According to final data from a small mid-stage trial, Amgen’s Denosumab, a bone drug is useful in stopping progressive bone destruction and tumour spreading in patients suffering from a rare type of non-malignant bone cancer.

Clearly, the data adds to recent positive results for the drug seen as a key sales driver for the U. S. bio-technology company, including offering a promising treatment option for rare inoperable giant-cell tumours (GCT).

After Amgen announced Denosumab’s final phase trials in men with advanced prostate cancer showed it to work better than Novartis’s Zometa in delaying and reducing the risk of fractures and other bone complications, the firm’s shares rose Monday.

Denosumab to be marketed under brand name Prolia is the first of a new class of drugs developed to inhibit proteins responsible for activating bone-destroying cells.

Analysts view the drug being developed to treat cancer which has spread to the patients’ bones, including as an osteoporosis treatment, to be more important than others in Amgen’s development pipeline, with sales expected to reach $3.1 billion in 2014.

Thirty-seven patients from the United States, Australia and Europe, all suffering from non-malignant GCT participated in the rare bone tumour trial. They were given monthly injections of denosumab, including additional doses on the 8th and the 15th of the first month. They were also given daily calcium and vitamin D supplements.

Writing in The Lancet Oncology, the study’s findings researchers said, 86% or 30 of the 35 patients they assessed after treatment, had responded to the drug. Of the 31 patients assessed for other benefits, 84% reported reduced pain and better mobility, while 26% showed bone repair.

Side-effects were reported by almost all the patients, albeit a large number of them seemed to be relatively mild problems like back pain and headaches.

The U. S. Food and Drug Administration (FDA) reviewing Denosumab as a treatment for several uses, including post-menopausal osteoporosis, as treatment for bone loss in breast and prostate cancer patients undergoing therapy osteoporosis, has asked for more clinical trial data before giving its’ approval.