What happened

Shares of Inhibrx (INBX 3.52%), a clinical-stage biotechnology company, jumped when the market opened today. Investors excited about the company's latest clinical trial readout pushed the stock 26.8% higher as of 11:29 a.m. on Tuesday. 

So what 

Today, Inhibrx reported top-line data from a phase 1 trial with INBRX-101. This is the company's specialized version of alpha-1 antitrypsin (AAT), a protein that protects lung tissue. 

Scientists looking at clinical trial data.

Image source: Getty Images.

A lack of AAT can be treated with weekly infusions of a substance extracted from human plasma. Inhibrx designed INBRX-101 to remain at therapeutic concentrations for at least a few weeks after each infusion.

Today, Inhibrx reported encouraging results from a phase 1 dose determination study that suggest the biotech is on the right track. Patients given multiple doses of INBRX-101 every three weeks maintained functional AAT levels between doses that exceeded target concentrations for traditional replacement therapy.

Now what

An estimated 100,000 Americans are living with AAT deficiency, and a new treatment option that greatly reduces infusion frequency could generate more than $1 billion in annual sales. Earlier this year, the market hammered shares of Vertex Pharmaceuticals (VRTX -0.57%) after an oral candidate for AAT deficiency failed to hit high marks in a clinical trial. 

Inhibrx's gain today would be much larger if it weren't for two RNA interference drug candidates already in midstage clinical trials. Next year, Arrowhead Pharmaceuticals will wrap up a phase 2 study with ARO-AAT. Belcesiran from partners Dicerna and Alnylam is also in a phase 2 trial with top-line results expected next year.