This paper discusses the recently published decision of the Intellectual Property Appellate Board (IPAB) in the case of Sankalp Rehabilitation Trust v F Hoffmann-La Roche in the post grant opposition of patent 198952 ('952 for short), owned by F Hoffmann-La Roche. The '952 patent titled "A physiologically active branched PEG-IFN alpha conjugates" is related to a hepatitis-C drug.

The constituted opposition board found that the claims lacked inventive step and was invalid under section 3(d) of the Act. The assistant controller of patents rejected the recommendations, and held the patent to be valid. On appeal, after holding that Sankalp Rehabilitation Trust had locus standi to file the post-grant opposition, IPAB overturned the decision of the Patent Office and found the patent to be invalid under section 3(d) of the Act, as well as for lacking inventive step. The present article will focus on the findings of IPAB on the issues of locus standi and section 3(d).

Locus standi

Under section 25(2) of the Act, a post-grant opposition can only be filed by an interested person. Based on UK jurisprudence and precedent of the Delhi High Court, the respondent contended before IPAB that for an entity to be an interested person, it must have a "genuine commercial interest". The appellant, Sankalp Rehabilitation Trust, on the other hand, was a not-for-profit organisation that aimed at providing care and support to drug users. The appellant contented that the term interested person could cover those who are vitally interested in the grant and revocation of the patent, and therefore, could cover competing researchers and even beneficiaries or consumers.

IPAB noted that the term interested person has been defined in the Act to "include a person engaged in promoting research in the same field as that to which the invention relates", and therefore, could not be limited to only those having a commercial interest. Referring to a number of precedents, IPAB was of the view that the term "include" in the definition is a prima facie indication that the definition of interested person was intended to be broader and not more restrictive. IPAB was of the view that throughout the entire scheme of the Act, the legislature was designed to counter unjustifiable inventions in a number of ways. IPAB held that so long as the personal interest is justified by a "common sense approach" and not a mere "fanciful" interest, a party will satisfy the required threshold for locus standi. Taking this approach, IPAB held that the appellant, who works for a community that needs the medicine covered by the patent in question, is clearly an interested person under the Act. IPAB attempted to balance this broad view, by warning that the cause of justice could be balanced by awarding exemplary costs against those who really have no interest in the proceeding.

As is obvious from this judgment, IPAB made an attempt to balance various conflicting positions and has given a general approach that is not limited to pharmaceuticals. However, the judgment is vague when it refers to a common sense approach and something beyond just a fanciful interest. It is a reasonable fear that the decision may be construed as a precedent to claim that persons interested in the welfare of the people, may become an interested person under the Act, and one only needs to recollect the history of public interest litigation to fuel this fear. From this perspective, the imposition of costs to balance on this slippery slope may not be a strong enough deterrent.

Section 3(d) of the Act

The independent claim under challenge read as follows:

A physiologically active branched PEG IFNα conjugate having the formula…wherein R and R' are independently lower alkyl; X is NH or O; n and n' are integers having a sum of from 600 to 1500; and the average molecular weight of the polyethylene glycol units in said conjugate is from 26,000 daltons to about 66,000 daltons.

It was contended by the appellant that a certain linear PEG IFNα conjugate was already known and the respondent had failed to prove significantly enhanced efficacy over this known compound. On the other hand, the respondent contended that the known compound for the purpose of comparison under section 3(d) was the unmodified IFNα, since the claimed branched PEG IFN conjugate was directly derived from the unmodified IFNα, and not the linear PEG IFNα conjugate. With respect to unmodified IFNα, the specification, in examples, had shown an increase in vitro, in vivo antiproliferative activity and significant reduction in tumor cells. The Patent Office accepted the contention of the respondent.

IPAB rejected the contention of the respondent by simply referring to the complete specification, which consistently indicated that the invention was directed to a new class of PEG derivative of IFNα and was a new form of PEG IFNα conjugate. Keeping this in mind, IPAB noted that neither the specification nor any other contemporaneous evidence provided any information as to how the claimed molecule showed better activity than the known PEG IFNα conjugates. IPAB took notice of the fact that the Patent Office had decided the issue of section 3(d) in favour of the patentee on the basis of probabilities and held that "efficacy should be proved with certainty".

This decision demonstrates how deciding what is the 'known substance' for the purposes of section 3(d) was equally important compared to deciding whether there was an enhancement of efficacy. Although the patentee had data relating to enhanced results from one known form of the known substance (unmodified IFNα) IPAB concluded that the other known form of the known substance (PEG IFNα) is the appropriate benchmark for section 3(d). Importantly, this conclusion was reached solely on the basis that it was the patentee who referred to the claimed molecule showing better results than known PEG IFNα. The language of section 3(d) only implies that data relating to enhanced efficacy should, logically, relate to the 'known substance' of which the claimed compound is a 'new form', a derivative, and not every other known form. The decision of IPAB, however, appears to have assumed that the claimed compound is a 'new form' of known PEG IFNα. Such a view may not be entirely justifiable in light of the language used in section 3(d).

It is also interesting to note that IPAB placed emphasis on the contemporaneous nature of the evidence to be used to prove enhancement of efficacy, indicating that information or evidence generated after the priority date may not be allowed to overcome section 3(d).

Further fine tuning

The decision of IPAB in Sankalp Rehabilitation Trust v F Hoffmann-La Roche is a reasoned one, and is an interesting development in patent law jurisprudence. While the Supreme Court's pending decision in the Novartis case may prove useful in settling the jurisprudence surrounding section 3(d), IPAB's judgment on the interpretation of the term interested person will require some further fine tuning.