Second Circuit Affirms Exclusion of Medical Causation Testimony Linking Rezulin with Cirrhosis

The Second Circuit has published an opinion affirming the trial court's exclusion of medical causation evidence offered by a plaintiff to prove that Rezulin caused the decedent's cirrhosis. The plaintiff's expert relied on a differential diagnosis purporting to rule out all causes except Rezulin, but the trial and appellate courts agreed that the plaintiff had not offered a sufficient basis to "rule in" Rezulin as a potential cause of cirrhosis in the first place. The appellate panel left open the possibility that differential diagnosis might be probative of both general and specific causation in an appropriate case. See Ruggiero v. Warner-Lambert Co., No. 04-6674 (2d Cir. Sept. 16, 2005) (Jacobs, B.D. Parker, & Hurd, JJ.).