U.S. FDA Approves Drug to Treat Facial Wasting

3 August (Reuters Health)—The US Food and Drug Administration (FDA) has approved Aventis' injectable drug Sculptra to treat facial wasting disease common among HIV-infected patients.

“FDA expedited review of the product because of its importance to people with HIV/AIDS,” the FDA said in a statement.

Aventis subsidiary Dermik Laboratories makes the drug, which is already marketed in Europe as a wrinkle-filler under the name New-Fill and is used in more than 30 countries.

Made from the same type of material used in dissolvable sutures, Sculptra is used to fill sunken cheeks, eyes, and other areas affected by fat loss, a common side effect of highly active antiretroviral treatment.

As a condition for approval, Dermik will conduct additional studies to monitor long-term safety, particularly in women and patients with darker skin, the FDA said.

New Anti-Inflammatory Drugs Increase TB Risk

5 August (Reuters Health)—Recently developed drugs called TNF-blockers have brought relief to many people with inflammatory conditions such as rheumatoid arthritis or Crohn's disease. However, the drugs do carry a risk.

In a report, federal health officials at the Centers for Disease Control and Prevention (CDC) in Atlanta point out that patients taking TNF-α antagonists, such as Remicade (infliximab), Enbrel (etanercept), and Humira (adalimumab), have an increased risk of tuberculosis (TB).

As of January 2004, “several hundred reports” of active TB in patients taking drugs in this class had been received by the US Food and Drug Administration's adverse events reporting system, according to an article in the Morbidity and Mortality Weekly Report.

While most of these cases occurred outside the United States, where the risk of TB infection is higher, the report describes 12 instances of active TB diagnosed among Californians who were being treated with TNF-blockers.

Eleven patients had TB disease after taking Remicade and 1 while on Enbrel therapy. Most of the cases probably represent progression of latent TB infection to active TB disease, according to CDC, because all but 1 patient had at least 1 risk factor for having latent TB.

In some of these cases, patients had not been screened for TB prior to starting TNF-blocker therapy. The CDC notes that many patients who need TNF-blockers may also be less sensitive to tuberculin because of their underlying condition or its treatment. Therefore, “tuberculin skin test results at the time of initiating TNF-α antagonist therapy might be falsely negative.”

The CDC recommends that doctors consider treating latent TB in patients with negative tuberculin test results whose circumstances “suggest a probability” of latent TB.

Postponing TNF-blocker therapy, when possible, until treatment of TB is complete, should also be considered.

Source: MMWR Morb Mortal Wkly Rep 2004; 53:683.

Editor's comment. Clinical Infectious Diseases recently published a report on the relationship between infliximab use and TB (Clin Infect Dis 2004; 39:295–9).

Mismatched Flu Vaccine Still Provided Benefit

12 August (Reuters Health)—Even though the influenza vaccine administered in the United States during the 2003–2004 influenza season was not optimally matched with the predominant circulating strain that season, substantial health benefit was realized among vaccinees, according to a report in the 13 August issue of the Morbidity and Mortality Weekly Report.

However, study results show that children between 6 and 23 months old should receive 2 doses of vaccine to optimize protection.

Dr. D. Ritzwoller, at Kaiser Permanente Colorado in Denver, and associates conducted a retrospective cohort study in children and a case-control study in adults to assess the effectiveness of the 2003–2004 influenza vaccine.

From electronic medical records, the investigators identified 5139 children between 6 and 23 months old enrolled in the Kaiser Permanente Colorado HMO between 1 October and 31 December 2003. By 7 December, 15% were fully vaccinated with 2 doses.

The estimated hazard ratio for medically attended influenza-like illness was 0.75 in vaccinated children compared with unvaccinated children, translating to a vaccine effectiveness of 25%. The vaccine was 49% effective in preventing medically attended pneumonia and influenza.

Children who received partial immunization did not have a significantly reduced risk of influenza-like illness, pneumonia, or influenza, compared with unvaccinated children, the investigators found.

For the adult study, the research team identified and contacted 330 patients between 50 and 64 years old who had laboratory-confirmed influenza between 1 November and 31 December. These subjects were matched with 1055 controls recruited through random-digit-dialing sampling.

Dr. Ritzwoller's group estimated the vaccine was 52% effective in preventing laboratory-confirmed influenza for subjects without a high-risk medical condition. The effectiveness was 38% for those with medical conditions associated with an increased risk for influenza-related complications.

The authors note that, when vaccine and circulating strains are well-matched, the expected vaccine effectiveness among healthy adults is 70% to 90%.

Overall, these figures support “recommendations to continue influenza vaccination efforts despite a suboptimal match between the predominant influenza A (H3N2) circulating and vaccine strains,” Dr. Ritzwoller's team concludes.

Source: MMWR Morb Mortal Wkly Rep 2004; 53:707–9.

FDA Approves Herpes Antibody Test

3 August (Reuters Health)—Trinity Biotech PLC said it received US regulatory clearance to market a diagnostic blood test to detect antibodies to herpes simplex virus- 1 (HSV-1) and HSV-2, commonly associated with oral and genital herpes, respectively.

The Captia test, unlike others, can differentiate between the 2 types of viruses, the Ireland-based company said.

Potential for Pandemic Seen with H9N2 Bird Flu Virus

10 August (Reuters Health)—A bird flu virus commonly found in chickens in Hong Kong's markets could mutate and become easily transmissible in humans, possibly leading to the next influenza pandemic, scientists said.

Researchers found the H9N2 virus in about 2% of chickens in a study between 2001 and 2003.

“H9N2 is widely circulating in this geographical region, and that increases the chance of this virus jumping to other species and degenerating into a novel subtype of influenza that is able to infect humans,” said Leo Poon, a microbiologist at the University of Hong Kong.

“Eventually, we will have a new pandemic strain. We don't know when, we don't know where, but better surveillance could help delay this disaster from happening,” he said. Poon was part of a team that conducted the study.

H9N2 has been detected in pigs and at least 3 people since 1999 in Hong Kong. It has a lower mortality rate than H5N1, but that means there is also a greater likelihood of it passing between species and mutating into something deadlier.

“Most of the infected chickens don't die, which means it can jump more easily to pigs, which are mixing vessels (for viruses) to mix and mutate,” Poon said. “And if it mutates and jumps to humans, it will be more virulent,” he added.

Pigs can be infected with viruses from different species, such as ducks and humans, at the same time. If this happens, genetic reassortment is possible, resulting in a new virus that could be deadly to humans.

Scientists say major flu pandemics occur every 30–35 years. The deadliest in the past century was the Spanish Flu pandemic of 1918–1919 that killed between 20 million and 50 million people worldwide, including 500,000 in the United States.

The exact source of that virulent strain is unknown but is thought to have been wild birds.

The virus behind the last major flu out break, the Hong Kong Flu pandemic of 1968, is thought to have originated in wild aquatic birds, such as ducks.

Editor's comment. Of interest, the US government has contracts for the production of vaccine for human use against both the H9N2 and H5N1 strains of avian influenza, as reported in the following news item.

U.S. Asks Chiron to Develop Human Vaccine Against H9N2 Bird Flu

17 August (Reuters Health [Maggie Fox])—The National Institute of Allergy and Infectious Diseases (NIAID) said it had awarded Chiron Corp., of Emeryville, California, a contract to develop a vaccine against the H9N2 strain of avian influenza.

Avian influenza has been sweeping through poultry farms and markets across Asia this year, killing or forcing the cull of more than 100 million birds and devastating the industry in some areas.

Some varieties cannot infect people, but some—notably, the H5N1 and H9N2 strains—have jumped to humans and can cause an especially serious and deadly disease in people.

Under the contract, Chiron will produce up to 40,000 doses of the vaccine, using an inactivated strain of the H9N2 virus developed by the Centers for Disease Control and Prevention. NIAID will conduct the clinical studies to see if the vaccine is safe and effective in people.

Chiron also has a US government contract to make vaccine against the H5N1 bird flu strain, along with Aventis-Pasteur, Inc.