The European health regulator said it extended a safety review of chronic hepatitis C treatments after new data showed patients taking the drugs were at risk of their liver cancer returning.

“The study suggested that these patients were at risk of their cancer coming back earlier than patients with hepatitis C who were not treated with direct-acting antivirals,” the European Medicines Agency (EMA) said. (bit.ly/1MxDslL)

The review covers some of the top-selling products in the multi-billion dollar hepatitis C market. These drugs cure well over 90 percent of patients with the liver disease and cut down the treatment duration.

The EMA cited Bristol-Myers Squibb Co’s Daklinza, AbbVie Inc’s Exviera and Viekirax, Gilead Sciences Inc’s Harvoni and Sovaldi and Johnson & Johnson’s Olysio in its statement.

The safety review extension follows the release of new data this month from a study.

The EMA started its review last month after the hepatitis B virus re-activated in patients who were infected both by hepatitis B and C viruses, and were being treated with the heptatitis C drugs.

(Reporting by Vidya L Nathan in Bengaluru; Editing by Saumyadeb Chakrabarty)

Source: Reuters