United Therapeutics Corporation (Nasdaq: UTHR) today announced that its collaborator, XVIVO Perfusion, Inc., a subsidiary of XVIVO Perfusion AB (STO: XVIVO), has received Premarket Approval (PMA) from the U.S. Food and Drug Administration (FDA) for the products XPS™ and STEEN Solution™. This approval means that STEEN Solution, XPS and the accompanying single-use articles are the only medical device products that are approved in the United States for ex-vivo lung perfusion (EVLP) of initially unacceptable donated lungs at body temperature.