ViiV Healthcare Company v Gilead Sciences Pty Limited
[2020] FCA 1455
At a glance
Source factsCourt
Federal Court of Australia
Decision date
2020-10-09
Before
Beach J
Source
Original judgment source is linked above.
Judgment (14 paragraphs)
- The applicants' interlocutory application seeking to strike out the respondent's amended particulars of invalidity be adjourned sine die.
- Within 7 days of the date hereof, the parties submit minutes of proposed orders to give effect to these reasons concerning the respondent's interlocutory application seeking discovery.
- The parties' costs of both interlocutory applications be their costs in the cause.
- Liberty to apply. Note: Entry of orders is dealt with in Rule 39.32 of the Federal Court Rules 2011.
BEACH J: 1 The patent in suit, which is Australian patent no. 2006239177, concerns polycyclic carbamoylpyridone derivatives having HIV integrase inhibitory activity. The invention relates to compounds possessing such an antiviral activity and compositions containing such an anti-HIV agent. 2 As I explained in my earlier judgment (ViiV Healthcare Company v Gilead Sciences Pty Limited (2020) 152 IPR 31; [2020] FCA 594), HIV is a retrovirus which causes AIDS. It is an RNA virus, rather than a DNA virus. HIV produces, inter-alia, an enzyme being a retroviral integrase. The function of the integrase is to insert the viral genome of HIV into the chromosomal DNA of a host human cell through the formation of covalent bonds. Let me explain the process. 3 Once the viral RNA has entered the human cell and after the RNA has been liberated from the viral capsid that has entered the cell through endocytosis, the single-stranded viral RNA is reverse transcribed into double-stranded viral DNA. The double-stranded viral DNA is then transported to and enters the cell's nucleus. Such viral DNA is then integrated into the cell's chromosomal DNA with that process facilitated by the retroviral integrase. The functionality of the retroviral integrase is to catalyse two reactions. First, two or three nucleotides are removed from the 3' ends of the viral DNA. Second, the processed 3' ends are then covalently ligated to the cell's chromosomal DNA. 4 The compounds and compositions of the patent are designed to inhibit such integrase activity so achieving the desired antiviral activity. In short, the integration is stymied. The zombie macro-molecule is not activated. 5 The applicants (collectively, ViiV) have brought an infringement suit against the respondent (Gilead) concerning Gilead's product marketed as Biktarvy. The marketing and sale of Biktarvy, a pharmaceutical composition containing as one of its active ingredients bictegravir as a sodium salt, is said to infringe claims 1 to 10, 28, 29, 43, 44 and 47 of the patent. 6 The patent is some 277 pages in length with some further inserted pages (pp 2a to 2h). There are 53 claims, but for present purposes I need only set out extracts from claims 1, 5 and 6. 7 The first part of claim 1 is in the following terms: 1. A compound of the formula: wherein, A ring is optionally substituted heterocycle; R14 and RX are independently hydrogen, optionally substituted C1-C10 alkyl, optionally substituted C3-C8 cycloalkyl, optionally substituted C3-C8 cycloalkyl C1-C10 alkyl, optionally substituted C2-C8 alkenyl, optionally substituted C1-C10 alkoxy, optionally substituted C2-C8 alkenyloxy, optionally substituted aryl, optionally substituted aryl C1-C10 alkyl… … a broken line represents the presence or absence of a bond, provided that when the broken line represents the presence of a bond, RX is not present; R1 is hydrogen or C1-C10 alkyl; X is a single bond, a heteroatom group selected from O, S, SO, SO2 and NH, or C1-C6 alkylene or C2-C6 alkenylene each may be intervened by the heteroatom group; R2 is optionally substituted aryl; R3 is hydrogen, halogen, hydroxy, optionally substituted C1-C10 alkyl, optionally substituted C3-C8 cycloalkyl, optionally substituted C2-C8 alkenyl, optionally substituted C1-C10 alkoxy, optionally substituted C2-C8 alkenyloxy, optionally substituted aryl, optionally substituted aryloxy, optionally substituted heterocyclic group, optionally substituted heterocycleoxy or optionally substituted amino); or a pharmaceutically acceptable salt, or solvate thereof; and wherein: (a) a group which is optionally substituted, other than optionally substituted amino, optionally substituted carbamoyl or optionally substituted phosphoric acid, is a group which is unsubstituted or substituted at any position by 1 to 4 substituents B, which are the same or different, B being selected from hydroxy, carboxy, halogen, halo C1-C10 alkyl, halo C1-C10 alkoxy, C1-C10 alkyl, C2-C8 alkenyl, ethynyl, C3-C8 cycloalkyl, cycloalkenyl, C1-C10 alkoxy C2-C8 alkenyloxy, C1-C10 alkoxycarbonyl, nitro, nitroso, optionally substituted amino, acylamino, aralkylamino, hydroxyamino, azido, aryl, aralkyl, cyano, isocyano, isocyanate, thiocyanate, isothiocyanate, mercapt, alkylthio, alkylsulfonyl, optionally substituted alkylsulfonylamino, optionally substituted carbamoyl, sulfamoyl, acyl, formyloxy, haloformyl, oxal, thioformyl, thiocarboxy, dithiocarboxy, thiocarbamoyl, sulfino, sulfo, sulfoamino, hydrazino, azido, ureido, amizino, quanidino, phthalimide, oxo, phosphoric acid residue, C1-C10 alkyl which is substituted with a phosphoric acid residue and may be intervened with a heteroatom group(s), aryl substituted with a phosphoric acid residue, aralkyl substituted with a phosphoric acid residue, hydroxyl C1-C10 alkyl, carboxy, halogen, halo C1-C10 alkyl, halo C1-C10 alkoxy, C1-C10 alkyl, C1-C10 alkoxy, optionally substituted amino, oxo and phosphoric acid residue; … [I do not need to set out (b) and (c)] 8 Claim 5 is in the following terms: 5. A compound according to Claim 1, pharmaceutically acceptable salt, or solvate thereof, wherein A ring is an optionally substituted and optionally condensed 5- to 7- membered heterocycle containing 1 to 2 hetero atom(s). 9 Further, claim 6, in part, is in the following terms: 6. A compound of the formula: wherein, A ring is an optionally substituted and optionally condensed 5- to 7- membered heterocycle containing 1 to 2 hetero atom(s); … [No further details need be set out by me] 10 Now before proceeding further, I should repeat what I said in my earlier judgment about rings given that an integer of claim 1 is expressed as an "A ring [which] is [an] optionally substituted heterocycle" and an integer of claim 6 is an "A ring [which] is an optionally substituted and optionally condensed 5- to 7- membered heterocycle containing 1 to 2 hetero atom(s)". There are a number of propositions concerning general structural features of heterocycles that are not presently contentious. First, a heterocycle is a cyclic structure (ring) that includes one or more non-carbon atoms, also known as heteroatoms. Heterocycles can be of any ring size, and can vary as to the number, type and position of heteroatoms. Second, rings can be joined together to form bicyclic or polycyclic ring structures. Relevantly to the present context, there are three realistic ways in which rings can be joined. The structures are spiro, fused, and bridged. In the spiro structure two rings share a single atom. In the fused structure, two rings share two adjacent atoms. In the bridged structure, two rings share two non-adjacent atoms. These can be shown as follows: 11 Now ViiV says that Gilead has infringed each of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 28, 29, 43, 44 and 47 of the patent by its dealings in the pharmaceutical composition known as Biktarvy. Biktarvy is a pharmaceutical composition indicated for the treatment or prophylaxis of an HIV infection in humans being a fixed-dose combination containing the following active ingredients: (a) bictegravir as a sodium salt, an integrase strand transfer inhibitor having a molecular formula of C21H17F3N3NaO5 and the following structural formula: (b) emtricitabine, a nucleoside reverse transcriptase inhibitor; and (c) tenofovir alafenamide as fumarate, a reverse transcriptase inhibitor. 12 Gilead denies infringement. And importantly for present purposes, it has cross-claimed for revocation of the asserted claims on the ground that, inter-alia, the invention as claimed is not useful. 13 Gilead's amended particulars of invalidity filed on 3 July 2020 allege this lack of utility in the following fashion (at [2] and [3]): 2. The alleged invention as claimed in claims 1 to 10 (inclusive), 28, 29, 43, 44 and 47 of the Patent is not a patentable invention, in that it is not useful within the meaning of section 18(1)(c) of the Act, because compounds of the invention cannot be made. Particulars a. The object or promise of the alleged invention is set out at pages 1 and 2 of the specification as follows: "The present invention relates to novel compounds possessing an antiviral activity, in detail polycyclic carbamoylpyridone derivatives possessing an inhibitory activity against HIV integrase and a pharmaceutical composition containing the same, especially as an anti-HIV agent. …. The present inventors have intensively studied to find that a novel polycyclic carbamoylpyridone derivative possesses [sic] a potent HIV integrase inhibitory activity. …. Moreover, the present inventors have discovered that a compound of the present invention and a pharmaceutical composition containing the same are useful as an antiviral agent, an antiretroviral agent, an anti-HIV agent, an anti-HTLV- 1 (Human T cell leukemia virus type 1) agent, an anti-FIV (Feline immunodeficiency virus) agent or an anti-SIV (Simian immunodeficiency virus) agent, especially an anti-HIV agent or anti-AIDS agent, to accomplish the present invention shown below." b. The specification does not teach the skilled addressee how to make compounds of the invention which include, for example, an oxazine A ring as falls within claims 1, 5 and 6 of the Patent, and claims dependent on them, with: i. two bulky substituents at the carbon next to the nitrogen; ii. two bulky substituents at the carbon next to the oxygen (2 position of the A ring); and iii. bulky substituents cis to each other at the 2, 3 and 4 position carbons of the A ring, and the skilled addressee could not do so without undue experimentation, if at all. c. The skilled addressee could not, without undue experimentation, if at all, make compounds of the invention which include, for example, an oxazine A ring as falls within claims 1, 5 and 6 of the Patent, and claims dependent on them, with: i. a fully substituted carbon with anything larger than a methyl and isopropyl next to the nitrogen; ii. a compound with the 2, 3 and 4 position carbon of the A ring substituted with a methyl; iii. a compound with the 2, 3, and 4 position carbon of the A ring di-substituted with an methyl, because the skilled addressee could not produce the amino acid alcohol intermediates required for that synthesis or perform the necessary cyclisation reactions required to produce those compounds of the invention. d. The Cross-Claimant reserves the right to provide further particulars. 3. The alleged invention as claimed in claims 1 to 10 (inclusive), 28, 29, 43, 44 and 47 of the Patent is not a patentable invention within the meaning of section 18(1)(c) of the Act, in that it is not useful, because compounds of the invention are not sufficiently active or effective to meet the promise of the Patent. Particulars a. The Cross-Claimant refers to and repeats the object or promise of the alleged invention set out in the particulars at paragraph 2(a) above. b. Claims 1, 5 and 6 of the Patent, and claims dependent on them, encompass compounds, or compositions or uses of compounds, including (but not limited to) the following compounds, that do not meet that stated object or promise, and in particular do not possesses potent HIV integrase inhibitory activity. i. The following compounds within claims 1 and 5 of the Patent, and claims dependent on them, where R1 is one of C1 to C10 alkyl: and in which the C1 to C10 alkyl disrupts the intramolecular hydrogen bonding with the pyridone core carbonyl. ii. The following compounds within claim 6 of the Patent, and claims dependent on it, where R1 is one of C1 to C10 alkyl: and in which the C1 to C10 alkyl disrupts the intramolecular hydrogen bonding with the pyridone core carbonyl. iii. The compound identified in Confidential Annexure A. iv. Each of the following compounds: (A) (B) (C) (D) c. Claims 1, 5 and 6 of the Patent, and claims dependent on them, encompass compounds, or compositions or uses of compounds, including (but not limited to) the following compounds, which do not meet that stated object or promise, and in particular are not useful as an antiviral agent, an antiretroviral agent, an anti-HIV agent, an anti-HTLV- 1 (Human T cell leukemia virus type 1) agent, an anti-FIV (Feline immunodeficiency virus) agent or an anti-SIV (Simian immunodeficiency virus) agent, especially an anti-HIV agent or anti-AIDS agent. i. The following compound, which is identified as compound Z-27 in the Patent: ii. The compounds enumerated in paragraphs 3(b)(i) - 3(b)(iv) above. d. It is not possible to identify which, if any, of the many millions of compounds of the invention meet the stated object or promise of the invention without undue experimentation. e. The Cross-Claimant reserves the right to provide further particulars. 14 The amended particulars at [2(b)] refer to "compounds of the invention which include, for example, an oxazine A ring as falls within claims 1, 5 and 6 of the Patent". An oxazine is a 6 membered ring containing a carbon and a nitrogen atom, with two double bonds. For example, a 1,4 oxazine (in this case the 4H) can be represented as follows: 15 I should also make two other points here. First, it is not necessary for understanding the dispute between the parties to set out Confidential Annexure A referred to in [(3(b)(iii)] of the amended particulars. Second, the amended particulars also assert a lack of fair basis and a lack of clarity, but it is not necessary to deal with these matters at this point. 16 More generally in relation to the patent, I should also note that there are related proceedings in the United States and Canada. In the United States proceeding, ViiV and a related entity allege that Gilead Sciences, Inc has infringed US patent no. 8,129,385. In the Canadian proceeding, ViiV and a related entity allege that Gilead Sciences Canada, Inc. has infringed Canadian patent no. 2,606,282. Now the patent in suit before me, US patent no. 8,129,385 and Canadian patent no. 2,606,282 are related, and each claim priority from Japanese patents no. JP2005-131161 and no. JP2005-312076. 17 Let me now turn to the current dispute and the two interlocutory applications before me. 18 By its application, Gilead seeks discovery of documents in six categories relevant to its allegation that the invention claimed in the asserted claims is not useful, in that compounds of the invention either cannot be made or are not sufficiently active or effective to meet the promise of the patent. I have already set out relevant extracts from Gilead's amended particulars which are said to make relevant the documents sought. ViiV opposes that application. 19 By its application, ViiV seeks orders striking out certain parts of [2] and [3] of the amended particulars. This application may be seen as having been provoked by Gilead's application for discovery. It is appropriate to deal with the strike out application first.