A subsidiary of billionaire Patrick Soon-Shiong’s NantWorks health care technology company has secured $100 million in equity funding, according to regulatory filings.

NantBioscience, a drug developer, secured the funding from an unnamed source at the end of April and has raised $200 million to date, according to Securities and Exchange Commission documents. A NantWorks representative was not immediately available for comment.

The firm has previously announced a collaboration with Summit, N.J., drug maker Celgene Corp., which bought Soon-Shiong’s pharmaceutical firm Abraxis BioScience for $2.9 billion in 2010.

Celegene has agreed to license two of its drugs to NantBioscience for further development. In exchange, the New Jersey pharmaceutical company has an option to license some of NantBioscience’s product candidates. Celgene invested $90 million in the company in the first quarter of 2014, according to SEC filings.

NantWorks’ various units have raised about $800 million in funding to date plus another $1 billion from Soon-Shiong’s own fortune. The physician entrepreneur, who’s held the top spot on LABJ’s Wealthiest Angeleno’s List for six years, has said the company’s NantHealth division should go public by the end of the year.