What happened

Shares of AnaptysBio Inc. (NASDAQ:ANAB), a clinical-stage biotech developing novel anti-inflammatory drugs, took flight after the company reported positive data from a clinical trial with its eczema candidate. Although it was just a 12-patient proof-of-concept study, the stock soared about 70.7% higher as of 10:15 a.m. EDT on Tuesday.

So what 

Today's excitement is due to a big hint that the company's first-in-class IL-33 inhibitor has a shot at becoming an ultra-convenient treatment option for people with atopic dermatitis, the most common type of eczema. At an interval of 57 days after receiving a single dose of ANB020, 10 of 12 patients achieved a 50% or greater improvement. Responses also appear rapid, nine of the 12 patients had achieved a 50% improvement at the 15-day assessment.

Three scientists celebrating in a laboratory.

Image source: Getty Images.

You don't normally see a company's market cap rise more than $500 million overnight on the back of phase 2 proof-of-concept data. Celgene and Tesaro have licensed anti-PD1 candidates from AnaptysBio, but this is the first of the company's wholly owned new drug candidates to show it really has a shot at the big time. An estimated 3% of America's adult population has some form of eczema, which means ANB020 has blockbuster potential if it continues to impress.

Now what

AnaptysBio will continue assessing these 12 patients up to 140 days after they were given a single dose of ANB020. In the first half of 2018, look for the initiation of a larger study with at least 200 eczema patients receiving multiple doses.

The company is also developing ANB020 for adults with severe peanut allergies, and another wholly owned psoriasis candidate, ANB019, should wrap up its first clinical-stage trial before the end of the year.

Cory Renauer has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.