By Ben Hirschler
LONDON (Reuters) - Roche of Switzerland has bought the rights to a second type of experimental Alzheimer's drug from privately-held AC Immune, raising its bet on finding a treatment for the degenerative brain disorder.
The deal reflects continuing interest in Alzheimer's among big drugmakers, despite past setbacks and low expectations for two other drugs from rival companies that will report advanced-stage clinical trial results in a few months time.
Roche's Genentech unit will make an undisclosed upfront payment and pay up to 400 million Swiss francs ($420 million) in milestones, based on the success of the anti-Tau antibodies in clinical development, AC Immune of Lausanne said on Monday.
The deal tightens the relationship between the two firms as Roche has already acquired rights to another drug, crenezumab, that is designed to bind to beta amyloid, which causes plaques in the brain linked to Alzheimer's.
Some scientists think that Tau protein may be a second major cause of Alzheimer's besides amyloid, since it forms twisted fiber and tangles inside brain cells.
Roche is best known as the world's biggest maker of cancer drugs but the Basel-based company hopes it can also apply its understanding of disease complexity to the equally difficult world of Alzheimer's.
The first deal with AC Immune for crenezumab, signed in 2006, won a notable vote of confidence last month when the U.S. government decided to back a clinical trial testing the drug among members of an extended family in Colombia who carry a gene that causes early Alzheimer's.
Many large drug companies are pursuing Alzheimer's treatments, despite previous setbacks, and the field is seen as opening up a potentially huge commercial opportunity, although the risks are very high.
"While expectations are appropriately low, commercial prospects for success rival that of the industry's largest $20 billion-plus markets, and could transform the outlook for some of the developers," Deutsche Bank analysts said in a lengthy report on Alzheimer's on Monday.
Two amyloid-targeted approaches - Eli Lilly's solenezumab and bapineuzamab, from Pfizer, Johnson & Johnson and Elan - are currently completing final-stage Phase III clinical testing.
Results from these two programs will be reported at clinical meetings in October, and Deutsche believes headline results could be announced through brief press releases in around August.
Hopes for solenezumab and bapineuzamab, however, are not high, in large part because there is a growing belief among experts that patients may have to be treated much earlier in order to get any benefit from such amyloid-targeting drugs.
Still, the therapies might be shown to work in a subset of patients, which would underscore the case for further trials.
Scientists and drugmakers have been targeting deposits of beta amyloid in Alzheimer's patients for decades, and some have succeeded in removing the sticky plaques that are a hallmark of the disease. But so far, none of the drugs has succeeded in improving patients' thinking and memory capabilities.
Researchers say the reason is likely to be that tests were carried out on people whose brains were already wrecked by Alzheimer's, the most common form of dementia that affects 35.6 million people worldwide.
The trial of Roche and AC Immune's crenezumab in Colombia should be different because it will be tested on people before the disease has done much damage to brain cells.
($1 = 0.9513 Swiss francs)
(Reporting by Ben Hirschler; Editing by Mark Potter and Hans-Juergen Peters)