Amoxicillin patent case

download Amoxicillin patent case

of 20

  • date post

  • Category


  • view

  • download


Embed Size (px)

Transcript of Amoxicillin patent case

  • 1. BEECHAM GROUPS Nishidh Patelnishidh41@gmail.comAMOXYCILLIN APPLICATION 1

2. AMOXYICILLIN-PATENT HISTORY A patent that covered an extensive class of -amino acid derivedpenicillins comprising various amino acyl substituted (the aminopatent) was registered in 1959. In 1962, a fur ther patent of addition was included in the UK (but notNZ) for the preparation of all three regio isomeric phenolderivatives/variants of -amino-- phenyl penicillins from thecorresponding o-, m- and p-hydroxyphenyl--amino acids; three pair s ofepimers (diastereoisomers ) ensued as a result of using the racemicaminoacids. This patent is known as the OMP patent as it claimed allthree epimeric pair s; amoxycillin is the (R) --amino-p-hydroxyphenylisomer In 1969, Beecham led for a patent for amoxyicillin in NZ. It wasreferred to in the specication as a development of our [Beechams]British patent No 978178 (the OMP patent ). Beechams subsequent discoveries on the use of naturally occurring -lactamase inhibitors in conjunction with the semi-synthetic derivativesof penicillin have also been attentively patented.2 3. AMOXYICILLIN-PATENT HISTORY In 1984, a combination of amoxycillin with clavulanic acidwas introduced and Beecham gained multiple NZ patentscovering dif ferent processes for the preparation of clavulanicacid, its salts, and its use with penicillins, such asamoxycillin. Beecham subsequently patented 39 dif ferent compositions ofamoxycillin with clavulanic acid and has continued to patentmethods of producing salts of clavulanic acid; the IPONZdatabase lists twenty dif ferent patents for Beecham andclavulanic acid. Of all the Beecham penicillin-related patents, the mostcontroversial in NZ is that for amoxycillin.3 4. AMOXYICILLIN-PATENT HISTORY The Bristol-Myers Company was not pleased with the world-wide amoxycillin applications that extended Beechamsproperty rights for the compound. The NZ amoxycillin patent was disputed on the grounds ofnovelty and obviousness (lack of inventive step) because ofthe OMP patent led in the UK in 1962 and subsequentlypublished in NZ. The UK OMP patent ran from 19621976 and the amoxycillinpatent from 19681982, thus extending protection by sixyears. OMP was not patented in NZ but amoxycillin was covered, to apoint, by the 1959 amino patent (19591973 protection). Theamoxycillin patent in suit would extend protection by ten yearsto 1983. 4 5. SELECTION INVENTION Selection invention allows patenting of compounds which fallwithin disclosure of earlier patent if:1. compounds not specifically disclosed in earlier patent, and2. compounds have unexpected advantages over those compoundsspecifically disclosed in earlier patents. The three par t novelty test: The claimed range must be narrow It must be suf ficiently distant from preferred known ranges It must not be an arbitrar y chosen par t of prior ar t All of the compounds which are the subject of a selection inventionmust exhibit some unexpected proper ties, or overcome adisadvantage, of the earlier class of compounds. Therefore,selection inventions tend to be directed to a narrow class ofcompounds.5 6. COLLOCATION OF KNOWN AGENTS A further example of a patentable invention is the combinationof two or more previously known agents which together exhibit aworking interrelationship to produce a benet or to overcome adisadvantage. An example of this could well be a process which normally occursat a very slow rate, but which is sped up by an otherwise inactivecatalyst, or a combination of drugs exhibiting synergistic activity. For example, amoxyicillin is an effective antibiotic to whichbacteria quickly became resistant. Clavulanic acid is a beta-lactamase inhibitor with no bactericidal activity in itself, butwhen co-administered with amoxyicillin, potentiates theantibiotic effect of amoxyicillin. Subsequently, this combinationwas patented because the effectiveness of the combination wassuperior to what could be expected by simply adding the twocompounds together.6 7. NEW ZEALAND-THREE LEVELS OF COURTS OF RECORDSupreme New Zealand is aCourtcommon law(Estd. in 2004) country.The Patents Act Court of1953 is the relevant legislation. AppealUnicameral legislature so issues Highof federalism do not Court arise. 7 8. Court ofAppeal AMOXYICILLIN-PATENT CASEHigh CourtAssistantCommissioner8 9. ?? A S S I S TA N TCOMMISSIONERSDECISION?Beecham Group Ltd v Bristol-Myers Co. 9 10. BEECHAM GROUP LTD V. BRISTOL-MYERS CO. ASSISTANT COMMISSIONERS DECISION In the Beecham case, Beecham Group Limited applied for apatent relating to amoxyicillin (a semi-synthetic penicillin)which had been found to have outstanding levels ofabsorption into the human body in comparison with relatedsemi-synthetic penicillins. Bristol-Myers opposed the patent application on the groundsof prior publication and obviousness, relying on the priorpublication in New Zealand of a British patent owned byBeecham. The opposition succeeded on both grounds and was appealedto the High Court. 10 11. ?? HIGH COURTSDECISION?Beecham Group Ltd v Bristol-Myers Co. [1980] 1 NZLR 185 (HC) 11 12. BEECHAM GROUP LTD V BRISTOL- MYERS CO. [1980] 1 NZLR 185 (HC) The benefit of the doubt has to be given to the patentee inopposition proceedings, particularly where there appears tobe conflict of fact or credible expert opinion. This wasdiscussed in Beecham Group Limited v. Bristol Myers Company(No2) [1979] NZLR 629 at 632-634, which includes, at 634, aquote from Lord Diplock in General Electric CompanysApplication [1964] RPC 413 at 453: The right principle is that if on the face of the written evidence filedthere appears to be a bonafide Conflict of fact or credible expertopinion upon a question on the answer to which the existence or non-existence of the ground of refusal specified.depends, the[Commissioner] should not exercise his jurisdiction to refuse thegrant unless, after cross-examination of the witness if he thinks fitfor to order it, the conflict is clearly resolved in favour of the partyopposing the grant. 12 13. BEECHAM GROUP LTD V BRISTOL- MYERS CO. [1980] 1 NZLR 185 (HC) The prior art relied on by Bristol-Myers was a British patent in thename of Beecham that was directed to a broad group of semi-synthetic penicillins. The Court held that the prior art patent didnot provide clear and unmistakable directions to makeamoxyicillin because it did not give full and explicit directions forthe entire process of preparing the compound. The Court stated that even though it was common ground that askilled chemist could resolve the necessar y issues tomanufacture the compound by following routine methods, thiswas not enough for the invention to be considered as publishedin New Zealand: If such a compound has not been made before, its properties oftencannot be predicted with any condence; and where that is the case wedo not consider that the invention claimed can fairly or accurately bedescribed as published, even if a skilled chemist would realise that tomake the compound by routine means would be practicable. A making of the compound and a discovery of its properties is necessarybefore the invention has occurred and can be published.13 14. BEECHAM GROUP LTD V BRISTOL- MYERS CO. [1980] 1 NZLR 185 (HC) The Court referred to the judgment of Buckley LJ in E.I. Du Pontde Nemours & Co. (Witsiepes) Application in support of thisview. The E. I. Du Pont de Nemours & Co. judgment also considered aselection invention, and Buckley LJ stated that: Something which has never yet been made can clearly not have beenknown or used; nor can it, in my view, be properly described as knownif it has been no more than predicted as a theoretically possiblechemical compound. The fact that the special qualities of the compoundwere unknown untilthey were discovered by the applicants emphasizes that the compound,although it was chemically predictable, was not a known substance untilthe applicants made it. The High Court overturned the Assistant Commissioners decisionand directed that the patent be sealed. This decision was in turnappealed to the Court of Appeal. 14 15. ?? COURT OFAPPEAL?Beecham Group Ltd v Bristol-Myers Co.[1981] 1 NZLR 600 (CA) 15 16. BEECHAM GROUP LTD V BRISTOL-MYERS CO. [1981] 1 NZLR 600 (CA) The Cour t in Beecham also indicated that a mere scintilla ofinvention is sufcient to provide patentable subject matter. Thesetests are used by the Intellectual Proper ty Ofce of New Zealand toassess selection inventions. In most instances selection inventions relate to chemicalinventions, but the issue of selection is not conned to chemicalinventions (see e.g. Clyde Nail Co. Ltd. v. Russell , (1916) 33 RPC291 (mechanical) and Boschs Application , (1909) 26 RPC 710(electrical)). Although both these applications were refused, the cour ts statedthat selection inventions are patentable in the mechanical andelectrical elds provided they show an advantage or avoid adisadvantage. More recently a clear statement was issued by the UK Cour t ofAppeal in Hallen v. Brabantia [1991] RPC. 195, p 217, that amechanical selection invention is a possibility. 16 17. BEECHAM GROUP LTD V BRISTOL-MYERS CO. [1981] 1 NZLR 600 (CA) To anticipate the patentees claim the prior publication mustcontain clear and unmistakable directions to do what thepatentee claims to have invented. A signpost, however clear, upon the road to the patentees invention will not sufce. The prior inventor must be clearly shown to have planted his ag at the precise destination before the patentee. This test was discussed and approved by the New ZealandCourt of Appeal in Beecham Group Limiteds (New Zealand /amoxyicillin Application) i.e. present case.17 18. BEECHAM GROUP LTD V BRISTOL-MYERS CO. [1981] 1 NZLR 600 (CA) The Court in Beecham held that prior publication requires thatthe compounds have to be made , even if a skilled chemist wouldunderstand that the compound could be made by routine means. However, the requiremen