An exclusionary definition for the term ‘efficacy’ under section 3(d) of the Indian Patent Act

An exclusionary definition for the term ‘efficacy’ under section 3(d) of the Indian Patent Act:  continuation of “numerical quantifier to section 3(d)”
In an earlier post, I had discussed about a numerical quantifier for the term ‘efficacy’ under the Patent Act.  In the post, it was stressed that the current interpretation of the term ‘efficacy’ employed “circular logic” and such logic was flawed.  The logic is circular because the Indian patent office states: “ The efficacy need not be quantified in terms of numerical value to determine whether the product is efficacious because it is not possible to have a standard numerical value for efficacy for all products including pharmaceutical products.”
The Chennai High Court in the case of Novartis A.G. v Union of India had stated that “efficacy means therapeutic efficacy.”  In the judgment, the High Court had observed that the patent applicant is expected to be aware of the difference between the therapeutic effect of the patented drug and the drug in respect of which patent is asked for.   (Emphasis added).
A difference is a difference, and whether it is of a minute order or in magnitudes of order, it is still a difference.  Therefore, an Applicant who shows that there is a difference (say 10^(-5)) in the new form of a known substance, has succeeded in passing the test as laid down.  The term ‘significant’ cannot be used while interpreting the section because it is vague (the term varies with regard to the application).
Therefore, a negative definition that defines the bounds of the term efficacy may be appropriate.  Recently, the Court of Appeals for the Federal Circuit (CAFC) decided the case of Adams Respiratory Therapeutics v. Perrigo.  This case construed a key term: ‘bioequivalent’ and its interpretation may be used to define the bounds of the term ‘efficacy’ under the Indian Act.
US patent 6372252 describes an extended release formulation containing Guaifenesin, an expectorant used to thin, loosen and help expel mucus that causes congestion.  The preferred embodiment of the 252′ patent is Mucinex®.
In this case, the CAFC discussed applicability of certain FDA guidelines.  In 1989, the US Food and Drug Administration (FDA) published standards for IR guaifenesin products in a Final Monograph (Monograph). The FDA determined that IR guaifenesin products that complied with the Monograph would be deemed safe and effective. The Monograph did not address the safety and efficacy of extended release guaifenesin products.
Adams established the safety and efficacy of Mucinex® by showing that it was “bioequivalent” to a standard IR product (Organidin®) that complied with the Monograph.   Adams in an ex-parte proceeding while prosecuting the patent had asserted that “one of ordinary skill in the art would recognize ‘equivalent’ as being the FDA bioequivalence guidelines of 80–125%.” Adams attached an excerpt of the guidelines, U.S. Department of Health and Human Services, Approved Drug Products with Therapeutic Equivalence Evaluations, p. ix-x (19th ed. 1999) (FDA guidelines), which state:
Two formulations whose rate and extent of absorption differ by – 20%/+25% or less are generally considered bioequivalent.  The use of the -20%/+25% rule is based on a medical decision that, for most drugs, a -20%/+25% difference in the concentration of the active ingredient in blood will not be clinically significant.
These FDA guidelines give a proper basis from which to extract a negative definition; and applying the definition to section 3(d).
Therefore, in order for a new drug (in respect of which a patent is asked for) to have greater efficacy when compared to a known drug, the new drug must not be bio-equivalent to the new drug i.e. the new drug must lie outside the defined range of bio-equivalency when compared to the existing drug.
It is stressed that the range of bio-equivalence can be different for drugs, crystalline/amorphous/hygroscopic/dried substances, isomers, metabolites, combinations of plurality of forms, salts, hydrates, polymorphs, esters, ethers, or particle sizes.  I am not arguing that the range should be fixed at -20/+25%, but rather I am arguing that there should be quantification and the quantification may be an exclusionary one such as one described above.  This kind of definition is quite common in other fields of law.  For example the Hindu Marriage Act is applied to a Hindu, and a Hindu is negatively defined.
Having such a defined range would ensure that there is a uniform interpretation of section 3(d).

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6 thoughts on “An exclusionary definition for the term ‘efficacy’ under section 3(d) of the Indian Patent Act”

  1. It is a pleasure and privilege to commend the learned Author for his excellent article focusing on a possible ‘metric’ for ‘therapeutic efficacy’.
    I wish to submit the following for the Authors comments:
    The Author with his DSP background would appreciate that the Statistical & Econometric Models (say in DSS) include only significant ‘numerical’ parameters and ignore ‘qualitative’ parameters, however important they may be! Hence, the reliance of Managers on their ‘sixth sense crystallized by vast experience’.
    Exactly the same way, I present the argument that ‘LAW SHOULD NEVER attempt to QUANTIFY’ and so pursue ‘precision’. Law should purposefully be left ‘VAGUE’ so that the erudite Judge could use his experience in judging a case in the backdrop of the continuously changing socio-economic factors of the society that can only be qualitatively gazed by him.

    Poolla R.K. Murti

  2. Law should be interpreted in the backdrop of the continuously changing socio-economic factors. However, law can never left to be vague. The drawbacks could be significant as you can appreciate in the chain of events relating to sec 3 (d) post year 2005.

    I feel in all this debate about sec 3 (d) quantifying, interpreting the section in light of words such as efficacy and significantly, the true intention of legislature : ‘To check exploitation of patent regime by way of evergreening of drugs’ seems to have been diluted. Section 3 (d) in my opinion is an example of how a poorly drafted legislation can dilute the true intention of the legislature.

    @ Rajiv – A very nice analysis. However, can we come down to a quantifiable range for exclusion is still a point of debate.


  3. Dear Dr. Murti,

    Thank you for your comment.
    In order to answer your query, consider the following questions:

    In the case of patents, it is the Examiner/patent office who first determine whether something is prohibited/patentable. If the law is vague, what stops the Examiner from arbitrarily granting/refusing patents?

    Then when a patent is litigated, what stops a judge from granting or refusing an injunction on an arbitrary basis?

    The answer to both is that if the law is precise, then it is not vague-less room to grant/receive favors and follow exact procedures.

  4. sir the term in 3( d) r pharmacological term it it can not be put in matrix of numerical the term inovation must be seen in to it pl note that if is injection than 100 persent bioavilable than your logic failed of bioavalibility fail pl think [email protected]

  5. It is all medical practitioners, who decide the bio-equivalency, and not the law. Of course there is some disparity by which others may exploit it. Even in common law this happening.

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