Clinical Trial of an Antiviral Drug Combo to Treat Fibromyalgia Has Promising Results

Patient Expert

Earlier this year I told you about a new theory, put forth by Dr. William Pridgen of Innovative Med Concepts, that fibromyalgia may be caused by a virus. I also reported that a Phase II clinical trial of an antiviral drug combo to treat it was nearing completion. That trial has now been completed and an abstract, which summarizes the study, was presented at the recent American College of Rheumatology annual meeting. The results are very promising.

Birth of a Theory

Pridgen's theory first began to take form as he observed his fibromyalgia patients. He suspected that the herpes simplex virus type 1 (HSV-1) was causing their gastrointestinal problems, so he gave them the antiviral medication Famvir (famciclovir). Some of those patients also had symptoms of arthritis, for which he prescribed Celebrex (celecoxib), an anti-inflammatory with some antiviral properties. Those who took just the Famvir said they felt better but not 100% better. However, the patients who took both the Famvir and the Celebrex reported that virtually all of their FM symptoms were gone!

HSV-1 is the virus that causes cold sores. It lives forever in the body of anyone exposed to it, which includes about 90% of the population. Pridgen's theory, in a nutshell, is that HSV-1 takes up residence in the nerves. While our immune systems are usually good at containing the virus, when the immune system is compromised by some physical, hormonal or emotional trauma (common triggers for FM), the virus is reactivated, traveling down various nerve pathways and resulting in the pain and other well-known symptoms of fibromyalgia.

Study Design and Results

A total of 143 fibromyalgia patients were randomized (1:1) to receive a proprietary combination of celecoxib and famciclovir or a placebo for 16 weeks. Patients taking the combo drug showed impressive improvement in pain, function, symptoms and overall impact. They also showed significant improvement in fatigue as well, but not quite as impressive as in the other measures.

A less impressive result was reported for a secondary measurement called the Patient Global Impression of Change (PGIC) scale, with only a third of patients in the treatment group meeting the criteria. It's not yet clear how to explain why there is such a difference between the PGIC results and the more impressive results seen using other evaluation tools.

The researchers concluded, "A proprietary combination of famciclovir, which we postulate is inhibiting herpesvirus replication, and celecoxib, known to inhibit both herpesvirus replication and reactivation, was efficacious in treating multiple symptoms of FM. Given the simultaneous improvement in many domains and the surprising tolerability of this combination of drugs, we believe this combination warrants further study as a potential new therapy for fibromyalgia patients."

What's Next?

In order for the FDA to even consider approving this (or any) new drug, Phase III trials are required. Phase III involves testing a lot more patients - usually 1,000 to 3,000 - in order to confirm the drug's effectiveness, further insure its safety, monitor any side effects and possibly compare it to other commonly used treatments.

In addition to pursuing funding for this very expensive phase of trials ($50 - $100 million), virologist Carol Duffy, an associate professor in the Department of Biological Sciences at the University of Alabama, says she is working to develop diagnostic tests that can be used to determine which patients would benefit from taking the new drug combo. The team is also planning to conduct toxicology tests to see if a larger dose would be safe and potentially make the treatment more effective.

My Thoughts...

I find this theory and possible treatment incredibly exciting! Although scientists have found numerous biological abnormalities in the fibromyalgia body (i.e. the brain, small nerve fibers, substance P, serotonin, etc.), they all seem to be results or evidence that something is definitely wrong - not the cause. Is it possible that HSV-1 could be the underlying cause of fibromyalgia, resulting in all the other abnormalities and symptoms? Hopefully the next phase of clinical trials will provide some answers.

If you would like to learn more about this study and the story behind it, here are two excellent articles:

"Drug Combo in Pridgen Antiviral Fibromyalgia Trial Identified - Some Results Available" by Cort Johnson for Simmaron Research

"Professor-Surgeon Team Headed to Third Phase Clinical Trials" from University of Alabama News

Image by Naypong courtesy of


Pridgen W, et al. "A Combination of Celecoxib and Famciclovir Is Efficacious in the Treatment of Fibromyalgia: Results of a Phase IIa Randomized, Double-Blind, Placebo-Controlled Study." Presented at the 2014 ACR Annual Meeting.