Shares of Verve Therapeutics (VERV -0.96%) sank as much as 30.7% this week, according to data from S&P Global Market Intelligence. The gene-editing company focused on the cardiovascular market posted updated data on one of its clinical trials with concerning results. As of this writing, shares of Verve Therapeutics are off 26% this week and off 84% from all-time highs.

Gene editing and heart attacks

Verve is trying to build cutting-edge, gene-editing tools to help people deal with cardiovascular disease. Specifically, it hopes to commercialize its Verve-101 tool to edit human genes in people with naturally high LDL cholesterol (the bad cholesterol), which is correlated with heart disease. There are an estimated 3 million people in the United States and Europe affected by this condition, which indicates a potentially huge market for Verve if they can get this treatment commercialized.

This week, the company released some updated data for investors regarding a trial it is doing with the Verve-101 tool in humans. The market seems to be reacting to some concerning news with the 10 people Verve has trialed, as two of the patients died from heart attacks after receiving the treatment. Seeing this headline, the market reacted swiftly with investors likely concerned over the efficacy of this early-stage technology.

However, if we look under the hood, these heart attacks, from a research perspective, may not be as bad as they seem. Verve is purposefully looking for patients with extreme cardiovascular conditions, meaning they were already highly likely to have a heart attack before taking the drug. On a positive note, the trial indicates a 55% reduction in LDL levels for the patients, which is a huge improvement from current cholesterol-reduction methods.

The future is uncertain

The news about heart attacks is concerning, but I don't think anyone can come to conclusions about Verve Therapeutics technology yet. The company was formed just a few years back and is still in the early days of building its gene-editing technology. Gene editing as a whole is also a very unproven technology, and it is still unclear how these medications and procedures will fully impact the complex human body and all its organs.

If you are still a believer in gene editing and Verve Therapeutics, you should make it a small portion of your portfolio. With a tiny market cap below $1 billion, the stock is going to soar if it starts selling the Verve-101 treatment to its entire target market. But if it fails -- as a lot of biotechnology start-ups do -- you won't be kicking yourself for making it too large a position in your portfolio.