‘Efficacy’ vis-a- vis S.3(d) of the Patent Act
The interpretation of ‘Efficacy’ vis-a- vis S.3(d) of the Patent Act
By the Patent Amendment , which came in to effect in the year 2005, India limited the patentability of the pharmaceutical substances to New Chemical Entities (NCEs) . It introduced section 3(d) in the Patent Act with the aim to prevent ever-greening which excludes incremental innovation from patent protection unless it satisfies the condition of efficacy as laid down in the section. This section is unique to the Indian Patent Act, and a similar provision is not found in any other Act. The key concept of Efficacy as such, has not been defined under the Act, and hence the term ‘efficacy ‘has been a subject of much debate and discussion .
In Novartis AG vs Union of India & others, 2007 , the Madras High Court clarified the meaning of ‘efficacy’ for the first time.
The Hon’ble Court held that: Going by the meaning for the word efficacy and therapeutic extracted above, what the patent applicant is expected to show is, how effective the new discovery made would be in healing a disease/having a good effect on the body. In other words, the patent applicant is aware as to what is the ‘therapeutic effect of the drug for which he had already got a patent and what is the difference between the therapeutic effect of the patented drug and the drug in respect of which patent is asked for.
The first hitch here is the fact that even when scientifically supported interventions are implemented in the community, their effectiveness in real life situations often falls short of the efficacy demonstrated in clinical trials. There are a number of reasons for this phenomenon, including lower rates of medication adherence, a higher prevalence of adverse events due to drug-drug interactions, and the impact of multiple co-morbid conditions. Thus, the real-world performance may not replicate that demonstrated in a “clean” and controlled research environment, further contributing to the efficacy-effectiveness gap. The nearest one comes to this gap in the patent context is <clinical> vs <therapeutic> efficacy. The Honourable High court above presumably sees <Therapeutic> efficacy as its benchmark.
It needs to be borne in mind that the bio-indicators of clinical efficacy do not always match with real world patient benefit or therapeutic efficacy as explained above. And even this <efficacy> as it appears in the section 3(d) has a further difficulty. Section 3 (d) provides that the mere discovery of a new form of a known substance, which does not result in the enhancement of the efficacy of that substance, is not patentable. Does efficacy here mean a more effective drug in terms of bioavailability, or as in a more stable composition? Section 3(d) talks about efficacy but whether it is limited to therapeutic efficacy, or does it include clinical efficacy and other advantages such as heat stability, is left open. What does the phrase significant increase in efficacy means? What are the objective criteria to determine significant increase in efficacy? Variations in the theraputic efficacy and numerical correlates thereof would vary with the class of substances under review and thus even a numerical standard would be insufficient to define a <significant> change for all classes of molecules. The objective criteria would vary case by case. There are no guidelines in the Section about these important criteria, and given the gap that exists between the clinical vs therapeutic efficacy of most drugs, the section also fails to look after the patient welfare, which is its avowed aim. In this respect, Section 3(d), though noble in intent, is a poorly and vaguely drafted legal text.
This is further compounded by the decision of the Madras High Court in Novartis vs Union of India & Ors, since the term ‘efficacy’ has been interpreted to be therapeutic efficacy . The practical difficulty of patent applicants to even give details of ‘efficacy’ studies at the time of application , has not even been remotely considered. At the time of making a patent application, even animal studies are rarely completed. A realistic ‘Therapeutic efficacy’ sometimes can be ascertained only after ‘clinical trials. Hence this judgement places an unrealistic expectation on the patent Applicants.
The significance of this omission becomes clear in two of the recent high profile Patent disputes in India :
The pre-grant opposition Hearing held on August 25,2008 in the matter of Erlotinib hydrochloride compound disclosed in US Patent 4757498, the court surmises that the applicant (M/s OSI Pharmaceuticals Inc, USA) not shown any unexpected surprised benefits or efficacies related to the polymorph of the impugned invention, according to the submissions made by the applicants and thus found to be not patentable under section 3(d).
In respect of the criteria for enhanced efficacy, another interesting case is the decision of controller in respect of application no. 1602/MAS/98 (Novartis AG Vs Cipla Ltd. ) where the solubility was not considered to be a enhancement in therapeutic efficacy.
Going back to the earlier discussion, both these judgments state what does not constitute Efficacy as a criteria for patentability, what is needed however, is a clear guideline as to what does constitute efficacy of a molecule against a given indication in order to see whether section 3 (d) of the Indian Patents Act might be applied to it. This issue would come up repeatedly in future litigation, unless positive criteria are laid down.
Rca Godbole
22nd July 2009
