Men's Osteoporosis Support GroupStrontium ranelate and denosumab for osteoporosis J Bone Miner Res. 2009 Oct 19. Epub 2009 Oct 19. Bone Material Quality in Transiliac Bone Biopsies of Postmenopausal Osteoporotic Women After 3 Years Strontium Ranelate Treatment. Roschger P and others. PMID: 19839773. Strontium ranelate (Protelos) is a new medication used to treat osteoporosis that is approved in Europe, but not in the U.S. or Canada yet. It functions both to block bone resorption and to stimulate bone formation. This study used multiple very high technology means to test transiliac bone biopsies from postmenopausal women treated for three years with 2 gm/day of Protelos plus calcium/vitamin D and compared the findings with controls who got only the calcium/vitamin D. The authors stated, "In conclusion, our findings indicate that after SrR treatment, Sr is heterogeneously distributed in bone and preferentially present in bone packets formed during treatment. The effect of SrR on the [bone mineral density distribution] BMDD seems to be mainly due to the uptake of Sr and not by changes in bone calcium content. Taken together, these data provide evidence that the investigated bone quality determinants at tissue level were preserved in postmenopausal osteoporotic women after 3-year treatment with 2g SrR/day plus calcium/VitD." Editor's comments. There are several other Updates with information about strontium ranelate on this site. The most recent is here. The Roschger and others study provides new information on the microscopic level suggesting the clinical benefits having been shown so far regarding increased bone mineral density and fracture reduction in other studies are warranted by the microscopic results. This study should provide evidence that the FDA could use in approving Protelos for use in the U.S. Some things to remember about Protelos is that it must be taken daily on an empty stomach, it is more radiographically dense than calcium so a correction factor must be used when doing BMD testing, and it can also affect serum calcium test results. Denosumab There are several recent articles regarding denosumab (Prolia) which is apparently nearing some form of FDA approval. Some of these are positive and at least one is negative as it is the first case of osteonecrosis of the jaws reported after Prolia useage. Here two recent articles with brief comments on them. Br J Oral Maxillofac Surg. 2009 Oct 15. Epub 2009 Oct 15. Osteonecrosis of the jaws induced by anti-RANK ligand therapy. Taylor KH, Middlefell LS, Mizen KD. PMID: 19836866. Having the first case report of osteonecrosis of the jaws (ONJ) before Prolia is approved for treating osteoporosis is not a good sign. A previous Update discussing denosumab is here. The ONJ probably results because denosumab apparently blocks bone turnover even more than Fosamax (alendronate). And studies have shown that when the bone turnover is highly restricted this can lead to ONJ. Additionally here is an AP News report of Amgen shares falling when the FDA asked for data on the drug as a potential treatment for bone loss in patients undergoing cancer treatment. So it appears it will be approved for some therapies, but probably not all that Amgen requested. If so, news of the FDA approval should come fairly soon. N Engl J Med. 2009 Aug 20;361(8):745-55. Epub 2009 Aug 11. Denosumab in men receiving androgen-deprivation therapy for prostate cancer. Smith MR and others. PMID: 19671656. This study involved men on androgen deprivation therapy for prostate cancer for 24 months. There were increases in BMD in the spine and hip in the treatment group. The authors concluded, "Denosumab was associated with increased bone mineral density at all sites and a reduction in the incidence of new vertebral fractures among men receiving androgen-deprivation therapy for nonmetastatic prostate cancer." Editor's comments. Also check the Related Articles at PubMed for more information on recent studies of Prolia. For now it appears that Prolia is effective at building BMD and reducing some fractures, and it has the benefit of being a single injection every six months. The case report of ONJ is a bit disconcerting, especially when it is hoped that new therapies will not have any of the severe side effects of the bisphosphonates. Time will tell how much of a problem this might be. Of course, Prolia will not get approval for treating osteoporosis in men since the company's request involved women only, but I assume it will have no problem being used as a off-label medication should men ask for it.
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