Time to get it right? Patent Office rejects BI patent on wrong reading of a date

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The Patent Office recently rejected a patent application filed by Boehringer Ingelheim (BI) based on a wrong reading of the date of the prior art! The invention relates to the creation of Dabigatran etexilate methansulphonate (BIBR 1048 MS) which is the salt form of the free base BIBR 1048. The priority date for this invention is August 2003 (a PCT application). The Patent Office strangely relied on a publication dated September 2003, which allegedly discloses this invention, to hold that the salt existed in ‘prior’ art! The IPAB has asked the Patent Office to reexamine the matter without considering that particular publication (see order). 

A priority date is basically the ‘effective filing date’. If a patent application is filed as an international (PCT) application and then filed domestically, the application that is filed domestically can claim the international date of filing as its priority date. It is against this date that claims of novelty and obviousness need to be tested. Therefore, the term ‘prior’ in ‘prior art’ means art that existed before the priority date of the patent application. If such art in relation to the invention exists then in all probability the invention is not ‘novel’ or ‘inventive’. However, in this case, the disclosure/prior art was made after and not ‘prior’ to the priority date. Therefore, clearly that publication does not qualify as ‘prior art’. Maybe in this case, the Patent Office got confused with the date of the Indian application - 924/DEL/NP/2006 and the priority date - 2003! 

“Comedy of Errors”? 

The Patent Office has made similar errors in the Sugen case and Thomson Reuters case, blogged about here and here. To briefly recapitulate- in Sugen (2012), the Patent Office was negligent about several requirements – it accepted Sugen’s Form I application (an essential part of a patent application that establishes ‘proof of right’) 40 months after the prescribed date of filing and after taking into consideration delay, no opportunity was given for pre-grant opposition as the application was published after the patent was granted and the examiner conducted the hearing and granted the patent himself with no involvement of the Patent Office. 

In the Thomson Reuters case (2013) the IPAB had to send back the matter to the Controller due to procedural irregularities. The Assistant Controller had repeatedly provided vague statements such as “official requirement raised in a FER have not been met” which did not highlight what the objections to the claims raised by Thomas Reuters really were and hence was held to be an unfair rejection of the application. 

Facts of the case 

Though the IPAB sent the case back to the Patent Office for reconsideration, the order highlights some of the arguments - 

The appellant had invented BIBR 104 MS which is a polymorphic form of the free base BIBR 1048. This form of the Methanesulfonate salt was found to be crystalline, have a low amorphization rate, was non hygroscopic and dissolved very easily in physiologically acceptable solvents. According to the appellants, this salt showed unexpectedly better qualities than the free base (which both parties agreed was disclosed and was a part of prior art) and other salts. While the solubility of BIBR 1048 MS in water is 3.1 mg/mi, the free base shows a water solubility of only 0.00.3 mg/ml. This is difference shows that this form of methansulfonate salt will prove to have higher bioavailability (an important pharmacological feature). 

The Patent Office observed that salts are generally more stable than their free bases and the search for suitable salts was a standard procedure in pharmaceutical chemistry hence any skilled person could in the normal course prepare this salt. However, they did not provide any authority for the above argument. Moreover, they cited the prior art dated September 2003 to prove lack of novelty. 

However, the appellants denied this contention and argued that though salts are generally more stable than their free bases, this salt showed extraordinary quality not shown in other salts. Moreover, a skilled person could not have got to this salt from the prior art as the prior art did not mention the existence of methanesulfonate in different polymorphic forms. 

On the 3(d) argument the Patent Office held ‘the new crystalline form II exhibit same efficacy as documents D1 to D8.’ Here again D1 dated 2003 which was the ‘prior’ art that allegedly disclosed the salt was taken into consideration hence the IPAB sent the matter back. 

Patentability/Patent Eligibility 

As a side observation, the Patent Office seems to be testing the invention on a twofold basis – first checking for ‘patentability’ under S. 2(1)(j)– the three step test – novelty, inventive step and industrial application and then moving on to S. 3(d). However, since a S. 3(d) examination would entail a determination on non-obviousness, such an examination would coincide with a S. 2(1)(ja) examination and therefore should not be taken as a separate test. Or S. 3(d) should be considered first without going into S. 2(1)(ja) as S. 3(d) is a ‘patent eligibility’ criteria. For the distinction between ‘patentability’ and ‘patent eligibility’ see here. 

Shamnad has blogged about previous BI patent rejections here and here. Against its previous cases, the present case seems to comply with the requirement of ‘comparative data’ under S. 3(d) as it has been shown that this salt as compared to many others has certain extraordinary qualities. However, these qualities relate to solubility, stability etc. which may or may not qualify as ‘enhanced therapeutic efficacy.’