Biogen success offers hope for Alzheimer’s treatment

Biogen success offers hope for Alzheimer’s treatment

Biogen offered a rare glimmer of hope in the increasingly fruitless field of Alzheimer’s treatment on Friday by saying it intended to take an experimental drug into the final stages of testing following promising results from a clinical trial.

The decision sent shares in Biogen up 18 per cent at the open in New York, adding about $10bn to its market valuation, after the US biotech company and its partner, Japan’s Eisai, said the medicine had performed favourably in a mid-stage “Phase II” study. 

The positive results offered some validation of the “amyloid hypothesis” — the most common explanation for what causes Alzheimer’s — which posits that the build-up of sticky plaques in the brain causes memory loss and other impairments. 

The amyloid hypothesis has fallen in popularity in recent years after a string of high-profile failures from companies including Merck & Co, Eli Lilly, and AstraZeneca. Big Pharma has tested several drugs that target the beta amyloid plaques, but all of them have ended up flunking the final Phase III trials. 

“Our next step is to talk to regulatory authorities to determine the best path forward, but our goal is to deliver potentially the first therapy to alter the course of Alzheimer’s disease,” Alfred Sandrock, chief medical officer at Biogen, said in an interview. 

15 years

Since a new drug for Alzheimer’s was launched

Asked whether the companies planned to test the medicine in a final round of trials, known as Phase III, Dr Sandrock replied: “Depending on how those discussions go, this is the drug to do that; we’d like to move it forward as rapidly as possible.”

It has been 15 years since a new drug for Alzheimer’s was launched, reflecting one of the longest and most expensive losing streaks for the industry. The medicines approved so far can only ameliorate symptoms rather than slowing the disease down. 

But the sector continues to plough billions of dollars into finding a medicine that can arrest the illness, tempted by the economics of a product that could help the roughly 44m sufferers worldwide.

Biogen and Eisai said that patients taking the highest dose of their medicine, codenamed BAN-2401, lost their cognitive abilities more slowly than those taking a placebo, according to a final analysis conducted after 18 months. 

The drug also cleared the sticky plaque-like substance known as beta amyloid from patients’ brains, they said. 

“These are promising results but stay tuned since this is just Phase II,” said Eric Siemers, a neuroscience researcher who used to work at Eli Lilly. “But even trends for a drug targeting [amyloid] is of interest. The amyloid hypothesis wins a round.” 

Biogen is already testing an amyloid-clearing drug known as aducanumab in Phase III trials with results due in 2020. Some analysts interpreted the success of BAN-2401 as a positive omen for those studies. 

“This reads very good and investors’ odds going into aducanumab Phase III may likely go up,” said Umer Raffat, a pharma analyst at Evercore ISI. 

However, the companies did not report the full results from the trial, which will be presented at a forthcoming medical meeting, and some analysts pointed out potential flaws. 

For example, it was not clear how many of the patients on the roughly 856-person trial had been given the high dose. And the study used an unusual, novel scale to measure how quickly people lost their brainpower rather than more conventional methods. 

“There is very little detail about other more validated cognitive measures in the joint press release and we find no reason to believe this either proves or disproves the amyloid hypothesis,” said Geoff Porges, a pharma analyst at Leerink.

Others were perturbed by the fact that an earlier analysis of the trial — which was conducted after 12 months — did not show that the drug conferred a benefit. 

Dr Sandrock said that the earlier analysis had been done using experimental Bayesian statistical methods, which estimated the probability of success without the full test data. The final Phase II assessment was based on the full results, which included cognitive tests and brain scans. 

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