Source: Flickr user Steve Jurvetson.

What's happening: After announcing that it would pony up $7.2 billion for multiple sclerosis drug developer Receptos (NASDAQ: RCPT) and increasing its long-term guidance, shares in Celgene Corporation (NASDAQ:CELG) shot higher by 10% earlier today.

Why it's happening: Investors have been waiting to see what Celgene would do with its growing cash stockpile, and Celgene's deal to acquire Receptos for $7.2 billion in cash puts the debate over which company Celgene may target on the back burner -- at least for now.

Through this deal, Celgene lands itself ozanimod, a drug many believe could end up becoming the best-in-class oral therapy for treating relapsing multiple sclerosis.

In mid stage trials, ozanimod delivered impressive efficacy, but even more importantly, it did so with placebo-like safety -- an advantage that could prove critical to winning share in this $17 billion (and growing) market. Results from late stage trials that could support an FDA filing should be available in 2017. 

If results are positive and an approval follows, it remains to be seen just how much of the MS market Celgene could eventually capture -- but it could total in the billions of dollars. Currently, the two top selling oral MS therapies are Biogen's Tecfidera and Novartis' Gilenya, and those drugs delivered annualized sales of $2.4 billion and $3.2 billion in the first quarter, respectively. Because ozanimod could have an arguably better safety profile than both of these drugs, its revenue opportunity may be bigger.

Additionally, ozanimod may be able to eventually carve out sales in other indications too. Studies are under way evaluating its potential as a treatment for ulcerative colitis and Crohn's disease, two indications that Celgene's already targeting with its Otezla and GED-0301.  Overall, ozanimod's potential in MS and irritable bowel diseases has Celgene estimating that ozanimod's peak sales could be between $4 billion and $6 billion annually.

If so, then Celgene believes that ongoing growth in its existing drugs alongside upside from ozanimod will lead to revenue of at least $21 billion and adjusted EPS of at least $13 in 2020. That guidance, which is above the $20 billion in sales and $12.50 in adjusted EPS forecast in January, could mean that Celgene's shares aren't done heading higher. 

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