So I asked my rheumatologist about it today. She says that she has two major concerns.
1) In peripheral arthritis in AS, you see additional bone formation (joint space narrowing) rather than the erosions you see in PsA. There is evidence that secukinumab may increase new born formation, which is a problem.
2) There is some evidence that it might unmask underlying IBD. 60% of AS patients have IBD (although most of us have it subclinically with no symptoms or very subtle symptoms) and she worries that it will cause previously asymptomatic patients to flare.
She is much more excited about STELARA (ustekinumab) and other new anti-IL23 antagonists.
