News in brief - April 3, 2006

MS drug given green light to re-enter the market with limits - Pneumonia vaccine and mortality risk - HPV linked to skin cancer - Asthma perceptions may cause poor self-management

MS drug given green light to re-enter the market with limits

A Food and Drug Administration Advisory panel voted unanimously March 7 to allow the multiple sclerosis drug natalizumab, or Tysabri, to re-enter the market with restrictions on its use. The drug was withdrawn a year ago after three patients developed progressive multifocal leukoencephalopathy and two died from the brain infection.

A study published in the March 2 New England Journal of Medicine found no evidence of the serious disorder in a trial of more than 3,000 people treated with Tysabri for a range of conditions that included MS, Crohn's disease and rheumatoid arthritis.

The drug was approved November 2004 to treat relapsing-remitting MS. Studies had shown it substantially reduced the frequency of relapses.

The FDA advisory committee concluded that the drug should be made available once again. The move is unusual. The only other drug allowed back on the market after safety concerns led to its withdrawal was Lotronex.

The agency will determine what restrictions should be placed on the use of Tysabri, said Robert Temple, MD, director of FDA's office of medical policy.

The drug's manufacturers pledged to work with the FDA to finalize details of a risk management plan. They said FDA action was expected by the end of March.

Pneumonia vaccine and mortality risk

Adults hospitalized for pneumonia who have received the pneumococcal vaccine are at lower risk of dying from the disease than those who haven't been vaccinated, said a study published in the April 15 Clinical Infectious Diseases and available online.

Researchers analyzed data from nearly 63,000 patients hospitalized for pneumonia between 1999 and 2003. Vaccinated patients were 40% to 70% less likely to die during hospitalization than either unvaccinated patients or those whose status was unknown. Vaccinated patients also had a lower risk of developing respiratory failure, kidney failure, heart attack or other ailments.

Twelve percent of the patients were known to have received the vaccine before being hospitalized, 23% were unvaccinated and the status of the rest was unknown.

Questions have been raised about the effectiveness of the vaccine, said lead author David Fisman, MD, MPH, a visiting scholar at Princeton University in New Jersey. "However, the benefits of vaccination seem evident in the new study," he said. The pneumococcal vaccine impairs the development of a serious condition called bacteremia. "Even if you're really sick, prevention of the bacteria getting into the bloodstream ... might save your life."

HPV linked to skin cancer

The human papillomavirus might increase the risk of squamous cell skin cancer but does not appear to make basal cell carcinoma more likely, according to a study published in the March 15 Journal of the National Cancer Institute.

Researchers used multiplex serology to detect variations of the virus in the skin of those with these types of cancer and compared them with those who were cancer-free. HPV antibodies were 60% more likely in those with squamous cell carcinoma, but no significant difference was found when skin samples from healthy volunteers were compared with those with the basal cell form of the disease.

Those who developed tumors on skin that had been heavily exposed to the sun were more likely to be carrying the virus than those who developed the cancer elsewhere on their bodies. The risk of cancer also was increased if there were more viral subtypes present.

The authors suggest that this research might lead to new treatments for this type of cancer.

"While further study is needed, a potential role of viruses in skin cancer occurrence could represent a new line of investigation for the detection and treatment of squamous cell skin cancer," said Margaret R. Karagas, PhD, lead author and professor in the Dept. of Community and Family Medicine at Dartmouth Medical School in Lebanon, N.H.

Asthma perceptions may cause poor self-management

Asthmatic patients who believe they are disease-free when they are not experiencing symptoms are less likely to use maintenance medications, according to a study published in the March issue of Chest.

Researchers interviewed nearly 200 low-income minority adults hospitalized for asthma over 12 months. More than half believed they had asthma only when they had problems breathing. This perception also reduced the chance by one-third that a patient would adhere to an inhaled corticosteroid regimen.

The authors suggest that physicians need to educate patients about the chronic nature of this condition.

"[Patients] are treating asthma more like a cold or flu that will go away between attacks than as the serious, chronic disease it is," said Ethan A. Halm, MD, MPH, lead author and associate professor of medicine at Mount Sinai School of Medicine in New York. "We need to find ways to tailor our educational efforts to individual beliefs and behaviors if we are to make headway in improving outcomes."