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Shedding light on ulcers
Photonics Center start-up targets ulcer-causing bacteria
By Tim Stoddard
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The ulcer-causing bacterium Helicobacter pylori. Image courtesy of LumeRx. © LumeRx 2004 |
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A swig of Pepto Bismol or a couple of Tums usually does the trick for minor cases of heartburn. But gastric ulcers require sterner stuff: a two-week course of antibiotics to kill off the hardy bacterium, Helicobacter pylori, that causes over 80 percent of ulcers in the stomach. It's a brute force regimen of 18 pills a day — daunting for anyone, but particularly difficult for elderly patients — and there are growing fears that H. pylori will soon develop resistance to the antibiotics commonly used. Paul Zalesky and his colleagues are shedding light on a more elegant method of ridding the stomach of H. pylori without drugs.
Zalesky is president and CEO of LumeRx, a privately owned company that recently joined the Photonics Center's business acceleration program. With technical support and seed capital from the center, LumeRx is pioneering a novel light-based therapy that kills H. pylori with blue light. “It's Star Wars in the gut,” Zalesky says.
“We think LumeRx has a very creative idea,” says Glenn Thoren, deputy director of the Photonics Center. “Through the business accelerator program, we'll be able to assist them in the design of their products, connecting them to both suppliers and customers, and providing them with business advice. Most importantly, we'll provide a location where they can engage in their particular technology in a very active medical community.”
When it finally came to light in 1982 that a bacterium causes gastric ulcers and stomach cancers, the idea was a little hard for the medical establishment to swallow. It had been widely believed that spicy food, excess stomach acid, and stress caused holes to form in the lining of the stomach and duodenum, the first section of the small intestine. The evidence made doctors eventually come around to the idea that ulcers are caused by a squid-shaped bacterium that lives in the stomach lining, awash in acid that kills off most other microbes. About two-thirds of the world's population is infected with H. pylori, and in the United States, the bacterium is more prevalent among older adults, African-Americans, and Hispanics.
Light-based therapy has been used by dermatologists in the past to kill acne-causing bacteria, but until now, no one has tried photodynamic therapy on H. pylori. After about two years of laboratory research on H. pylori, LumeRx has found its Achilles heel: pigments in the bacterium called porphyrins absorb blue light and generate oxygen free radicals, which wreak havoc by punching holes in cell membranes, swiftly killing the bacteria. Shining blue light on the bacterium essentially causes it to push a self-destruct button.
LumeRx is now developing a “light wand” that can be inserted into the stomach during a normal endoscopy procedure, where the stomach is inflated with air (to the size of a large football) so that its entire surface is visible to a camera the doctor threads down the esophagus into the stomach. The LumeRx device will look like aquarium tubing that radiates blue light, surrounded by several small balloons that hold the tube away from the wall of the stomach.
“If you test positive for H. pylori,” Zalesky says, “your doctor would put in our device, turn it on for 5 or 10 minutes, and kill all of the bacteria colonies that are in the wall of your stomach.” He adds that H. pylori is the only bacterium present in the stomach, unlike the small intestine, which is colonized by a diversity of microbes, many playing an essential role in digestion. The light therapy doesn't appear to have any side effects, he says, and it kills H. pylori through a mechanism that shouldn't lead to resistant strains.
Fertile ground
Zalesky, a biomedical engineer who's headed up four previous ventures, says the Photonics Center is an ideal venue for bringing LumeRx's products to market. “We took a hard look at the BU Photonics Center, and it has a lot going for it,” he says. “We have a lab here with a sophisticated optical table, laser equipment, and electronics. There's a shop upstairs where we can get some specialized fabrications done. There's usually an engineer or two wandering the hallways asking if we need help with anything. I'm five minutes from Beth-Israel Deaconess and Brigham and Women's, where we'll do clinical studies, and 10 minutes from Mass General, where we do microbiology data studies. It certainly sets you up to move quickly. If we were in Iowa, we couldn't do half the things we're doing this month.”
Donald Fraser, director of the Photonics Center, agrees. “Within days of LumeRx entering our business acceleration program,” he says, “the company was conducting tests on equipment that would normally have taken six months to procure and make ready for use. We're very optimistic that within a year or two, LumeRx will be able to graduate out of our business acceleration program as the top medical device company treating H. pylori in the industry.”
The center has helped launch 17 companies over the past five years, 15 of which are still in business and doing well, says Thoren. “Those companies have raised an additional $200 million in venture capital in the past five years — which has been an awful marketplace. It's a very strong portfolio that's probably the envy of most mutual fund investors.”
LumeRx's small office on the sixth floor of the center currently serves as a “virtual space,” Zalesky says. “We do the thinking and analysis right here, and then we work with selected consultants and contractors to actually do the building. Once we get those test samples in here, we'll do all the bench testing in the Photonics Center, and then build more of them and take them to the clinic right here in Boston.”
Considering that H. pylori is responsible for more than 500,000 new cases of gastric ulcers in the United States every year, light-based therapy could have a dramatic impact on gastroenterology. “It's remarkable how common this is in the United States, and even more so in places like Japan,” Zalesky says. “We're coming up with a really new approach to treating these patients. It's a one-stop shop: they're cured and they don't have to worry about it again. That's pretty exciting.”
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April 2004
Boston University
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