Green Cross Holdings vs Controller Of Patents

D.P.S. Parmar, Technical Member

1 . This appeal is made against the order of the Deputy Controller of Patents dated 13th August 2009 refusing the application No. 1563/DEL/2005 dated 16th June 2005 filed by Green Cross Holdings, a Korean Corporation, for the invention relating to 'Pharmaceutical preparation of recombinant factor VIII lyophilized without Albumin as a stabilizer'.

The matter came up for hearing on 20/05/2014. We heard the arguments of learned counsel for the appellants Ms. Anuradha Salhotra. No one appeared for the Respondents.

Facts of the case

In the hearing notice, following objections were communicated by Respondent 2 :-

1 . Claim-1 do not sufficiently define the invention with respect to the term pharmaceutical preparation as the claim defines constituents of stabilizer before lyophilisation rather than pharmaceutical preparation.

Claims 1-9 fall within the scope of such clause (d) and (e) of section 3.

Subject matter of claims lack inventive step in view of cited documents (i) WO9910011 (ii) US5407671 (iii) US 4297344 and (iv) WO9322336.

During the prosecution of the case, the appellants have restricted their claims to six claims. The finally amended claim 1 reads as under:-

A pharmaceutical preparation of recombinant factor VIII lyophilized with a stabilizer comprising arginine having a concentration of 6 to 100 mm, isoleucine having a concentration of 3.5 to 50mM and glutamic acid having a concentration of 10 to 100 mM, the stabilizer stabilizing the recombinant factor VIII, which is used as a therapeutic preparation of hemophilia.

5 . The Learned Deputy Controller rejected the application as the invention is lacking inventive step and therefore does not constitute invention under section 2(i)(j) of the Patents Act, 1970 (hereinafter referred as Act) and also the claims failed to define any pharmaceutical composition since what is being claimed is a lyophilized recombinant factor VIII.

6 . He relied in his findings on teaching of WO9910011 (D1), US4297344 (D3) and WO9322336 (D5) by stating that the stabilizers as defined in the claim have been already disclosed in the prior art documents No. WO9910011 (D1) as cited in the examination report such as amino acid and carbohydrate and US4297344 (D3) and WO9322336 (D5) disclosing use of argentine, glucamatamic acid as stabilizer whereby such recombinant factors have been lyophilized.

The Learned Deputy Controller further stated that

The comparative chart provided by the agent for the applicant vide their letter dated 9th February, 2009 further states that lyophilized composition of their invention is without albumin but comprising amino acid. The applicant's agent further stated that the use of albumin is susceptible to viral infection. However, such a statement has been substantiated neither in the description nor in the submissions. In view of the above observation, I am of the opinion that the invention as claimed in the claim still lacks inventive step therefore does not constitutes an invention under section 2(1) (j) of the Act.

The Learned Deputy Controller further observed that

Further, as observed above the claims failed to define any pharmaceutical composition since what is being claimed is a lyophilized recombinant factor VIII.

9 . In respect of the pharmaceutical composition, the learned Deputy Controller observed that--

At the outset, it can be noted that the so called pharmaceutical preparation of recombinant factor is nothing but a recombinant factor VIII lyophilized with stabilizer or a lyophilized recombinant factor VIII. Therefore, such a lyophilized recombinant factor alone would not quality for being considered as composition in the absence of at least more than 1 ingredient. The later part of the claim defines only a stabilizer composition of aregnine, isoleucine and glutamic acid. Therefore, the claims are not properly defining a so called pharmaceutical composition.

Appellant submissions and arguments

The learned counsel for the appellants submitted that there is a clerical mistake in the order that where it is mentioned that in the matter of "Divisional Application" It is submitted that the present application is not a "Divisional Application". We agree with the appellants and the order of the learned Deputy Controller stands amended by deleting the word "Divisional".

The learned counsel for the appellants submitted that the learned Controller has erroneously rejected the application on the grounds that the Applicant has failed to substantiate that "use of albumin is susceptible to viral infection".

The learned counsel for the appellants submitted that it is clearly stated that in the specification Since the human blood derived albumin is isolated from human blood plasma, it is vulnerable to infection with blood-derived viruses such as hepatitis, HN or IT virus. Therefore, the human blood derived albumin cannot be suitably used for hemophilia therapeutic agents produced by recombinant DNA technology.

The present invention provides a novel pharmaceutical preparation recombinant factor VIII lyophilized without albumin, which exhibits substantially the same pharmaceutical efficacy with an albumin-containing product while capable of Preventing viral infection caused by the use of human blood derived albumin as a stabilizer of the conventional recombinant factor: [ page 5 line nos. 19-23]

The learned counsel for the appellants submitted the Applicant had also submitted a copy of an article titled "TT virus contaminates first-generation recombinant factor VIII concentrates" along with the response submitted on February 09.2009 to substantiate the same. Therefore the observation of the learned controller the "...... stated that the use of albumin is susceptible to viral infection. However, such a statement has been substantiated neither in the description nor in the submissions." is incorrect.

If we see the specification we find it disclosed three kind of factor VIII. First one is human blood derived (1st Generation), second one recombinant animal cell culture product (2nd Generation) and third being severed recombinant factor r-VIII SQ (3rd Generation). It was the human blood derived (1st Generation) which was susceptible to viruses such as hepatitis, human immunodeficiency virus (HIV) or TT virus' that is inherent with factor VIII being isolated from human blood plasma. The sole purpose of developing 2nd and 3rd Generation factor VIII using recombinant method was to cure this inherent defect. This being the case it does not matter whether albumin used as stabilizer in general is susceptible to viral infection. It is rather obvious not to use albumin as stabilizer in recombinant animal cell culture product (2nd Generation) and severed recombinant factor r-VIII SQ (3rd Generation) which are inherently virus free. We do find any infirmity in the statement of the respondent that 'the invention as claimed in the claims still lack inventive step' as we also find the claims are for the recombinant factor VIII and not for human blood derived factor VIII.

Lack of inventive step

1 5 . The learned counsel for the appellants argued that the respondent 2 has erroneously rejected the application on the grounds that the claims of the present application lacks inventive step in view of the cited prior art documents WO9910011 (Dl), US5407671 (D2), US 4297344 (D3) and WO 93/22336 (D5).

The learned counsel for the appellants submitted that the inventive features of the present invention as compared to the prior art are as follows:-

WO9910011 (Dl)

• D1 is directed towards a dried, heat-treated product comprising a heat labile, biologically or therapeutically active protein or peptide preparation and (ii) a stabilising effective amount of a composition comprising sucrose, trehalose and at least one amino acid.

• The protein or peptide preparation is preferably a Factor VIII concentrate.

• The field of the invention provides that "for the stabilisation of such Factor VIII preparations which are to be subjected to a terminal dry heat treatment step, such as heating at 80øC for 72 hrs. used as a viral inactivation step. "

• D1 provides the formulations have the potential to provide another alternative to the adding back of protein such as human serum albumin (HSA) as a stabilizing agent for high purity FVIII concentrates (Page 9, line nos. 18-20).

• The stabilizing composition of D1 consists of sucrose, trehalose and amino acid. The composition may have only lysine or Synthemin 17, which is a combination of following amino acids: Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine, Alanine, Arginine, Histidine, Proline, Serine, Glycine. Synthemin 17 does not comprises Glutamic acid.

• In contrast. the purpose of the present invention is to provide a stable pharmaceutical preparation of Factor VIII which is free ft albumin as a stabilizer, as albumin used to stabilize Factor VIII is isolated from human blood which is susceptible to viral infection.

• Therefore, in the present invention, albumin has been replaced with another stabilizer, which is a combination of arginine, isoleucine and glutamic acid in the given range as provided.

• Further, in the present invention there is no requirement of additional heat treatment process as disclosed in Dl to render the pharmaceutical preparation virus free.

• Table 2 on Rage 11-13 of the present invention provides a comparative data of the activity of recombinant factor VIII with different stabilizers. Experiment 15 and 16 gives the activity of the preparation of the present invention, which is comparable to Experiment 1 (Factor VIII with albumin).

• Sugars, trehalose and amino acid as described in D1 have not been used in the present invention. Further, Experiments 4-7 in Table 2 on page 12 of the present invention indicates that addition of sugars induce very poor cake appearance of proteins.

• Therefore, D1 does not teach, suggest or motivate to arrive at the present invention.

US5407671 (D2)

• D2 provides a tissue adhesive containing fibrinogen, Factor XIII, a thrombin inhibitor III, prothrombin factors (Factor II, VII, IX, X), calcium ions and a plasmin inhibitor. D2 specifically does not discloses recombinant Factor VIII.

• D2 specifies that the tissue adhesive contains all active substances in pasteurized form and is then free of the risk of transmission of hepatitis and HTLV III (column 2, line nos. 30-33). Thus, to solve the problem of viral contamination. the components of the tissue adhesive are pasteurized.

• D2 further states that " To improve the reconstitution of the tissue adhesive after freeze-drying, it is possible for the latter to contain albumin and/or substances which contain the urea or guanidine residue and also contain, where appropriate, an amino acid with a hydrophobic side-chain or a water- soluble fatty acid and, in addition, heparin" (Column 3, line nos. 19-25). D2 does not specifically provides any stabilizer. However, in Example 1 and 2 of D2 it is disclosed that the composition contains aprotinin, Na glutamate, Human serum albumin and isloleucine.

• Therefore, human serum albumin is an element of the composition disclosed in D2.

• In contrast. the present invention provide a pharmaceutical preparation of Factor VIII which is free of albumin as a stabilizer.

• Further. in the Present invention there is no requirement of pasteurization of the recombinant Factor VIII to render the pharmaceutical Preparation virus free.

• Therefore, D2 does not teach, suggest or motivate a person having ordinary skill in the art the pharmaceutical preparation of the present invention in which the combination of three specific amino acids is mixed with the recombinant Factor VIII to stabilize the pharmaceutical preparation which is free from viral infection as provided in the present invention.

US 4297344 (D3)

• D3 describes a process for stabilizing Factor II, VIII, XIII, anti-thrombin III and plasminogen against heat. The preparation produced by the process are fee from coagulable fibrinogen.

• Column 3, line 45-50 of D3 states that "the subject of the present invention therefore is a process for the stabilization against heat of the coagulation factors II, VIII, XIII, of antithrombin III and of plasminogen, in aqueous solution, which comprises adding to the solution both an amino acid and a monosaccharide or an oligosaccharide or a Sugar alcohol."

• Thus. it is inferred that a monosaccharide or an oligosaccharide or a sugar alcohol is essentially required along with an amino acid for stabilization of composition of D3.

• The amino acids which can be used in the composition of D3 are glycine, alanine, hydroxyproline, glutamine, aminobutyric acid, and preferably glycine.

• To render the composition virus free. the composition of D3 is heated at 60 to 70øC for 10 virus free albumin has been re laced with another stabilize~ which is a combination of argonine, isoleucine and glutamic acid in the given range as provided.

• Amino acid and a monosaccharide, or an oligosaccharide or a sugar alcohol as described in D3 have not been used in the present invention. Further, Experiments 4-7.10. 12 and 14 in Table 2 on Rage 12 of the present invention indicates that addition of sugars induce very poor cake appearance of proteins.

• In addition to the above, there is no requirement of heating the pharmaceutical preparation to render it virus free.

• D3 does not teach, suggest or motivate a person having ordinary skill in the art the pharmaceutical preparation of the present application wherein the specific combination of three amino acids is mixed with recombinant Factor

VIII to provide a stable pharmaceutical preparation with better cake appearance and clarity.

WO 93/22336 (D5)

• D5 provides a process for solubilizing anti-hemophilic factor VIII preparation.

• It is disclosed on page 4, line nos. 14-15 of D4 that, histidine and human serum albumin may be added along with arginine for solubilizing anti-hemophilic factor VIII preparation. Thus, addition of human serum albumin is preferred as a part of the solubilizing agent.

• To inactivate viruses. the supernatant containing Factor VIII complex is treated with a solution containing 0.3% (wt/vol) tri-n-butylphosphate and 1% (wt/vol) TWEEN-80 and incubating at 25øC or 6 hrs (page 8 line nos. 34-37 and page 9 line 1)

• In contrast, to render the pharmaceutical preparation of Factor VIII of the present invention virus free, albumin has been replaced with another stabilizer. which is a combination of arginine, isoleucine and glutamic acid in the given range as provided.

• Further in the present invention there is no requirement of additional treatment of pharmaceutical preparation to render it virus free.

17 . According to the learned counsel the purpose of the present invention is to provide a pharmaceutical preparation of Factor VIII which is free of albumin as a stabilizer. In the present invention, albumin has been replaced with another stabilizer, which is a combination of arginine, isoleucine and glutamic acid in the given range as provided. When, the albumin has been replaced with a combination of arginine, isoleucine and glutamic acid the pharmaceutical preparation of the present invention is inherently free of any viral infection.

1 8 . The learned counsel for the appellants submitted that the activity of the pharmaceutical preparation of the present invention is comparable to that of activity of Factor VIII with albumin as evident from the analysis of Table 2 of the present invention. D1, D2, D3 and D5 provide different methods to render the composition virus free, each of these methods involves use of an additional process step(s) such as heating, pasteurization or incubation which are rigorous, time and energy consuming. In contrast, in the present invention, albumin has been replaced with a combination of three amino acids, isoleucine, arginine and glutamic acid in a fixed ratio.

The learned counsel for the appellants submitted that example 3 of the present invention provides that arriving at the combination of the three amino acids is not an obvious solution. Various experiments have been performed to arrive at the pharmaceutical preparation of the present invention comprising the combination of three amino acids so that the pharmaceutical preparation has comparable activity with that of a preparation comprising albumin as a stabilizer.

20 . The learned counsel contended that none of the prior arts, teach, motivate or suggest to arrive at the present combination of amino acids acting as, a stabilizer for a pharmaceutical preparation of Factor VIII which is also free from viral contamination. Therefore, the present invention involves an inventive step in view of the disclosures of prior art documents cited by the learned Controller.

21 . Before we proceed further let us see the invention as described in the specification. It is stated that Therapeutic agents for the treatment of hemophilia A have been produced for the last three decades by isolating the factor VIII from human blood plasma, purifying and concentrating the same. [para 5]

However, the human blood derived coagulating factor VIII, which is isolated from human blood plasma to be used as the conventional therapeutic agents for the treatment of hemophilia, encountered certain disadvantages, including susceptibility to infection with blood-mediated viruses such as hepatitis, human immunodeficiency virus (HIV) or TT virus.[para 6]

To encounter this disadvantage the specification further stated that

To overcome such problems, as reported in J. Gitschier et al., Nature 312, 330-37, 1984 and EP 160 457, preparation of recombinant human coagulating factor VIII generally involves isolating the same from recombinant animal cell culture products using recombinant DNA technology and purifying the isolated coagulating factors.

Here we pause for a moment to say that the 'susceptibility to infection with blood-mediated viruses such as hepatitis, human immunodeficiency virus (HIV) or TT virus' was inherent with factor VIII isolated from human blood plasma and the recombinant factor VIII was developed as also stated in specification

Kabi Pharmacia developed recombinant factor VIII products of 170 kDa with a B-domain deleted from human blood derived coagulating factor VIII. The severed recombinant factor, which is termed r-VIII SQ, and is produced by recombinant Chinese Hamster ovary (CHO) cell line from serum-free media by animal cell cultivation.

23 . In other words the recombinant factor VIII products are not susceptibility to infection. However the specification further stated that recombinant r VIII products commercially available use albumin as stabilizing agent inter alia products which were not using albumin.

In the specification, appellant stated that the prior art used other stabilizers for stabilizing recombinant factor VIII. Appellant contended that his inventive contribution lies in the discovery that the mixture of amino acids in predetermined ratio results in relatively good cake appearance, clarity and activity as compared to non ionic surfactants with same efficacy where albumin is used as stabiliser.

However, D1, D3 and D5 were not cited as prior art in the specification. These citations being the crux of the inventive step decision of the respondent 2 are contested by the appellant.

The specification surmised the invention as follows

The present invention provides a novel pharmaceutical preparation recombinant factor VIII lyophilized without albumin, which exhibits substantially the same pharmaceutical efficacy with an albumin-containing product while capable of preventing viral infection caused by the use of human blood derived albumin as a stabilizer of the conventional recombinant factor The pharmaceutical preparation of recombinant factor VIII lyophilized without albumin according to the present invention can be achieved using a mixture of arginine, isoleucine and glutamic acid as a stabilizer The pharmaceutical preparation of recombinant factor VIII without albumin according to the present invention is substantially the same with the conventional pharmaceutical preparation of recombinant factor VIII with albumin in view of cake appearance, post-reconstitution activity, and post-reconstitution clarity.

The Respondent 2 rejected these claims as obvious in view of three references: D1, D3 and D5.

2 8 . The admitted prior art WO 9910011 (D1) is for 'Dried biologically or therapeutically active preparations'. In D1 the product referred is stabilization of factor VIII wherein the said product is freeze dried (lyophilized). D1 also disclosed the use of mixer of amino acids including Isoleucine and Arginine. It may also be noted the addition of the albumin is optional the relevant Paras are reproduced below:

...Alternatively, however, the amino acid may be incorporated as a mixture of amino acids, particularly the mixture available commercially as Synthamin 17, or one or more of the amino acids present in Synthamin 17.

Synthamin 17 is a formulation of amino acids as follows:

Synthamin 17

Essential Amino Acids (mg/100mL) Nonessential Amino Acids (mg/mL) L-Isoleucine (600) L-Alanine (2070)

L-Leucine (730) L-Arginine (1150)

L-Lysine (580) L-Histidine (480)

L-Methionine (400) L-Proline (680)

L-Phenylalanine (560) L-Serine (500) L-Threonine (420) Glycine (1030)

L-Tryptophan (180)

L-Valine (580)

Such a mixture of amino acids is preferably used in the stabilising composition of the present invention in amounts of from 0.5 to 5% by weight, more preferably from 2 to 3% by weight.

As previously described, albumin (such as human serum albumin) may optionally be incorporated in the stabilising composition of the present invention. When incorporated, albumin may be present in an amount of from 0.1 to 10 mg/mL of the Factor VIII concentrate prior to freeze drying.

Whilst the present invention is principally directed towards the stabilisation of FVIII concentrates, particularly on drying high and very high purity FVIII concentrates, the compositions of the present invention may also be used in the stabilisation of other biologically or therapeutically active preparations, particularly those which are to be dried or lyophilised and subsequently treated to dry heat treatment as a viral inactivation step. Such other biologically or therapeutic preparations include, for example, other blood, plasma or serum fractions, enzymes, antibodies, antigens, vaccine components and the like.

29 . The admitted prior art D3, which employs amino acids as stabilizers, teaches almost all aspects of claimed invention. In US4297344 (D3) it is disclosed

The present invention in particular relates to a process for obtaining preparations of the coagulation factors., VIII,.........., these preparations being practically hepatitis-safe and free from fibrinogen, which comprises adding to a solution containing these factors, preferably a plasma or a placental fraction, from 1.0 to 3.0 mols/l of at least one of the amino acids comprising glycine,

à -or (á-alanine, hydroxyproline, glutamine, à -, (á-or ?-aminobutyric acid,....

The subject of the present invention is in particular the factor VIII preparation obtainable according to the above process, this preparation being poor in protein, free from coagulable fibrinogen and hepatitis-safe.

The storage-stability of the preparation is suitably improved by the addition of protein-stabilizing substances, for example proteins, amino acids or carbohydrates to the purified factor VIII concentrate. The preparation treated in this manner can, moreover, be lyophilized.

30 . If we see WO 09322336 (D5) for improved solubilization and stabilization of factor viii complex' it is disclosed that Arginine acts as a solubilizing agent and aids in the rapid reconstitution of the lyophilized Factor VIII complex. Further it is stated that other amino acids and/or proteins may be present in addition to Arginine. The addition of the albumin is optional here. The relevant paras are reproduced below:-

The starting material from which the high specific-activity Factor VIII complex product provided in accordance with the present invention is derived, may be cryoprecipitate or other blood plasma-derived fractions or it may be derived by recombinant-DNA or transgenic techniques.

It was discovered that, surprisingly, the arginine acts as a solubilizing agent and aids in the rapid reconstitution of the lyophilized Factor VIII complex.

A key step of the process of the present invention is that the high specific-activity Factor VIII complex, from whatever source, is lyophilized in the presence of a sufficient amount of arginine to enhance its solubility. As used herein enhanced solubility means the solubility of the Factor VIII complex which has been lyophilized in the presence of the solubilizing agent of the present invention compared to Factor VIII complex which has been lyophilized in the absence of the solubilizing agent of the present invention. Other amino acids and/or proteins may be present in addition to arginine.

In a preferred embodiment arginine is present at a concentration of about 0.05 M to about 0.5 M, and most preferably from about 0.1 to about 0.2 M, prior to lyophilization. Histidine, when added, is present at a concentration of about 0.025 M and the human serum albumin, when added, is present at a concentration of about 0.05% to about 3%, preferably about 0.5%, prior to lyophilization.

Given that use of amino acids arginine, Isoleucine and glutamine as stabiliser for recombinant factor VIII before lyophilisation is not novel, in view of D1, D3 and D5, the present invention claimed contribution to the art could only lie in the specific ratios of the mixer of three amino acids recited in the claims. The admitted prior art, which employs amino acids as stabilizers, teaches almost all aspects of claimed invention.

It is also given that the amino acids are in use as stabilizer to recombine factor VIII before lyophilisation apart from Albumin. One of ordinary skill would logically infer that optimising the amount of the amino acids (for stabilising recombinant factor VIII before lyophilisation) would lead to an increase in activity. Accordingly, one of ordinary skill would have experimented with various combinations of amino acids to obtain an optimum range and optimum ratio. Because the appellant does not contend that he has achieved unexpected results by increasing the number of amino acids disclosed in (D1) (arginine and Isoleucine) and by adding glutamine disclosed in (D3) or the ratio in which they are used for stabilising recombinant factor VIII before lyophilisation we find the prior art stabilizers in combination (D1, D3 and D5) created a prima facie case of obviousness.

33 . Therefore, the experimental discovery of new stabilizer mixture of particular amino acids in predetermined ratio for stabilization of recombinant factor VIII before lyophilisation in place of albumin and other combinations from known stabilizers such as amino acids and mixtures disclosed in D1, D3 and D5 for same purpose does not constitute a patentable contribution to the art. Even though applicant's modification results in some degree of improvement and utility over the prior art, it may still not be patentable if the substitution of stabilizer was within the capabilities of one skilled in the art, unless the claimed mixture produce a new and unexpected result which is different in kind and not merely in degree from the results of the prior art. We agree with finding of the learned Controller that claimed invention lack inventive step and we affirm his order.

The appellant also submitted that that pharmaceutical preparation of the present invention is well defined by the claims of the present invention. The preparation comprises recombinant factor VIII and a stabilizer consisting of arginine, isoleucine and glutamic acid in the given amount range. A recombinant protein will not be stable and will never exhibit its activity when it is lyophilized alone. Therefore, to keep a recombinant protein such as Factor VIII of the present invention stable so that it maintains its activity after lyophilization, it is lyophilized with a stabilizer. The lyophilized recombinant proteins commercially available in the market always comprise a stabilizer. Therefore, pharmaceutical preparation of the present invention is also well defined comprising recombinant factor VIII and a stabilizer.

35 . We think it not necessary to deal with this aspect as we otherwise found the invention lacks inventive step. The appeal, therefore, is dismissed. There shall be no order as to costs.