First Publication Date: 11th December 2009

Section 3(d) of the Patents Act provides that mere Discovery of a new form or new use or new property of a known substance is not patentable. The discovery of a new form of a known substance will be patentable only if it results in the enhancement of the known efficacy of that substance. Salts, esters, ethers, polymorphs, metabolites, pure forms, particle size, isomers, mixtures of isomers, complexes, combinations and other derivatives of a known substance will be considered to be the same substance and are not patentable, unless they differ significantly in properties with regard to efficacy. Efficacy may be shown by showing an improved effect in comparison with the original substance through objective scientific evidence.

Furthermore, the mere discovery of any new property or new use for a known substance is not patentable. The mere use of a known process, machine or apparatus is also not patentable unless such known process results in a new product or employs at least one new reactant.

Constitutional Validity of the Section – Novartis Case

The constitutional validity of section 3(d) was challenged by Novartis before the Madras High Court in the case of Novartis v. Union of India. In that case, Novartis filed for a patent over imatinib Masylate, which was a salt form of the patented molecule, imatinib. imatinib Masylate, commonly called as ‘Glivec’ is used for cancer treatment. The patent application was rejected by the Controller and the Appellate Board under Section 3(d) of The Patents Act on the ground that it was a salt form of a known substance. Novartis filed a writ petition before the high court of Madras challenging the constitutional validity of section 3(d).

The writ petition contended that section 3(d) of the Patents Act was not in compliance with the Agreement on TRIPs and that the section violated Article 14 of the Indian Constitution. It was argued that the section did not comply with Article 27 of the TRIPS Agreement, which provided for non-discrimination of inventions based on the field, by prohibiting patent protection for new forms of a known substance and thereby discriminating against such inventions. It was further argued that section 3(d) violated Article 14 of the constitution because it was vague by not defining the meaning of ‘efficacy’. It was also argued that the section was arbitrary and gave un-canalized discretion to the Controller of patents for making decisions on patentability.

After hearing the arguments, the court held that it did not have the jurisdiction to decide on the question of compliance of the TRIPS Agreement and that the Dispute Settlement Board of the WTO was the right forum for such a question. With regard to the second contention, the Court held that section 3(d) of the Act was not vague, ambiguous and arbitrary and therefore, would not violate Article 14 of the Constitution of India. The Court stated that the section along with explanation was very clear and had inbuilt measures under the Act to guide the Controller.

As per the court, in order to get patent protection over the new form of a known substance, efficacy could be proved by showing a better therapeutic effect from the new form, which could be shown by scientific and objective evidence. It also stated that the derivative of a substance should have better efficacy than that of the substance in order to be patentable.

In relation to the contention concerning the Controller’s discretion, the court stated that the Controller would use his discretion based on the materials placed before him and that any misuse of his discretion could be corrected by the appellate authorities. It then pointed out that the existence of discretion under the Act was a necessity as every case had to be decided on the facts. As the section was not vague and as there were well laid down guidelines and checks based on which the Controller would use his discretion, the Court held that the section was not arbitrary and does not violate Article 14 of the Indian Constitution.

Decision of the Appellate Board after the Madras High Court decision

The facts of the case have been recited once again hereunder for the reader’s benefit because the decision is based on technical aspects of the invention in question.

Novartis filed an application for patent in 1998 for an invention entitled “Crystal Modification of a N- Phenyl-2-Pyrimidineamine derivative, processes for its manufacture and its use. The application claimed the methanesulfonic acid addition salt form of the compound, Imatinib, hereinafter called as Imatinib Masylate. It specifically claimed the beta crystal form of Imatinib Masylate, which is non-needle shaped, having better flow properties, thus better processible, less hygroscopic and more thermodynamically stable, thus better storable than its needle-shaped, alpha crystal form, characterized by the differences in the melting points and the X-ray diffraction diagrams. The patent application of Novartis claimed priority from an application filed in Switzerland.

Pre-grant representations opposing the grant of patent were filed by Cancer Patients Aid Association, India, M/s Natco Pharma Limited, M/s Cipla Limited, M/s Ranbaxy Laboratories Limited, India and M/s Hetro Drugs Limited, India (“Opponents”). The Opponents claimed that the invention claimed in the application was not patentable because it claimed priority date wrongfully, lacked novelty and inventive step and fell within section 3(d) of the Patents Act. After considering the representations and hearing the parties, the Assistant Controller refused the grant of the patent. Aggrieved by the decision of the Assistant Controller, Novartis filed Writ Petitions before the High Court of Madras and the High Court converted the said writ petitions into appeals. After the constitution of the Appellate Board in 2007, the case was transferred to the Appellate Board.

The Appellate Board considered each of the arguments raised by the Opponents and refused to grant the patent over the claimed compound to Novartis. With regard to priority date, the Appellate Board stated that an issue relating to convention priority would be a ground for opposition under Section 25(1) of the Patents Act. It went on to state that the ground cannot be accepted for refusal of patent application in the case because Novartis could claim priority from a Switzerland Patent application in accordance with the amended Section 133 of the Patents Act.

Regarding novelty, the Appellate Board reviewed the prior art references cited by the Opponents and stated that the references do not disclose any specific crystalline form of imatinib mesylate as a substance, leaving apart the beta crystalline form, any pharmaceutical composition containing the same or any process for making the said beta form. It further observed that a person skilled in the art would not be able to predict the polymorphism and prepare the subject compound from the prior art. Furthermore, the Appellate Board stated that Beta Crystalline form of Imatinib Masylate was not inherently anticipated by the prior art because the salt existedin several polymorphic forms, there was no concrete method to prepare the salt form and because convention methods could not be used to prepare the compound based on the disclosure. In the light of its reasoning, the Appellate Board held that the compound was not anticipated and therefore, satisfied the novelty requirement.

With regard to the existence of inventive step, the Appellate Board stated that though the prior art provided various salt forms of Imatinib including the Masylate form and a person skilled in the art might choose the Masylate form, a person skilled in the art would not be able to discover the same and reach to the beta crystal form of imatinib mesylate, or to find its advantageous properties or to find a suitable process for its preparation or make a solid pharmaceutical composition containing the said crystal form because of polymorphism and related unpredictability in the art. It then stated that the invention had a technical advance as compared to the existing knowledge by way of demonstration of polymorphism, isolation, characterization of beta (and alpha) crystal forms of imatinib mesylate, identifying suitable properties in the beta crystal form usable in the making of oral solid drug formulation for curing cancer. As no one could predict the possibility of existence of polymorphism in imatinib mesylate and as there was no motivation in the prior art for an uninventive man to try for finding out different polymorphic forms and their relative properties suitable for preparing for solid dosage formulation for cancer treatment drug, the Appellate Board concluded that the Beta Crystalline form of Imatinib Masylate possessed inventive step.

The Appellate Board then discussed about selection patent, which is a patent granted to a compound that is selected from a group having certain characteristics and that shows unexpected results. It laid down certain minimum requirements that may be considered before granting a selection patent, which are:

(1) Whether there is any statement in the specification indicating that the nature of the invention concerns with some kind of selection;
(2) Whether the selection is from a class of substances which is already generally known;
(3) Whether the selected substance is new;
(4) Whether the selection is a result of any research by human intervention and ingenuity opposed to mere verifications;
(5) Whether the selection is unexpected or unpredictable; and
(6) Whether the selected substance possesses any unexpected and advantageous property.

As Imatinib Masylate was selected from a group of different salt forms cited in the prior art and as the Beta Crystalline form of the compound had surprising and unpredictable results, the Appellate Board stated that the compound in the patent application might be considered to satisfy requirements for grant of a selection patent.

The Appellate Board then analyzed the patentability of Imatinib Masylate under Section 3(d) of the Patents Act. It started its analysis by citing the definition of “efficacy” of the Madras High Court, which opined that efficacy means a therapeutic effect in healing a disease or having a good effect on the body. The Appellate Board then observed that therapeutic efficacy is different from advantageous property of a drug. As per Section 3(d) and its Explanation), the Appellate Board stated that Imatinib Masylate is a salt form of Imatinib, which was already known and would not be patentable unless it showed increased efficacy than Imatinib. Though the Beta Crystalline form of Imatinib Masylate had increased Bio-availability, the Appellate Board pointed out that it would not be sufficient to satisfy the efficacy requirement. Furthermore, the Appellate Board stated that though physical properties such as improved thermodynamic stability, improved flow properties and lower hygroscopicity were important to formulate the active ingredients in solid dosage forms such as capsules, tablets and so on, they had no contribution to actual therapeutic efficacy of the compound. As the Beta Crystalline form of Imatinib Masylate did not possess any improvement in the therapeutic effect of Imatinib for treatment of cancer, the Appellate Board held that the compound fell within the scope of Section 3(d) and was therefore, not patentable.

In the light of its analysis, though Imatinib Masylate satisfied the requirements of industrial applicability,, novelty and inventive step, the Appellate Board held that compound was not patentable as it fell within the scope of ineligible inventions under Section 3(d) of the Patents Act.

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