Abstract
Purpose: :
INCYTOB is a national, prospective, controlled, randomized multicenter trial to assess the efficacy and safety of interferon (IFN) alpha-2a compared to cyclosporine A (CSA) in patients with severe eye involvement due to Behçet's disease (BD). We present an interim analysis of the trial and evaluate problems that may arise during conducting an investigator initiated trial for a rare disease in Germany.
Methods: :
To be eligible for inclusion, patients have to suffer from complete BD and have to present with active ocular disease affecting the posterior eye segment. Patients are randomized in a 1:1 ratio either to IFN alpha-2a or to CSA. In case of inefficacy or side effects a crossover is planned. Treatment efficacy is assessed using the uveitis scoring system by BenEzra.
Results: :
Since 2005 thirty patients (of 100 patients who will be necessary for statistical analysis) in 10 sites have been included. Interim analysis with the focus on safety aspects has been performed in 28 of these patients. Fifteen patients have been randomized to CSA, 13 patients to IFN alpha-2a. To date, 6 patients switched from CSA to IFN alpha-2a (4 patients due to inefficacy, 2 patients due to side effects of CSA). Only one patient switched from IFN alpha-2a to CSA due of side effects. The number of serious adverse effects (SAE) was higher for IFN (n=10) compared to CSA (n=5) and led to discontinuation of the drug in 2 patients each. Unfortunately patient recruitment is far behind the expectations. There are several possible reasons for this problem. E.g., pre-treatment with CSA or IFN as exclusion criterion limits the number of eligible patients.
Conclusions: :
INCYTOB is the first prospective controlled trial that compares IFN alpha to standard immunosuppression for severe ocular BD. Our interim analysis suggests that the number of patients who switch from CSA to IFN alpha-2a due to inefficacy and side effects is higher than vice versa. In contrast, the rate of SAEs seems to be higher in the IFN group. To improve recruitment, the number of study sites has been increased to 16.
Clinical Trial: :
http://www.clinicaltrials.gov NCT00167583
Keywords: uveitis-clinical/animal model