04 四月 2013

Supreme Court rejects patent for new form of known pharma product

The Supreme Court of India in its recent judgment has upheld the denial of patent for the beta crystalline form of the chemical compound ‘Imatinib Mesylate’, a therapeutic drug for chronic myeloid leukemia. This landmark ruling by the Apex Court lays down various requirements for granting patents to pharmaceutical products while also deliberating on the scope of “invention” under the amended Section 3(d) of Patents Act, 1970.    

Claim on superior qualities

 The appellants had claimed that the invented product i.e. beta crystal form of Imatinib Mesylate, has (i) more beneficial flow properties; (ii) better thermodynamic stability; and (iii) lower hygroscopicity than the alpha crystal form of Imatinib Mesylate and that these properties made the invented product “new” as it “stores better and is easier to process”; has “better processability of the methanesulfonic acid addition salt of a compound of formula I”, and has a “further advantage for processing and storing”. It was contended that production of beta crystal form of Imatinib Mesylate from Imatinib involved two inventions, one for conversion to Imatinib Mesylate and another for conversion to its beta crystal form.    


Pharma products need to cross a higher bar

The Court however while dismissing the appeals, held that the Patents Act sets different standards for things belonging to different classes to qualify as “inventions” and the amended portion of Section 3(d) sets up a second tier of qualifying standards for chemical substances/pharmaceutical products in order to leave the door open for true and genuine inventions but, at the same time, to check any attempt at repetitive patenting or extension of the patent term on spurious grounds. It was also observed that this amendment was proposed by the Government in order to allay the fears of the members from the Opposition concerning the abuses to which a product patent in medicines may be vulnerable.


Product not satisfies tests of invention

On particular facts of the case, the court rejected the contention that Imatinib Mesylate was an invention under the tests of laid down in Section 2(1)(j) and Section 2(1)(ja) of the Patents Act. It noted that Imatinib Mesylate was covered under the Zimmermann patent and was a known substance from the said patent, its pharmacological properties were also known in the Zimmermann patent and the appellant did not seek patent for Imatinib Mesylate in non-crystalline form. Beta crystalline form of Imatinib Mesylate was a new form of known substance viz., Imatinib Mesylate, of which the efficacy was well known.

It was held that on the basis of some properties like more beneficial flow properties, better thermodynamic stability and lower hygroscopicity alone, the beta crystalline form of Imatinib Mesylate cannot be said to possess enhanced efficacy over Imatinib Mesylate, the known substance immediately preceding it, within the meaning of Section 3(d) of the Act. It was noted that not all advantageous or beneficial properties are relevant, but only such properties that directly relate to efficacy, which in case of medicine, is its therapeutic efficacy.


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