AmgenAmgen (NSDQ:AMGN) has acquired privately-held immunotherapy specialist Teneobio (Newark, California).

The transaction includes an upfront $900 million upfront payment and future contingent milestone payments worth up to an additional $1.6 billion.

Tenebio’s stated mission was to tap human heavy-chain antibodies to “redirect the immune system to safely fight disease.”

Earlier this year, it had three drug candidates—TNB-383B, TNB-486 and TNB-58—in Phase 1 trials. The company had 11 additional candidates in earlier stages of discovery and development.

Amgen believes that the acquisition will complement its work on T-cell engagers and bi- and multispecific biologics. “Teneobio’s expertise and technologies will further expand our repertoire of multispecific architectures and advance our overarching mission to develop transformative innovation to bring to market best-in-class products to serve our patients,” said Dr. David M. Reese, executive vice president of R&D at Amgen, in a statement.

Amgen noted that TNB-585, a bispecific T-cell engager for metastatic castrate-resistant prostate cancer, has the potential for near-term Investigational New Drug (IND) filings.

TNB-585 will become part of Amgen’s prostate cancer portfolio, including two other drugs in Phase 1 trials.

Before the acquisition, Teneobio distributed some assets to its equity holders related to three affiliates dubbed “TeneoTwo,” “TeneoFour” and “TeneoTen.” Among the included assets were TNB-486, anti-CD38 antibodies and bispecific antibodies targeting the hepatitis B surface antigen and CD3.

The company had partnerships with several Big Pharma firms, including AbbVie (NYSE:ABBV), Janssen (NYSE:JNJ), GSK (NYSE:GSK) and Gilead‘s Kite (NSDQ:GILD).