Founded in March 2015, the company has commercial operations in the USA and Europe, alongside a direct presence in select other markets across the globe.

In January 2019, the company announced that it has successfully completed the acquisition of the worldwide rights to Sylvant (siltuximab) from Janssen Sciences Ireland for $115 million. Sylvant is approved in more than 40 countries for the treatment of idiopathic multicentric Castleman’s disease (iMCD), and is the only approved treatment in the USA and Europe for the condition.

EUSA is currently plannning to invest in developing Sylvant in additional indications where IL-6 blockade may be indicated. Among these, the company is looking into cytokine release syndrome associated with CAR-T therapy.