Title : A Phase II, Randomized, Sham-Controlled Dose-Finding Study of the RD-X19 Treatment Device in Individuals with Mild-to-Moderate COVID-19

Abstract:

The EmitBio RD-X19 is a handheld, self-administered device that delivers doses of 425 nm visible light to the posterior oropharynx and surrounding tissues to serve as a potential new treatment option for outpatients with COVID-19. A Phase II, sham-controlled dose-finding study was conducted in 216 subjects at nine clinical sites across the United States in order to (1) evaluate the safety and efficacy of the RD-X19 in ascending doses and (2) identify a suitable subject population and dose for a subsequent pivotal trial.

Enrolled subjects had mild-to-moderate COVID-19 with at least two moderate or greater symptoms <72 hours from onset and a positive SARS-CoV-2 rapid antigen test. Subjects were randomized to receive the RD-X19 device delivering either 24 J/cm² (Cohort A) or 32 J/cm² (Cohort B) or a sham device. RD-X19 and sham treatments were delivered in five-minute doses twice daily for seven days. Eight COVID-19 symptoms were self-evaluated daily on a numeric score ranging from absent (0) to severe (3) and were monitored for 14 days. The primary efficacy endpoint was the time to the sustained resolution of COVID-19 signs and symptoms (defined as all symptoms being scored as absent (0) or mild (1) and remaining at this level through Day 14) in mild-to-moderate or mild COVID-19 subjects.

No serious treatment-related adverse events were observed among subjects receiving the 32 J/cm² (highest) light dose; this dose was found to be well-tolerated when compared to sham. Measures of the primary efficacy endpoint were not statistically significant in the full analysis set; however, a treatment benefit was observed in subjects with mild COVID-19. Consistent with studies of other COVID-19 therapies where greater treatment was observed in older subjects, post-hoc analyses suggested the greatest treatment benefit was in subjects aged 40 years or older with “FDA/NIH” definition of mild COVID-19 (hazard ratio 0.343; median times to sustained symptom resolution 111 hours [active] vs. 188 hours [sham]; N = 40 subjects; nominal log-rank p = 0.008).

Quantitative PCR assessments of SARS-CoV-2 viral load at each visit and change in α and β diversity in microbial flora from baseline on day 8 and day 14 as analyzed by 16S rRNA subunit analysis will also be presented. Importantly, there was a greater reduction in the SARS-CoV-2 nasopharyngeal viral load in subjects treated with RD-X19 compared to sham at all timepoints with no corresponding disruption of the oral microbiome.

Audience Take Away:

• Certain wavelengths and doses of visible light have antiviral effects by inactivating cell-free SARS-CoV-2 and reducing viral titers in productive infection models of the human airway.
• In a clinical study, visible light (425 nm) had antiviral effects at doses that did not disrupt the oral microbiome.
• In the same clinical study, symptomatic relief was greatest in subjects ages 40 and above with mild COVID-19 when compared to the sham control. Age has been shown to be both a predictive and prognostic indicator for treatment benefit for COVID-19 therapeutics.

Biography:

Dr. Kocher is the Director of Virology at EmitBio and is responsible for the preclinical evaluation of EmitBio’s proprietary visible-light based technology platform targeting upper respiratory viruses. He conducted his post-doctoral training in Dr. Ralph Baric’s group in the Gillings School of Public Health at the University of North Carolina at Chapel Hill. Prior to his post-doctoral work with betacoronaviruses (MERS-CoV and SARS-CoV), he obtained his Ph.D. in Biomedical and Veterinary Sciences from the research group of Dr. Lijuan Yuan at Virginia Polytechnic Institute and State University studying norovirus. He received his B.S. in Biology from St. Vincent College.