Johnson & Johnson and Vertex Pharmaceuticals are celebrating after regulators in Europe gave the green light to the firms' hepatitis C drug Incivo.

The European Commission has approved Incivo (telaprevir), a direct-acting antiviral protease inhibitor, for the treatment of genotype-1 chronic hepatitis C virus, in combination with peginterferon alfa and ribavirin. The approval was based on data from three Phase III studies involving 2290 patients.

Two of those studies, the ADVANCE and REALIZE trials evaluated Incivo in combination with peginterferon alfa and ribavirin versus standard care (the two latter drugs alone). Cure rates for previously untreated patients in the Incivo arm were 79% versus 46% for patients on the peginterferon alfa/ribavirin combo. In patients who had relapsed during previous treatment, the cure rates were 84% versus 22%.

J&J holds the European rights to Incivo, while Vertex will receive royalties. The latter launched the treatment in the USA earlier this year, as Incivek, and it has got off to a strong start. The drug was also co-developed by Japan's Mitsubishi Tanabe Pharma Corp.

Telaprevir belongs to a new class of medicines that can directly inhibit viral replication in infected host cells which can lead to the eradication of the virus, and thus a cure of chronic hepatitis C. Some 70% of hepatitis C virus infections in the Western world are genotype 1.

Charles Gore of the World Hepatitis Alliance, noted that the arrival of direct-acting antivirals "is the first treatment breakthrough in more than 10 years and a significant step forward for the hepatitis C community. It will offer more patients hope for a cure".

Telaprevir is going to compete with Merck & Co's Victrelis (boceprevir), which was approved for hep C by the US Food and Drug Administration in May.