US regulators have given the thumbs-up to Novartis to market Reclast, the first once-yearly treatment to be approved for post-menopausal osteoporosis.

The US Food and Drug Administration’s green light for Reclast (zoledronic acid), which comes a few weeks after the Committee for Medicinal Products for Human Use issued a positive opinion on the medicine in the European Union, under the brand name Aclasta, is based on a three-year trial, which showed that the drug increases bone strength and reduces fractures in the hip, spine, wrist and rib. Novartis noted that it is “the only treatment proven to reduce fractures across all these key sites” and unlike oral bisphosphonate therapies that have to be taken daily, weekly or monthly, Reclast is given as a once-yearly 15-minute intravenous infusion.

The study, involving more than 7,700 women, revealed that Reclast reduced the risk of spine fractures by 70% and hip fractures by 41%. The reduction in spine fractures was sustained over three years (60% in year one, 71% in year two, and 70% in year three) and bone mineral density increased in the spine by 6.7% and in the hip by 6% in women on Reclast compared to placebo.

The once-a-year dosing with Reclast is seen as a major breakthrough in managing the disease, which is responsible for 1.5 million fractures in the US every year and statistics suggest that 20% of women over the age of 50 who suffer a hip fracture will die within a year. Felicia Cosman, professor of clinical medicine at Columbia University in New York, noted that “for the first time we can ensure women receive a full year of the treatment they need to protect their bones".

Reclast is already approved in more than 60 countries to treat Paget's disease the second most common metabolic bone disorder. Additional studies are ongoing to examine the drug’s use to prevent fractures following a hip fracture in men and women, treatment of corticosteroid-induced osteoporosis and male osteoporosis.

The active ingredient in Reclast is also available in a different dosage (4mg) under the brand name Zometa for use in certain oncology indications.

Sales of the latter reached $636 million in the first half and analysts have predicted that Reclast will have peak sales of up to $1 billion.