Bisphosphonates versus Infliximab in Ankylosing Spondylitis

Today I’ve read an abstract by O. Viapiana and colleagues: “Bisphosphonates vs infliximab in ankylosing spondylitis treatment”. They looked at 60 patients, who “were consecutively assigned in a 1:1 ratio in a 6-month open-label, single-centre study on active AS to receive monthly i.v. neridronate (100 mg) or standard infliximab (5 mg/kg) therapy.” Conclusion: “High i.v. doses of the amino-bisphosphonate neridronate are as effective as infliximab therapy in reducing disease activity in AS patients, with additional benefits on BMD changes. Further studies to confirm these results over a longer time frame are warranted together with the possibility to explore the long-term efficacy of a combination of lower anti-TNF doses with bisphosphonates.” Link: http://rheumatology.oxfordjournals.org/content/early/2013/09/24/rheumatology.ket321.short?rss=1

In another study G. Santra and colleagues looked at: “Assessment of the efficacy of pamidronate in ankylosing spondylitis: an open prospective trial.” They treated 35 patients for 6 months with 60 mg pamidronate i.v. every month. The authors saw 85% of patients achieving ASAS-20 and 77% a BASDAI-50 response. Conclusion: “Intravenous pamidronate has good efficacy for the treatment of AS.” Link: http://www.ncbi.nlm.nih.gov/pubmed/21140116. Full Text at http://smj.sma.org.sg/5111/5111a8.pdf including a review of prior studies on pamidronate in AS.

And I have selected a third abstract by G. Slobodin and colleagues: “The synergistic efficacy of adalimumab and pamidronate in a patient with ankylosing spondylitis.” [OT: Writing down this I note that the study comes from the Department of Internal Medicine A, Bnai Zion Medical Center, in Haifa / I’d like to take the opportunity to thank Dr Jochanan E Naschitz, also from the Department of Internal Medicine A, Bnai Zion Medical Center, for his letters to help me in the pre-internet era on panniculitis]. Abstract: “A patient with ankylosing spondylitis, after demonstrating incomplete clinical response to adalimumab, received three monthly infusions of pamidronate along with continuing TNF-alpha blockade. Complete disappearance of the back pain was reported after the second pamidronate infusion. The perspectives of the combination therapy with TNF-alpha inhibitor and pamidronate are discussed.”

Why aren’t we using more bisphophonates? Because it’s off-label. And I don’t think any drug company selling pamidronate would be interested in proving that it works in ankylosing spondylitis as we are already past the patent protection time. So, I think a big chance lies in neridronate to achieve patent protection for treatment of ankylosing spondylitis, which would give us an alternative to TNF alpha inhibitors. We could treat patients who can’t receive TNFi for various reasons, for instance history of cancer. Also combination therapy could be an option.

I hope that neridronate comes to the market as a treatment option for ankylosing spondylitis.