French pharmaceutical giant Sanofi announced on Wednesday its second acquisition of a US firm in as many months, buying transplant drug company Kadmon for $1.9 billion (1.6 billion euros).

Sanofi has been on a buying spree in recent years and last month finalised its acquisition of US firm Translate Bio, which is working on an mRNA COVID vaccine, for $3.2 billion.

Kadmon makes Rezurock, a treatment for patients as young as 12 who suffer from chronic graft-versus-host disease, a complication that can occur after a or stem .

"The acquisition supports Sanofi's strategy to continue to grow its General Medicines core assets and will immediately add Rezurock (belumosudil) to its transplant portfolio," the French firm said in a statement.

Rezurock is a "real gem" that adds to Sanofi's transplant medicine portfolio, said executive vice president for general medicines, Olivier Charmeil.

Kadmon is also testing the drug to treat diffuse cutaneous systemic sclerosis, a that affects the skin and .

Kadmon shareholders will receive $9.50 per share in cash in the deal, which was unanimously approved by the boards of both companies. Shares in Kadmon had closed at $5.23 in Tuesday trading.

The acquisition is expected to be completed in the fourth quarter.