Abstract
Purpose:
In therapeutic studies in dry eye disease (DED), the placebo response is well documented with a magnitude of effect of 20-35% on signs and symptoms of DED compared with baseline. This response is believed to be principally a result of two components: the placebo response typically seen in therapeutic drug trials and the wetting or lubricating effect of the topically applied vehicle. A third component, however, may play an important role in the vehicle response: the use of rescue artificial tears.
Methods:
EBI-005 is a novel, potent IL-1R1 inhibitor that was rationally designed to treat ocular surface disorders, such as DED. In a double-masked, placebo-controlled study, 74 subjects with moderate to severe DED were randomized to receive vehicle control or EBI-005 (5 or 20 mg/mL). Subjects received the study medication 3x/day for 6 weeks and were allowed to use rescue artificial tears provided by the sponsor (Refresh plus®, Allergan Pharmaceuticals, Irvine, CA). Subjects recorded the number of vials of artificial tear used in a diary and were not allowed to use rescue tears within two hours of dosing of the study medication.
Results:
Mean rescue artificial tear use over the six week study period was 11.1 vials for subjects receiving EBI-005 and 31 vials for subjects receiving vehicle control (p value=.005). Median rescue artificial tear use over the six week period was 1 vial for subjects receiving EBI-005 and 10.5 vials for subjects receiving vehicle control. There was a lower percentage of users of large amounts of rescue artificial tears (defined as user of more than 50 vials during the 6 week study period) among subjects receiving EBI-005 (5% or 2 of 39) compared with vehicle control (35% or 9 of 26) (p value= .005). Of the 10 heaviest artificial tear users, eight (80%) were subjects receiving vehicle.
Conclusions:
Subjects treated with EBI-005 used fewer rescue artificial tears than vehicle control treated subjects over the six week study period. Increased use of rescue artificial tears may play a key role in the magnitude of the vehicle response seen in many DED studies. Although not a currently acceptable regulatory endpoint in the United States, reduction of rescue artificial tear use by a study medication may have an important pharmacoeconomic impact that warrants further study.
Keywords: 486 cornea: tears/tear film/dry eye •
466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials •
490 cytokines/chemokines