ABSTRACT
These studies aimed to further understand the antiviral effects of safe, visible light and demonstrate a therapeutic effect of an investigational treatment device for outpatients with mild to moderate COVID-19. RD-X19 is a handheld medical device precisely engineered to emit blue light through the oral cavity to target the oropharynx and surrounding tissues. At doses that are well-tolerated in an in vitro human epithelial tissue model, the monochromatic visible light delivered by RD-X19 results in light-initiated expression of IL-1 and IL-1{beta} cytokines with corresponding inhibition of SARS-CoV-2 replication. A randomized, double-blind, sham-controlled early feasibility study using the investigational device enrolled 31 subjects with a positive SARS-CoV-2 antigen test and possessing at least two moderate COVID-19 signs and symptoms. Subjects were randomized 2:1 (RD-X19 to sham), treated twice daily for four days, and evaluated over one week. Prespecified outcome measures included assessments of SARS-CoV-2 viral load and clinical assessments of COVID-19. There were no local application site reactions and no device-related adverse events. The time-weighted average change in log viral load throughout the study demonstrated a favorable reduction for RD-X19 compared to sham and at the end of study the mean change in log10 viral load was -3.29 for RD-X19 and -1.81 for sham at Day 8, demonstrating a treatment benefit of -1.48 [95% confidence internal (CI), -2.88 to -0.071]. Among the clinical outcome measures, differences between RD-X19 and sham were also observed, with a 57-hour reduction of median time to sustained resolution of COVID-19 signs and symptoms.
