Mon, Mar 06, 2017 - Page 7 News List

Drugmakers abandon caution in search for Alzheimer’s therapy

Drugmakers are pouring hundreds of millions of dollars into lengthy clinical tests in a bid to find a cure and tap a market worth US$30 billion in the US alone

By Naomi Kresge and Doni Bloomfield  /  Bloomberg

Alzheimer’s disease is upending the rules of drug discovery, with a handful of companies abandoning caution to keep pursuing an elusive hypothesis because the potential payoff is so great.

Even the merely forgetful, whose lives have yet to be derailed by the disease, have become candidates for clinical tests.

Scanning the brain for telltale signs of Alzheimer’s earlier — and ratcheting up drug dosage — might help turn failures into breakthroughs, AC Immune SA chief executive officer Andrea Pfeifer said.

The Swiss company’s partner on its experimental drug, pharmaceutical giant Roche Holding AG, last week said it would embark on a second advanced test, undeterred by a failed intermediate trial.

Pfeifer’s optimism is a case study of the industry’s unusually high risk tolerance on Alzheimer’s, where more than 100 experimental drugs have already failed — with two recent setbacks from Merck & Co and Eli Lilly & Co. Like Roche and its partner, Biogen Inc is chipping away at the same target that has eluded rivals. Merck and Lilly have opted to keep testing their medicines in patients showing only hints of the degenerative disease.

Each advanced trial can cost hundreds of millions of US dollars, according to Lilly.

“It’s always a question — are you throwing good money after bad?” Zurich-based Rahn & Bodmer Co fund manager Birgit Kulhoff said. “If you were to be successful, it would be an extremely big market.”

Drugs that halt the progress of Alzheimer’s disease could be a market worth as much as US$30 billion in the US alone, Sanford C Bernstein & Co analysts estimate.

Cancer is the only other disease for which companies are this willing to look deep into a failed study for a positive trend to chase, Kulhoff said, adding that Alzheimer’s tests are probably more expensive because researchers follow patients for longer and monitor them closely.

The drugmakers would not disclose how much they have spent on clinical tests.

A final-stage trial in Alzheimer’s disease can cost more than US$200 million, Cowen & Co analyst Eric Schmidt said.

Such a study in a cancer like melanoma would tend to be much smaller and could cost about US$50 million to US$100 million, he said.

Just arranging and administering the brain scans needed to make sure people have signs of the disease cost about US$15,000 to US$20,000 per person in a small test, AC Immune said.

Roche made its cost-benefit calculation two-and-a-half years ago. Crenezumab, the medicine it is working on with AC Immune, had failed to help patients think more clearly or retrieve memories in a mid-stage trial, a hurdle potential drugs usually must clear before they go into the last, largest and most expensive stage of clinical studies.

Instead of abandoning the compound, Roche looked at a trend toward benefit in the least sick patients and spent the next two years figuring out how high it could safely ratchet up the dose. Then last year, it started another 750-patient study, with results expected in 2021.

Now it is embarking on a separate trial, also with 750 patients with a very mild form of the disease. It is unclear how that test is to differ from the first one. It is also trying a higher dose for another Alzheimer’s compound, gantenerumab, after a late-stage trial failure.

Both Roche drugs are aimed at protein pieces called beta amyloid that clump together in the brain and are thought to play a role in triggering the disease. Trouble is, so did the Lilly medicine that failed a test in patients last year. Last month’s unsuccessful trial from Merck also centered on beta amyloid as a target, although the type of medicine was thought to prevent the substance from forming. Those failures have cast doubt on the whole approach.

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