The U.S. FDA authorization of aducanumab, the first new medication to treat Alzheimer’s disease in 18 years, has drawn a mixed response among the scientific community in Canada.

It's the only drug that U.S. regulators have said can likely treat the underlying disease, rather than manage symptoms like anxiety and insomnia.

Aducanumab's developers stopped two studies earlier this year because it didn’t seem to be working, then did a stunning about-face in October and said new results suggest it was effective at a high dose.