Last month, Roche Pharmaceuticals announced a global recall of its HIV/AIDS drug Viracept, after discovering that some batches had been contaminated with a carcinogen during a flawed manufacturing process at its Swiss plant. Patients should immediately discontinue the drug and switch to other medicines, Roche said.

In Europe the recall caused little stir, since the drug has mostly fallen out of use, replaced by newer, more expensive alternatives. But tens of thousands of people take Viracept worldwide, most of them poor people with AIDS in developing countries. And in places, newer substitutes are not available to patients, either because they are not licensed or are substantially more expensive.

Roche, which had revenues of 42 billion Swiss francs, or $35 billion, last year, said it would cover the “reasonable costs” of the recall, but so far, patients or HIV treatment programmes have had to make up the difference in cost.
Officials at the World Health Organisation in Geneva and the European Medicines Agency in London said that Roche had not provided information they consider essential for safeguarding public health: which countries the tainted medicine was shipped to, the concentration of the contaminant and what the company will do for its patients. The European agency has cancelled Roche’s license to market the drug.

Dr Lembit Rago, an official at the WHO, in Geneva, called the total recall “sort of a disaster” for patients in poor countries.

In response to e-mailed questions, Martina Rupp, a spokeswoman for Roche, said it had shipped “at least one packet of Viracept with high levels of the impurity to 35 countries”. But she declined to say which countries, as a matter of policy. High levels of the contaminant “were observed in batches of Viracept that had been released to countries since March 2007,” she said.

The company made the recall worldwide “in order to avoid confusion”, she said. Roche has estimated that about 45,000 patients were affected by the recall. Rupp said that the toxic substance, ethyl mesilate, should be called an “impurity” rather than a contaminant because it was created in the manufacturing process and because this type of chemical can be found in very low levels in other medicines, although it was not supposed to be present in Viracept.

At high doses, ethyl mesilate has been shown to cause cancer in animals, and at lower levels it has caused genetic mutations, but data are extremely limited. It is particularly harmful to children and pregnant women.

The global market for HIV drugs is checkered with different drugs available at different prices in different places. HIV specialists now prefer Kaletra, made by Abbott Laboratories. It is in the same class of drugs as Viracept and has fewer side effects. But it has not been licensed in many middle-income and poor countries.

In Venezuela, 3,000 people were on Viracept when the recall was announced, and the effect was “severe”, since many had no other options, according to Edgar Carrasco, an AIDS activist in Caracas. Alberto Nieve, another activist, said that Roche had promised to make a donation of another medicine. The company insisted that it receive a list of people, who were on Viracept, before it would make the donation, he said.

Viracept had been sold in 49 countries since 2004, according to the WHO, with over 12 million units sold in 2006 and 2 million in 2007 before the recall. Canada, Japan and the United States, were not affected by the recall since another company, Pfizer, makes a version of Viracept in those nations.

The effect of the recall on patients is still being assessed, but would vary considerably depending on a country’s finances and the organisation of its HIV treatment programmes, Rago of the WHO said. Unicef records show that Viracept was recently sold to Benin, Ivory Coast, Moldova, Mali, Niger, Nigeria, Pakistan, Philippines and Yemen.