FDA Approves New Drug
The Food and Drug Administration (FDA) today approved Tyzeka
(telbivudine) for the treatment of adults with chronic hepatitis B (HBV), a
serious viral infection that attacks the liver and can cause lifelong infection,
scarring of the liver (cirrhosis), and eventually liver cancer, liver failure,
and death. Tyzeka is a new molecular entity, which is a term used by the FDA to
describe a medication containing an active substance that has never before been
approved for marketing in any form in the United States.
“In a typical year, an estimated 70,000 Americans become infected with
chronic HBV, and some 5,000 of them will die of the complications caused by the
disease,” said Dr. Steven Galson, Director of the Center for Drug Evaluation and
Research. “Tyzeka offers prescribers another option for treating these
Tyzeka was studied in a year-long international clinical trial in 1,367
patients with chronic HBV. Three-quarters of the trial participants were male,
and all were 16 years of age or older. The trial produced evidence of antiviral
effectiveness, including the suppression of hepatitis B virus, and improvement
in liver inflammation comparable to Epivir-HBV (lamivudine), one of five other
medications approved to treat patients with chronic HBV.
HBV is spread when blood from an infected person enters the body of a
person who is not infected, sometimes by sexual contact or blood contamination.
Tyzeka is not a cure for hepatitis B, and long-term treatment benefits of this
drug are not known. Use of Tyzeka has not been shown to reduce the risk of
transmission of HBV to others through sexual contact or blood
clinical studies Tyzeka was generally well tolerated, and most reported adverse
events were mild to moderate. The most common side effects were elevated CPK
(creatinine phosphokinase, an enzyme that is present in muscle tissue and is a
marker for breakdown of muscle tissue), upper respiratory tract infection,
fatigue, headache, abdominal pain and cough.
Also, after several weeks to months of Tyzeka use, some patients
developed symptoms ranging from transient muscle pain to muscle weakness. Those
who developed muscle weakness experienced significant improvement in their
symptoms when Tyzeka was discontinued.
Patients should only stop Tyzeka after a careful discussion with their
doctor. As has happened with other forms of treatment for hepatitis B, some
patients who discontinued Tyzeka experienced a sudden and severe worsening of
their hepatitis B. Therefore, patients who discontinue Tyzeka should be closely
monitored by their doctor for at least several months.
Among drugs in the same class as Tyzeka, some cases of lactic acidosis
(too much acid in the body due to buildup of lactic acid) and severe enlargement
and accumulation of fat in the liver, including fatal cases, have been
Tyzeka is manufactured by Novartis Pharma
Stein AG, Stein, Switzerland and marketed and distributed by Idenix
Pharmaceuticals, Inc., Cambridge, MA.
If You Have Chronic Hepatitis B Virus Infection
If you have chronic hepatitis B virus infection (HBV), you are not alone. Today, approximately 1.25 million people in the United States are chronically infected with HBV. The majority of infected people feel healthy for their entire lives and do not demonstrate any evidence of ongoing liver damage. Other people progress to levels of more severe disease. Some people ultimately develop liver scarring (cirrhosis), liver failure, or liver cancer. It is important that you take care of yourself. And because it is possible to spread HBV to others, you have to know how to protect your family, friends, and others from this disease.
How you can take care of yourself
People who have chronic HBV infection need regular monitoring of their liver condition to determine whether their disease is progressing, whether treatment is needed, or whether a liver cancer is developing. Make sure you do the following:
- See your doctor for evaluation of your liver’s condition once or twice a year. Certain blood tests need to be performed periodically to monitor your liver’s health. Discuss with your doctor if you are a candidate for antiviral medication. These medicines are given to certain people with chronic liver disease.
- Discuss with your doctor about getting periodic ultrasounds, alpha-fetoprotein blood tests, or other studies to make sure there is no evidence of a developing liver cancer. Physicians may recommend different schedules for ultrasounds and blood tests depending on the patient’s age, sex, ethnicity, age at which the infection was initially acquired, family history, HBeAg status, and liver enzymes. Usually, ultrasounds and blood tests are recommended every six to 12 months.
- Review with your physician all medications you take. Even some “over-the-counter” medications can injure your liver.
- If you are pregnant, tell your physician that you have chronic HBV infection. It is essential that your baby be given hepatitis B immune globulin (HBIG) and started on hepatitis B vaccine within 12 hours of birth.
- Avoid alcoholic beverages. Alcohol can damage your liver.
If your liver disease has progressed…
If your liver disease progresses, here are some extra precautions you should take:
- Get your yearly influenza vaccine. Patients with severe liver disease should also receive pneumococcal polysaccharide vaccine.
- Get vaccinated against hepatitis A. Hepatitis A can further damage your liver.
- Don’t eat raw oysters. Raw oysters may carry the bacteria Vibrio vulnificus which can cause a serious blood infection in individuals with liver disease. Approximately 40% of these cases are fatal.
How to protect others from HBV infection
People can get HBV infection from you by coming in contact with your blood, serum, semen, or vaginal fluids. HBV has also been transmitted by human bites. Although HBV has been detected in low concentrations in other body fluids, including tears, sweat, urine, feces, and breast milk, these fluids have not been associated with transmission. Fortunately, HBV is not spread by sneezing or coughing, or from casual contact such as holding hands. Here are some important guidelines for you to follow so that others are protected:
- Tell your sex partner(s) that you are infected with HBV. Your sex partner(s) must see a physician for hepatitis B blood testing. If, according to the blood tests, your partner has never had hepatitis B, he or she should be vaccinated. After the series of three shots is completed, your partner needs to return to the doctor for blood testing to make sure the vaccine protected him or her. Use condoms until your partner is proven to be protected from HBV.
- Make sure all household members see their physicians for hepatitis B testing and vaccination.
- Tell your health care providers that you are infected with HBV.
- Cover all cuts and open sores with a bandage.
- Throw away used personal items such as tissues or menstrual pads in a bag so others will not be exposed to your blood.