Selection Patents

1Selection patents constitute a problematic area for patent law. (See Philip W Grubb, Patents for Chemicals, Pharmaceuticals and Biotechnology: Fundamentals of Global Law, Practice and Strategy, OUP, 1999, p 196; Terrell on the Law of Patents, fifteenth edn, 2000, p 167; Lionel Bently and Brad Sherman, Intellectual Property Law, OUP, 2000, pp 436-38.) Selection patents are patents which claim particular compounds to be individually new, but as falling within an earlier disclosure of a broader group of compounds for which protection is already claimed. Selection patents are inventions based on a selection of a particular compound or a relatively small group of compounds from a larger group previously disclosed in broad terms. Selection patents were developed in response to a particular problem that arose in certain fields like chemistry, where the researcher may discover that a particular combination of molecules may produce a particular result. Once a particular result is identified, the researcher extrapolates from the initial discovery to assert that the same qualities will be produced by a range of variants or homologues. This is regarded as a generic disclosure, where the researcher would disclose a very broad range or class of compounds. (See Lionel Bently and Brad Sherman, Intellectual Property Law, OUP, 2000, p 436.)

2When later discoveries show that the some of the compounds outlined in the generic disclosure have particular advantages or uses other than what was originally discovered, the issue arises whether such discoveries could qualify for a separate patent. Logically, the earlier generic disclosure would prevent any subsequent claim to be made on any of the individual member or members of the group. But the problem imposed by this situation was that if the earlier generic disclosure is to be regarded as anticipating the latter discovery, it would be a disincentive for further research to be carried out on the materials already disclosed. Thus, the following question arises in the case of selection patents: whether a prior generic disclosure anticipates subsequent inventions in the same field and if so, to what extent. (Ibid.)

3The rules that apply to selection patents do not differ from the general rules of patent law. (See IG Farbenindustrie AG’s Patent (1930) 47 RPC 289, pp 322-23; Esso Research & Engineering Co’s Application (1960) RPC 35.) Some specific rules have been devised with regard to selection patents as laid down in some decisions by the UK courts. (See Clyde Nail Co Ltd v Russell (1916) 33 RPC 291, p 306; IG Farbenindustrie AG’s Patent (1930) 47 RPC 289, pp 322-23; Esso Research & Engineering Co’s Application (1960) RPC 35; Du Pont (EI) de Nemours (Witsiepe’s) Application [1982] FSR 303; Hallen Company v Brabantia (UK) Ltd (1991) RPC 195. See also Ram Narain Kher v Ambassador Industries AIR 1976 Del 87, p 88.) In IG Farbenindustrie AG’s Patents, Maugham J elucidated that the following conditions must be shown, which are by no means exhaustive, for a selection patent to be valid: ((1930) 47 RPC 289, pp 322-23.)

(1) the selection must be based on some substantial advantage to be secured by the use of the selected members;
(2) the whole of the selected members must possess the advantage in question; and
(3) the selection must be in respect of a quality of a special character which can fairly be said to be peculiar to the selected group.

4In Farbwerke Hoechst v Unichem Laboratories (1968) the Bombay High Court adopted Jenkins J’s statement that “Even where an invention consists of the production of further members of a known series whose useful attributes have already been described or predicted, it may possess sufficient subject-matter to support a valid patent provided the somewhat stringent conditions prescribed by Maugham, J. ... are satisfied” (p 66–67).

5The above rules have been approved and followed in a number of decisions. (See Esso Research & Engineering Co’s Application (1960) RPC 35 (CA); Du Pont (EI) de Nemours (Witsiepe’s) Application [1982] FSR 303; Hallen Company v Brabantia (UK) Ltd (1991) RPC 195.) Though selection patents will have a significant impact on pharmaceuticals, the above rules were framed in a case involving textile dyes. The patent for a process of manufacturing certain azo and aromatic amine dyestuffs claimed by IG Farbenindustrie was challenged by a revocation application on the ground of lack of novelty that the prior disclosure in an expired patent revealed the invention. The patentees took a defence that though the disclosure made in the earlier patent revealed millions of combinations of dyes, the particular group of dyes selected by the patentee had certain beneficial properties not previously known. Applying the above rules, the court came to the conclusion that the patent was invalid. In United Kingdom, the above rules opened up the possibility of many selection patents to be filed and entertained. (Du Pont (EI) de Nemours (Witsiepe’s) Application [1982] FSR 303, p 309.)

6There is lack of clarity with regard to the issues arising out of selection patents. Some of the uncertainties arise due to the difficulties in differentiating the issues of novelty and inventive step. (As can be seen by the treatment of selection patents by various authors: Lionel Bently and Brad Sherman, Intellectual Property Law, OUP, 2000, pp 436-37, discusses selection patents under the chapter on novelty. P Narayanan, Patent Law, fourth edn, p 431, treats the subject under the heading ‘Obviousness or lack of inventive step’. Terrell on the Law of Patents, fifteenth edn, 2000, however plays it safe, selection patents are discussed under the headings of both novelty and obviousness, at paras 7.17 and 7.40.) Patent offices throughout the world do not have any consensus with regard to the grant of selection patents. Germany does not treat applications for selection patents favourably. (See Philip W Grubb, Patents for Chemicals, Pharmaceuticals and Biotechnology: Fundamentals of Global Law, Practice and Strategy, OUP, 1999, p 199.) The practice of the EPO in granting selection patents does reveal some inconsistencies. (See Lionel Bently and Brad Sherman, Intellectual Property Law, OUP, 2000, p 437, fn 129. Compare T1048/92 Pfizer/Penem [1995] EPOR 207 with T658/91 Sanofi/Enantiomer [1996] EPOR 24.) Their relevance in United Kingdom, after the changes in law brought about by the UK Patents Act, has also been questioned. The position in United Kingdom is summarised well in the following passage: (Lionel Bently and Brad Sherman, Intellectual Property Law, OUP, 2000, pp 437-38.)

To argue that under British law the doctrine of selection patents should be jettisoned in favour of the more general rules about novelty is not as radical as it may first seem. This is because the issues which arise with selection patents are really no different from the question which Lord Hoffmann said underpinned the novelty of examination more generally: viz how specific must a disclosure be for an invention to be ‘known’ or ‘made available’ to the public? (The key difference is that with selection patents the question is rephrased to be: How specific must a generic or general disclosure be for it to destroy the novelty of a subsequent invention which incorporates the prior knowledge?) While Lord Hoffmann wisely answered that it always depends on the invention in question, the doctrine of selection patents has attempted the impossible and tried to stipulate in advance the type of disclosure that is needed to anticipate. Given the futility of this, it may be better if the novelty of selection patents were answered through the general rules about novelty. If this approach were adopted, it would mean that a prior generic disclosure placed a skilled person in a position whereby they could ‘work’ the invention in question.

7Selection patents may involve a selection from a small class, selection from a patent disclosure, selection from optical isomers, and selection from overlapping groups. (Ranbaxy UK Ltd v Warner-Lambert Co [2006] FSR 14. The issue in the above case was one of construction. The question was whether the claim covers the single enantiomer or does it only cover racemic atorvastatin, ie, the mixture of two enantiomers. The court held that the claim covered the racemate and the individual enantiomers.) The scope of selection patents is described in Boehringer Mannheim GmbH v Genzyme Ltd, where it was observed that selection patents has existed for at least 60 years and the concept: (For details see, Philip W Grubb, Patents for Chemicals, Pharmaceuticals and Biotechnology: Fundamentals of Global Law, Practice and Strategy, OUP, 1999, pp 198-200.) ([1993] FSR 716, p 725.)

enables a valid patent to be obtained for the selection of a product or process from a range of known or obvious products or processes because of surprising and non-obvious advantages over the others…The selection must be based on a substantial advantage of special character. The selected member or class must have the advantage, and the specification must direct the mind of the skilled reader to the advantage of the selection from the class [Emphasis supplied].

8It follows that selection patents may be claimed with regard to products or processes. Such patents are claimed from a set of known substances or known processes. The main claim for the grant of such patents is the discovery of a substantial advantage which can be regarded as a new use. It has been pointed out that selection patents may also be made with regard to discovery of new substances, new uses for old substances, and new purposes for old substances used in old ways. (Lionel Bently and Brad Sherman, Intellectual Property Law, OUP, 2000, p 437.)

9Section 3(d) encompasses the situations stated in the preceding paragraph. In the case of selection patents claiming a new property or a new use, the second part of s 3(d) of the Patents Act will act as a bar for patenting such inventions. A selection patent may be allowed if it satisfies the conditions stipulated in the first part of s 3(d) of the Patents Act. The selection patent should show that a new form of a known substance results in the enhancement of known efficacy.

10As stated earlier, s 3(d) of the Patents Act will be seen as prohibiting the grant of selection patents on the grounds of novelty as well as lack of inventive step (obviousness). The obviousness question that arises in the case of selection patents is, whether the inventive step can reside in the ‘discovery’ that one or more members of a class have some special advantage (new property) for some particular purposes (new use). (Terrell on the Law of Patents, fifteenth edn, 2000, p 193. ‘The inventive step in a selection patent lies in the discovery that one or more members of a previously known class of products possess some special advantage for a particular purpose, which could not be predicted before the discovery was made.’ See Beecham Group Ltd v Bristol Laboratories (1978) RPC 521, p 579 per Lord Diplock.) As discussed above, the second part of s 3(d) of the Patents Act comprehensively bans patents for the discovery of a new property or new use of a known substance. To this extent, selection patents will not be allowed in India. Obviousness is a broader ground where a granted patent can be revoked on the ground that the earlier disclosure enabled a person skilled in the art to make the selected patents from the earlier disclosure.

11In F Hoffmann-La Roche v Cipla (2012) the Delhi High Court held that “the following material facts are essentially required to be established by the counterclaimant:”

The selection of the impugned invention is taken from the examples of the known prior art.
That the selected invention is not far removed from the known range illustrated in the example. Rather, the same is closer to the known range.
That the selection area is not on the basis of any purpose of the inventor and is merely an arbitrary picking up the compound. (para 66)

12The identification of a previously unmade class of chemical compounds will in itself not be entitled to a patent, as it is possible to create different compounds without any inventive step. (Pharmacia Corpn v Merck & Co Inc (2002) RPC 41, para 164.) Selection patents must sufficiently disclose the technical contribution, ie, the specification must identify the characteristics of the class and a method of manufacture, and all the claimed compounds must in substance have the characteristics of the class. Selection patents may also be revoked on grounds of insufficiency. (Pharmacia Corpn v Merck & Co Inc (2002) RPC 41, paras 50, 56. See also order of the Controller in Novartis Application (1602/MAS/98) (Unreported) where the application was also opposed under s 25(1)(g) on the ground that the complete specification does not sufficiently and clearly describe the invention. The Controller held that ’the present patent specification does not bring out any improvement in the efficacy of the beta crystal form over the known substance rather it states the base can be used equally in the treatment of diseases or in the preparation of pharmacological agents wherever the beta crystal is use.’)