Nant Health is postponing its planned initial public offering, according to a report in the Los Angeles Times. Billionaire biotech entrepreneur Dr. Patrick Soon-Shiong told the publication that he was delaying the IPO, only five months after he said that he planned to take the company public by year’s end.

“We’re basically ready. The problem is, we don’t want to go out in the current market. There is no reason for us to go out there in a bear market,” Soon-Shiong, was quoted as saying in the article. Nant Health, a health care data unit of Nant Works, is based in Culver City.

The announcement comes as biotech stocks have tumbled as a growing number of voices call for regulatory agencies to rein in drug prices.

The Nasdaq Biotechnology Index, a collection of biotech and pharmaceutical companies, has fallen 15 percent from a recent high in July, the Los Angeles Times notes.

While stock in Soon-Shiong’s NantKwest Inc., a biotechnology company, jumped 39 percent on its first day of trading in July, its shares have dropped 53 percent since then, according to the Times.

Soon-Shiong, who ranked No. 1 on Los Angeles Business Journal’s 2015 list of wealthiest Angelenos, has an estimated net worth of $13.9 billion.