Although the developments were heart-breaking for the medical community – the investment community always looks at price action and the price action was impressive despite the bad news.
Piper Jaffray estimated Biogen spent $75 million to $100 million on the failed trial alone.
"Yet, the stock barely took a hit," said Cramer.
In part that's because Biogen also has a major hemophilia program in the pipeline, one that could potentially generate $3 billion in sales by the second half of the decade.
However, the relative strength in the stock price more likely reflects Biogen's position in n the multiple sclerosis market.
As you may know, MS is it's a life-long, chronic, often disabling disease that attacks the central nervous system. Although there's no cure for MS, there are drugs that can keep the disease at bay by preventing relapses.
"And currently Biogen has two of them on the market, two blockbuster MS drugs, Avonex, which is one of the traditional treatments, and Tysabri, a newer, more effective drug that also has a higher risk of bad side effects," Cramer explained..
Also Biogen's is working on a third multiple sclerosis drug, BG-12, one that can be taken orally rather than injected.
Management has said it would appeal to a very broad patient population. In fact, BG-12 could become the new leading first-line treatment for MS, potentially doing $2.4 billion worth of sales in 2016.
"That's a big deal," said Cramer.
And chatter on the Street suggests the FDA could approve this new drug as soon as late March.
All told, Cramer is bullish.
"Biogen is a classic biotech stock with a bright future and I think it's exactly the kind of thing you should think about buying when we get broad market-wide weakness," he concluded.
Find out more about this company and drugs in the pipeline from Dr. George Scangos, the CEO of Biogen Idec, in the video above.