How do you decide when to add steroid-sparing immunotherapy for myasthenia gravis after starting prednisone and Mestinon?

My approach is generally to add a steroid-sparing agent if the patient experiences worsening of their symptoms during prednisone wean, such that they cannot tolerate a prednisone dose lower than 7.5 mg/day without functionally limiting symptoms. However, there are many patient-specific consideration...