Supreme Court of Appeal of South Africa: Deciding on an appeal which concerns infringement of a patent entitled ‘Anti-parasitic composition for the treatment and protection of pets’ by the respondent and challenge of invalidity of the patent by the respondent on the basis of lack of clarity, the Court by a majority held that Court of the Commissioner of Patents erred by not concluding that the appellants had proved on a balance of probabilities that there was an infringement of claim 1 and the other dependant claims. The Court further concluded that challenge to the patent on the basis of lack of clarity also failed as the respondent did not satisfy the onus of proving the invalidity of patent. Claim 1 postulates a composition which includes four constituents, namely, fipronil, a solvent, a co-solvent and significantly for the invention, a crystallisation inhibitor.
In the instant case appellant is the holder of the patent ‘Anti-parasitic composition for the treatment and protection of pets’ while the respondent since 2008 made, used, sold, offered for sale and imported a composition ‘Fiprotec’ in the form of a ready to use solution for the treatment and protection of domestic animals which are infested with parasites. Both parties had adduced evidence by respective experts in relation to the crystallisation inhibitor test set out in integer.
After perusal of the contentions and tests conducted by expert witnesses, M S Navsa, Additional Deputy President on behalf of the majority observed that expert witness from the side of the respondent was of no assistance as the tests were conducted in a careless manner and had a lot of discrepancies. However, expert witness of the appellants was a person skilled in the art and thus an addressee of the patent. It was further observed that there was no evidence on which it might be found that respondent’s fipronil was in a different polymorphic form The Court noted that respondent presented evidence by a non-expert witness, who applied Fiprotec to a sample of dogs and that they all had crystals on their coat thereafter, which was countered by evidence presented on behalf of the appellants. The Court ordered the respondent to pay costs of suit and deliver up to the appellants all infringing Fiprotec products in its possession or under its control. [Merial v. Cipla Vet (Pty) Ltd, (20772/2014)  ZASCA 57, decided on 1 April 2016]