Canadian Court Strengthens Patent Protection

In a landmark ruling that could have major implications for generic drugmakers in Canada, the Supreme Court of Canada ruled that a selection patent for a key ingredient in best-selling Plavix clot buster is valid and dismissed an appeal from Apotex, which sought to invalidate the patent.

In its 7-to-0 ruling, the court decided that Sanofi Synthelabo Canada put significant effort into refining a group of chemical compounds that it discovered and patented many years earlier. And by investing millions of dollars of research into creating this refinement, the drugmaker was entitled it to a new, 20-year period of patent protection, The Globe and Mail reports.

The status of patents covering second-generation refinements - known as ‘selection patents' - have long been a controversial topic in the patent and pharmaceutical world, the paper notes. Selection patents involve rights that are secured for a fraction of a larger class of compounds. The ruling is likely to be criticized by some as a blow to the availability of cheaper, generic drugs.

But Patrick Kierans, a lawyer who argued for a legal intervenor - Canada's Research-Based Pharmaceutical Companies - tells the paper that seven to eight out of every 10 brand-name drugs on the market involve selection patents and, for this reason, the ruling was "absolutely critical...selection patents are desperately important in the pharmaceutical industry."

“We argued in the Supreme Court that if you say selection patents are bad and you can't have them, then what incentive would there be for a scientist to go back into the ‘galaxy' and look? None. Society wants them to go back to the well, where we already believe there are potential winners.”

In March 2003, Apotex applied for approval from the federal health ministry to market its generic Plavix. The Canadian company based its application on the argument that the patent held by Sanofi Synthelabo repeated the previous patent and the compound could have been recreated based on information from that one, the CBC notes.

Apotex argued that Sanofi's patent was invalid on the grounds that it was an obvious development which required no special creativity or research, and that giving patents on components mentioned in previous patents effectively served to evergreen, or extend, Sanofi's exclusive rights.

In the court's ruling, Justice Marshall Rothstein that the Plavix compound was "not self-evident" based on the previous patent and required "inventive" steps to develop the compound. Sanofi spent millions of dollars and several years developing Plavix as a "less toxic" and "better tolerated" alternative, Rothstein said.

"The inventor selects only a bit of the subject matter of the original genus patent because that bit does something better than and different from what was claimed in the genus patent," Rothstein wrote. Rothstein said Apotex's concern about evergreening was not justified, adding that it is important to allow such "selection patents" because it encourages improvements by industry.