In a recent landmark decision taken on 1st June 2015, the Indian Patent Office rejected an application filed by US-based Abraxis BioScience relating to a new composition for Paclitaxel, an anti-cancer drug marketed under the trade name Abraxane, citing lack of novelty and inventive step. A pre-grant opposition was filed by the Opponent NATCO Pharma Limited, under section 25(1) which argued that the claimed composition was merely a new form of a known substance and, hence, under Section 3 (d) of the Indian Patent Act was not patentable unless it exhibits enhanced efficacy.

BRIEF TIMELINE1

The Applicant Abraxis Bioscience, a US based company filed a national phase application number 4572/ CHENP/2006 on 14/12/2006 for the grant of patent for their invention titled 'TREATMENT METHODS UTILIZING ALBUMIN-BINDING PROTEINS AS TARGETS'. The said application is based on the priority of US application No. 60/571,622 and US application No. 60/654,261. A pre grant opposition by the way of representation was filed by NATCO Pharma Ltd, Hyderabad on 08/09/2008. A revised set of claims were filed by the Applicant on 16/07/2013 based on the FER issued on 31/10/2012. The supplemental representation filed by the Opponents were refuted by the Applicant who requested the Controller not to take the supplemental representation on record. Subsequently, a hearing was held on 06/12/2013 and an opportunity was given to both the parties to be heard.

CONTROLLER'S DECISION ON ISSUE OF SUPPLEMENTAL REPRESENTATION FILED BY THE OPPONENT

During hearing the Applicant argued that "there are no provisions in our current law to file supplementary representations..." hence such representations should not be taken on record. After carefully considering the arguments of the Applicant and the opponent as well as the relevant sections and rules, the Controller agreed with the Opponent's argument that the proceedings of the Section 25(1) of the Patents Act 1970 are primarily to assist the Controller for taking the informed decision to grant good and valid patents only. The Controller further mentioned that the Opposition under Section 25(1) of the Patents Act 1970 can be filed by any person up to the grant of the patent, once the prior art documents along with matter pertaining to the grounds given under section 25(1) of the Patents Act 1970 has been brought to the controller's notice before the grant of the patent. Hence the controller considered the supplemental representation and took on his record.

The main grounds of opposition under section 25(1) of the Patents Act emphasized by the Opponent's agent are as follows;

1.Obviousness/ Lack of inventive step (Section 25(1)(e))

2.Not Patentable/Not an invention (Section 25(1)(f ))

Section 25(1)(e)-Obviousness/ Lack of inventive Step

The product claimed in independent claim 1 of the instant application is for the composition of paclitaxel coupled to an anti-SPARC antibody or fragment thereof which binds specifically to osteonectin with a pharmaceutically acceptable carrier. The Applicant clarified in a submission while replying to the other grounds of opposition that ' the excipients on acting on its own will yield no effect, whereas the surprising effect conferred in the present invention is only by the virtue of the therapeutic agent paclitaxel conjugated to the anti- SPARC antibody and not the excipients per se'. The Applicant has not quoted anywhere about the inventive features of the composition per se. Further the Applicant mentioned the section 59 of the Patents Act, 1970 as a basis for claiming the compound per se invention as composition of that compound.

The Controller considered the cited documents submitted by the Opponent in order to decide whether the conjugate of paclitaxel and anti-SPARC antibody of the fragment is obvious to a person skilled in the art pertaining to the teachings of the cited documents.

Annexures

Prior Art

Teachings

III

US 5439686

To deliver pharmacologically active agent (taxol) in an "ummodified form" in a Composition

 

IV

US6096331 ('331 patent)

Pertains to in vivo delivery of biologics such as the anticancer drug paclitaxel. The preparations enabled in this patent are cremophor free and the compositions is delivered as nanoparticles and the paclitaxel is often stabilized by a polymer. It teaches the polymeric shells can be conjugated to monoclonal (mAb) or polyclonal antibodies or antibodies can be incorporated into the polymeric shell. Use of mAb antibodies against nuclear receptors to target the encapsulated product to the nucleus of certain cell types is also contemplated. Antibody targeting of paclitaxel nanoparticles were taught in '331 patent

V

US67498686 ('868 patent

Example 17 teaches invivo targeting of paclitaxel nanoparticles, where certain targeting moieties such as proteins, antibodies, enzymes, peptides, and the like are used to target specific sites in the body. The targeting ablility can be utilized for therapeutic or diagnostic purposes..

IX

Taxene antibody conjugates Afford Potent Cytotoxicity, Enhanced solubility and Tumor Target Selectivity- Cancer Res 2001; 61: 694-699 Guillemard and Saragove. et .al

 

The problem of selectivity of paclitaxel can be addressed by using mAb that target 'tumor markers' which are proteins upregulated in tumor cells. The cytotoxicity, selectivity and specificity of the conjugate were better than that of free paclitaxel. The study conducted first-time reported the use of paclitaxel-antibody conjugates and proposed a general method to selectively target cancer cells by concentrating cytotoxic drugs near the tumor site and inside the tumor..

X

SPARC: A potential Diagnostic Marker of Invasive Meningiomas; 1999; 237-241. Clin Cancer Res.Sandra et.al

 

Teaches SPARC and gp60 share homology and anti- SPARC antibody is also known to bind to gp-60

From the cited prior art disclosures, it is obvious that the teachings of conjugates of paclitaxel with antibodies is already known in the art. The Controller mentioned that the cited prior art as discussed above are clearly stating that the SPARC is a tumor marker and hence it can be inferred that, the person skilled in the art will have to try with the binding molecule of the SPARC which he knows as its antibody. The controller further added that that the claimed composition i.e paclitaxel coupled to an anti-SPARC antibody or fragment thereof which bonds specifically to osteonectin is obvious to the person skilled in the art in view of the teachings in above cited documents.

Hence, the Controller concluded that since the Applicant has not quoted any of the specific inventive features for the dependent claims 2 to 14, they can also said to be obvious to a person skilled in the art and do not involve any inventive step u/s 2(1)(j) of the Patents Act, 1970.

Section 25(1)(f): Not Patentable/Not an invention

The Opponent contended that the claimed composition is a new form a known substance. Further, the opponent submitted that under section 3(d) a combination of a new form of known substance is patentable only if it exhibits enhanced efficacy. The present composition as claimed in the claims of the impugned patent application is a combination of known substances, namely paclitaxel and anti-SPARC antibody. The Opponent pointed that there is no demonstration of enhanced efficacy failing patentability under section 3(d). Also, such composition claimed in the impugned application is a mere admixture and not patentable under Section 3(e) of the Act thereby demanding refusal of claims 1-14 owing to not being patentable under Section 3(e) of the patents Act, 1970.

The Applicant refuted the Opponent's allegations that section 3(d) is not pertinent in respect of such an entity adding that "A substance can be deemed a "combination" only when there two entities exist separately and unconnectedly and each of these entities confer their individual effect(s) on their own accord. Such is not the case in the present claims, where it is clear that the paclitaxel is "conjugated" to anti-SPARC antibody and hence the molecule is now a lone entity. Apropos to the allegation concerning the violation of Section 3(e), it was elucidated that and Section 3 (e) cannot be raised in a blindfolded manner on a mere reflection of the term "composition" in the preamble of a claim."

Also, the applicant mentioned that the surprising technical effect has indeed been demonstrated in the description at pages 19 in Example 4, para [0072], lines 4-6 of the present application, wherein it has been categorically established that the transport of paclitaxel from ABX (abraxane) was inhibited by the presence of anti-SPARC antibody, which is known to bind gp60, the receptor required for caveolar mediated transcytosis inhibits the binding of albumin itself to gp-60.

CONTROLLER'S DECISION WITH REGARDS TO SECTION 3(D) AND 3(E)

The Controller pointed that there is no submission by the Applicant of comparative efficacy data between the paclitaxel and paclitaxel coupled to an anti-SPARC antibody or fragment thereof which binds specifically to osteonection. Therefore, the Controller agreed with the Opponent that the invention paclitaxel coupled to an anti-SPARC antibody or fragment thereof which binds specifically to osteonectin in the absence of enhanced efficacy is not patentable under section 3(d) of the Patents Act 1970.

With regards to Section 3(e) of the Patents Act 1970, the Controller disagreed with the Opponent as the novelty and inventive step of the present invention lies mainly in the paclitaxel coupled to an anti SPARC antibody or fragment thereof which binds specifically to osteonectin and hence cannot be considered as an admixture.

CONCLUSION

Therefore the Controller refused to proceed with the application for the grant of patent under section 15 of the Patents Act 1970 citing claims 1-14 of the present invention lack inventive step under section 2(1)(ja) of the Patents Act , 1970 and the claimed composition is not patentable under section 3(d) of the Patents Act 1970.

Footnotes

1.http://ipindiaservices.gov.in/decision/4572-CHENP-2006-10560/4572-chenp-2006%20order-Final.pdf

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