Roche and Trimeris ( TRMS) said European regulators have approved the AIDS drug Fuzeon for use in the European Union. The action means Fuzeon can be marketed in all 15 member countries of the E.U. Fuzeon was approved by the Food and Drug Administration in the U.S. in March, and Swiss regulators cleared the drug earlier this month. The companies expect to introduce Fuzeon over the next several months on a country-specific basis. Fuzeon works by preventing HIV from entering a cell, unlike other drugs that fight the virus after the fact. Shortly after the drug received approval in the U.S., Adam Feuerstein, a columnist for RealMoney.com, took an in-depth look at Fuzeon. In early afternoon Nasdaq trading, shares of Trimeris were down 9 cents to $48.42.