Biological products, which are becoming more popular to treat a variety of disorders, have more safety problems compared with chemical drugs, according to a study published today in the Journal of the American Medical Assn.
Biological products are made from natural sources, such as human or animal tissues or microorganisms. They include enzymes, antibodies, growth factors, hormones and vaccines. Since 1982, 250 biological products have been approved in the United States and Europe. Between 2003 and 2006, biological products represented 24% of the new drug approvals in the United States.
That makes understanding their risks and benefits important. Biological products, however, are harder to assess for safety, say the authors of the study, from Utrecht University in the Netherlands. While the structure of chemical substances is known, biological products are complex and contain components that are not easily recognized and categorized, says Dr. Phil B. Fontanarosa, executive deputy editor of JAMA who presented the study today at a news conference in Washington, D.C. "The safety of these drugs is not always completely defined at the time of approval," he says.
The new study found that 1 in 4 biological products approved since 1995 had at least one safety-related regulatory action issued within 10 years of their approval, and 11% of the biological products were required to put a "black box" warning on the product. On average, the safety issues arose about four years after the product had been on the market.
There are no head-to-head comparisons of the safety of biological products versus chemical drugs. But, says Fontanarosa, a 2002 JAMA study found about 10% of drugs had received black box warnings or had been withdrawn. About half of those actions occurred within two years of the drugs' approvals.
The authors of the study said the results show that more effort should be spent before a biological product is approved to understand its mode of action and thus possibly predict potential risks. Moreover, close surveillance of the products should continue after approval and doctors should be aware that biological products, in general, pose more safety risks.
In an editorial accompanying the paper, JAMA Editor in Chief Catherine D. DeAngelis and Fontanarosa said:
"Given the current imperfect process for approval and the flawed postmarketing surveillance system, the drug and device regulation process is at best an inexact and incomplete science. Until these deficiencies in the system are remedied, some patients inevitably will continue to experience harm from the use of newly marketed products as well as from use of other approved medications."
For more information on biological products, see this website from the Food and Drug Administration.
-- Shari Roan
Photo: The biological therapy, Enbrel, used to treat rheumatoid arthritis, was required to put a "black box" warning on the product earlier this year because it may increase the risk of tuberculosis and other infections. Credit: Immunex / Bloomberg News.