News in brief - June 26, 2006

HPV vaccine gains FDA approval - FDA OKs limited use of Tysabri - Asbestos exposure can raise cancer risk - Osteoporosis increasingly affecting men

HPV vaccine gains FDA approval

The Food and Drug Administration approved on June 8 the first vaccine to prevent cervical cancer, precancerous genital lesions and genital warts caused by the human papillomavirus, types 6, 11, 16 and 18. It was approved for girls and women ages 9 to 26.

The vaccine, Gardasil, manufactured by Merck & Co., was evaluated and approved in six months via the FDA's priority review process.

Gardasil is a recombinant vaccine given as three injections over a six-month period. It will not eliminate the need for routine Pap screening, as women are not protected if they had been infected with the virus prior to receiving the shot. Also, while it protects against the HPV strains that most commonly lead to disease, it doesn't protect against all types.

Merck tested the safety of the vaccine in about 11,000 people. The most common adverse effects included mild moderate local reaction including pain or tenderness at the site of the injections.

Merck reported five congenital anomalies in babies born to women who conceived within 30 days of receiving the vaccine, prompting monitoring of women who received Gardasil while unknowingly pregnant.

There is also an ongoing study to evaluate the safety and effectiveness of the vaccine in males.

FDA OKs limited use of Tysabri

The Food and Drug Administration decided June 5 to allow Tysabri (natalizumab) to be prescribed once more, although this time with numerous restrictions. The drug had been approved in November 2004 for patients with relapsing forms of multiple sclerosis but was removed from the market in February 2005 by its manufacturer after three patients in the drug's clinical trials developed a serious brain infection -- two died as a result.

The drug, a monoclonal antibody, had been hailed as an important new treatment.

Under the new prescribing restrictions, Tysabri is to be used alone rather than in combination with other immune-system-modifying drugs and only for patients who have not responded adequately to, or cannot tolerate, other treatments for MS.

In addition, the FDA is adopting a requirement recommended by its Peripheral and Central Nervous System Drugs Advisory Committee that there be mandatory patient registration and periodic follow-up to identify as early as possible any cases of progressive multifocal leukoencephalopathy, or PML, that may occur and to try to determine the reason for the infection.

Prescribers, pharmacies and infusion centers who handle the drug also will have to register with the risk management plan, called the TOUCH Prescribing Program, developed by manufacturer Biogen Idec. Before initiating the therapy, patients must have an MRI scan to help differentiate potential future multiple sclerosis symptoms from PML.

Asbestos exposure can raise cancer risk

Sufficient scientific evidence exists to indicate that asbestos exposure can cause cancer of the larynx, says a new report from the Institute of Medicine. Some evidence also was found that suggested, but ultimately did not prove, that asbestos can cause cancer of the pharynx, stomach, colon and rectum, concluded the committee that wrote the report, which was released June 6.

The IOM undertook the study to answer questions raised in congressional discussions about compensation for people with ailments associated with asbestos exposure. The committee studied the quality, limitations and applicability of 120 epidemiological studies of exposure and cancers of the throat and digestive tract as well as 200 experimental studies.

The committee found compelling evidence that asbestos is associated with an increased incidence of laryngeal cancer and that the risk increases with the intensity and duration of exposure. Laryngeal cancer is relatively rare -- about 9,500 new cases will occur this year -- and 3,740 people will die from it. Smoking and heavy consumption of alcohol have been considered risk factors.

The committee found that there is a suggestion that asbestos is linked to a slightly increased risk of stomach, pharyngeal and colorectal cancer, but the cumulative results of the study were not strong enough to draw conclusions.

Osteoporosis increasingly affecting men

A growing number of men are developing osteoporosis, and the economic impact is and will be considerable, according to several studies presented at the International Osteoporosis Foundation's World Congress in Toronto this month.

"People are not really aware that this disease also occurs in men as well as women," said Rick Adachi, MD, professor of medicine at McMaster University in Hamilton, Ontario. He was an author on several papers at the meeting.

For example, one of his studies analyzing expenses related to osteoporosis in managed care found that men were responsible for 30% of the costs related to fragility fractures.

These expenses, however, are expected to grow, and other researchers are predicting the incidence of this disease among men will increase significantly over the next few decades because of the aging of the population. A study from Tufts-New England Medical Center in Boston and Procter & Gamble Pharmaceuticals found that men currently experience about 595,000 osteoporotic fractures annually with a cost to the health care system of $4.1 billion. The authors of this paper project that the number of fractures will increase to 925,000 annually by 2025 with an estimated cost of $6.7 billion.