NantPharma LLC, a company controlled by billionaire Patrick Soon-Shiong, has signed a licensing agreement with Amgen Inc. for AMG 337, an experimental cancer drug, NantPharma announced Monday.

Under the agreement, Amgen, the Thousand Oaks biotech, gave NantPharma the exclusive rights to develop and commercialize AMG 337 worldwide, excluding Japan, Russia and certain other Asian countries. Financial terms of the deal were not disclosed.

Earlier this year, NantPharma’s parent company NantWorks and Amgen entered an exclusive license agreement for the immunotherapeutic drug ganitumab.

Soon-Shiong made his fortune by developing cancer drug Abraxane. In May, Los Angeles Business Journal estimated his net worth at $15.3 billion.

Shares of Amgen closed down $2.21 or 1.4 percent to $151 on the Nasdaq.