Sanofi to buy US biotech firm Amunix for $1 billion

French pharma giant Sanofi said on Tuesday that it had signed a billion-dollar deal to buy US-based biotech firm Amunix, which develops cancer treatments that enlist the body's immune system.

"Sanofi will acquire Amunix for an upfront payment of approximately $1 billion (890 million euros) and up to $225 million upon achievement of certain future development milestones," the French firm said in a statement.

Immuno-oncology firm Amunix is developing cancer therapies based on cytokines -- small proteins that play a role in controlling the immune system -- and T-cells, a type of white blood cell.

Its technology could "precisely tailor-deliver medicines to become active only in tumor tissues while sparing normal tissues," said Sanofi research and development chief John Reed.

Its most promising candidate medicine, dubbed AMX-818, is "expected to enter the clinic in early 2022" for trials, according to Sanofi.

Amunix is the latest in a string of acquisitions by the French company, including September's $1.6-billion buyout of US biotech firm Kadmon, which is developing treatments for transplant patients.

It also bought messenger RNA research firm Translate Bio for $2.7 billion.

Sanofi aims to complete its acquisition of Amunix in the first quarter of next year.