If a patient develops itching with their first dose of Tysabri despite pre-treatment, does this indicate that further cycles of Tysabri are contraindicated or do you continue Tysabri at the next cycle?   

I generally stop natalizumab in patients with hypersensitivity. In this case, it may be a little more nuanced depending on how bad the symptoms were. I have had cases with very mild itching that have successfully been re-challenged with minimal steroid pre-treatment for a dose or two, then back to t...