1. Written informed consent must be obtained before any assessment is performed. 2. Male and female patients aged between 18 and 55 years, inclusive. 3. Diagnosis of clinically unilateral acute demyelinating optic neuritis (ADON) 4. Clinical signs and symptoms of ADON starting within the 14 day prior to intended randomization (loss of vision, pain on movement, impairment of color vision). 5. The qualifying episode of optic neuritis must be the first clinical episode of optic neuritis in the affected eye. 6. Able to undergo treatment with intravenous methylprednisolone or Acthar gel. [clinicaltrials_resource:2e3b5cad5bfcdff10f368670af4949f2]

1. Written informed consent must be obtained before any assessment is performed. 2. Male and female patients aged between 18 and 55 years, inclusive. 3. Diagnosis of clinically unilateral acute demyelinating optic neuritis (ADON) 4. Clinical signs and symptoms of ADON starting within the 14 day prior to intended randomization (loss of vision, pain on movement, impairment of color vision). 5. The qualifying episode of optic neuritis must be the first clinical episode of optic neuritis in the affected eye. 6. Able to undergo treatment with intravenous methylprednisolone or Acthar gel. [clinicaltrials_resource:2e3b5cad5bfcdff10f368670af4949f2]