Age related macular degeneration – Who will bring more light!
Age related macular degeneration is the leading cause of people over the age of 50 going blind in western countries. There is 2% chance for a middle aged to catch this disorder and the chance rises to more than 30% in 70s. In addition to having no definite cure for AMD, it is further disheartening that the detection is also slow with AMD patients going undetected for at least 7 years of onset. AMD presents itself in two forms; exudative (wet AMD) and non exudative (dry AMD). Wet AMD carries more chances of patients going completely blind than the dry one. With the ever increase number of cases, scientists around the world are spending millions of dollars and doubled the efforts to find better treatments along with positive early detection techniques.
Anti-VEGF therapy – Gold standard therapeutic option
Anti-VEGF injections are currently the most effective treatments for AMD, there are three gold standard treatments for wet AMD in the market: Lucentis (Novartis/Roche), Avastin (Roche) and Eylea (Regeneron/Bayer). However there is also a major unrest going alongside among the physicians and patient community for using the three. Lucentis and Eylea costs around 1800-2000 dollars per injection compared to Avastin with similar improvements in patients costing only 50 dollars per injection. With a huge decrease in cost of treatment per year from 23000 to 600 dollars, Lucentis or Eylea’s prescription is always questioned by multiple patients advocates. One of the major discouraging factor for choosing a 2000 dollar drug over a 50 dollar drug could be off label use of Avastin for wet AMD since Genentech (Roche) asked for it approval for the treatment of colorectal cancer and not AMD.
Internal competition is evident among these top players with Eylea outperforming Lucentis at a lower cost and low dosing schedule than Lucentis. However, Novartis is set to conquer market again with RTH258 being a potential threat to Bayer/Regeneron’s Eylea and Lucentis. Running in phase III clinical trials, RTH258 shows similar effects as Eylea but with further low dosing schedule. While Avastin or Lucentis required 8-12 injections per year, with this new anti VEGF antibody, the dosing can go down to as low as 4 injections per year. With Lucentis sale dropping to 16% in 2016, and Novartis set to file regulatory approval in 2018, analyst have already predicted sweeping sales of the new drug. Other invasive anti-VEGF therapy include Pegaptenib sodium (Macugen) marketed by OSI pharma in US and Pfizer outside US.
NON – INVASIVE THERAPIES
Keeping aside the cost factors, the invasive nature of above treatments is also another discouraging factors for patients suffering from AMD. Recently John Hopkins researchers landed onto a peptide gel, AXT107, with studies in mouse models suggesting prolonged effective treatment. Compared to anti-VEGF nature of Eylea, AXT-107 targets three signaling pathways, VEGFR2, c-Met and PDGFRβ. Moreover, AXT-107 in combination with Eylea shows more pronounced effect compared to either treatment alone. Other than this, there is Verteporfin marketed by Valeant Pharmaceuticals International, which is a photodynamic therapy being often used in combination with an ti VEGFs.
Personalized stem cell treatment therapies from REIKO center Japan, is another light in the blind world, however with mixed results. In this, induced pluripotent stem cells (iPS), derived from patient, are used to transplant retinal sheet of epithelial cells in the defective eyes. Due to some negative results in further clinical trials done in US, FDA has not approved stem cells based therapies for AMD. With no clear reasons presented for the negative results, iPS treatment is still considered an upcoming potential therapeutic option for AMD patients.
A very potential therapy introduced by California-based Oraya Therapeutics involves treating retina with low beam X-ray radiations (INTREPID study). Being in an advantageous position of being non invasive compared to anti VEGF therapies, Intrepid study also demonstrates 2 year safety profile. Another promising non invasive therapy based on radiation showing promising results and launch in near future is a radiation device by US based Salutaris MD. It involves a hand held ophthalmic device using radioactive strontium 90 that directly targets macula.
The non-invasive therapies are raising new hopes among AMD patients to get off without the unpleasant feeling of getting injected into the eyes.