Biogen Idec’s Alzheimer’s candidate aducanumab has slowed down the impairment in cognition and memory in the early stages of the disease in a phase Ib trial.
The beta amyloid-targeting drug – formerly known as BIIB037 – is the first to have combined a significant reduction in the amyloid plaques that are found in the brains of Alzheimer’s patients with slowing of clinical impairment, according to the company.
Biogen Idec intends to take aducanumab into phase III trials later this year on the strength of the data, hoping to succeed where dozens of other amyloid-directed therapies have failed in the past.
The phase 1b trial – called PRIME – is still ongoing and to date has enrolled 166 people with mild Alzheimer’s or prodromal disease, where the subject is showing some very early signs of cognitive impairment but is not yet formally diagnosed with Alzheimer’s.
Patients on the drug showed smaller declines over 12 months on clinical efficacy scales than placebo, although the control group did seem to decline a bit more quickly than might typically be expected.
Despite the earliness of the data, the fact that dose-response relationship seemed to be evident in the data sparked a surge in Biogen Idec’s share price, driving it to an all-time record of $480 ahead of the weekend.
It will however take years for Biogen Idec to carry out its phase III trial and – in the interim – other amyloid-targeting drugs are also being tested in very early-stage patients.
A string of failed late-stage trials in established Alzheimer’s – including Eli Lilly’s solanezumab and Pfizer’s bapineuzumab – have prompted speculation that the key to unlocking the potential of amyloid-targeting drugs lines in treating earlier in the disease process.
That view took a knock last December however when Roche announced it was halting a phase III trial of its gantenerumab candidate in prodromal Alzheimer’s after an independent panel concluded it had failed a futility test.
Biogen Idec remains hopeful that its candidate will succeed where others have failed however, and takes comfort from a rigorous screening process that ensured every patient entered into the trial had Alzheimer’s and not some other form of dementia.
Biogen Idec licensed aducanumab from Swiss company Neurimmune in 2007. It was derived from antibodies taken from donors who were cognitively normal despite advanced age, on the hypothesis that these donors’ immune systems had successfully resisted Alzheimer’s disease.