DALLAS - Dry mouth can devastate patients and frustrate dentists. So the report of a promising new treatment excited researchers attending the American Association for Dental Research annual meeting here today.
A drug so new it's still known only by a number -- 552 02 -- appeared in a phase I clinical trial to moisten the mouths of patients with Sjögren's syndrome, said Athena Papas, D.M.D., Ph.D., a professor of dental public health at Tufts University.
After hearing Dr. Papas' results, Jason M. Tanzer, D.M.D., Ph.D., a University of Connecticut oral medicine professor and leading Sjögren's researcher, told DrBicuspid he was enthusiastic. "I'm quite excited," he said. "If I had patients, I'd want to give them this drug."
Dentists and their patients will have to wait a while. Although it is also being studied as a cystic fibrosis treatment, the drug is not yet on the market in any form. It's just beginning its phase II trials for Sjögren's and must undergo considerably more research before it becomes eligible for FDA approval.
An autoimmune disorder, Sjögren's afflicts between 1 million and 2 million people in the United States, mostly postmenopausal women. White blood cells attack moisture producing glands, causing dryness of the mouth and eyes. By decreasing saliva flow, it increases the long-term risk of caries. "These patients are desperate," Dr. Papas said. "We have to do something to help them."
Current treatments include artificial saliva and two prescription medications, Pilocarpine hydrochloride (Salagen) and cevimeline (Evoxac). Both belong to the class of sialagogues which work by stimulating moisture-producing glands. These drugs can improve caries. And in another paper presented in the same session, Dr. Papas' group showed that they can also reduce pocket depth and periodontal inflammation. But they can cause severe side effects including sweatiness, headaches, frequent urination, nausea and cardiovascular effects.
By contrast, 552 02 works by blocking sodium channels, the route by which saliva is reabsorbed into the epithelium. "The idea was to reduce the amount of fluid lost," said Dr. Papas.
Other researchers are studying 552 02, which was developed by Parion Sciences, as a treatment for cystic fibrosis. As a Sjögren's treatment, its effects are topical, said Dr. Papas. "It doesn't penetrate very deep."
In this study, patients took the drug as a rinse, but Dr. Papas also plans to study it as a spray. And she speculated that it might help patients who are suffering from dryness of the mouth for reasons other than Sjögren's.
The study was only a pilot trial with 30 patients. Still the researchers were able to show statistically significant improvement in dryness of the mouth and tongue and ability to sleep. The improvements were similar to those seen in patients taking sialagogues, Dr. Papas said. Patients even looked less desiccated. Better yet: "There were no serious drug adverse events." Nor were there any differences in vital signs.
The researchers divided the 30 patients into two groups. One rinsed six times a day with a flavored mouth wash containing 552-02 for a month. The other followed the same regimen, but with a placebo mouth wash.
After a wash-out period of 28 days, the two groups switched: Those who had been getting the 552-02 got the placebo and vice-versa. The patients rated their symptoms on a Visual Analog Scale, from "dry as a desert" to "not dry at all."
As expected, rinsing six times a day benefited patients even when the rinse only contained the placebo. But the rinse containing the active medication benefited them significantly more -- an impressive result considering the small number of patients. "We were surprised," said Dr. Papas. "This was mainly a study on safety."
The study was funded by Parion Sciences and the National Institutes of Health, but neither Dr. Papas nor Dr. Tanzer reported any conflicts of interest.
