Reprinted from Veterinary Product News

Alvin Smollin, DVM, has a busy practice in Ft. Lauderdale, FL where he sees 70-100 horses per week. Since 95% of his patients are Thoroughbreds at area racetracks that are either in training or returning from layoffs, acute and chronic muscle inflammation are common problems.

So when Dr. Smollin was asked to test a new product that supposedly relieved inflammation quickly and safely without drugs, he was intrigued.

"I tested the medication, code name C-9, on horses that were totally refractory to any other treatment," he reported. "The results were remarkable. The substance had the effect of a cure for the myositis and myofascial pain I was treating, rather than just a palliative."

After years of development and testing by veterinarians like Dr. Smollin, C-9, now called Rubella Virus Immunomodulator (RVI), will soon be available to practitioners. According to the manufacturer, Eudaemonic Corporation in Omaha, NE, RVI is a safe, fast-acting treatment for muscle inflammation that is based on a unique patented immunomodulating agent.

"RVI represents a breakthrough in the treatment of chronic myositis," said Eudaemonic president Richard Wood. "It is different because it addresses the source of the problem – the immune system’s complex role in the body’s ability to deal with prolonged pain and swelling. By modulating the immune system, scientists postulate, RVI restores the intracellular balance associated with good health.

While traditional treatment for these conditions has required extended rest, RVI’s results are apparent within days, says Eudaemonic. Other benefits of this new medication include:

Eudaemonic is distributing this medication nationally through veterinarians.

Acute and chronic inflammation including myositis, tendonitis, osteoarthritis, fascitis, and neuritis, are well-known problems for equine athletes. The symptoms are well known to equine practitioners: painful response to palpation along the back and excessive heat in that area; "trembling" of the muscles and skin overlying the back; difficulty in flexing or bending; subtle but definite gait defect; pain response to saddling or riding, or even an unwillingness to move, and spasms or tying up.

It is believed that the stressful conditions of chronic and acute inflammation can trigger an autoimmune reaction in which the immune lymphocytes recognize the body’s products of inflammation as "foreign."

Conventional Therapy

There is evidence that what is attacked in this response is the body’s own tissue – muscle, fascia, and connective tissue. Consequently, the inflammation worsens.

"This theory of immune system involvement may help explain why the clinical problems may fail to respond to conventional therapy like anti-inflammatory steroids, or NSAIDs, like "Bute" and Banamine, yet do respond to immunomodulation," stated Eudaemonic.

Researchers in the past decade have made great progress in understanding how the immune system works and regulates itself. It is well documented that there are different kinds of "T-cells" that signal the immune response to begin, attack infected cells, and stimulate "B-cells" to produce antibodies. Essential to the whole system is the control of these T-cells by "suppressor T-cells" to prevent a runaway immune response. Otherwise, immune cells multiply and attack the body’s own tissues. Unfortunately, suppressor T-cells are the most sensitive to stress, dietary change and environmental toxins. Not surprisingly, studies of chronic and acute inflammation show a decrease in suppressor T function (though not necessarily a decrease in absolute numbers of cells.) Impairment of their role threatens the health of the whole body.

John McMichael, Ph.D., an immunologist whose pioneering work led to the development of RVI, noticed the dramatic effects its particular combination of modified, inactivated rubeola virus and histamine had on animals suffering from various forms of inflammation. Because RVI worked regardless of dosage size, he theorized the mechanism might involve some sort of immune system signaling – that the medication acts on a specific site on the suppressor T-cells to trigger, in a controlled fashion, their correct activity. The hypothesis is that the result is the re-establishment of the normal balance between various subpopulations of T-and B- lymphocytes, which would aid in the healing process and lead to a decrease or elimination of myofascial inflammation and pain in afflicted animals. "The problem is addressed at its source," he states.

Microbiologist Ellis Kline, Ph.D., who helped develop RVI, has been conducting continuing research on this therapeutic agent with his laboratory team in South Carolina. He notes that RVI’s effect on inflammation differs from other anti-inflammatories. "Steroid therapy shuts down the immune response, leaving the body’s systems vulnerable to other threats," he explains, "and pain relievers primarily suppress symptoms."

According to Kline, the precise mechanism by which RVI works is still not completely known. But it appears that RVI’s selectivity involves only those parts of the system causing the inflammation. It allows other defenses to remain normal and "ready" without blanketing the system or masking symptoms.

Clinical Trials

Ohio equine practitioner Kent Vasko, DVM, chief clinical investigator for Eudaemonic, supervised a number of double blind clinical trials over the past five years. The primary test for efficacy and safety involved 60 horses: 20 in each of three sites. These tests covered a range of geography and horse type, from Thoroughbred racehorses in Florida and Quarterhorses in Nebraska to dressage and show jumpers in Ohio.

The horses were evaluated clinically on their degree of myofascial pain and were assigned "grades." Severe clinical signs were represented by a "3", down to "0" for horses with no clinical signs of disease. All the horses were evaluated daily. Blood samples were collected on days, one, two, three, and 14 of the trial and were monitored with respect to hemogram, SMAC21, chemistry profile, plasma cortisol levels, and serum protein electrophoresis.

Ten horses at each site were given 14 consecutive daily injections of "C-9", while 10 received a placebo. Neither the participating veterinarians nor the owners were informed as to the contents of any vial until the entire vial was completed.

The results were unequivocal, maintains Eudaemonic. Every horse receiving RVI showed positive clinical improvement, with 94% of them declared sound at the end of the trial. The remaining 6% continued to improve throughout the treatment period but did not reach "0" by the completion of the trials. "The most severely affected animals had the most dramatic responses, and those mildly affected had the least noticeable responses both clinically and biochemically," stated Dr. Vasko in his summary of the trials.

The onset of clinical improvements with the test product was noted as early as 24 hours, and no later than 72 hours after initiation of therapy: Fifty percent of the horses who were declared sound were classified as being clinically normal at 72 hours, and the balance (44%) were graded "0" by day 6. The rapid improvements were especially remarkable given that many cases were chronic, Eudaemonic stated.

No Adverse Reactions

The test medication was administered subcutaneously in the neck, and the dosages were the same regardless of size or weight. There were no undesirable side effects noted, so laboratory data was examined to discover whether there were any sub clinical indices of adverse reactions – there were none.

In fact, one horse in the Nebraska study had a control sample positive Coombs test indicative of immune hemolytic anemia. This horse seroconverted on the first treatment day and remained Coombs negative throughout the test period.

Of special interest, noted Dr. Vasko, was the observation of a gradual increase, within 48 to 72 hours, in lymphocyte concentration in animals treated with the test agent. "This increase is believed to be principally T-lymphocytes because of the finding in earlier laboratory results during one of the feasibility studies," Dr. Vasko’s report continues. "This is the subject of ongoing research, as is the identification of specific populations of T Cells affected." The increase leveled off at 72 to 96 hours and coincided with clinical improvement.

Dr. Smollin in Florida treated 20 horses in various stages of myositis for the efficacy and safety testes with RVI.

"Many of them had not responded to any other treatment," he said. "In horses that were just muscle sore, this medication affected a cure. In some others, it acted as a preventative. I was most impressed with the effect it had on my cases of tying-up syndrome. During the clinical trials, this medication was actually preventing tying-up in the sore horses I had chosen for the test. I administered it at the first signs and the syndrome disappeared.

"I also noticed a definite attitude improvement in horses who experienced relief from ‘C-9’," he continued. "But it did more than just alleviate pain, it seemed to alleviate what was causing the pain."

He noted that RVI is a biologic, not a drug or a masking agent, and will not show up on a drug test. "I’ve been waiting for this treatment to be ready for the market," he said. "Would I recommend it to any vet? Absolutely!"