By Leila Abboud, The Wall Street Journal
Drug companies are racing to develop drugs for a highly debilitating disease that has confounded doctors and plagued patients for years. The disorder, called fibromyalgia, causes people to feel chronic pain all over their bodies and suffer from a constellation of symptoms, including sleep disturbances, fatigue and headaches. An estimated four to six million Americans have fibromyalgia. Women are seven times as likely as men to develop it. Despite the large number of people afflicted, because of the mysterious nature of the disease, there is currently no drug approved specifically to treat it.
Now, as researchers gain a better understanding of the condition, pharmaceutical makers see treating fibromyalgia as an area with enormous opportunity. Pfizer Inc., Eli Lilly & Co., Celgene Corp., Cypress Bioscience Inc. and others are testing a variety of drugs — including antidepressants, epilepsy and cancer treatments — for their effectiveness on fibromyalgia. Several clinical trials are under way or about to start, including studies of a cancer drug, an epilepsy drug and other still-unnamed treatments at the Pain Evaluation and Treatment Center at Duke University.
The hope is that if drug makers can unlock the secrets of fibromyalgia, the findings will apply to a wide range of chronic-pain conditions. Patients currently make do with a range of medications including antidepressants, sleeping pills, antianxiety medications, even drugs for Parkinson's that can tame the jerky leg movements that many people with the disease get. Regular light exercise such as swimming or yoga is also recommended.
For years, doctors couldn't figure out what was causing the often-incapacitating pain associated with fibromyalgia. Some dismissed the patients as hypochondriacs. Until recently, scientists thought fibromyalgia may be a problem of the muscles and bones, or inflammation. Pain medications, such as opioids and anti-inflammatory drugs, were prescribed but were generally ineffective. With modern brain-imaging technology, researchers say they have shown fibromyalgia to be a disease of the central nervous system in which the pain-processing system between the brain and spinal cord is out of whack. As a result, doctors who treat fibromyalgia, mostly rheumatologists, have tried prescribing drugs that are meant for other conditions but that also affect the central nervous system — including antiepileptic medicines and antidepressants. These "off-label," or unapproved, uses have shown promise during recent years, though the drugs have proved far short of a cure. And the latest push from drug makers seeks to build on what doctors have learned in practice. A list of clinical trials that are now enrolling patients can be found online at www.ClinicalTrials.gov.
A faction of physicians remains unconvinced that fibromyalgia really exists. Nortin Hadler, an immunologist at the University of North Carolina at Chapel Hill and a prominent skeptic, calls the disorder "a sociocultural phenomenon." But most doctors today accept that it's a distinct disorder. The drugs being studied for fibromyalgia each approach the disease from a different angle.
Clinical trials done by Pfizer show that its new drug Pregablin, which is being developed to prevent epileptic convulsions, pain and anxiety, seems to help the pain and sleep disturbances of fibromyalgia by affecting pain transmission in the spine. Pfizer expects Pregablin to be approved for at least its three main uses in the U.S. this year, and it was recently approved for use in Europe. Pfizer scientist Howard Welgus said it was a "strong possibility" that the company would also seek approval for Pregablin to treat fibromyalgia. The trials are still being planned and aren't yet enrolling patients.
Eli Lilly has shown in early studies that the antidepressant Cymbalta alleviates pain associated with fibromyalgia. The new drug is thought to work better in pain than the most widely used class of antidepressants, which affect serotonin in the brain. Cymbalta affects different brain chemicals, norepinephrine and dopamine. A Lilly spokesman wouldn't comment on whether the company plans to seek Food and Drug Administration approval for Cymbalta in fibromyalgia specifically, or if the company would get the word out by presenting research results in academic papers and at conventions. There are no clinical trials now enrolling patients.
Celgene has started one trial and plans two more involving its cancer drug thalidomide, infamous for causing birth defects when used by women early in pregnancy. The company expects it will soon enroll patients for trial. Celgene hit upon the idea after a woman with multiple myeloma who also happened to have a severe chronic-pain condition made a remarkable recovery from both her cancer and pain when treated with thalidomide. "It was serendipity," said Jerome Zeldis, chief medical officer of Celgene, adding that there has been other similar anecdotal evidence. But it is a relatively unknown company, Cypress Bioscience, with 15 employees and no other products, that is the closest to getting the first drug approved for fibromyalgia. The San Diego company has worked intensely with the FDA to craft the clinical trials, and is in the final stage of testing of its drug, milnacipran. Cypress licensed the dual-action antidepressant, which is similar to Lilly's Cymbalta, from a French firm. Chief Executive Officer Jay Kranzler said Cypress hopes to file for FDA approval during 2006.