U.S. Food and Drug Administration
FDA Consumer magazine
September-October 2001
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People with hepatitis C now have more flexible treatment options. In July, the FDA approved a stand-alone package of Rebetol (ribavirin) Capsules, an anti-viral drug for use with Intron A (interferon alfa-2b) for the treatment of chronic hepatitis C infection.
In 1998, the FDA approved Rebetol in a combination package with Intron A. This package, Rebetron Combination Therapy, was approved for treatment of people with chronic hepatitis C infection who have not had previous interferon therapy or who have relapsed following successful interferon therapy. Both ribavirin products are marketed by Schering Corp., Kenilworth, N.J.
This separate packaging of Rebetol Capsules gives health-care providers flexibility in adopting individualized ribavirin and interferon-based therapies for people with hepatitis C. These therapies do not cure the infection, but work together to suppress the level of hepatitis C virus in the blood. Rebetol Capsules are not effective when used alone.
People who buy Rebetol Capsules will receive a medication guide that explains side effects associated with Rebetol Capsules and Rebetron Combination Therapy.
The most important side effect of Rebetol Capsules is anemia. People taking the drug should have their red blood cell counts checked regularly. Fatal and nonfatal heart attacks have occurred in people with anemia caused by Rebetol Capsules. People with a history of significant or unstable heart disease should not be treated with Rebetol Capsules.
Rebetol Capsules may cause birth defects and may lead to death of a fetus. To avoid birth defects, extreme care must be taken to prevent pregnancy in women being treated with Rebetol Capsules and in women whose male sexual partner is being treated.
Other common adverse events associated with Rebetol Capsules include fatigue, nausea, rash and itching.
Hepatitis C infection is a chronic condition caused by a virus, spread mainly by contact with an infected person's blood, that damages the liver. (See "Hepatitis C: An Update" in the July-August 2001 FDA Consumer.)
An adjustable elastic silicone band that in essence "shrinks" the stomach has been approved to help severely obese people lose weight.
The Lap-Band Adjustable Gastric Banding System is a device that is placed by laparascopic "keyhole" surgery around the upper part of the stomach to create a small gastric pouch. This limits food consumption and creates an earlier feeling of fullness. The band is inflatable and connected to an access port placed close to the skin that allows surgeons to either tighten or loosen the band to meet an individual's needs. Once the band is in place, it is inflated with a salt water solution (saline). The procedure is reversible and does not require cutting or stapling of the stomach.
In June, the FDA approved the device for people who are more than 100 pounds overweight or who weigh at least twice their ideal body weight, and who have failed to lose weight by other means. People who use the Lap-Band will need to diet and exercise to help maintain their weight loss.
Severely obese people often develop serious health problems such as hypertension, gallbladder disease, and diabetes as a result of their excess weight. For them, being overweight is a serious health issue, not just a cosmetic problem.
The only surgical treatments for severely overweight people prior to approval of the Lap-Band were more invasive procedures such as stomach stapling and gastric bypass.
The manufacturer, BioEnterics Corporation of Carpinteria, Calif., did a three-year study of 178 people treated with the Lap-Band at eight U.S. medical centers. Most participants steadily lost weight and after 36 months had lost an average of 36 percent of their excess weight. Two percent gained some weight, and 5 percent neither lost nor gained.
The most common side effects reported included nausea and vomiting, heartburn, abdominal pain, and band slippage or pouch enlargement.
College freshmen living in dormitories have a higher risk of contracting meningitis than other college students, a recent study indicates.
Researchers, led by Michael Bruce, M.D., of the Centers for Disease Control and Prevention, say that vaccinating incoming freshman each year could substantially decrease their risk of contracting meningococcal meningitis--a bacterial infection of the membranes around the brain and spinal cord. The infection can be spread by kissing or sharing utensils.
Meningococcal meningitis is fatal in about 10 percent of cases and causes significant harm in another 10 percent. Another form, viral meningitis, generally is less serious. Earlier studies have shown that students who live on campus have a higher risk of developing the disease than students who live in off-campus housing.
The latest study, published in the Aug. 8 issue of the Journal of the American Medical Association, analyzed the records of 96 American college students ages 18 to 23 who were found to have had meningococcal infection between Sept. 1, 1998, and Aug. 31, 1999. According to Bruce, 68 percent of the 79 students for whom information was available had infections that may have been prevented through vaccination. The study also found that the overall incidence of meningococcal meningitis was 0.7 per 100,000 students, compared with 5.1 per 100,000 for freshmen living in dormitories.
According to the study, crowded conditions and the possibility that upperclassmen may have developed protective immunity to the disease may explain the differences.
Increasingly, colleges and universities are warning incoming students of the bacterial disease and are sponsoring vaccination clinics. The vaccine is effective for three to five years.
A capsule containing a tiny camera that, when swallowed, takes pictures of the inside of the small intestine has been approved by the FDA.
The Given Diagnostic Imaging System is a technological advance for detecting polyps, cancer, or causes of bleeding and anemia in the gastrointestinal tract. Snapping pictures twice a second, the camera-capsule also contains lights, a transmitter, and batteries and has a clear end that allows the camera to view the lining of the small intestine.
Prior to the approval of the tiny camera, the standard method of detecting abnormalities in the intestines was through endoscopic exam, in which doctors inserted a scope down into the small intestine through the mouth. But these scopes are unable to reach through the entire 20-foot-long small intestine, and provide a partial view. Available only by prescription, the camera capsule enables doctors to see areas that the endoscope cannot reach.
To do an examination using the device, a person swallows the camera-capsule and the muscles of the digestive tract propel it forward first through the stomach, then into the small intestine, into the large intestine, and then out in the stool. The device transmits images to a data recorder, which is worn on a belt around the person's waist. The physician then transfers the stored data to a computer for processing and analysis.
The battery has an eight-hour life expectancy, which generally is long enough to photograph the small intestine, but not the entire gastrointestinal tract.
The FDA clearance of the device was based on its safety, lack of side effects, and its ability to detect abnormalities in the small intestine, including parts that can't be reached by the endoscope.
The device must be used along with other endoscopic and radiological evaluations of the small bowel and is not intended to be used as a replacement for them.
The device is made by Given Imaging Ltd., an Israeli company with North American headquarters in Norcross, Ga.
The FDA has cleared for marketing a new device designed to prevent blood clots in people who undergo heart surgery. The PercuSurge Guardwire Plus device is intended for use on people who have previously had coronary bypass surgery and whose bypass vein graft has become blocked.
Coronary bypass surgery creates new routes for blood flow to the heart muscle when coronary arteries become blocked. This involves taking a healthy blood vessel from another part of the body and grafting it onto the heart. About 500,000 people have coronary bypass vein grafts each year. It is estimated that after a decade, at least half will have blockages in those vein grafts.
These blockages require treatment such as insertion of a stent during angioplasty, which opens up a narrowed vessel. The PercuSurge device is used during these procedures to collect and remove debris that results from treatment. The debris--small blood clots, cholesterol crystals, and other particles--may cause serious problems, such as heart attack, if it is swept down the vein graft into the heart. Major problems from loose debris occur in 10 percent to 20 percent of patients. The new device was shown in clinical trials to significantly minimize this risk.
Clinical investigators compared the results of 406 people who underwent angioplasty or stenting to unblock coronary bypass veins with the device and compared them to 395 people who received treatment without the device. The incidence of major problems caused by loose debris was 17 percent in the standard care group compared with 10 percent in the group treated with the new device.
PercuSurge, Inc., a division of Medtronic AVE, Sunnyvale, Calif., makes the PercuSurge Guardwire Plus.
The FDA and the National Cancer Institute (NCI) have announced a new joint research and clinical program that holds great promise for developing better and more targeted treatments for cancer. The new program, called the Clinical Proteomics Program, unites the study of all proteins in living cells (proteomics) to the clinical care of patients for the first time.
"This new approach to treatment holds the potential to revolutionize cancer detection and care," says Health and Human Services Secretary Tommy G. Thompson. "With this expanded collaboration, the FDA and NCI are employing powerful, new technologies they developed jointly." The agency collaboration, which began in 1997, is led by Emanuel Petricoin, Ph.D., of the FDA's Center for Biologics Evaluation and Research and Lance Liotta, M.D., Ph.D., of NCI's Center for Cancer Research.
The new Clinical Proteomics Program, funded for three years with $1.1 million per year, relies on recently developed tools capable of rapidly scanning cells for hundreds of proteins at once. Petricoin and Liotta also have created new technologies to generate protein fingerprints that may provide early warning of drug side effects. In addition, they have already invented or refined several key technologies used in proteomic analysis.
"The great challenge now in proteomics research is to begin to apply these technologies to clinical care," says Petricoin. "We hope to take these techniques out of the lab to assess their benefit for people with cancer, in a true bench-to-bedside clinical research program."
"The potential payoffs for this program are great," says Liotta. "Everything we learn while refining these cutting-edge technologies will benefit cancer patients and the people trying to help them."
Potential benefits of the joint program include:
Petricoin and Liotta have identified more than 130 proteins in cancers of the breast, ovary, prostate, and esophagus that change in amount as the cells in these tissues grow abnormally, which may provide new means of diagnosing and treating cancers earlier.
The new FDA-NCI collaborative program, announced in July, is the first step in moving these techniques out of the laboratory and into clinical settings for the benefit of patients. Cells from cancer patients at the National Institutes of Health are extracted before and after treatment with the aid of a special microscope invented in Liotta's laboratory. The microscope allows researchers to isolate normal cells, pre-cancerous cells, and tumor cells from the same patient. By capturing cells directly from tissue, the original protein pattern of the cells is maintained, which is not the case with traditional methods of isolating cells.
Next, the scientists analyze the patterns of proteins in the extracted tumor cells after the patient has been treated. For example, the researchers are trying to determine how a particular treatment changes the pattern of the proteins in a cell or whether the protein patterns change if the tumor returns after treatment.
The NCI has recently begun clinical trials using proteomics to help make decisions about the course of the patients' experimental treatments.
The FDA has approved Marquis (ponazuril), the first drug to treat equine protozoal myeloencephalitis (EPM). EPM is caused by a parasite (Sarcocystis neurona) and is the most commonly diagnosed neurological condition in horses in North and South America. In some areas of the United States, as much as 80 percent to 90 percent of the horse population may have been exposed to EPM. An estimated 1 percent of the horses exposed to the disease will develop clinical signs of EPM and require treatment.
The clinical signs may vary, and they may include weakness (particularly on one side), serious lack of coordination, and muscle wasting involving all four limbs. EPM is most often found in horses younger than 5 years old and in horses older than 13. Diagnosis of EPM is difficult, since there are at least four other central nervous system diseases in horses that can closely resemble the disease.
The FDA expedited the approval process for drugs to treat EPM in an effort to reduce the suffering and death associated with the disease, and because there were no approved therapeutics for treating this devastating illness.
Marquis is packaged as an oral paste to be given once a day for 28 days in adult horses. Bayer Animal Health, Shawnee Mission, Kan., is the manufacturer of the drug, which will be available by prescription only from a licensed veterinarian.
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2001-AUG-23.