Acute Adenoviral Conjunctivitis Treatment: A Phase 2 Interim Analysis of OKG-0301

Abstract

Purpose : Treatment of acute adenoviral conjunctivitis remains an unmet medical need, with no approved therapies available worldwide. OKG-0301 is a topical ophthalmic formulation of ranpirnase, an RNAse A family member, with broad-spectrum antiviral properties.

Methods : The RUBY trial is a 219 patient, prospective, multi-center, double-blind, vehicle controlled, Phase 2 trial evaluating the safety, tolerability, and efficacy of OKG-0301 0.03% and OKG-0301 0.012% versus vehicle. Patients within 72 hours of the onset of signs and symptoms of adenoviral conjunctivitis, along with a positive QuickVue (Quidel) adenoviral conjunctivitis test were randomized and dosed in both eyes QID for five days. Four visits at days 1, 4, 7, & 14, each included a clinical assessment and an ocular swab for viral titer determination. The primary outcome was safety and tolerability of OKG-0301 and secondary outcomes included viral titer (Least Square Means [LSMean] comparison) and clinical assessments, including redness and discharge. An interim analysis was performed to evaluate the initial safety and efficacy of OKG-0301.

Results : Fifty-eight subjects were randomized and included in the Intent To Treat (ITT) population. The modified ITT (mITT), defined prospectively as subjects with > 100 viral copies/mL via PCR at visit 1 and who received at least a single dose of investigational product, included 41 patients. In the ITT population, there were no Treatment Emergent Serious Adverse Events and one patient with a Treatment Emergent Adverse Event suspected due to study medication in the vehicle control group. In the mITT evaluation, OKG-0301 had an antiviral effect via reduction of viral titers relative to placebo (day 7 placebo vs OKG-0301 0.012% vs OKG-0301 0.03% (LOG10 transformed, LSMean +/- SE): 1.06 +/- 0.22 vs 0.34 +/- 0.27 vs 0.62 +/-0.27, respectively, p<0.05; Fig 1). There was neither a better nor worse (NS = non-significant) difference in the clinical resolution of redness and discharge in the active vs placebo groups at day 7.

Conclusions : OKG-0301 is a safe and effective antiviral for the treatment of acute adenoviral conjunctivitis. Its main biological activity appears to be limited to acceleration of viral eradication, with no observed effect on redness and discharge. Further formulation and additional clinical evaluation is warranted to develop OKG-0301 as the first approved treatment of acute adenoviral conjunctivitis.

This is a 2021 ARVO Annual Meeting abstract.