Xolair - Can One Build Up A Resistance?

[Guest guest]

I've been on Xolair at 375 mgs every 2 weeks now for 16 months. I've

noticed some improvement in asthma and also in sinus headaches.

However, starting this spring I got worse. My last spirometry test

showed FEV1 at 63% of predicted. That's where it was BEFORE I went on

Xolair.

I'm wondering ... is it possible to build up a resistance to Xolair?

My last injection was 4 days late due to the doctors not communicating

properly and thereby claiming they did not have insurance authorization.

I don't really notice any difference after the shots, unlike some people

who have an immediate change. I feel like I'm reacting more to

everything.