Head-to-head randomized trials are mostly industry sponsored and almost always favor the industry sponsor.
Flacco ME, Manzoli L, Boccia S, Capasso L, Aleksovska K, Rosso A, Scaioli G, De Vito C, Siliquini R, Villari P, Ioannidis JP. Head-to-head randomized trials are mostly industry sponsored and almost always favor the industry sponsor. J Clin Epidemiol. 2015 Jul; 68(7):811-20.