In 2009 Jamaican pharmaceutical companies Medimpex Jamaica Limited and Lasco Distributors Limited won a patent infringement battle over amlodipine besylate (also known as salts of amlodipine), in a case initiated by Pfizer Limited in 2002. However, their victory was shortlived as Pfizer successfully obtained a stay of execution of the judgment while it appealed the Supreme Court decision to the Court of Appeal.
Having waited seven years for the Supreme Court to hand down its judgment, the local pharmaceutical companies had to wait another three years for the Court of Appeal to rule on the matter. However, it was worth the wait as in May 2012 the appellate court upheld the Supreme Court's ruling that Pfizer's Jamaican letters patent for amlodipine besylate was invalid, given that a foreign letters patent for the same substance had expired before the Jamaican letters patent was granted.
However, the battle is not completely over as Pfizer, dissatisfied with the Court of Appeal's ruling, successfully obtained leave to appeal the decision before the Judicial Committee of the Privy Council in the United Kingdom - Jamaica's final appellate court.
Through equivalent letters patents granted in several jurisdictions, Pfizer has held the monopoly in amlodipine besylate - a drug known to treat hypertension and marketed by Pfizer under the brand Norvasc.
Pfizer's Jamaican application for a letters patent was filed in 1992 but was granted only in January 2002, by which time the earliest patent for amlodipine besylate, which had been granted in Egypt, had long expired. Local pharmaceutical distributors began to market generics containing the drug and were sued by Pfizer in 2002 for infringement of its Jamaican letters patent.
In their defence, Medimpex and Lasco argued that by virtue of Section 29 of Jamaica's Patent Act 1857, which essentially ties the subsistence of a Jamaican patent to the validity of the earliest foreign patent for the same invention, Pfizer's Jamaican patent was invalid and that they therefore needed no licence from Pfizer to distribute the drugs in Jamaica.
Pfizer, however, argued that Section 29 of the Patent Act applies only where the applicant for the Jamaican letters patent is the same as the applicant for an earlier equivalent foreign patent and that, in this case, the applicant for the Jamaican patent for amlodipine besylate was not the same at the applicant for the earlier patents, including the Egyptian patent which had expired in 1997.
The application for the Jamaican patent was filed by and in the name of attorney at law Maurice Robinson on Pfizer's instructions. In filing the application Robinson declared, as is settled practice in Jamaica, that the invention was communicated to him from abroad by Pfizer and that he was the 'first and true inventor'. On January 22 2002 the letters patent was granted to Robinson, who then assigned it to Pfizer for a nominal J$2 consideration within days of recording it with the registrar. Based on Section 3 of the act, which provides that patents are granted for a term of 14 years, Pfizer believed that it had a valid Jamaican patent that would expire on January 22 2016.