Roche has regained its Viracept license following the drug's withdrawal from the market in August after a carcinogenic compound was found to have contaminated several drug batches. The EC decision allows the company to recommence manufacture of the drug for distribution in the EU, but Swiss authorities have yet to reinstate the company's license, and several other countries are still deliberating whether to allow the drug back on the market. Many countries (including those in the Middle East, Far East and some African countries) follow the lead of the Swissmedic agency, and so are still holding back on making the drug available to patients again. There are additional countries operating independently that are also still keeping the drug off the market. Roche heard that European regulators had recommended the return of the Viracept marketing authorisation towards the end of last month, when in-PharmaTechnologist reported that up to 25,000 patients could have been affected by highly contaminated drug batches. Roche had been forced to recall the drug following a spike in levels of ethyl mesylate (EMS), a known genotoxic compound, caused by errors in cleaning process at its Swiss plant. The company lost its marketing authorisation for the drug altogether in August, when it was realised that EMS has always been present in the treatment at low levels and that the safety of the drug in its normal condition could therefore not be guaranteed. All patients who were being prescribed Roche-manufactured Viracept were taken off the medication and switched to alternative treatments. The recall has so far cost the company CHF115m (€69m). Today's decision gives the company the go-ahead to restart manufacturing activities and get the HIV drug back on the market, but given that no patients anywhere in Europe are currently taking the medication, it is unlikely that uptake of Viracept will be particularly high. "We do not anticipate great demand for the medicine," a Roche spokesperson told in-PharmaTechnologist.com from the company's Basel headquarters. "But we still wanted to make it available as a treatment option to patients." Roche altered its manufacturing processes to limit the formation of EMS in the final drug, and has introduced a series of checks during the production process to ensure that the compound can be detected as early as possible. These steps convinced regulators and the EC that the company had taken sufficient steps to warrant the reinstatement of its license, and the return of Viracept to the market. Given the time scales involved in manufacturing, packaging and getting the drug back into the supply chain, the medication will still not be available to patients for several months and will reach different countries at different times. As part of the original license suspension, Roche was also ordered to carry out toxicology studies to help determine how harmful the EMS compound is to humans, data on which is currently extremely limited. Roche initiated two studies, looking at gene mutations and chromosomal damage caused by EMS. Final results are expected during the first half of 2008, but according to a Roche spokesperson preliminary data from one of the studies suggests that there is a distinct threshold for EMS toxicity. This essentially means that below this threshold, EMS is unlikely to cause any damage to DNA. Although the threshold suggested by this early data was not disclosed, Roche has implemented a 0.6ppm limit for EMS levels in the final drug product, in line with the Threshold for Toxicological Concern (TTC). Given the anaemic patient return to the drug expected by the company, and the relatively low profile it had in the firm's portfolio, the question arises as to whether the resources dedicated to Viracept would be more profitably allocated elsewhere. As to whether Roche might consider dropping the drug altogether or using the manufacturing capacity for other more popular drugs, the company spokesperson was unwilling to speculate, saying only that the company still sees Viracept as "a valuable treatment option" that should remain available to HIV patients. Roche was unable to provide Viracept sales figures for this year, but 2006 sales totalled CHF160m, with the company generally expecting CHF100-150m annually. While the firm had noticed a steady decline in Viracept sales over recent years, the events of the last quarter are likely to have taken a real toll on not only the sales of the drug for this year, but could also be expected to have had a major impact on any future sales of the drug.