NantHealth Inc. announced Monday that President Robert Watson will step down and become a consultant for the company.

Watson made the decision in order to move to the East Coast for family reasons, according to the company. His replacement was not named, but Patrick Soon-Shiong – who is NantHealth’s chief executive and chairman – said in a statement Watson would remain with the biotech firm in some capacity until 2018.

“In his transitional role, Bob will remain an important member of our team through the end of the year,” said Soon-Shiong, who topped the Business Journal’s 2016 list of wealthiest Angelenos with a net worth of $15.4 billion. “Bob oversaw the integration of several acquisitions and was instrumental in leading our company’s transition from a private to public company.”

Part of Soon-Shiong’s portfolio of Culver City-based biotech companies, NantHealth went public in June trading at $18.59, but has since lost more than 80 percent of its value, bottoming out May 1 at $2.95. The stock closed Monday at $3.24 per share, up 2.2 percent for the day.

While there has been a steady decline in NantHealth stock price since its IPO, a March report from health and medicine industry news outlet Stat caused the stock to plunge sharply. The report said $10 million of a $12 million philanthropic research donation to the University of Utah from Soon-Shiong made its way back to NantHealth. During the first two weeks of March, the company’s share price dropped more than 45 percent.

Soon-Shiong has denied any wrongdoing in relation to the donation and called aspersions about his intent “maliciously false” in an interview with the Los Angeles Times.

Deals & Dealmakers reporter Henry Meier can be reached at [email protected]. Follow him on Twitter @henry_meier.