193 As can be seen from the structures depicted above, both names describe the tricyclic core ring structure in the same way: namely, thieno[2,3-b][1,5]benzodiazepine. Both names describe the identity of the substituents in the same way: the CH3 substituent on the thiophene ring is described as "methyl", and the substituent ring at the top of the structure is described as "4-methyl-1-piperazinyl".
194 Eli Lilly submitted that even though the chemical name used in claims 1 and 2 of the Patent is not strictly IUPAC-compliant, Apotex cannot contend that it is outright "wrong". This is because the person skilled in the art would not approach the task of identifying the compound with the chemical name used in claims 1 and 2 on the assumption that the name is strictly compliant with IUPAC guidelines. Eli Lilly contended that the IUPAC nomenclature system is not, and was not at the priority date, universally used.
195 Some expert evidence in this proceeding on the construction issue was given by way of an evidential "hot tub" (more formally known as "concurrent expert evidence"). Dr Watson and Dr Robertson were hot tub participants.
196 Prior to trial Dr Watson and Dr Robertson prepared a joint expert report on the construction of the claims, in which both experts attempted to give answers from the perspective of the skilled addressee at the priority date (25 April 1990), without regard to knowledge acquired after that date. For convenience, I will, in describing their evidence, refer to claims 1 and 2 (as they contain the same chemical formula).
197 In the report, both Dr Watson and Dr Robertson agreed that, when read in isolation from the rest of the Patent, claims 1 and 2 concern a single compound. When the claims were read with the rest of the Patent, and considering the 235 Patent referred to in the Patent, Dr Watson and Dr Robertson still believed claims 1 and 2 to claim a single compound. They believed this compound to be olanzapine. However, they both agreed that the nomenclature used in the Patent was "unconventional".
198 I should indicate that, in answer to contrary suggestions by Apotex, I do not consider that the reference to the 235 Patent detracts from the conclusion reached by the experts. Nor do I accept that the nomenclature underpinning the 'dictionary' at pp 3 and 4 of the Patent can only be understood by the use of 235 Patent. The nomenclature on those pages of the Patent was readily understood by the experts, without the need for any further reference or source.
199 Dr Watson and Dr Robertson then went on to consider whether that single compound could be the subject of more than one system of chemical nomenclature, regardless of whether the nomenclature in the Patent was "unconventional". In response to the question: "in 1990, was IUPAC nomenclature universally applied in the naming of chemical compounds?", both Dr Watson and Dr Robertson stated that:
IUPAC nomenclature was not used on a daily basis by practising synthetic organic chemists.
It was universally accepted that IUPAC nomenclature was the most detailed reference for naming compounds.
Chemical [A]bstracts was often used as a guide to nomenclature.
200 There were no areas of disagreement between the two experts in relation to this question.
201 As IUPAC nomenclature was not used on a daily basis by practising chemists at the priority date, it is therefore possible that a skilled addressee would not exclude the possibility that a non-IUPAC name was used. Perhaps the more relevant question to ask was whether a skilled addressee at the priority date would consider that a formal document, such as a patent, would only use IUPAC-compliant naming. Nonetheless, I accept that even in this context, a non-IUPAC name could be used.
202 Eli Lilly submitted that the numbering system in the Patent relies on a "convention or a nickname" specific to the 235 Patent (which they characterised as a "genus patent"). As the Patent states, the "lead compound" described in the 235 Patent is flumezapine (7-fluoro-2-methyl-10-(4-methyl-1-piperazinyl)-4H-thieno[2,3-b][1,5]-benzodiazepine). The naming convention used to name flumezapine is the same as that used in the Patent. That convention, according to Apotex, was "created and used solely by [Eli Lilly]", and "describes the three isomers of the core structure of thienobenzodiazepine in the 235 Patent".
203 Australian Patent No 502678, granted to American Cyanamid, was also raised in the proceeding. It refers to a molecule that is closely related to that which is the subject of the Patent in suit. Under cross-examination, Dr Watson was provided with a copy of the American Cyanamid patent. Dr Watson knew that American Cyanamid was, prior to 1990, engaged in primary research and development in relation to chemicals and pharmaceuticals. Dr Watson accepted that the numbering scheme deployed in the American Cyanamid patent was not an IUPAC-compliant method of numbering, but it was the same method of numbering used in the Patent.
204 In closing, Eli Lilly submitted that the difference between the 235 Patent, the American Cyanamid patent and the Patent in suit is that the 235 Patent "expressly gave… a numbering convention". Apotex submitted that the American Cyanamid patent expressly gives its own numbering convention, but the Patent specification in this case does not give a specific, self-contained numbering convention. As I will explain further below, Apotex contended that there were rival and inconsistent naming conventions within the Patent specification.
205 Evidence was also led to the effect that chemists, on a day-to-day basis, used alternative naming systems. In cross-examination, Professor Nichols said that he had used non-IUPAC naming systems for molecules he had synthesised, "simply because it seemed the most logical way to do it". Later he said:
Formally, in a strict sense, there is one formal name. But in terms of being able to name where the substituents are, where things are put together and being able to recreate that molecule there may be other ways to do it. In this case, there are two ways to do it, one of which is probably the more recent way, the IUPAC way, the other is an older way that was used to name when the work was first done.
206 This evidence reinforces the conclusion in the joint expert report: IUPAC was not the only system of chemical nomenclature used prior to the priority date.
207 Nonetheless, in pursuit of its submission that there was only one correct way to name olanzapine, Apotex pointed to a number of instances where olanzapine was ascribed the IUPAC-compliant name.
208 Apotex tendered a number of documents which showed olanzapine or similar compounds named using the IUPAC-compliant numbering system, on or before the priority date. There was evidence that Eli Lilly used the IUPAC name for olanzapine internally before the priority date.
209 Professor Nichols agreed in cross-examination that the US Adopted Name (USAN) for olanzapine, shown in a document dated 30 October 1991, is IUPAC-compliant. Professor Nichols explained that when a drug is developed, the inventor can propose a name, or the USAN Council can assign one. Professor Nichols said "so that's where the name olanzapine would be sort of officially adopted by its USAN name".
210 The role of the Merck Index was discussed at length by both parties. Dr Robertson said that he was familiar with the Merck Index as "containing monographs on commercially relevant compounds, including pharmaceutical compounds". It will be recalled that the Index is an encyclopaedia of chemicals, drugs and biologicals produced by the pharmaceutical company Merck & Co Inc on a not-for-profit basis.
211 In the joint expert report, Dr Robertson and Dr Watson agreed that:
The Merck Index may be used for key references or for identifying key patents of known drugs and for providing basic information on a compound such as crystallinity, solubility, structure etc…
It is used in the same way today as it was used in 1990. It remains a handy reference book.
212 Professor Nichols deposed that the Merck Index was "widely used and respected… among organic chemists, including medicinal chemists" and he had no reason to doubt its accuracy.
213 Apotex tendered a 1996 copy of the Merck Index (12th ed), which on p 6957 lists olanzapine as "2-Methyl-4-(4-methyl-1-piperazinyl)-10H-thieno[2,3-b][1,5]benzodiazepine". It was accepted by the parties this would have been the position at the priority date.
214 Apotex also tendered a copy of the Australian Zyprexa Product Information Sheet. Zyprexa is the marketed name for olanzapine. The product information sheet depicts the structural formula of olanzapine, with IUPAC-compliant numbering. It also cites the IUPAC-compliant name for olanzapine. Professor Nichols agreed in cross-examination that the structure was olanzapine, and that the number '4' indicated the location of the piperazine substituent, and '10' indicated the saturated atom.
215 The Chemical Abstracts Service is another service for identifying the chemical name of a compound. Dr Robertson deposed that Chemical Abstracts has adopted a similar but not identical naming system to IUPAC.
216 The Chemical Abstracts reference for olanzapine identifies the name as "10H-Thieno[2,3-b][1,5]benzodiazepine, 2-methyl-4-(4-methyl-1-piperazinyl)." Although the name has been "moved around", Professor Nichols agreed with counsel for Apotex that the '10' is associated with the "H" (indicating that the saturated atom is at the '10' position), and the '4' identifies the position of the piperazinyl group.
217 There was also evidence that the Patent's inventors otherwise used the IUPAC nomenclature. Apotex tendered a 1980 article entitled "4-Piperazinyl-10H-thieno[2,3-b][1,5]benzodiazepines as Potential Neuroleptics" (emphasis in original). The article is written by, inter alia, the three inventors of the Patent. The first page of the article features a similar compound to olanzapine, which is described using IUPAC-compliant numbering. A saturated hydrogen is at position 10, and the piperazinyl group is at position 4.
218 In light of my conclusions on the joint expert report and conventions used in other patents, this evidence reinforces the comments of Professor Nichols that, "strictly speaking", there is one formal name for olanzapine. That would be the one that is featured in the Merck Index. However, this does not disturb the foregoing conclusion that Eli Lilly used a name in the Patent that would be understood by the skilled addressee to be olanzapine. That Eli Lilly used a different name internally is of no consequence to this conclusion. I do not see it as an admission that the name used in the Patent was wrong. If anything, it shows that at the time of filing the specification, the patentee understood that there was more than one naming convention.
219 Central to Apotex's submissions was that the claims did not just ascribe the wrong name to olanzapine, but the name unambiguously claimed a completely different compound. To this end, Apotex relied on a structure that Dr Watson drew in his first affidavit.
220 The solicitor for Apotex asked Dr Watson to draw the structure of "2-Methyl-10-(4-methyl-1-piperazinyl)-4H-thieno-[2,3-b][1,5]benzodiazepine". He did this firstly from his knowledge as a skilled addressee and later by use of the computer software program ChemDraw. Dr Watson said that four structures could be drawn from the name in claims 1 and 2 of the Patent. Two could be immediately discounted as not feasible. The two remaining structures were:
221 Dr Watson said that structure 1(b) was the compound more correctly identified by the name in claims 1 and 2. To draw the structures, Dr Watson said he drew the basic ring system by drawing the benzodiazepine and the thieno group and fusing them together. He then used "accepted principles of nomenclature to add the substituents". Dr Watson said he typically used IUPAC principles of nomenclature.
222 Dr Watson deposed that the basic rule of nomenclature is to begin numbering at the atom within the compound having the highest atomic weight; in this instance, sulfur. Numbering could then go clockwise or anti-clockwise. Four structures should thus result, but two would not make sense. Dr Watson then attached the piperazine group at the atom occurring at the '10' position, which is carbon in compound 1(a) and nitrogen in compound 1(b).
223 Dr Watson said he was not "certain" as to which of the compounds drawn was intended to be identified by the name in claims 1 and 2 of the Patent. He "expected", however, that compound 1(b) is described, because the reference to "4H" (which was unusual and therefore probably important) indicated that the carbon at position 4 is saturated. At trial, in examination-in-chief, Dr Watson said he "marginally" preferred structure 1(b) to structure 1(a).
224 The solicitor for Eli Lilly attempted to test Dr Watson's evidence, by asking Dr Robertson whether three structures drawn by that solicitor were consistent with the name used in claims 1 and 2 of the Patent, or the IUPAC or Chemical Abstracts nomenclature conventions. The first of those structures I will ignore, as it arose due to an error in Dr Watson's first affidavit. However, the second and third structures drawn by Eli Lilly matched the structures 1(a) and 1(b) respectively, as drawn by Dr Watson.
225 In his second affidavit, Dr Robertson said that structure 1(a) is not consistent with the chemical name in claims 1 and 2 of the Patent because it is a thieno[3,2-b][1,5]benzodiazepine, not a thieno[2,3-b][1,5]benzodiazepine. The thieno[2,3-b][1,5]benzodiazepine is common to, and an essential feature of, the compound claimed by the Patent and the IUPAC name. Dr Watson agreed in his third affidavit that structure (1)(a) was erroneous, on the basis that it was not a [2,3-b] structure. However, Dr Watson stated that this would not have been in his working knowledge as at the priority date, and he was not asked to review the IUPAC Blue Book in drawing the compounds.
226 Dr Robertson's second affidavit further stated that structure 1(b) is not consistent with the name in claims 1 and 2. On an initial study of structure 1(b), Dr Robertson stated that there were two saturated atoms in this structure at positions 4 and 5 (unlike in structure (1)(a)). Dr Robertson deposed that he did not know at the time of swearing his second affidavit, and would not have known at the priority date, precisely how to name this feature according to IUPAC nomenclature. Dr Robertson thus referred to the IUPAC Blue Book, which said that the saturation at the carbon atom (position 4) would be reflected in the name. As such, "dihydro-" would be a prefix to "4H". Dr Watson, in his third affidavit, agreed that the compound in (1)(b) includes a dihydro group. However, Dr Watson stated that the saturation of position 4 (and the specification of '4H' in the name of the compound claimed to indicate this fact) makes the "dihydro-" prefix redundant, as the structure will not allow for any other constitution of the diazepine ring.
227 I should add that the solicitor for Apotex asked Dr Watson to draw his structure by only looking at the claimed compound. Dr Robertson, by contrast, was asked by the solicitor for Eli Lilly to draw his structure after looking at the Patent as a whole. The approach that Dr Watson was asked to take is somewhat artificial. It is clear that the claims are to be read in context. It is the degree of context that the Patent provides that varies from case to case, depending on the clarity of the claims.
228 Dr Watson said that his analysis of structure (1)(b) is supported by ChemDraw. According to Dr Robertson, ChemDraw is a software program widely used by medicinal chemists to draw chemical structures and name chemical compounds. The software purports to generate accurate IUPAC names for structures. Both parties used ChemDraw in giving evidence.
229 Dr Robertson referred to ChemDraw in his first affidavit. The solicitor for Eli Lilly asked him to generate formula (I), the structure that appears on p 3 of the Patent. The software generated the name "2-methyl-4-(4-methylpiperazin-1-yl)-10H-benzo[b]thieno[2,3-e][1,4]diazepine" (emphasis in original). Dr Robertson stated that this is "significantly different to the name used in the Merck Index [also the IUPAC name] in that the name for the core ring system is different". The manner in which the core ring is numbered was, however, consistent with the Merck Index system. Dr Robertson stated that both were valid and useful approaches to nomenclature.
230 Dr Watson tested this "significantly different" name, the Merck Index (IUPAC) name, and the name claimed in the Patent in the same software. He spoke of the results in his second affidavit.
231 Both the "significantly different" name and the Merck Index name produced the same structural formula as on p 3 of the Patent. The name claimed in claims 1 and 2 of the Patent produced a different structure, depicted below:
232 Dr Watson stated that this structure is the same structure as 1(b), as identified in his first affidavit. On this basis, Apotex submitted that claims 1 and 2 claim an entirely different structure to olanzapine.
233 The usefulness of ChemDraw was raised by all parties. Dr Robertson said that:
I worry about placing too much reliance, I suppose, on computer programs because they're only as good as the data that you put into them, and even the vendor of ChemDraw will say that they are right only 99 per cent of the time… But it means it's wrong one time every hundred and it seems that it's wrong in this case, and it is wrong in this case because the… name rather, is not IUPAC, the computer has had to make some assumptions.
234 The ChemDraw product information confirms that it is only 99% accurate, and that:
The last percent includes a lot of names that are ambiguous in a variety of ways. [ChemDraw] is designed to interpret names in the most common and reasonable way possible.
235 Eli Lilly submitted that the computer had to resort to assumptions in this instance because ChemDraw applies IUPAC rules, and both parties agree that the compound claimed in claims 1 and 2 of the Patent is not strictly IUPAC-compliant.
236 Eli Lilly also submitted that ChemDraw was not available at the priority date, so its utility in resolving the issue of construction is limited. Dr Watson was similarly reticent about the accuracy of the software as it would not have been used at the priority date.
237 Dr Watson did not show that structure (1)(b) was the only structure that could be named by claims 1 and 2 of the Patent. First, Dr Watson found that four structures were theoretically possible, but only two were feasible in practice. But Dr Robertson indicated that there were flaws in the naming of Dr Watson's structures, and to this end, Dr Watson ultimately agreed in respect of structure (1)(b) that, strictly speaking, "dihydro-" would be a prefix to the "4H". In this regard, Dr Watson's evidence was uncertain on the unambiguous name for, and depiction of, the structure claimed. Then, despite the drawbacks of ChemDraw, the software seemed to confirm that there was ambiguity surrounding the name in the Patent, the name of Dr Watson's structure 1(b), and the name of the structure that both parties agreed accurately depicted olanzapine. The ChemDraw software presumes that IUPAC conventions underlie the generation of a structure or a chemical name. However, the evidence shows that the skilled addressee at the priority date would not make such an assumption, or proceed to read the Patent document on this basis. In any event, the claims must be read in context, and the exercise undertaken by Dr Watson is not determinative of the construction issue.
238 Putting aside the context of the Patent itself, I have already indicated that I am satisfied that, at the priority date, IUPAC was not the only system for ascribing names to chemical compounds that would be recognised by a skilled addressee. Both Dr Robertson and Dr Watson agreed that IUPAC nomenclature was not used on a daily basis by practising chemists. Although it seemed common ground that there was only one, strictly 'formal' name, the balance of the evidence shows that the skilled addressee would not exclude the possibility that the patentee may not have used IUPAC nomenclature. Indeed, IUPAC nomenclature is neither required by law, nor is it referred to in the Patent.
239 There have been many published instances in which olanzapine has been referred to by its IUPAC-compliant name. However, this does not mean that there is only one way to identify olanzapine that would be understood by the skilled addressee at the priority date. As Professor Nichols put it:
The chemical structure is, I mean that is an absolute, but there are different ways to name it. You name someone Richard and then you called him Dick. Well, it's a nickname for Richard. It's the same person; it's just a different way to do the name.
240 Whatever be the conclusion as to the normal usage of terms, the question in this proceeding must be answered in the context of the Patent. I stress again, this is a task for the Court, aided by relevant expert evidence.
241 The Patent claims must be read in context of the specification. I am satisfied that reference to the specification is necessary at first instance, not at some later stage when ambiguity is thought to arise. This latter approach is unduly artificial.
242 All parties agreed that on p 4 of the Patent, formula (I) is ascribed the name "2-methyl-10-(4-methyl-1-piperazinyl)-4H-thieno[2,3-b][1,5]benzodiazepine". Formula (I) is described as the "compound of the invention". As previously stated, all parties also agree that the structure of formula (I) is olanzapine.
243 Dr Robertson and Dr Watson stated in their joint expert report that:
We understand when the patent is read as a whole that the invention described to be the compound olanzapine, its salts and pharmaceutical compositions and the process to make this compound.
244 Furthermore, the experts agreed that the name on p 4 of the Patent "specifically relates" to the structure depicted as formula (I) on p 3 of the Patent. This name is the one which is recited in the claims.
245 Dr Robertson and Dr Watson also agreed in the joint expert report that when there is information provided in the form of a structural formula and a chemical name, the person skilled in the art would generally place more emphasis or importance on the structural formula. In the words of Professor Nichols, chemical structures are the "universal 'language' of organic chemistry, including medicinal chemistry". Considerable weight can therefore be given to the structure depicted as formula (I) on p 3 of the Patent when the skilled addressee is construing the claims in the context of the specification.
246 Professor Nichols' evidence was to the same effect: the "compound of the invention" is said to be formula (I), on p 3, and the name recited in the claims immediately follows formula (I) on p 4 of the specification.
247 Professor Nichols' first affidavit states that the Patent, on pp 3 and 4, identifies the "compound of the invention" by a depicted structure and a name. As this name was identical to that in claims 1 and 2 of the Patent, he understood the structure of the compound claimed was the same as that on p 3. Professor Nichols maintained this position under cross-examination, and Dr Robertson's affidavit evidence was largely to the same effect.
248 Apotex took issue with this interpretation of the evidence, submitting that Eli Lilly offered a construction that relies on the assumption that the claimed chemical name is the same as formula (I) on p 3. However, I find that this interpretation of the evidence strained; and I think it skips over what Dr Watson and Dr Robertson agreed upon in the joint expert report.
249 The evidence suggests that reading the claims in context is sufficient to identify the claim to formula (I), being olanzapine. I am aware that this conclusion largely derives from a very small extract on pp 3 to 4 of the Patent. However, as I will explain later, nothing else in the specification detracts from this conclusion. It is not a matter of correcting a wrong name that is claimed, but of determining, in proper context, what is claimed.
250 Eli Lilly directed considerable attention to authorities which stated that the law permits the hypothetical addressee to use the specification as a "dictionary" to interpret jargon in the claims where the draftsman shows an intention that the specification is to be used in this way. I have already adverted to these authorities in these reasons for judgment. Eli Lilly said that the specification is a dictionary in the sense of the term used by the High Court in Welch Perrin (1961) 106 CLR 588, and later by Bennett J in Inverness Medical (2010) 85 IPR 525 and H Lundbeck (2009) 177 FLR 151. That is, for the purpose of this Patent, formula (I) and the name on p 4 of the Patent are a definition for the jargon in the claims of this Patent.
251 For the foregoing reasons, I am satisfied that the clear conclusion in this case is that formula (I), and the name ascribed to it on p 4, are a definition for the claims. That the name on p 4 of the specification is the same as that recited in the claims of the Patent makes this reasonably clear. The evidence supporting this conclusion is the same as I have already outlined in relation to context.
252 Eli Lilly submitted as an alternative argument that if the claims must be read in isolation, then they are ambiguous. Given the conclusions already reached, it is not strictly necessary to deal with these arguments, but I make the following comments.
253 Eli Lilly contended that the Court could find ambiguity in a number of ways. The first is that, if Dr Watson's evidence is accepted over Dr Robertson's, there is still ambiguity. Dr Watson narrowed his construction of the claims down to two structures: 1(a) and 1(b). Dr Watson said in evidence in chief that he "marginally" preferred 1(b) over 1(a). The second way to find ambiguity is to treat the evidence of both Dr Watson and Dr Robertson with equal weight, in which case (it was submitted by Eli Lilly) the claims are ambiguous. Dr Watson considered structure 1(b) to be the best fit; Dr Robertson drew the structure on p 3 of the Patent.
254 Apotex submitted that even if reference to the specification is permissible, the specification is unclear in itself. Apotex said that this is really a question of "how much work can the skilled addressee be required to do, given the statutory function [of the claims], which is to define the invention". Apotex submitted that the interpretation of this Patent required too much work on the part of the skilled addressee. It is perhaps trite to say, as the High Court did in Welch Perrin (1961) 106 CLR 588 at 610:
If it is impossible to ascertain what the invention is from a fair reading of the specification as a whole, that, of course, is an end of the matter.
255 Apotex took particular issue with an inconsistency between the naming convention used on pp 3 to 4 of the Patent, and pp 18 and 19. I have discussed what appears on pp 3 and 4 of the Patent at length. From pp 17 to 19, the Patent goes through a number of examples, "example 1" of which is the first of two ways to synthesise olanzapine. The third step is entitled "4-Amino-2-methyl-10H-thieno[2,3-b][1,5]benzodiazepine, hydrochloride". This was an intermediate step in producing the compound claimed in claims 1 and 2. This intermediate compound is numbered according to IUPAC conventions. This is the first inconsistency to which Apotex points.
256 The second inconsistency is that the fourth step of example 1 is entitled "2-Methyl-10-(4-methyl-1-piperazinyl)-4H-thieno[2,3-b]-[1,5]benzodiazepine", which is the same chemical name as in claims 1 and 2. In going through the method to arrive at this target compound, the fourth step says that the structure of the resulting compound "was confirmed spectroscopically". The Patent then depicts that structure as:
257 Other data appear after the structure. It was clear, on the evidence, that the numbers ascribed to this structure as it appears on p 19 are different to the numbers ascribed to formula (I) by the name on p 4 of the Patent. Further, this numbering is IUPAC-compliant.
258 Apotex submitted that as such, if recourse is had to the specification, two rival and irreconcilable naming conventions appear for the one compound. Particular confusion is said to arise with respect to claim 5. Claim 5, not in suit, refers to "a process for producing a compound according to claim 1…", which is described in example 1 of the Patent. Apotex said that if the Patent was as Eli Lilly contended, claim 1 is defined on p 3 of the Patent. However, the process for synthesising the compound referred to in claim 1 appears on pp 18-19, where two rival numbering conventions are used. Both step three on p 18 of the specification and the structure on p 19 were drafted with IUPAC-compliant numbering. Similar problems arise with respect to claims 6 and 7, also not in suit. It is for these reasons that Apotex submitted that there is too much work for the skilled addressee to do to understand the Patent.
259 It will be apparent from the foregoing reasons that I think the simple answer to this particular confusion in this proceeding is the view of both experts. In preparing the joint expert report, Dr Robertson and Dr Watson were asked: "Do the structure shown on p 19 of the Patent and the structure shown in formula (I) on p 3 of the Patent represent the same compound?". Dr Robertson and Dr Watson stated that:
The structure shown on page 19 of the patent and the structure shown in Formula (I) on page 3 of the patent represent the same compound.
260 Dr Robertson and Dr Watson also agreed that the primary purpose of the numbering shown with respect to the structure on p 19 is to aid with interpretation of nuclear magnetic resonance (NMR) data. Dr Robertson gave evidence that NMR is a spectroscopic analytical tool used by chemists to confirm that the structure they have synthesised in theory is in fact the structure synthesised in practice. The numbers in the structure therefore have a specific purpose which may be unrelated to IUPAC nomenclature. In cross-examination, Dr Watson said that NMR data gives chemists a signal for each hydrogen or carbon atom in the molecule, to confirm whether they are consistent with the predicted structure. In giving evidence-in-chief, Dr Watson said that he would consider that this numbering is "not just any sort of numbering to help the NMR interpretation, it's also what I would say is the correct IUPAC numbering".
261 It seems to me that the real function of the numbers at p 19 of the Patent is to aid with the interpretation of NMR data. I agree with Eli Lilly's submission that this numbering, in the context in which it appears, does not detract from the "definition" provided on pp 3 and 4 of the Patent for the purpose of considering the claims in suit.
262 On the basis of the foregoing conclusion, I need not consider the so-called "best fit" argument put in the alternative by Eli Lilly.