What happened

Shares of the clinical-stage biotech ImmunoGen (IMGN) rose by as much as 13.8% on heavy volume in early-morning trading today. The catalyst?

ImmunoGen's shares are heading higher in response to a positive interim data review for its experimental ovarian cancer drug, mirvetuximab soravtansine, or mirvetuximab for short. Specifically, the company said that an Independent Data Monitoring Committee recommended that the drug's late-stage trial in women with platinum-resistant ovarian cancer should continue without modification.

A doctor discussing a chart with a female cancer patient.

Image Source: Getty Images.

ImmunoGen's shares have cooled off somewhat since the opening bell, but they are still up by a healthy 9.51% as of 11:45 a.m. EDT Friday in response to this news. 

So what 

ImmunoGen has pegged mirvetuximab as its potential flagship product because of the enormous commercial opportunity proffered by ovarian cancer treatment. The company thinks that even as a later-line treatment for platinum-resistant ovarian cancer, for example, the drug could easily generate hundreds of millions in sales.

That being said, ImmunoGen also has its eye on expanding mirvetuximab into earlier lines of therapy as part of a combination treatment. And if this line of inquiry pans out, ImmunoGen could have a blockbuster on its hands. 

Now what

ImmunoGen expects this ongoing late-stage trial to produce top-line data sometime in the first half of 2019. So, if things go according to schedule, mirvetuximab should be on the market by early 2020.

While that's definitely encouraging news for shareholders, the downside is that the company will probably take advantage of this bump in its share price to raise capital soon. Although ImmunoGen did exit 2017 with a respectable $267 million in cash and cash equivalents, this amount simply isn't sufficient to support a commercial launch and advance the biotech's other clinical assets simultaneously, after all. In short, it might be wise to wait until the inevitable capital raise takes place before buying shares.