TREATMENT DATABASE

Nexavir (formerly Kutapressin) is a peptide and amino acid solution derived from porcine (pig) liver.  In the late 1920s, it was discovered that liver helped patients with acne vulgaris. As a result of this observation, attempts were made to isolate the active factor from liver. Not until the 1940s was a specially purified liver fraction isolated. Subsequent refinements in the isolation of the active material led to the development of what was then called Kutapressin, a biological (as opposed to synthetic) medication which had anti-inflammatory properties. Over the following decade, Kutapressin was used to treat a variety of dermatological conditions, including poison ivy, hives, eczema, and severe sunburn. 

USES IN ME/CFS: Kutapressin's value as an ME/CFS treatment did not become generally known until Dr. Thomas Steinbach and Dr. William Hermann used Kutapressin successfully in the early 1980s to treat shingles and what was then referred to as Epstein-Barr virus reactivation (CFIDS Chronicle, Summer 1990). Dr. Steinbach had observed that Kutapressin's antiviral and anti-inflammatory properties made it an effective treatment for infectious mononucleosis. Because of Kutapressin's excellent safety record and the positive results in treating Epstein-Barr virus infection, they conducted an informal unblinded study of some 270 patients with ME/CFS.

The results were impressive. Of the study participants, 75% showed improvement, and in some cases marked improvement, after only 40 injections of Kutapressin. Even more promising was that many of these patients had been ill with ME/CFS for more than five years.

A second study published by Dr. Steinbach and Dr. Hermann demonstrated the same impressive results (presented at the International CFIDS Conference, Albany, N.Y., 1992). Of the 130 patients who participated in the second study, 85% reported notable or marked reduction of symptoms while receiving Kutapressin injections. Of 111 patients who reported significant reductions in symptoms, 103 noted results within six months of treatment. As a result of these studies, many ME/CFS clinicians began to incorporate Kutapressin in their treatment plans, particularly when there was evidence of viral activity (high titers of human herpesvirus 6 and high interferon levels).

Some researchers have theorized that Kutapressin must have had both antiviral and immunomodulatory properties to simultaneously curtail viral reactivation and immune system upregulation. A study published by Dr. D.V. Ablashi and colleagues proved that Kutapressin was a potent inhibitor of herpesvirus 6 in vitro without causing cell damage (In Vivo, 1994). A later study conducted in 1996 by Dr. E. Rosenfeld and colleagues found that Kutapressin was also effective against Epstein-Barr virus (In Vivo, 1996). However, its role in immunomodulation remains speculative. Dr. Steinbach and Dr. Hermann postulated that Kutapressin may have acted to mediate the action of lymphokines, the immune system chemicals that are thought responsible for many of the symptoms characteristic of ME/CFS.

The ownership of Kutapressin has since changed hands. The distributor, Schwartz Pharma, sold Kutapressin, along with its client list, to Nexco Pharma, a Texas-based company. The product was renamed Nexavir, and while patients and doctors were assured that it was identical to the original formulation, this turned out not to be the case. Nexavir contains preservatives as well as tyrosine, an amino acid. Some doctors have switched to Hepapressin, a bovine liver alternative.

Treatment rating for Nexavir