Late last month we recommended looking at Delcath Systems, Inc. (Nasdaq: DCTH) in the article “This Small Biotech Firm’s Shares Could Rocket in the Next 30 Days.” Well, guess what? DCTH’s shares have, in fact, rocketed on positive results in its Phase III trial on its Delcath PHP system, which treats liver cancer. Shares today closed at $14.80, for a +119% gain in about a month. With that much upside behind us, is DCTH still worth buying?

I think so.

Delcath CEO Eammon Hobbe said last week that its proprietary device has a U.S. market potential of $745 million a year. He also said that it could be used as a platform technology to treat other types of cancer and that the potential U.S. market is $5.5 billion.

The company did not discuss — and Wall Street isn’t really considering — the device’s international opportunities. According to curelivercancer.org, 500,000 to 650,000 new cases of liver cancer are diagnosed globally each year, only 2% of which are in the United States.

Additionally, Delcath will announce the full trial data on June 5th, which could propel the shares further upward. The company also plans to submit an FDA application for its first approval by the middle of this year.

Keep in mind, Delcath has no revenue. If the company gets its drug approved — the ultimate profit catalyst in this industry — or a major pharmaceutical company buys it, an investment could pay off big time. In the meantime, good news in the coming months could move shares further upward. The company expects its first treatment to be approved in the United States in middle of next year.

Investors looking for big potential upside may still want to consider DCTH. Keep in mind, however, that bad news from its clinical trials or from the FDA could push shares down even quicker.