Varenaciline is marketed by Pfizer world wide as Chandix or Champix. Varenaciline is marketed as tartarate salt form, this salt form is protected by US patent 6890927 and its indian equivalent is 204091 (863/MUMNP/2003).
This ‘091 patent is opposed by Dr Reddy’s under section 25(2). Patent is revoked on lack novelty under 25(2)(b) and not an invention under 3(d). Interestingly granted claim 1 of ‘091 patent seems to be product claim of varenacline not as tartarate salt.
Decision date is May 23, 2011.