FDA panel recommends against 1st drug for chronic fatigue syndrome

The advisors weighed the risks and benefits associated with the intravenous drug rintatolimod (suggested brand name Ampligen). The drug's maker, Hemispherx Biopharma of Philadelphia, also failed to win FDA approval in 2009 because of concerns about the methodology of clinical trials used to study the drug.

In Thursday's 8-to-5 vote, the advisory panel said the company hadn't provided enough data to support the approval of Ampligen. Although the FDA isn't bound to follow the recommendations of its advisory committees it usually does so.

The central issue Thursday was whether Ampligen works and is safe. The FDA said there wasn't sufficient data in clinical trials to determine the drug's safety. Possible concerns include infections and liver problems, The Wall Street Journal reported.

Several panel members said they struggled with their decisions because it seems the drug works in some patients, the newspaper reported.

Experts have said they would welcome a treatment for chronic fatigue syndrome, a disabling condition that affects as many as 4 million Americans, mostly women. There is no cure, but Ampligen appears to reduce symptoms for some patients.

"It does seem to help at least a subset of patients significantly. For others, there isn't a significant response," said K. Kimberly McCleary, president of the Chronic Fatigue and Immune Dysfunction Syndrome Association of America.

"This drug has been studied in chronic fatigue syndrome since the late 1980s, so it's been around for a while," McCleary added.

Dr. Nancy Klimas, professor of medicine at Nova Southeastern University College of Osteopathic Medicine in Fort Lauderdale, Fla., who is part of an ongoing trial of the drug, said some of her patients have benefitted from the drug. Now there needs to be a way to identify which patients would do well on the drug, she added.

According to the drug company, Ampligen is a new type of drug called a nucleic acid compound, which uses specially made RNA to target a variety of diseases. Hemispherx believes the drug has the potential to fight HIV, kidney cancer and melanoma in addition to chronic fatigue syndrome.

The drug is said to work by modulating the immune and antiviral functions in diseased cells.

One drawback of the treatment is that it needs to be infused twice a week, Klimas said. It also is very expensive, she said.

The maker of the drug couldn't estimate the retail cost but said the manufacturing cost is about $1,000 a month per patient.

The FDA denied approval for Ampligen in November 2009 because of concerns about the way two studies were conducted—too few patients, a protocol change and an early end to one study.

Some experts think chronic fatigue syndrome is caused by a virus; others believe it is linked to a bacteria. It can begin after an illness from which a patient doesn't quite recover, or the symptoms can appear almost overnight, McCleary said.

Symptoms often include flu-like weakness. The one common thread is the inability to do almost anything without becoming exhausted, McCleary said. Even simple tasks like reading a magazine can set off a cascade of symptoms that last for days or weeks, she said.

"It's a bone-crushing exhaustion," McCleary said. "There is pain in the muscles and joints that can move from one body part to another, sore throat, headaches like migraines, and trouble falling asleep or staying asleep."

There are mental symptoms as well, including difficulty processing information and a "big problem" with short-term memory, McCleary noted.

More information: For more on chronic fatigue syndrome, visit the U.S. National Library of Medicine.

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