIO and has the advantage of year-long compliance and sustained osteoprotection."
This is the fifth indication for Aclasta, which is approved to treat osteoporosis in men and postmenopausal women, including those who have experienced a low-trauma hip fracture. Aclasta is the only bisphosphonate approved in the EU and US to reduce the risk of fractures at all key osteoporotic fracture sites, like the hip, spine, and other bones in the treatment of postmenopausal osteoporosis. It is also approved to treat Paget's disease of the bone.
In the US, the same medicine under the trade mark Reclast has also been approved by the Food and Drug Administration (FDA) to treat and prevent GIO in men and women. In May it was approved in the US as the only therapy to prevent postmenopausal osteoporosis with less frequent dosing (i.e. a single dose every two years).
The GIO indication is important because it is estimated that between 700,000 and 1.3 million adults in Western Europe, and between 1.5 and 2.7 million adults in the US, are receiving prolonged courses of oral glucocorticoids. Up to 50 per cent of patients receiving long-term glucocorticoid therapy are at increased risk of fracture, as their use is associated with side effects such as bone loss and consequently osteoporosis.
"This European approval marks another important achievement for Aclasta by adding to the broad spectrum of patients who can now be treated with this therapy," said Trevor Mundel, global head of Development at Novartis Pharma AG. "Aclasta has a strong efficacy and safety profile established during eight years of clinical trials. Since its launch in 2007, Aclasta has been used in more than 500,000 patients, demonstrating that an annual infusion has become a valuable treatment option."
The latest approval was based on a study of 833 men and women which investigated both the prevention and treatment of GIO (288 and 545 patients respectively). The study had several advantages over previous trials studying the effects of bisphosphonate drugs on GIO, including the large sample size, the inclusion of both prevention and treatment subgroups, and an excellent retention rate.
The study showed that over one year, a single intravenous infusion of Aclasta produced increases in BMD of the lumbar spine and femoral neck, trochanter and total hip that were significantly greater than those seen with once-daily oral risedronate (Actonel).
In this trial there were no cases of osteonecrosis of the jaw or delayed fracture healing, and no evidence of an increased risk of atrial fibrillation.
Zoledronic acid, the active ingredient in Aclasta/Reclast, is also available under the trade name Zometa for use in oncology indications.