Purpose
To evaluate the efficacy and safety of Sustained Release Dexamethasone (OTX-DP) as a one-time administered sustained release drug (dexamethasone) depot when placed in the canaliculus of the eyelid for the treatment of the signs and symptoms of chronic allergic conjunctivitis.
Methods
The OTX-DP is a punctum plug containing dexamethasone within a biodegradable PEG hydrogel matrix. The OTX-DP is designed to release dexamethasone into the tear fluid in a tapered profile. This was evaluated in a Phase 2 human study, wherein subjects underwent a series of allergen challenges using a modified Ora-CAC model to induce the inflammatory component of chronic allergic conjunctivitis. After showing a reproducible allergen response for itching and redness, and meeting eligibility criteria, subjects were randomized (1:1) at Day 1 to receive OTX-DP or Placebo Vehicle Punctum Plug (PV), bilaterally. The primary efficacy measures (ocular itching and conjunctival redness) were assessed at 14 days post-insertion, with scoring based on zero to 4 scales, with zero being symptom free, and 4 representing the most extreme. Subjects were followed further at 4 weeks and 6 weeks post-insertion for assessing continued therapeutic effect for allergic conjunctivitis.
Results
35 and 33 subjects were randomized to OTX-DP and PV, respectively. At 14 days post-insertion, a single OTX-DP dose was statistically superior to PV in ocular itching and conjunctival redness at all-time points (3, 5, and 7 minutes for itching and 7, 15, and 20 minutes for redness) post-CAC, as shown in Table 1. The differences (p-values) observed for itching and redness, were respectively: -0.78 (0.0031), -0.98 (0.0002), -0.88(0.0007), and -0.51 (0.0100), -0.70 (0.0006), -0.67 (0.0008). [JP1] The treatment difference was > 0.5 units for itching and redness at 14, 28, and 42 days, showing consistent efficacy on itching and redness, as shown in Figure 1. No serious treatment-related adverse events were noted in either group.
Conclusions
Overall, OTX-DP treatment was shown to be well tolerated. Treatment effects were evident for at least 42 days. The data supports the continued development of this drug product in the Ora-CAC® model.