A recent press release from Oraya Therapeutics revealed some promising news for those who receive regular eye injections to treat wet macular degeneration (AMD). Wet AMD gets its name from the fluid that is leaked from fragile blood vessels that start to grow under the macula, resulting in distorted vision.
The INTREPID - IRay Plus Anti-VEGF Treatment For Patients With Wet AMD study is a clinical trial sponsored by Oraya Therapeutics, Inc. a privately held company that started in 2007 in Newark, California. The stated purpose of the study is
" .. to confirm the safety of low voltage external beam radiotherapy using the IRay System at two dose levels for the treatment of CNV secondary to neovascular AMD and to determine if the IRay System is effective in sparing the number of Lucentis injections during the first 12 months."
Several healthcare sites in Austria, Czech Republic, Germany, Italy, and the United Kingdom recruited over 230 patients who had been diagnosed with wet AMD in the previous 3 years, had received at least 3 eye injections of Lucentis or Avastin within the previous year and still have the need for more anti-VEGF therapy due to increased fluid, leakage or persistent cysts.
Low levels of precisely directed radiation are given one time to the targeted lesions without affecting healthy tissue.
The equipment is used in an outpatient office setting and the treatment takes approximately 20 minutes with the patient sitting comfortably in a chair with the head positioned on a chin rest.
Radiation treatment has been used for years to treat rapidly dividing cells and vascular cells. The ionizing form of radiation works by disrupting DNA and preventing cells from dividing.
Doses of 16 and 24 Gy have been administered to hundreds of patients, many of whom have been monitored for several years. According to Oraya Inc, "There have been no clinically significant radiation or procedure-related adverse events."
The Oraya website explains, "The patient total-body effective dose is only about 0.3 mSv, comparable to a head radiography series, or one-tenth of a head CT scan. This is approximately the same background radiation dose as a person would naturally receive in a month."
Oraya Inc. reports that "Full results of the three-year safety follow-up data from the INTREPID study of Oraya Therapy for wet age-related macular degeneration further demonstrated a favorable safety profile and also showed that there was no significant difference in vision outcomes in patients treated with Oraya Therapy compared with those receiving anti-vascular endothelial growth factor (anti-VEGF) injections alone. "
Oraya Therapy presented recent study results at the EURETINA Conference in Milan, Italy in September 2012. Timothy Jackson, PHD, FRCOphth, King's College Hospital, London and lead investigator for the study reported that "the year one results of the INTREPID trial are very encouraging for people with wet AMD - the prospect of fewer eye injections will appeal to all those receiving anti-VEGF therapy."
The February 27, 2013 press release stated:
"Results of the trial showed that further injections were reduced by 32 percent in the radiotherapy groups compared with the control group. These radiotherapy groups were twice as likely to receive no injection over the course of a year and were approximately half as likely to need four or more injections over the course of a year.
Also, post hoc analysis looked at the best responders to stereotactic radiotherapy and identified a group of patients which experienced a 54 percent reduction in the number of injections and a mean visual superiority of 6.8 ETDRS letters compared to equivalent patients in the control group"
The results of the Intrepid study were recently published in Ophtalmology, 2015. The name of the publication, Stereotactic radiotherapy for neovascular age-related macular degeneration: year 2 results of the INTREPID study concluded, " A single dose of SRT significantly reduces intravitreal injections over 2 years. Radiation can induce microvascular change, but in only 1% of eyes does this possibly affect vision. The best response occurs when AMD lesions fit within the treatment zone and they are actively leaking."
Ophthalmology. 2015 Jan;122(1):138-45. doi: 10.1016/j.ophtha.2014.07.043. Epub 2014 Sep 7.
“We need additional therapies to anti-VEGF injections in treating wet AMD. With the availability of Oraya Therapy, we’ve been able to offer patients an adjunctive treatment that has been shown in a clinical study to reduce the number of injections required and to potentially enhance the patient's quality of life," said Mr. Christopher Brand, FRCOphth, Consultant Ophthalmologist at Royal Hallamshire Hospital, Sheffield.
This type of treatment for wet macular degeneration is now provided in Germany, Switzerland and the United Kingdom
In the United States, the IRay System is considered an investigational device at this time and treatment is not yet available.