What happened

Shares of the clinical-stage cancer specialist Five Prime Therapeutics (FPRX) gained a stately 312% over the course of November, according to data from S&P Global Market Intelligence. The drugmaker's shares blasted higher last month in response to positive mid-stage trial data for its novel stomach cancer candidate known as bemarituzumab.

So what

Bemarituzumab, as a first-line treatment for fibroblast growth factor receptor 2b-positive (FGFR2b+) stomach cancer, is thought to be capable of generating combined U.S. and EU sales in the range of $700 million per year, according to Cowen analyst Boris Peaker. When adding other high-value markets like China into the picture, the drug's first indication could therefore be worth over $1 billion a year in revenue. That's quite a potential haul for a company with a market cap of $651 million at present.

A rocket taking flight.

Image source: Getty Images.

Even more impressively, though, Five Prime has indicated that it plans on exploring the possibility of trialing bemarituzumab in several additional indications, such as FGFR2b+ breast, liver, lung, ovarian, and pancreatic cancers. So while it's still early days in terms of the drug's overall clinical development, Five Prime may, in fact, have a bona fide franchise-level cancer drug under its roof. 

Now what

Five Prime has yet to lay out specific plans for bemarituzumab's future development. The most likely reason seems to be the outside chance that regulators in the U.S. and/or the EU might be willing to entertain an accelerated regulatory filing based on these impressive mid-stage results. If true, this small-cap biotech's shares could quite possibility go on another healthy run in 2021. Aggressive investors may want to keep a close eye on this name going forward.