The differences between US and European patent law can often trip up practitioners unless they are careful – while most European patent law is (fairly) well harmonised, US patent law is quite different.  While the two are closer in some ways than they have been – obviousness in the US has become much more like inventive step in Europe since KSR v. Teleflex, for example – there are some sharp differences.  One subtle one is the interplay between confidentiality and sale.  The recent decision in Helsinn Healthcare S.A: v. TEVA Pharmaceuticals USA INC., et al., reported here in IPKat, shows that one very real trap still exists. (more…)