What happened

Shares of uniQure (QURE -0.22%) were down more than 11% as of 1:06 p.m. on Tuesday after the gene-therapy company announced that the Food and Drug Administration (FDA) had cleared its investigational new drug (IND) application for AMT-260, a treatment for refractory mesial temporal lobe epilepsy (MTLE).

The disease is a chronic neurologic disorder, considered the most common form of focal epilepsy (which affects one side of the brain). More than 600,000 people in the United States suffer from MTLE.

At one point on Tuesday morning, the stock fell to a 52-week low of $7.40.

So what

The healthcare stock dropped for two reasons. First, investors who were waiting for an opportunity to sell a stock that was down more than 65% this year sold on the news. A phase 1/2 clinical trial for AMT-260 is expected to begin in the fourth quarter.

Second, the company will be delisted from the S&P 600 index as of Sept. 18, following an announcement by the index on Sept. 1. The S&P 600 is used by 18 different exchange-traded funds (ETFs) in the United States. uniQure initially was added to the S&P 600 list in 2021, and falling off the list means the stock is less likely to be traded, weakening its position.

Now what

The company is not yet profitable, but it has enough cash to potentially develop AMT-260. As of the second quarter, uniQure said it had $628.6 million in cash. It also reported second-quarter revenue of $2.4 million, up 380% year over year, and a net income loss of $46 million, compared to a loss of $46.2 million in the same period a year ago.

Most of the company's increased revenue is from increased manufacturing payments related to producing hemophilia B gene-therapy Hemgenix for the CSL Behring division of CSL.