La Jolla-based biotech Ambrx Inc. secured a $15 million payout from Bristol-Myers Squibb, with milestone payments tallying as much as $97 million.

Ambrx received $15 million last month from Japanese drug maker Astellas Pharma Inc., which could bring in $285 million in additional research, development and regulatory milestones.

Ambrx, a privately held company, employs 55 in the San Diego area. It has similar drug discovery collaborations underway with Merck & Co. Inc., Eli Lilly and Co. and several other companies.

This is the third agreement between Ambrx and Bristol-Myers Squibb. In September 2011, the companies penned two separate research and development agreements, which are still underway today.

"Bristol-Myers Squibb is a global biopharmaceutical leader with expertise developing and commercializing novel medicines for the treatment of cancer and other diseases, and we are pleased to enter into a third collaboration with the company to include another aspect of our technology platform," said Lawson Macartney, the chief executive officer of Ambrx. "We look forward to working together to further utilize Ambrx's technology to discover and advance these antibody drug conjugates for oncology indications."

— Meghana Keshavan