In an attempt to dissuade physicians from following Express Scripts Holding Co.'s advice to prescribe compounded pyrimethamine/leucovorin as an alternative to Turing Pharmaceuticals AG's high-priced Daraprim (pyrimethamine), Turing is arguing that the combination compound should be considered a risky "unapproved drug."
However, the firm Express Scripts has contracted to fulfill prescriptions for the compounded product, Imprimis Pharmaceuticals Inc., maintained that...