Back in March 2013, Dainippon Sumitomo Pharma signed a deal worth $50 million or more to Mountain View, CA-based Edison Pharmaceuticals, a developer of drugs for disorders of energy metabolism.  The big pharmaceutical company from Japan liked the results. Less than a year later, it came back for more.

The two companies have now formed a larger collaboration—worth as much as $4.2 billion to Edison—and their goal is equally large-scaled. They plan to prepare 10 new drug candidates for clinical trials within five years.

Read More: Edison Shedding Light on Energy Production in Diseased Cells