Bayer and partner Regeneron Pharmaceuticals have been boosted by late-stage data which demonstrates that their experimental eye drug, VEGF Trap-Eye, is as effective as Roche and Novartis' blockbuster Lucentis.

The companies have announced top-line results from two parallel Phase III studies in patients with age-related macular degeneration (wet AMD), the leading cause of blindness in people over 65 in the USA and Europe. In both studies, all regimens of VEGF Trap-Eye (aflibercept), including an injection every two months, achieved their primary endpoint compared to Lucentis (ranibizumab) dosed every month.

Specifically, in the 1,217-patient North American VIEW 1 study, vision with the drug was maintained or improved in 96% of patients receiving a monthly 0.5mg injection and in 95% on a 2mg dose once or twice monthly. That compared with 94% of patients injected with a 0.5mg dose of Lucentis every month, and an international study, VIEW-2, involving 1,240 patients, came up with a similar result.

Ursula Schmidt-Erfurth of the University Eye Hospital in Vienna, and VIEW 2 principal investigator, said the results of both studies indicate that VEGF Trap-Eye "could establish a new treatment paradigm for the management of patients with wet AMD; predictable every-other-month dosing without the need for intervening monitoring or dosing visits".

Lucentis is currently the only approved treatment for wet AMD, though Roche's much-cheaper Avastin (bevacizumab) is heavily prescribed off-label, and brought in around $2.40 billion in sales, split fairly evenly between the partners (Roche in the USA and Novartis elsewhere). Bayer and Regeneron want a slice of that market and are planning to submit regulatory applications for marketing approval in Europe and the USA in the first-half of 2011.

Analysts believe that the slice could be considerable, given that the injection for VEGF Trap-Eye is only once every two months. This less frequent dosage has led some to predict peak sales of up to $2 billion.