The Hindu Business Line : Solution to an objective problem that didn't exist?

EXCITING things are happening in the patent field, both as new findings and fresh lawsuits. Thus, the site of EPO (European Patent Office) http://ep.espacenet.com speaks about `Electronic component mounting apparatus and electronic component mounting method' published on Wednesday. A posting on the same day, on http://patentbaristas.com, reads "Andrx files patent infringement suit against GlaxoSmithKline over Wellbutrin XL."

There is more, if you look around: "Patent fight weighs on RIM's growth," as Globe and Mail, Canada, informs about Research In Motion Ltd. Register, UK informs, "20 Japanese giants sue US processor patent holder." Auctionbytes has a piece on "eBay Patent Wars: Behind-the-Scenes Battles". Australian Financial Review opines, "Patent review key to BlackBerry fate." Scripps Howard News Service says, "Welcome to the dysfunctional world of patent litigation," in an article titled, "Misadventures in the wacky world of patent law." And http://home.businesswire.com speaks of `An Overview of Patent Infringement Law' available from researchandmarkets.com.

Anticipation and obviousness

The earlier article in these columns ("What's the racemate in `Formula I' of the pharma race?" Business Line, December 21) was about European patent 0247633 of Pfizer that Ranbaxy disputed against and lost out in the hands of Mr Justice Pumfrey at the High Court of Justice, Chancery Division, Patents Court, in the UK.

What Ranbaxy could, however, cheer at was the blow that Pfizer suffered in the same judgment, when Justice Pumfrey held that Pfizer's patent 0409281 (281) was `invalid for anticipation and obviousness'. Because novelty is a requirement for a patent, anticipated inventions are not patentable, educates a glossary on www.nolo.com.

"Anticipation can occur when a prior invention or printed publication matches all of the primary characteristics of the invention, or it can happen when the invention is displayed or offered for sale more than a year prior to filing a patent application."

The site provides an interesting example: "A bird owner invents a device to keep her bird from picking at its tail feathers. She applies for a patent, but her application is rejected on the ground that the same device was in use 3500 years ago in Egypt. In patent-speak, the inventor's creation has been anticipated by previous developments (the prior art.)"

When is a patent obvious? To this question, www.iusmentis.com answers thus: "A patent is obvious if what is claimed is novel, but the novel aspects were not the result of any inventive activity." Obviousness is an attack on a patent based on its lack of inventiveness, explains www.law.unb.ca. "The attacker, says, in effect, `Any fool could have done that.'"

Patent 0409281

Paragraph 43 of the judgement narrates that claim 1 of the 281 patent is to "the hemicalcium salt of [R-(R*,R*)]-2- (4-f1uorophenyl)- (,(-dihydroxy-5- (1-methylethyl)-3-phenyl-4- [(phenylamino)-carbonyl]- lH-pyrrole-1-heptanoic acid". This can be conveniently referred to as atorvastatin calcium, and it is the commercial material of interest, said Justice Pumfrey. A 19-page `European Patent Application' with publication number 0409281 A1 mentions `Inventor: Roth, Bruce David' and `Applicant: Warner-Lambert Company'.

The section titled `background of the invention' cites US patent 4,681,893 for compounds `having usefulness as inhibitors of cholesterol biosynthesis', and adds, "It is now unexpectedly found that the enantiomer having the R form of the ring-opened acid... provides surprising inhibition of the biosynthesis of cholesterol." (893, filed in 1986, "is related to compounds and pharmaceutical compositions useful as hypocholesterolemic and hypolipidemic agents," as informed by a document on www.uspto.gov.)

In `detailed description of the invention' one learns that the pharmaceutically acceptable salts of the invention are generally derived by dissolving lactone in solvents. "Addition of calcium chloride to a solution of the sodium or potassium salt of the compound of the formula I will give the calcium salt thereof," it explains.

Ranbaxy raised two grounds of invalidity against this patent: One, `anticipation by WO 89/07598 (598)'; and two, `obviousness in the light of the application for 633'. Dr Cunningham spoke for Ranbaxy, while Dr Spargo gave evidence for Pfizer.

Formula in 598

Justice Pumfrey observed that 598 is "an application for ways of making, particularly, formula I, which is the same as formula I of 633 save that group X is explicitly ethyl, -CH{-2}CH{-2}-."

He cited the following portion from 598: "In the ring-opened dihydroxy acid form, compounds of the present invention react to form salts with pharmaceutically acceptable metal and amine cations formed from organic and inorganic bases. The term `pharmaceutically acceptable metal salt' contemplates salts formed with the sodium, potassium, calcium, magnesium, aluminum, iron and zinc ions."

Comparing the formulas of 281 and 598, Justice Pumfrey pointed out that they were "identical, save that in 281 the calcium salt, and in 598 the acid, are shown." He added, "In fact, the synthetic route described in `598 actually produces a racemate... . It is no answer to an allegation of anticipation that the specification gives clear and unmistakable directions to use the common general knowledge to produce a specific material."

Justice Pumfrey, therefore, concluded, "This is a clear case of anticipation of claim 1 of 281." He said that 598 gave specific directions to make the three preferred enantiomers, one of which fell within the claim.

A March 29 press release on www.ranbaxy.com, titled `Austrian patent office issues favourable ruling for Ranbaxy on Atorvastatin' speaks of how a panel of five judges agreed that the specific patent claims are invalid as anticipated by "Pfizer's international patent application PCT/US89/00719, which published as WO 89/07598". The Court agreed with Ranbaxy that the patent claims lack an inventive step over Pfizer's United States Patent No 4,681,893, says the release.

`Obvious' observations

Pfizer argued that 598 did not disclose `pharmaceutical compositions of atorvastatin'. This was `incorrect', said Justice Pumfrey. "It is occasionally said that there cannot be clear and unmistakable directions to do something which is described as optional. I do not agree: to describe the thing as optional is to describe the thing. It is rather like the disclosure of something as adjustable: it necessarily also discloses something that is not adjustable," he said, citing a 1913 decision, Gillette vs Anglo-American.

By 1989, resolution of racemates with pharmaceutical activity was well established, informed the judge. The skilled ones knew that the active form was not the lactone but the open chain acid and its salts, he said. "It was also known that the salts would be likely to be more soluble, and so possibly more bioavailable, than the free acid."

To test salts for their properties, it is standard practice for the skilled person to carry out a `salt screen', one learns from the judgment. "In the case of an acid, this would include the standard sodium, potassium and calcium salts. These are the most commonly used salts." The screen includes a test for hygroscopicity, rate of dissolution and solubility. "The hygroscopicity test is carried out in a controlled humidity chamber, or otherwise using the standard equipment of any formulation laboratory. The whole process is entirely routine."

Justice Pumfrey asked, "Is the difference obvious?" And answered, "In my judgment it most certainly is." Reason: "The resolution of the racemate was common general knowledge at the date. It was becoming preferred in the industry generally, and this particular resolution did not, on the evidence, involve any work that was not common general knowledge. Seven salts are specifically described. How can it be inventive to use one?"

Racemate Report

The UK judgment refers to `Racemate Report' presented as a document in the case, and also a letter from Pfizer to EPO saying that "the sodium salt showed poor hygroscopicity and a tendency to become sticky, which was not shared with the calcium salt", and leading to recharacterisation of the `problem'. Justice Pumfrey pointed out, "But there was no objective problem: the calcium salt was being tested alongside the sodium salt."

He said, "We find ourselves in the strange position that if the sodium salt had been satisfactory, there would have been no invention in going for the calcium instead, but since it was not, there was an invention." The judge asked, "How can one solve an (objective) problem that one did not know existed?"

Concluded

ZeroBase@TheHindu.co.in