A new study published today in the Journal of the American Medical Association suggests that biological products have more safety problems compared to chemical drugs. These medicines are made from natural sources, such as human or animal tissues, proteins derived from living cells, and they include enzymes, antibodies, growth factors, hormones and vaccines. They are typically prescribed to treat a range of conditions including anemia, rheumatoid arthritis, hepatitis and cancer.

Thijs Giezen of Utrecht University in the Netherlands and colleagues looked at 174 medicines called biologicals or biologics, that were approved in the USA and/or the European Union between January 1995 and June 2007. 136 of the 174 biologicals were approved in the U.S., 105 in the European Union and 67 in both. Despite the fact that 41 of the biologicals examined were the subjects of 82 safety-related regulatory actions, none was withdrawn from the market.

The authors of the study found that 1 in 4 biological products approved since 1995 had at least one safety-regulatory action issued within 10 years of their approval. 11 percent of the medicines were required to put a “black box” warning on the product, the study’s authors noted.

“The safety of these drugs is not always completely defined at the time of approval,” said Dr. Phil B. Fontanarosa during a news conference in Washington D.C. He added that a 2002 JAMA study found about 10% of drugs had received “black box” warnings or had been withdrawn.

Biologics are made from a variety of natural resources—human, animal, and microorganism—and may be produced by biotechnology methods, according to the Food and Drug Administration. They can be composed of sugars, proteins, or nucleic acids, or a combination of these substances.