Researchers are hailing results of a new experimental drug treatment for Alzheimer's disease.

According to findings released earlier this month by Cambridge-based drug maker Biogen Idec (now Biogen), the drug sharply slowed the decline in mental function among the nearly 165 participants.  

The drug works as an antibody that attacks beta-amyloids -- proteins in the brain believed to be involved in the development of the disease. 

Dr. Rudolph Tanzi -- a Chair of the Cure Alzheimer’s Fund Research Consortium, Joseph P. and Rose F. Kennedy Professor of Neurology at Harvard University, and Director of the Genetics and Aging Research Unit at Massachusetts General Hospital -- tells WGBH News the results are "undeniably exciting.”



On what distinguishes BIIB037 from previously-developed Alzheimer's drugs: 

Amyloid-targeting drugs in the past failed - either because they weren’t potent, or weren’t safe. Others that looked like they should have worked were given too late. We now know that amyloid accumulates 15 years before symptoms, so you need hit amyloid early. Biogen hit the disease more in the early stages, and the way they designed the drug — which is an antibody — is based on the naturally-protective mechanisms in the body; they mimicked what the body does to protect the brain versus making something anew. 

On the drug's side effects: 

In the highest dose that they gave, where they saw the most significant effects on cognition and improvement, there were cases of swelling and, in rarer cases, some hemorrhage. It looks like the swelling comes early, and then subsides. In the case of hemorrhage you might have some drop-out of patients. So it does have some adverse effects and that might affect the doses they can use in Phase 3 of the trials.

On what patients and researchers should expect next:

Researchers are going directly from phase 1 to phase 3, so that’s good news in terms of timing for patients. But the drug still has to be designed and approved by the FDA; they have to recruit the patients — which in this case will be many hundreds — and then carry out the study for at least a year. I don’t think we’ll get read-outs from Phase 3 for another three years. 

On the drawbacks of the study: 

Biogen now offers up the up the first evidence that if you reduce amyloids, you improve cognition. That’s really exciting. But the caveat is it’s still phase 1, it’s a small study, and to replicate that with lots more patients in phase 3 isn’t a walk in the park. There’s till a lot of work to do.

--> You can listen to the full interview with Dr. Rudolph Tanzi above