What happened

Shares of Cassava Sciences (NASDAQ:SAVA) jumped 145.1% in February, according to data from S&P Global Market Intelligence. Progress on the company's experimental drug treatment for Alzheimer's has driven incredible gains for the stock. 

SAVA Chart

SAVA data by YCharts

Cassava published a press release on Feb. 2 announcing that an interim analysis from an open-label study of the company's simufilam for treating Alzheimer's showed improved cognition and behavior scores following six months of treatment. The study also found that there were no safety issues associated with the treatment. The biotech company then announced positive results from its end-of-phase-2 meeting with the FDA on Feb. 22, and it outlined a path to phase 3 studies in the second half of this year.

Illuminated strands of neurons against a dark blue background.

Image source: Getty Images.

So what

Cassava Sciences study was funded by the National Institutes of Health and found that a six-month treatment of simufilam improved average cognition scores by 10%. Tested levels for dementia-related behavior improved by 29% over the course of the treatment. 

Simufilam is Cassava's lead drug candidate for treating Alzheimer's, and the promising results from the clinical study prompted big gains for its stock. The fact that the clinical study showed simufilam treatment not only stabilized cognitive and behavioral decline but actually improved performance is hugely encouraging, and the drug's safety profile looks great as well. 

Now what

Cassava stock has given up some of its gains early in March's trading, but it has held up relatively well in the context of a broader pullback for growth-dependent stocks. The company's share price is down roughly 13% in the month so far. 

SAVA Chart

SAVA data by YCharts

Cassava Sciences has a market capitalization of roughly $1.7 billion and is valued at approximately 34 times this year's expected sales. The stock is up about 633% over the last year even after the recent pullback.

More than 5 million people in the U.S. alone have Alzheimer's, and that figure will likely rise substantially as the overall population continues to age. Alzheimer's is one of the most common untreated degenerative diseases in the world, and simufilam could represent a huge step forward in managing the condition.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.