New drugs used in spondyloarthritis

Could you comment on the new drugs used in spondyloarthritis?

Filip Van den Bosch: There is an interesting evolution. When we started with tumor necrosis factor (TNF)-blocking agents about 15 years ago, they seemed to work for all rheumatic diseases: rheumatoid arthritis, ankylosing spondylosis, psoriatic arthritis. It gave us the impression that making a diagnosis was not so crucial, because anyway when your disease was inflammatory you would be able to treat with a TNF-blocking agent.

Then we went looking for other modalities and one of them was interleukin (IL)-6 blockers or abatacept, which is a T-cell costimulatory blockade. They were perfectly valid in rheumatoid arthritis but it turned out they did not work at all in ankylosing spondylitis; on the contrary, what we see now is we see drugs mainly targeting the access with IL-17, IL-12, IL-23 that seem to be working fairly good to very good, for example, in psoriasis, with regard to the spondyloarthritis complex, but they do not work for rheumatoid arthritis.

So again, it becomes important to make the right diagnosis. At least, what we know from the phase 3 studies with IL-17 blockade is that these agents seem to be in the same ballpark of magnitude of response as anti-TNF agents, so it seems like a worthwhile alternative to treatment with TNF-blocking agents.