What happened

Shares of Deciphera Pharmaceuticals (DCPH 0.62%) erupted for gains of over 115% today after the clinical-stage pharma reported promising results for its lead drug candidate. In a phase 3 trial evaluating the potential to treat advanced gastrointestinal stromal tumors (GIST), patients taking ripretinib achieved an average progression-free survival (PFS) of 6.3 months. Those taking placebo reported an average PFS of one month. The risk of disease progression or death was reduced by 85% in patients receiving the drug candidate. 

Deciphera Pharmaceuticals also reported updated results from a phase 1 study evaluating the potential of ripretinib to treat second-line and above GIST. (The phase 3 results were for advanced, or fourth-line and fourth-line plus, GIST.) The drug candidate performed even better in less severe cases of GIST, resulting in a PFS of 9.7 months in patients with second-line GIST. 

As of 1:18 p.m. EDT, the stock had settled to a 80.4% gain.

A businessman viewing his laptop while sitting on a cartoon rocket.

Image source: Getty Images.

So what

Today's news sent shares soaring because Wall Street had begun to write off Deciphera Pharmaceuticals. Shares haven't traded at current levels since mid-2018, shortly after the company reported a promising first-look at ripretinib in GIST at the 2018 American Society of Clinical Oncology (ASCO) annual meeting. At that time, the drug candidate demonstrated an overall response rate (ORR) of 24% in second- or third-line GIST and 9% in fourth-line or later GIST. That was impressive considering existing treatments delivered ORRs of 7% and 4.5%, respectively, in second- and third-line GIST.

The latest results show that ripretinib has essentially maintained those impressive response rates even as the drug candidate was tested in more patients.

Now what

Deciphera Pharmaceuticals intends to submit a new drug application (NDA) with the U.S. Food and Drug Administration (FDA) in the first quarter of 2020. The company will ask regulators to approve ripretinib as a treatment for advanced GIST in patients who have received prior treatment with three other drugs. If approved, and the drug candidate continues to impress in earlier stages of the disease, then the company could later earn marketing approval in a much larger patient population. First things first, of course: Investors will have to patiently await the initial decision of regulators sometime in late 2020.