By Sadie Gray
07 June 2007
An HIV drug taken by 550 people in the UK was recalled last night over fears that it may be contaminated with a substance that could cause cancer.
The Medicines and Healthcare products Regulatory Agency (MHRA) said patients prescribed Viracept "should contact their doctor immediately".
The agency said in a statement that it was recalling the drug, manufactured by Roche, to minimise risk to patients. Production of all batches of Viracept was affected by contamination with a "genotoxic substance" - a substance that can affect the genes and trigger cancer, the agency said.
A spokeswoman for the MHRA said the problem had been detected at a Roche manufacturing plant in Spain. "They don't know how long they have had the problem so all batches have had to be recalled. We have a duty to alert doctors and patients in the UK to the risk." She said it was not yet clear if batches had been contaminated deliberately.
A spokeswoman for Roche said there was no indication that the contamination was deliberate. "I would doubt that would happen," she said.
William Burns, the chief executive of Roche's phamaceutical division, said that the impurity had been caused by an interaction between two chemicals, one of them a cleaner, in a vessel in which the product was made. The contamination was caused by human error, the company added. "Analysis of the affected tablets showed they contain higher than normal levels of methane sulfonic acid ethyl ester," Roche said.
Six patients had reported that the drug, which comes in powder and tablet form, was giving off a strange odour. Viracept, introduced in the EU 1998, made £68m for the Basel-based Roche last year.