Genentech shares dip 1.5% after stroke warning on predicted blockbuster Lucentis

US biotehcnology firm Genentech says that its new wet age-related macular degeneration drug Lucentis (ranibizumab) might raise the risk of stroke.

The company made these points in a letter posted on its web site which it also sent to retinal specialists, stating that 1.2% of patients treated with a high dose of Lucentis in a clinical trial suffered a stroke versus 0.3% of those who were given a low dose. The findings could hurt sales of the drug as the warned-off dosage strength, 0.5mg per injection, is the one that is marketed.

Co-developed with Swiss drug major Novartis, Lucentis is the first drug shown in clinical trials to improve vision and vision-related quality of life in a significant number of people suffering from wet AMD, as opposed to just slowing the rate of decline. In third-quarter 2006, Genentech, which is majority-owned by Swiss group Roche, reported a 34% leap in net income to $1.94 billion, aided by good acceptance of Lucentis (Marketletter October 16, 2006), which has seen the drug earn $380.0 million since its US launch in June 2006.