Avoiding hindsight in non-obviousness determination: case law review of pharmaceutical patents and guidance from the KSR v Teleflex decision.

: Hindsight bias is the tendency to estimate an outcome once it is known. Legal systems are often prone to hindsight bias. In patent law, the non-obviousness or inventive step is the most critical determinant of patentability and often subjected to hindsight bias.: Scholarly literature confirms the existence of hindsight bias in different patent systems. This communication hence addresses factors, which lead to hindsight bias specifically in chemical and pharmaceutical arts, guidance from the case law that can be helpful in avoiding hindsight bias in non-obviousness determination.: The Supreme Court in 2007, advocated a more expansive and flexible approach to where the Teaching Suggestion or Motivation test could come from. In the case of chemical and pharmaceutical active compounds, the considerations such as i) was there sufficient motivation to modify the lead compound and arrive at the claimed compound and its properties, ii) was there a reasonable expectation of success to achieve the claimed property and other such considerations highlighted in this review may contribute to avoid hindsight bias in non-obviousness determination.