What happened

Shares of Abeona Therapeutics Inc. (ABEO 2.19%), a clinical-stage biotech developing novel gene therapies to treat rare genetic disorders, popped as much as 14% higher on Wednesday morning after an important announcement concerning a candidate that succeeded in an early-stage trial earlier this month. Although the initiation of a pivotal expansion to the study is indeed good news, that pop had fizzled to a gain of 3.3% as of 12:03 p.m. EDT.

So what 

Abeona Therapeutics is developing ABO-102 as a potential gene therapy for the treatment of MPS IIIA, a rare metabolic disease caused by a faulty SGSH gene. There are no available treatments for the life-threatening disorder, but results of a small, early stage clinical trial announced earlier this month suggest Abeona could have the first.

Hand drawing an upward sloping chart.

Image source: Getty Images.

MPS IIIA patients seldom survive past their second decade because their bodies can't break down heparin sulfate, which builds up in the body, leading to liver and brain damage. One year after receiving a single injection of ABO-102, though, two patients demonstrated a 69% heparin sulfate reduction in the fluid that bathes the brain, and dramatically reduced liver volumes as well.

Investors were thrilled with Wednesday's announcement because the company has expanded the ongoing trial in a way that could be enough to support its first new drug application. Because the highest dose appeared well-tolerated, the highest-dose cohort will be used to support the new drug application. And since even the lower dose appears highly effective, ABO-102 has a solid shot at an eventual approval.

Now what

ABO-102 is just one of several irons Abeona has in the fire at the moment. In August, its shares jumped higher when the FDA granted EB-101 a breakthrough therapy designation for the treatment of recessive dystrophic epidermolysis bullosa, a debilitating skin disease. The company will begin a  phase 3 study for it early next year.

Although the stock has already soared by about 337% this year, its recent market cap of about $856 million suggests it could provide market-beating long-term gains if either of these candidates succeeds