What happened

Shares of BeyondSpring (BYSI -2.70%), a clinical-stage biotech company, have been surging this week in response to a lucrative new partnership with Jiangsu Hengrui Pharmaceuticals in China. Investors are justifiably excited about the partners' new agreement to commercialize and co-develop BeyondSpring's neutropenia-prevention candidate, called plinabulin.

By the time U.S. markets closed on Thursday, BeyondSpring's stock price had already climbed 49.4% from its closing price last Friday.

So what 

Chemotherapy kills cancer cells when it catches them trying to divide, but the ubiquitous class of treatments also makes it hard for bone marrow to produce enough white blood cells. This is why a granulocyte colony-stimulating factor G-CSF treatment from Amgen (AMGN -0.53%) called Neulasta was able to generate more than $2 billion in sales last year despite launching way back in 2002.

Smiling physician.

Image source: Getty Images.

While G-CSFs are a big help, white blood cell loss, or neutropenia, is still a huge challenge for oncologists and their patients. BeyondSpring's lead candidate, plinabulin, is a first-in-class drug that protects white blood cells from chemotherapy while leaving cancer cells vulnerable. 

Now what

The Food and Drug Administration is currently reviewing an application that could make plinabulin a treatment given to a huge cross-section of cancer patients undergoing chemotherapy. The agency is expected to announce an approval decision in November, and investors can reasonably expect a green light.

During clinical trials supporting the application, adding plinabulin to G-CSF dramatically reduced the risk of severe neutropenia. Just 0.9% of patients given plinabulin plus G-CSF ended up with severe neutropenia compared to 3.6% of the group randomized to receive G-CSF plus a placebo.

Neutropenia is a life-threatening condition on its own, plus it forces patients to suspend treatment, which allows disease to continue progressing. Plinabulin isn't getting a lot of attention from the wider investment community, but it's going to be impossible for oncologists to ignore the data. BeyondSpring's new tie-up with Hengrui, one of China's largest drugmakers, could also give plinabulin's potential launch a huge boost throughout that country. 

At its recent market cap of just $1.2 billion, BeyondSpring stock is trading at a fraction of sales expectations for plinabulin. There are no guarantees of success, but this stock looks well worth the risk at the moment.