Researchers aim for rare treatment of macular degeneration

Friday, May 1, 2009
Researchers aim for rare treatment of macular degeneration
By Marc Songini

One of the most prevalent eye diseases is age-related macular degeneration, affecting millions in the United States, and there are few if any cures, or even approved treatments, say experts. That makes the work of a group of local researchers developing an implanted treatment particularly vital.

The AMD ailment takes two forms: One is “wet” and involves blood vessels and has limited treatments, including Lucentis, a drug from San Francisco-based Genentech Inc. (now part of Swiss firm Roche). The other is “dry” and occurs when light-sensitive cells malfunction. An estimated 15 million Americans have AMD.

For the 10 percent to 20 percent of AMD patients that have the wet form, the treatments are “reasonably effective,” said Paul Ashton, president and CEO of Watertown-based pSivida Corp., which develops eye treatments. “We have nothing for the 80 percent to 90 percent who have the dry form.” In part, this is because big pharma didn’t realize the huge market for eye treatments until about a decade ago, he said. Additionally, “Getting drugs into the eye without getting very high levels of drug everywhere else is very hard,” noted Ashton.

For dry AMD, in particular, there’s “a huge unmet need and a huge market,” said Emmett Cunningham, a partner with Cambridge-based Clarus Ventures LLC, a life sciences investment company. In part, said Cunningham, a doctor and eye expert based in Clarus’ South San Francisco office, this is because dry AMD is “complex,” and there is no one easily discerned cause. Also, there are no reliable animal models for testing.

“You’d have to take a big bet to get human proof of concept data,” he said. A venture capital firm would be prone to waiting till a dry AMD startup was in the Phase 2 or Phase 3 stage before investing the $20 million to move toward full approval.

However, one research team based at Boston College and the University of Massachusetts Medical School in Worcester is trying to solve the problems of AMD and other eye diseases by creating nano-structured retinal implants. These are tiny devices placed in the eye to take the place of the malfunctioning rods and cones in the retina, explained Michael Naughton, a professor of physics at BC, whose team is working on the nanotechnology of the implant.

“The implant is designed to reconnect to the surviving cell circuitry and provide the electronic stimulus formerly provided by the rods and cones,” said Naughton. Ideally, these implants could have a form factor similar to contact lenses. They would be widely available, although requiring retinal surgery. “Until such a time as genetic engineering can cure or regenerate rods and cones, these artificial retinas could provide a viable path to restoring vision.” Potentially, the market is worth hundreds of millions of dollars annually, he estimated.

Currently, he estimates that he needs $42 million to pay for the prototype and the animal and human studies over the next 18 months. He said there are no implants on the market for consumer use at this time, though a number are in development.

Cunningham noted that for an investor, implants are an interesting area, but the key is getting compelling data that the technical risks associated with the device have been met, because it requires surgical implantation. Also, a startup must demonstrate the size of the market is big enough related to the cost of the device, he said.

Other firms working to treat AMD and other eye ailments include Lincoln, R.I.-based Neurotech Pharmaceuticals Inc., whose lead candidate NT-501 is an intraocular implant made of genetically modified human cells. In March, it released Phase 2 exploratory study data that indicated positive results in AMD treatment, with no “serious adverse events,” said Ted Danse, president and CEO of Neurotech.

Also, pSivida’s drug Iluvien is in Phase 2 trials for both forms of AMD, said Ashton. And New Haven, Conn.-based Optherion Inc. is developing a diagnostic service and drug platform for AMD. By year’s end, Optherion plans to file an independent new drug application (IND) submission to the U.S. Food and Drug Administration for its drug, said Colin Foster, CEO and president.

For the past several years, Bedford-based Resolvyx Pharmaceuticals Inc. has been evaluating its Resolvin inflammation control drug’s effectiveness against AMD, as well.