Antiviral Combo May be Next Blockbuster Fibromyalgia Drug

Antiviral Combo May be Next Blockbuster Fibromyalgia Drug

By Donna Gregory Burch

skip pridgen MD

Skip Pridgen, MD

A general surgeon with a small practice in Tuscaloosa, Alabama, Dr. William “Skip” Pridgen admits he’s an unlikely creator for the next blockbuster fibromyalgia drug.

But the U.S. Food and Drug Administration (FDA) has fast tracked Pridgen’s novel pairing of famciclovir (Famvir), a common antiviral, with celecoxib (Celebrex), an anti-inflammatory arthritis drug, for a phase III trial next year. Based on data from a 2014 phase II trial, the combo known as IMC-1 could give some stiff competition to Lyrica and Cymbalta, two of the most profitable drugs prescribed for fibromyalgia.

Like so many discoveries, Pridgen’s was accidental. He’d been treating patients with chronic gastrointestinal conditions for years and started to notice a pattern: Their symptoms would wax and wane over time, increasing whenever patients would become overly stressed. Pridgen’s mother is a virologist, and the pair speculated the stressors could be activating a virus, which in turn aggravated gastrointestinal and other symptoms. He’s concluded the HSV1 virus, commonly associated with cold sores, may be a culprit in fibromyalgia.

“Many herpes viruses are known to significantly upregulate COX enzymes in the body, which in turn are important for efficient viral replication,” he explained in a media release. “In theory, physical or emotional stress in patients can reactivate the virus and result in perpetuation of the symptoms of fibromyalgia. Effectively suppressing latent viruses may significantly improve the pain and related symptoms of fibromyalgia.”

But almost everyone on the planet has been exposed to the HSV1 virus. So, why do some people develop fibromyalgia while others do not?

“There’s a group of people who are genetically damaged in a way,” Pridgen explained. “There’s something that’s wrong with the immune system such that most people can force the virus to go into dormancy. These patients can’t.”

Pridgen thinks the virus remains active in the gastrointestinal tract and possibly in the sinuses and pelvic region as well.

“The body thinks there’s an ongoing war 24/7; everything gets amplified,” he said.

(This story gives a more technical synopsis of Pridgen’s theory about the connection between HSV1 and fibromyalgia.

Years ago, Pridgen began testing his HSV1 theory by offering antiviral medications to fibromyalgia patients whose symptoms alternated over time, and they reported some minor improvements in functioning. These same patients often complained about their chronic pain, and he began giving samples of Celebrex, an anti-inflammatory commonly prescribed for arthritis, to see if it might help.

He noticed those who received the combination of an antiviral and Celebrex dramatically improved over time. They not only reported a decrease in their gastrointestinal issues, but they also had less pain, fatigue, headaches and other symptoms commonly associated with fibromyalgia. Pridgen realized he might be onto something, and so did his patients. Word of mouth spread, and more fibromyalgia patients began coming to his practice.

“It really was just the planets aligning for me,” he says. “I knew each drug alone didn’t do a whole lot, but when given together, they did something remarkable.”

In 2014, Pridgen’s biotech company, Innovative Med Concepts, released data from its phase II trial involving 143 fibromyalgia patients treated at 12 U.S. clinics. The patients either took IMC-1 or a placebo for 16 weeks.

“We had pain reduction levels that rivaled or were comparable to other fibromyalgia drugs,” Pridgen said. “It wasn’t just that we reduced their pain. In all the measures we looked at [including fatigue, anxiety, headaches, TMJ, etc.], we seem to have an impact overall.

“We’re radically different [from other fibromyalgia drugs],” Pridgen continued. “Instead of just trying to reduce pain perception, we think we’ve discovered what is at the root cause [of fibromyalgia].”

Carol Duffy, associate professor of biological sciences at University of Alabama at Tuscaloosa, began partnering with Pridgen on his research in 2011. She believes IMC-1 works because it’s hitting HSV1 on two fronts: Famciclovir keeps the virus from replicating, and celecoxib stops reactivation and replication.

“When he gives them the meds, those fibro-like symptoms of widespread pain [and] fatigue, seem to go away, but it takes a while. It usually takes two months of being on the meds. … I think it’s much better than narcotics as far as treating symptoms. I feel like it’s treating it further up the line than narcotics.”

Annie George, a 22-year-old college student from Boston, is one of Pridgen’s success stories. She was diagnosed with fibromyalgia in high school and has tried numerous pharmaceutical treatments over the years. None of them helped, and most caused bad side effects.

When she first started seeing Pridgen in 2014, she was struggling to complete her undergraduate degree in engineering. She’d landed in the hospital several times with unexplained fevers, severe stomach pain and other symptoms. Her fatigue was so debilitating that she’d get up in the morning, take a shower, eat breakfast and then have to take a nap before she could attend classes. After a two-hour class, she’d come home and sleep for 12 hours, only to wake up exhausted again.

“I basically gave up all hope of living a normal life, of wanting to be a doctor, of wanting to be an independent person,” George said.

George and her mother flew to Tuscaloosa to meet with Pridgen after reading about his promising drug combo. She’s been on IMC-1 for about a year now, and it’s changed her life.

“Within two months, I started noticing a very big difference,” she said. “I could go to class and not get a fever. I could be out of the house for eight hours straight, which I hadn’t done since high school. I could do more, and the pain is just a lot less.”

She’s pain free most days, and her fatigue is nearly gone. George is working on her master’s degree and applying to medical school.

“It’s a day and night difference,” she said. “I’m not even the same person. I’m actually a normal 22-year-old girl.”

Like every fibromyalgia treatment, IMC-1 doesn’t work for everyone. Phase II results showed 37.9 percent of patients reported a 50 percent or greater reduction in pain after 16 weeks of treatment. That’s slightly better than Cymbalta, the most effective of the three FDA-approved fibromyalgia drugs.

Side effects were low, with more patients from the placebo group dropping out of the trial due to adverse reactions than those taking IMC-1.

Pridgen expects even better results from next year’s phase III trial because it will use the dosage he’s been perfecting in his practice for the past six years. Phase II used a lower, less effective dose.

Phase III may enroll up to 1200 patients at around 60 sites, some of which could be international. Several major pharmaceutical companies have already expressed interest in IMC-1, and a new drug could be on the market within three years.

Pridgen thinks the combo might also benefit patients with ME/CFS and irritable bowel syndrome, and trials are tentatively planned for those conditions.

More information about IMC-1 can be found on Innovative Med Concepts’ website.


Donna Gregory Burch

Donna Gregory Burch was diagnosed with fibromyalgia in 2014 after several years of unexplained pain, fatigue and other symptoms. She covers news, treatments, research and practical tips for living better with fibromyalgia on her blog, Donna is an award-winning journalist whose work has appeared online and in newspapers and magazines throughout Virginia, Delaware and Pennsylvania. She lives in Delaware with her husband and their many fur babies.

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Authored by: Donna Gregory Burch

Donna Gregory Burch was diagnosed with fibromyalgia in 2014 after several years of unexplained pain, fatigue and other symptoms. She was later diagnosed with chronic Lyme disease. Donna covers news, treatments, research and practical tips for living better with fibromyalgia and Lyme on her blog, You can also find her on Facebook and Twitter. Donna is an award-winning journalist whose work has appeared online and in newspapers and magazines throughout Virginia, Delaware and Pennsylvania. She lives in Delaware with her husband and their many fur babies.

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Lisa M. Smith

I will be speaking with Dr. Pridgen tomorrow regarding this. I am actually excited to talk to someone that may be able to help in my ongoing battle with left sided pain and severe nausea with some vomiting. I have not been diagnosed with FM, but like someone else said, that is just a preliminary thing and is probably around the corner. I have dealt with this going on probably two years now and no answers. I go to e.r. when I have to and they “dope me up”, do lab work, x-rays and most of the time a CT with everything coming back normal. They say they can’t find anything, give me prescriptions and send me on my way. Dr. Hooper FINALLY understood, as most have not, and put me in touch with Dr. P! I just love reading that I may get some relief soon!


I have always believed my fibro to be viral in nature. I find it interesting that after having severe shingles and picking up a super bug after an appendectomy my condition deteriorated into fibro. I find vitamin B beneficial and was on Celebrex for many years but it has left me with Barrett’s Oesophagitis after prolonged use. I wish you well in your work. It’s great to read a current article and to think research is being done on our up until lately largely ignored conditions. Maybe it’s different here in Australia but it is still in the category of too hard basket by many uninformed medical practitioners and miniscule offerings of help. We suffer mainly in silence.


How can we participate in phase 3 ?

Keith Gayler

Dr. P,

Have you been in contact with Dr. Jose Montoya at Stanford? He is an infectious diseases doctor who works primarily on CFS. His regimen for me was anti-virals and anti-inflammatories, and he is also very interested in herpes viruses. The protocol has helped me.

Keith G.

Tim Ollivier

Dr Pridgen
BTW, great work on your research. I am on a number of message boards related to your protocol and the one question that comes up is why significantly more women get FM. The HSV-1 does not discriminate. Would really like to get your thoughts on this.


DR. P, I am a chronic pain (spine) person (also with constant spinal nerve pain) who also suffers from Chronic fatigue/fibromyalgia. Also, I have a long Hx. of IBS, am positive for Epstein Barre and HV, have had shingles 3x, etc.
I believe that I am currently suffering from hyperalgesia from my opioids and the spinal nerve pain and fatigue is off the charts the past few months.
My life has shut down considerably due to it. I’m working on trying to figure it all out since I know that something is terribly wrong and different with my body. I would love to decrease or better yet be off of the opioids.
I had a discussion about all of this this week with my PCP.
We are wondering if a ‘maintenance treatment’ of daily Famvir and Celebrex could help me in the meanwhile? Please let me know your thoughts on that. And thank you for caring and all that you do to help your patients!!! There are not many like you out there anymore.

Sandy Horelica

Let me know if you have your phase 3 clinical trials in or near Houston! So tired of the side effects of the medications and more drugs that are added for those side effects! Not to mention the IBSD that has blessed me. On medication that works allright but makes me more tired and brainfogged. Please, please hurry!!!!!!!

Bless You

Michael G Langley, MD

Dr Pridgen, I never had a problem with celecoxib. But, Bactrim just nauseates me.

But, with all of the medications I take after my cauda equina injury, I don’t notice the muscle aches, ligament tenderness in the joints,or even experience trigger points! I still have a sleep disturbance, and IBS symptoms, at times. But, not being a, stressed out small town, general surgeon, life is a lot simpler!

William Pridgen

Actually only patients with sulfonamide allergies have to avoid celecoxib. Sulfa only allergies may take celecoxib.
Dr P


Sounds like a great idea! Unfortunately, I am allergic to sulfa drugs and cannot take Celebrex. So unfortunately that’s one more fibro drug that I won’t be able to tolerate. But good luck with your next study-any relief for this disease is very needed and welcome!

Zoann Murphy

What about people who can’t take Celebrex due to medication reactions? And, as Jeffrey asked, what about people who don’t have the gastrointestinal symptoms? I’m glad that this treatment could be very effective for many fibromyalgia patients and I hope the medication approval process will be expedited.

Actually about 60%-70% of FM patients suffer from significant IBS and chronic GI complaints.
Dr P


This is good news for those of us who suffer from fibromyalgia. My only concern is, how many patients will loose their lives before IMC-1 is fully approved as a pharmaceutical treatment? With drugs that are proven to easy the pain of fibromyalgia and many other painful diseases being taken away from so many, we here of people taking their own lives every day.
As I said in a previous comment on another article. It takes years of research and trials before the FDA will approve a drug for treating a disease. But the FDA’s sister, the CDC can limit or totally take a drug away that has been proven effective without any research to justify their actions.
I truly hope that IMC-1 passes all of the trials with flying colors. I hope that it’s made available to those who suffer from the pain ailments it’s designed to combat so that these people no longer need narcotics to manage their pain. I only wish that they could come up with effective non opioid medications to treat chronic pain caused by nerve damage before they take away the one drug that eases pain, opiates. I’m positive that the entire chronic pain community would be more than happy to turn over their opiates if there was an effective reliever of pain to replace opioid theropies.
Note to the CDC; Find effective drugs or theropies to treat chronic pain and illness before you suggest limits on the drugs that are proven to work.

Michael G Langley, MD

As a general surgeon practicing in a small town (had to be a GP, too!) I ran into quite a bit of fibromyalgia. Sadly, I was an expert, because I was a male with the symptoms. I could find trigger points with ease. The patients thought I was a genius, since their diagnosis had not been made, after several different doctors’ visits. (pretty typical) As a physician, with a graduate school education, I was interested in the science of medicine. I wondered how much of this had to do with the way we react to toxins in our environment, how much the adrenal and thyroid function were intertwined with the disease. I did independent study on toxins and noted that they were often involved with vitamin deficiency. I also noted that amantidine was a simple structure that looked a lot like the B vitamins. Tie this in with the way toxins (does not matter what type…viral, bacterial, plant based, man-made) seem to affect enzymatic functions, (organophosphate inhibition of acetylcholinesterase) and it becomes a very complex situation, affected by our environment. Phosphodiesterase affects so many of these enzymatic functions and is tied in with the metabolism of the body, as well as the repair and construction of RNA and DNA. Since toxins can be deadly to one person and not affect another at all, there has to be a wide variance. The identification of the genetic variation that you described is tantalizing! Anecdotally, Prozac was the perfect medication for me. It seemed to help me stay awake during the day and thus, sleep better at night. But, that same drug caused my wife to become homicidal!

After breaking my back, I have been on high doses of gabapentin to control the tingling neuropathy in my left ankle and foot. Interestingly, even without antidepressants, I have very few symptoms of the fibromyalgia, now! But, I am disabled and no longer work in the high stress job. I did not do well with the political part of small town surgical medicine!

I enjoyed reading the article!


What about fibromyloga patients that have no gastrointestinal symptoms, only a small percent of true fibromyloga diagnosis have gastrointestinal symptoms so my guess is that there is a misdiagnosed cause of fibromyalgia in these patients this Dr is treating.