(Adds Roche reaction)

BRUSSELS, Aug 7 (Reuters) - The European Commission has suspended Swiss drugmaker Roche's <ROG.VX> licence to market the HIV drug Viracept in the European Union, it said on Tuesday.

"The suspension is due to the contamination of certain lots of Viracept with ethyl mesilate, a genotoxic substance," the EU executive said in a statement.

The suspension follows the withdrawal of the drug from the market in June when Roche said its licence for Viracept was being temporarily suspended pending a review by authorities.

The Commission said Tuesday's announcement was based on the scientific conclusions from the European Medicines Agency (EMEA) and consultations with EU member states.

"The suspension could only be lifted by a further decision by the Commission, after the evaluation of new data given by the Agency," the EU executive said.

In June, Roche said it had identified a chemical impurity in the product, leading to the recall in Europe and some other regions.

A Roche spokeswoman said that the company was trying to solve the manufacturing problem with European health authorities and aimed to manufacture the drug again by September or October.

Viracept, known generically as nelfinavir, belongs to a class of HIV/AIDS drugs called protease inhibitors. It forms a key part of many drug cocktails used to treat people when they first need antiretroviral therapy.

Such drugs can slow the spread of the virus in the body and cut the risk of patients developing AIDS-related illnesses.

Viracept received marketing approval in Europe in 1998. It was cleared for use a year earlier in the United States, where it is sold by Pfizer Inc. <PFE.N>.

AlertNet news is provided by