September 20, 2013 - The Russian patent system is divided into one venue for patent infringement proceedings (the Russian court system) and another venue for determining patent validity and revoking patents (the Chamber for Patent Disputes).
Until now, that has meant that if a patent was found to be partially invalid, the entire patent would be nullified, and a new patent would issue with a new patent number and containing the claims that were still adjudged to be valid. Since the original patent no longer existed and infringement was thus impossible, patent litigation would come screeching to a halt - until the amended patent issued, at which point the patentee would have to file a new patent infringement lawsuit.
But in Bayer vs. Gedeon Richter et al., the Presidium of the Russian Supreme Arbitration Court ruled that even though Bayer's original patent on oral contraceptives was partially invalid, the amended patent had the same priority date as the original patent - so Bayer did not lose its exclusive right to the invention.
As a result of this landmark legal ruling, the Russian patent system will be somewhat more fair for patentees, allowing them to continue enforcing their patents even after a finding of partial invalidity.