Considered steroid-dependent if demonstrated improvement following initiation of corticosteroid therapy but continue to have generalized weakness on examination despite receiving 20 mg of prednisone (or equivalent) every other day and experience unacceptable symptoms on lower doses Prednisone and other immunosuppressive drug doses must not have changed within last 4 weeks May have had other immunosuppressive medication (azathioprine, cyclosporine, cyclophosphamide) or have received plasma exchange if these treatments were not initiated in the 2 months prior to study enrollment Must be receiving immunosuppressive medication for at least 3 months prior to study