Yes i have had success when i replaced mtx with arava. Mtx gave me horrible side effects and barely addressed my ra symptoms.
Arava was great though it takes a while to work. And i didnt notice any side effects even after taking it for years.

After I took Leflunomide, I did not have any issues for over a year and I am still on it. I am getting back stiffness, but the pain is in frequent. So far so good!

Areva is basically the same. Still had lung issues until I quit that as well.