LumiThera Inc., based in Seattle, WA has showed summary trial data on photo-biomodulation, termed “LIGHTSITE II” study, conducted by a multi-centre clinical trial in dry age-related macular degeneration (AMD). The photo-biomodulation (PBM) device is aimed to activate mitochondrial respiratory chain components resulting “in stabilization of metabolic function and initiation of a signalling cascade, which promotes cellular proliferation and cytoprotection”, according to the company. The medical device (termed as their Valeda Light Delivery System) has developed a CE mark to use wavelengths of light in the far red to near infrared spectrum (590, 660 and 850 nm) to modulate biologic function through direct and indirect cellular effects on mitochondrial respiratory chain components. PBM activation “of photo-acceptors in the mitochondria improves generation of adenosine triphosphate (ATP), modulates the production of intracellular signalling molecules such as reactive-oxygen species (ROS) and nitric oxide (NO), and triggers secondary effects that produce sustained changes in cell function and viability”.
According to the sponsor, the study provided a prospective, double-masked, randomized, multi-centre clinical trial, conducted at ten leading US retinal centres. The objective was to treat non-neovascular (dry) AMD subjects with PBM every four months for a duration of 24 months. One hundred (100) subjects were enrolled in a 2:1 ratio of PBM to sham in the treatment groups using a modified intent to treat population. The mean age was 75 years and mean dry AMD duration since diagnosis was 4.9 years prior to trial enrollment. Baseline best corrected visual acuity (BCVA) letter scores observed were a mean + SEM of 69.4 + 0.8 and 70.1 + 0.7 in the sham and PBM treatment groups, respectively. In brief, trial results demonstrated statistically significant improvement in the prespecified primary endpoint in BCVA at 13 months in the PBM treatment group over the sham-treatment group (p = 0.02). While a peer-reviewed publication may not be published to date, the company’s results indicated a sustained mean increase in ETDRS letter score of ~5.5 letters from baseline,seen at a 13-month timepoint with the PBM-treated subjects (p < 0.0001). In the PBM treatment group responders, 55% of the subjects showed a >5 letter improvement on the standard EDTRS eye chart with a mean of 9.7 letters and 26% achieved a >10 letter improvement with a mean of 12.8 letters.
Following the achievement, Diana Do, MD, and Quan Dong Nguyen, MD, MSc, FARVO, Professors of Ophthalmology and members of the Retina Division at the Byers Eye Institute at Stanford University, a clinical site for the LIGHTSITE III trial, stated that, “[t]he subjects had good starting vision with approximately 70% having between 20/32 to 20/40 vision. Study subjects were only enrolled in the study if their vision was 20/32 to 20/100 and no evidence of GA in the central macula. Moreover, Glenn Jaffe, MD, Robert Machemer Professor of Ophthalmology; Chief, Vitreoretinal Division and Director, Duke Reading Center, the central imaging center for the LIGHTSITE III study, also commented that, “[o]verall, the clinical results show improvements in vision; what is further interesting is the lack of drusen deposit in the PBM treated group, and potentially less patient conversions to wet form of disease. Patient progression to new GA was also evaluated and was less in the PBM group, and while the new GA progression numbers are small in this study group, all outcomes point in favour for PBM as a novel approach to treat dry AMD patients earlier in disease.”