The Conundrum of Clinical Trials for the Uveitides: Appropriate Outcome Measures for One Treatment Used in Several Diseases.

The uveitides consist of >30 diseases characterized by intraocular inflammation. Noninfectious intermediate, posterior, and panuveitides typically are treated with oral corticosteroids and immunosuppression, with a similar treatment approach for most diseases. Because these uveitides collectively are considered a rare disease, single-disease trials are difficult to impractical to recruit for, and most trials have included several different diseases for a given protocol treatment. However, measures of uveitis activity are disease specific, resulting in challenges for trial outcome measures. Several trials of investigational immunosuppressive drugs or biologic drugs have not demonstrated efficacy, but design problems with the outcome measures have limited the ability to interpret the results. Successful trials have included diseases for which a single uveitis activity measure suffices or a composite measure of uveitis activity is used. One potential solution to this problem is the use of a single, clinically relevant outcome, successful corticosteroid sparing, defined as inactive uveitis with a prednisone dose ≤7.5 mg/day coupled with disease-specific guidelines for determining inactive disease. The clinical relevance of this outcome is that active uveitis is associated with increased risks of visual impairment and blindness, and that prednisone doses ≤7.5 mg/day have a minimal risk of corticosteroid side effects. The consequence of this approach is that trial visits require a core set of measures for all participants and a disease-specific set of measures, both clinical and imaging, to assess uveitis activity. This approach is being used in the Adalimumab Versus Conventional Immunosuppression (ADVISE) Trial.