European regulators have recommended conditional approval of GlaxoSmithKline's new breast cancer drug Tyverb.

The European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) has issued a revised positive opinion confirming the positive benefit-risk profile for Tyverb (lapatinib), having been asked by regulators to look again at the drug in March after clinical data suggested that predominantly elevated liver enzymes could occur during treatment.

After reviewing new data submitted by GSK, the CHMP has agreed that the benefit-risk-balance for using Tyverb to treat patients with advanced or metastatic breast cancer was positive. However, the committee recommended that “the product information should be amended to add special warnings about the risk of hepatotoxicity".

Positive recommendations from the CHMP are normally endorsed by the European Commission within a couple of months. It will be indicated to be given in combination with Roche's Xeloda (capecitabine) for the treatment of patients with advanced or metastatic breast cancer whose tumours overexpress HER2.

Tyverb, which is already sold as Tykerb in the USA, looks set to face a tough battle for market share with Roche’s Herceptin (trastuzumab), although some analysts expect that it will eventually overtake its rival and generate peak annual sales well in excess of $1 billion. This view is due to the fact that GSK's drug has the advantage of being orally-active, while Herceptin is dosed by injection.

Volibris approved in Europe
GSK also noted that the European Commission has granted marketing authorisation for Volibris (ambrisentan) for the treatment of pulmonary arterial hypertension. The drug, a non-sulphonamide class endothelin receptor antagonist and co-developed with Gilead Sciences, is the first PAH medicine indicated for patients classed as World Health Organisation (WHO) Functional Class II and III in Europe.