Kickstart your patenting process and receive an assessment within 60 days.
4.83 If the invention is one of many possible alternatives, and there is no indication in the prior art that any particular alternative is more advantageous than another then the invention may be considered non-obvious. This most often arises in chemical applications, where Markush-style claims can cover a broad range of compounds, but only specifically disclose a limited range of embodiments. Subsequent applications which claim a specific subset of the compounds on the basis of an unexpected advantage may be patentable. Such situations are often referred to as “selections”.
4.84 The law on selection patents was first set out in I G Farbenindustrie AG’s Patent  47 RPC 289.
4.85 However, in Dr Reddy’s Laboratories (UK) Ltd v Eli Lilly & Co Ltd  RPC 9, Jacob LJ stated that as these rules related to pre-1977 law they could be regarded “as part of legal history, not as part of the living law”. Instead the criteria set out by the EPO Board of Appeal decision in T 939/92 AGREVO/Triazoles were followed:
(i) the selection must not be arbitrary but must be justified by a hitherto unknown technical effect;
(ii) a technical effect which justifies the selection of the claimed group must be one which can be fairly assumed to be produced by substantially all the selected members;
(iii) this technical effect can only be taken into account if it can be accepted as having been indicated in the specification as filed.
4.86 Jacob LJ noted that the criteria set out in I G Farbenindustrie AG’s Patent were formulated under the common law and did not draw a distinction between lack of novelty and obviousness. Instead these were dealt with under the general umbrella of “lack of subject-matter”. He stated that the “rules were carried over by the judges into the newly codified law in 1932 and remained, almost as a special sub branch of patentability, as part of English law until the “new law of patents” (a recital to the Patents Act 1977) came in.”
4.87 The judge also expressed concern that the final test – that the property be peculiar to the selected group – was not one that could be applied in practice without testing “quite a lot” of the prior class. On that basis he considered theapproach taken by the EPO in AGREVO was preferable. If dealing with selections, the AGREVO approach should be taken by Examiners.
4.88 A selection would be regarded as obvious if it has made no real technical advance. This was noted by Jacob LJ in Dr Reddy’s:
“… it regards what can fairly be regarded as a mere arbitrary selection from a class as obvious. If there is no more than an arbitrary selection then there is simply no technical contribution provided by the patentee.”
4.89 The “hitherto unknown technical effect” should be clearly indicated. This can be by explicit statement, or may be implied from tests provided in the application at the time of filing. Later-filed evidence may be used to provide support for the first two criteria, but unexpected bonus effects not described in the specification cannot form the basisof a valid claim to a selection invention (Glaxo Group Ltd’s Patent  RPC 43).
4.90 A “bonus effect” refers to the effects that are observed in an otherwise obvious invention. Generally, the situation is one where there is a “one-way street” – the invention is one which would be obvious to the skilled person, and any unexpectedresults are merely a bonus effect from following an otherwise obvious pathway.
4.91 If the specification as filed does not state the advantage (or if it cannot be implied from experimental data), then it cannot be amended later to include such a statement. In Richardson-Vicks Inc.’s Patent  RPC 568 at , Jacob J stated that whether or not the advantage was demonstrated “by experiments conducted after the date of the patent cannot help show obviousness or non-obviousness … and it would be quite wrong for later-acquired knowledge to be used to justify the amended claim.”
4.92 In this regard the usual considerations for amendments should be made– in particular would the skilled person learn something about the invention from the amended specification that they would not have learned from the specification as filed.