Amgen (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…