US FDA approves GSK's Tykerb with Xeloda, enters competition with Herceptin

The US Food and Drug Administration has approved GlaxoSmithKline's breast cancer drug Tykerb (lapatinib). The agency has cleared the UK drug major's targeted oral agent in combination with Roche's chemotherapeutic Xeloda (capecitabine) for patients who failed to respond to Roche's breakthrough drug Herceptin (trastuzumab).

This approval marks Tykerb's first step into a market worth $35.0 billion a year. Collins Stewart analyst Navid Malik predicted that the drug will achieve peak annual sales of $1.16 billion by 2012 while Gbola Amusa, an analyst for Sanford C Bernstein, believes that sales will peak at $1.5 billion in 2012. Many other analysts project yearly turnover of $1.0 billion by 2010.

However, observers are cautious on the short-term potential of Tykerb as new cancer drugs are normally used on a very small proportion of patients. Decision Resources analyst Mary Argent-Katwala noted that sales of Roche's breakthrough drug Herceptin did not soar until it was approved for early-stage breast cancer.