• Dr. Mohan Dewan

Sugen/Pfizer lost their patent rights relating to Sunitinib, a drug for treating renal cell carcinoma (RCC) and imatinib-resistant gastrointestinal stromal tumor (GIST) on account of weak and unplanned strategic Intellectual Property Management. They failed to understand the ground realities about the Patent System in India whichled to a complete letdown in forecasting the potential threats.Though the Assistant Controller accepted the novelty of the subject matter disclosed in IN209251, the patent was revoked on the grounds of lack ofinventive step based on the teachings of threeprior art patent documents namely, D1 (US5886020), D2 (WO199850356) and D3 (WO19961422), all of which were patent applications filed by Sugen.

The deficiency of strategic management resultedin subsequentfailure to overcome the objections relating to the inventive step during the opposition proceedings.This is more surprisingasthe inventive step was also questioned based on Sugen’sown earlier inventions (D1, D2 and D3) in the ISR (International Search Report)and the IPER (International Preliminary Examination Report)which were published way before the filing of the National phase entry in India. It is a well-known practice in Indiathat the objections raised inthe ISR are likely to be raised during the prosecution of the corresponding Indian patent application.The Sugen team lost sight of the legal way of avoiding the inventive step objections at least in respect of these 3 inventions.

The appropriate strategy would have been to:

  • File the inventionsdisclosed in D1, D2 and D3 as parent patent applications and thereafter file the instant patent application as a patent of addition; or combine D1, D2 and D3 intoa cognate document claiming priority from all the three patent applications and file the same followed by filing the instant application as a patent of addition; and
  • Withdraw the main/parent patent application(s).

This strategy would have obviated the objections relating to obviousness in view of D1 to D3 patent documents as per section 56(1) of Indian Patents Act.Had they adopted this strategy, the Controller could not have taken the objection of obviousness with respect tothe D1to D3 documents. By adopting the aforesaid strategy, Sugen would have demolished a large portion of the case built up against them.

Furthermore, Sugen could have strengthened the case/patent by providing clinical trial data at appropriate stages of prosecution. It is known that the applicant/patentee can file a request to allow amendment of the specification within the framework of the provisions of the Act (Section 57 to 59). In the present case, such a request would have been treated as an amendment of the specification by way of explanation in line with the provisions of Section 59 read with Section 57 of the Indian Patents Act.

For example, if the originally filed specification did disclose that the molecule of the instant invention exhibits efficacy, the applicant can crave leave to amend the specification by way of explanation of efficacy.

The applicant could have argued that the amendment requested is allowable in accordance with Section 59 because:

  • The applicant’s amendment is only by way of explanation,
  • The applicant’s amendment deals with incorporation of the actual fact (efficacy data),
  • The applicant’s amendment deals with “description of the matter” that has already been disclosed and
  • The applicant’s amendment is not incorporating matter which was not disclosed in substance earlier.

There is a distinction between “description of the matter which is already present in the description by way of explanation” and the incorporation of “the matter that is not disclosed in substance in the specification.” Section 59 is against the incorporation of “the matter” but not against the incorporation of “description of the matter” by way of explanation.

Another criterion for allowing the amendment under Section 59 is that the amendment should not result in broadening of the claims or it should not claim any matter which was not claimed before. In the present case, the applicant would have narrowed down the claimed matter and the issue of broadening of the matter would nothave arisen. It is also known that, even at the IPAB, the applicant can propose an amendmentunder section 58 of Indian Patents Act.

There is no strict rule as to when the specification can be amended. For instance, we can refer the following Indian case wherein the amendments in the specification related to efficacy/synergy data were allowed.

In DuPont v Solvay, (pertaining to the revocation of Indian Patent 175594 granted on 9th February, 1996 in the name of DuPont), Solvay alleged that the patentee made false representations about a chemical composition/compound to the Controller and that a patent should not have been granted because of the applicability of sections 3(d) and 3(e) of the Patent Act.The patentee challenged the revocation petition and brought an application to amend the specification to include data for overcoming the objections made under sections 3(d) & 3(e) of the Act. In the application for amendment, the patentee wanted to clarify that the invention is a synergistic composition, comprising a fire extinguishing agent and a propellant, which are two separate elements and distinct. Additionally, the patentee also submitted evidence that the combination had an unexpected advantage resulting from synergy between its components. In reply, Solvay claimed amongst other grounds, that the new statement proposed by the patentee would have the effect of claiming or describing the matter not substantially what is disclosed or shown earlier in the specification before the amendment.

The Controller did not object to the amendment and stated that the addition was acceptable. "As regards the proposed amendment which is by way of disclaimer, as far as the composition, of the invention is concerned the proposed disclaimer is within the limits of the principal claim, i.e. Claim (1) as accepted.”

The IPAB then analyzed the applicable law (Sections 57-59; Rule 81-83; Form-13) for amendment of a patent and analyzed the additional matter sought to be included and focused on the word 'synergy.'

The IPAB concluded that the addition of the term 'synergy' between the components in the description of the specification, was rather existing, but probably was not described and hence the amendment sought through this petition is only a disclaimer and by way of clarification. The Board therefore allowed the proposed amendments.Another plausible way could be explaining the fact that the specification at the time of filing was in compliance with the Act and its provisions prevalent at the time of filing of the application (2002).

In view of the above discussion, we believe that a fine blend of technical and legal strategy would have worked Sugen’s way instead of adoptinga strategy leaning towards legalarguments.Pharmaceutical companies should design proper strategies by taking into account the provisions of Indian Patent Act such as Section 3(d),the patent of addition provisions and amendments, instead of questioning the constitutional provisionsof the Act.


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