Thymosin-Alpha-1 (brand name Zadaxin) has been approved in Mexico as a flu vaccine booster. Hopefully, Mexican approval for the treatment of Hepatitis B and Hepatitis C will follow shortly. Thymosin is an injectable synthetic version of a naturally occurring hormone that circulates in the body. It has been studied for a number of years for the treatment of HIV, as well as Hepatitis B and Hepatitis C. One of its appealing aspects is that it has almost no side effects. Thymosin shows promise as an alternative to alpha-interferon as a first-line treatment for chronic Hepatitis B. And combinations of thymosin/alpha-interferon as well as thymosin/alpha-interferon/ribavirin look promising for the treatment of Hepatitis C. A lot of folks are interested in thymosin, but it's been increasingly difficult to get a hold of
It's approved for the treatment of Hepatitis B, Hepatitis C and/or as a flu vaccine booster in Cambodia, China, Singapore, the Philippines, Peru, Myanmar, Argentina, Kuwait and Italy. Hopefully, now that it's been approved for use in Mexico, it may be more readily available to bring into the U.S. under the FDA's Personal Use Guidance. We'll keep you posted.
SciClone Pharmaceuticals, the company that owns the rights to thymosin, has had more than its share of internal strife. But the company seems to be getting its act together, perhaps because SciClone is getting substantial financial assistance from its new partner, Schering-Plough. As Schering comers the market, future development of Hepatitis C treatments is worrisome.
In mid-December, Schering-Plough received expanded FDA approval for its bundled product, Rebetron, as a first-line treatment for Hepatitis C. Rebetron is a package that includes Schering's brand of injectable alpha-interferon (Intron-A) and ribavirin capsules. Prior to December's expanded approval, treatment failure with alpha-interferon monotherapy was required before you could try the combination, which has a much better success rate (about 15% on monotherapy compared to 49% on the combination). Now you no longer have to wait. If you decide that you want to begin treatment for Hepatitis C, you can start with the combination and, if you're insured, they'll cover it. When Rebetron was initially approved in June, it was the first time in FDA history that two drugs had been packaged together in such a way that you couldn't get one (the ribavirin) without having to take the other (see Notes from the Underground, Issue 37).
Many people would rather combine ribavirin with one of the other interferons on the market. By packaging ribavirin only with Intron-A, Schering-Plough and the FDA have drastically limited people's treatment options. Because of that and the astronomical price that Schering is charging for the bundled product, the PWA Health Group will continue to import ribavirin at a much lower price as we've been doing since it was first looked at as an anti-viral for HIV in the late 1980s.
Another old friend, 3TC (Epivir), was approved in December for the treatment of chronic Hepatitis B. The brand name of the Hepatitis B version of the drug is (you might want to sit down) Epivir-HBV. The drug was approved primarily based on four one-year trials that involved almost 1,000 people. Three of the trials were placebo-controlled. The results of other international studies have been presented recently, showing marked reductions in liver cell damage and liver enzymes after two years of daily treatment. The approved dose is 100mg once a day, compared to 150mg twice a day for HIV. The problem with the data is that it doesn't tell us enough about whether or not the virus is cleared once these folks stop treatment.
As in HIV, the Hepatitis B virus can develop resistance to Epivir if it's taken alone. Combination therapy for Hepatitis B may be a more useful way to go -- especially if you are coinfected with HIV.
Note: If you have active Hepatitis B and start an HIV combination that includes Epivir, you're going to be really sick for a month or two while the infected liver cells die off. Check for Hepatitis B before starting an HIV combination with Epivir.
Dr. Bernard Bihari has put out the results of an interesting observational study he conducted through his practice in New York. The study involved fifteen people with Hepatitis C, seven of whom are also HIV+. Each day, participants took between 2 and 7 capsules of HY2 (depending on each person's ability to tolerate the HY2) and 3mg of naltrexone (ReVia), an opiate blocker. HY2 is a form of St. John's Wort, a naturally occurring herb. Hypericin, a chemical derived from St. John's Wort, has shown strong anti-viral activity in the test tube against a wide variety of viruses. Each capsule of the HY2 used by Dr. Bihari's patients contains 750mg of St. John's Wort, with a 220% increase in hypericin content (2.25mg hypericin) over standard St. John's Wort preparations. This same HY2 is available at the PWA Health Group.
Dr. Bihari has followed his patients for up to two years. In almost all cases, Dr. Bihari's patients' latest lab reports show normal or close-to-normal AST and ALT results. These tests measure the levels of enzymes produced by the liver. The elevated enzymes which all of the participants had at the beginning of the study are usually an indication of liver inflammation or damage. Many study participants were using milk thistle and/or thioctic (lipoic) acid, popular supplements that enhance liver function. Four participants added ribavirin to their regimens.
With these additional, varied therapies, and even the naltrexone, many questions remain. How much the HY2 contributed to people's successful drop in liver enzymes isn't entirely clear.
One person who stopped taking HY2 and took regular St. John's Wort instead showed an increase in enzymes until he went back to the HY2. When two other study participants stopped their regimens for a while, their enzymes shot up, then decreased again after going back on the regimen. We know that taking ribavirin alone can sharply decrease liver enzymes; but when you stop ribavirin, enzymes pop back up. The same seems to be true of HY2 and the other treatments Dr. Bihari's patients are using. It may be helpful to give your liver a break for a period of time. But we don't know yet what will happen once these folks stop their regimen completely or whether anyone's virus will clear.