New oral medication shows promise in treating fibromyalgia

A new oral medication known as IMC-1, developed by Innovative Med Concepts, proved highly effective at reducing pain and other symptoms of fibromyalgia (FM) in patients in a recent clinical trial.

Detailed results of the randomized, double-blinded, placebo-controlled Phase II study, known as PRID-201, were presented today at the 2014 American College of Rheumatology annual meeting in Boston by William L. Pridgen, M.D., FACS, founder and CEO of Innovative Med Concepts.

According to Daniel J. Clauw, M.D., director of the Chronic Pain & Fatigue Research Center at the University of Michigan (Ann Arbor), commenting on the PRID-201 results, "IMC-1 shows promise as a potentially new treatment for the millions of people who suffer from this debilitating condition."

Fibromyalgia is a multi-symptom disorder involving widespread pain, fatigue, headaches, sleep problems, mood changes and inability to concentrate. Its causes are unknown. According to the National Fibromyalgia Association, an estimated 3-6 percent of people worldwide suffer from the condition—10 million people in the United States alone.

The 16-week study evaluated the efficacy and safety of IMC-1, a fixed-dose-combination of famciclovir and celecoxib. 143 FM patients were recruited at 12 U.S. clinics. Patients received either a combination treatment of IMC-1 or a matching placebo.

According to Dr. Pridgen, chronic tissue-resident herpes virus may be an underlying cause of fibromyalgia. IMC-1 represents a novel treatment by combining an anti-herpes virus nucleoside analog with the anti-herpes virus activity exhibited by a COX-2 inhibitor.

"Many herpes viruses are known to significantly upregulate COX enzymes in the body, which in turn are important for efficient viral replication," Pridgen said. "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 FM."

The PRID-201 clinical study tested this hypothesis using the IMC-1 fixed-dose-combination. Patients in the trial rated their pain over the course of the study using a 0-10 numeric rating scale, with the study's primary endpoint being the reduction in average pain from baseline to week 16. Pain measured on both a 24-hour and seven-day recall basis met statistical significance, with the seven-day recall data achieving high statistical significance (p=0.001). Other therapeutic domains studied that showed statistical significance were Patient Global Impression (PGIC), all three Revised Fibromyalgia Impact Questionnaire (FIQ-R) domains, 30% and 50% Pain reduction responder analysis and the NIH PROMIS fatigue instrument.

Other noteworthy results from PRID-201: there was a lower discontinuation rate among patients in the IMC-1 arm compared to placebo, with 82.6 percent of patients randomized to IMC-1 completing the full 16 weeks of treatment versus 60.8 percent of patients on placebo. The discontinuation rate due to adverse events was almost three times lower for patients in the IMC-1 group 5.8% than for those on placebo 16.2% (p=0.012). While 41 percent of patients randomized to placebo used rescue medication, only 25 percent of those in the IMC-1 group required rescue medication (p=0.037).

"Compared to placebo, the relatively high completion rate, improved pain scores and the low rate of discontinuation because of adverse events are consistent with a well-tolerated and effective therapy," Dr. Clauw said.