medication for polymyositis

I was diagnosed with myositis 6 years ago and later polymyositis. I was prescribed immune suppressants which didnt agree with my system over that time. I have felt loss of strength in my upper body e.g in lifting a pan from one side of the sink to the other some 3/4 years ago and had trouble straightening up my body after bending down or sitting down in the recent 2 years. I have discomfort in the back of my thighs especially when at rest or lying down with smarting, pinching,
stinging sensations. At present I am not on any medication for this complaint. Other medication I am taking - Actonel, Omacor, Verapamil, coated aspirin and calcium. These are for, in order :- osteoporosis, cholesterol, svt,
Question:- what would be you prescribe for polymyositis ? please.