ZURICH, Nov 10 (Reuters) - Novartis's bid to move in on Bayer's and Regeneron's eye-drug turf was buoyed on Friday by data showing patients on the Swiss drugmaker's new RTH258 drug showed less disease activity than those on its rivals' drug Eylea.
Active disease was observed in 23.5 percent of RTH258 patients versus 33.5 percent of Eylea patients at 16 weeks, Novartis said, of its investigational treatment for wet age-related macular degeneration (AMD), where abnormal, leaky blood vessels can cause blindness.
A second, similar study found active disease in 21.9 percent of RTH258 patients versus 31.4 percent of those on Eylea for the condition affecting 20-25 million people worldwide.
Novartis in June touted initial data showing its drug may require fewer injections directly into the eye than Eylea, while matching it on vision and safety measures.
The Basel-based drugmaker hopes this latest analysis lends RTH258 additional muscle when matched head-to-head with Eylea as well as Lucentis, which Roche sells in the United States.
"When you take all of that together ... we believe we have a very compelling proposition," Vas Narasimhan, Novartis's chief drug developer who will become CEO in 2018, said on a conference call.
Novartis, which released the data at the American Academy of Opthalmology conference in New Orleans, predicts RTH258 annual sales will top $1 billion and aims to file for U.S. approval in late 2018.
Making it a success is by no means clear sailing.
For one, Novartis owns Lucentis rights in Europe where it has contractual obligations to continue marketing that drug. Analysts say cannibalisation from RTH258 will be a challenge.
Competition abounds, too: Eylea, with $5 billion in annual sales, has made inroads against the $3.2 billion-per-year Lucentis, whose 2020 U.S. patent expiration will expose it to cheaper copies.
Moreover, Roche's cancer drug Avastin is effective in off-label AMD use and has won favour because it costs a fraction of Lucentis and Eylea. In Britain, Novartis and Bayer are fighting doctor groups aiming to switch to Avastin.
Other would-be rivals are racing to market, too.
Allergan, whose investigational Abicipar is in Phase III trials, is also trumpeting prospects of reduced injections compared to Lucentis. Gene therapies may also be on the distant horizon.
Still, Novartis's Narasimhan remains optimistic for RTH258's reception when it hits the market, likely in 2019.
"When you actually see an image of a patient having a needle inserted into their eye, this is something patients definitely want to avoid," he said.
"Retinal surgeons have busy offices and want to do more complex retinal surgery. Today, they have offices filled with patients waiting for injections." (Reporting by John Miller; Editing by Adrian Croft)