US sales of Roche's osteoporosis drug Boniva are set to take a tumble after the Food and Drug Administration gave the green light to the first generic versions of the drug.

The agency has approved copies of Boniva (ibandronate) once-monthly 150mg tablets to treat or prevent osteoporosis in women after menopause made by three companies - Mylan, Canada's Apotex and India's Orchid. According to the National Institutes of Health, in the USA more than 40 million people either already have osteoporosis or are at high risk due to low bone mass.

Keith Webber, deputy director of the Office of Pharmaceutical Science in the FDA’s Center for Drug Evaluation and Research, noted that men as well as women are affected by osteoporosis, "a disease that can be prevented and treated". He added that for people who must manage their health conditions over time, "it is important to have affordable treatment options".

Boniva belongs to the bisphosphonate class of drugs which help increase bone mass and reduce the chance of having a spinal fracture. Some 5 million people are estimated to be using bisphosphonates in the USA such as Boniva, Merck & Co's Fosamax (alendronate) and Novartis' Reclast/Aclasta/Zometa (zoledronic acid) and Procter & Gamble/Warner Chilcott's Actonel/Atelvia (risedronate), so the market for the three aforementioned generics companies is considerable.

Nevertheless, global sales of Boniva were down 31.3% last year to 696 million Swiss francs.