What happened

Shares of Achillion Pharmaceuticals (NASDAQ:ACHN) are jumping today, up 13.2% as of 3:07 p.m. EDT, after the biotech announced positive results from a phase 1 clinical study evaluating experimental oral factor D inhibitor ACH-5228.

So what

You might wonder why Achillion stock would jump so much on data from a phase 1 study. The answer is that the results were really that good.

Scientist looking through microscope

Image source: Getty Images.

ACH-5228 was given to 43 patients who received oral doses of the drug ranging from 40 mg to 200 mg twice each day for 14 days. There was also a single-dose cohort of 240 mg. At dosages of at least 120 mg twice per day, ACH-5228 demonstrated near complete and sustained alternative pathway (AP) inhibition with a mean value of greater than 95% at steady-state concentrations. The alternative pathway is a key component of the immune system. 

What all of this means is that ACH-5228 appears to hold significant potential in treating immune-related diseases where the AP pathway plays a critical role. The drug could even become the best-in-class AP inhibitor.

It also bolstered investors' confidence in Achillion's factor D program. The biotech's first-generation AP inhibitor, danicopan, first validated factor D as a target. Achillion plans to begin a phase 3 study for danicopan in early 2020.

Now what

This phase 1 study of ACH-5228 was conducted outside of the U.S. Achillion expects to file for approval in the fourth quarter of 2019 with the U.S. Food and Drug Administration to begin clinical testing in the U.S. The company hopes to also advance ACH-5228 into phase 2 studies targeting multiple diseases.

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