Fresenius Kabi succeeds in revoking Lapatinib Salt Patent at IPAB

In an order (No. 161/2013) dated July 27, 2013, IPAB-India has revoked the patent of Lapatinib Ditosylate Salt. Fresenius Kabi Oncology Ltd had filed the revocation petition against Patent No.IN221171 entitled “Quinazoline Ditosylate Salt Compounds”, the said patent belongs to Glaxo. In a decision main arguments were focussed on obviousness, S.3(d) and S. 8 in IPAB decision.

Below is the gist of decision and few important clarifications by IPAB on some points.

Section 3(d):

Citing the recent Novartis case judgement by Hon’ble Supreme Court, IPAB stated that efficacy relates to “therapeutic efficacy” and not all advantageous or beneficial properties. More importantly considering the genesis of S.3(d) the words “therapeutic  efficacy” must receive a narrow and strict interpretation.

Patentee argued that ditosylate salt absorb much lower amounts of water when exposed to a broad range of humidities and can be prepared in a stable crystal form. And that “Due to the improved moisture sorption properties of these compounds and increase in stability they exhibit enhanced efficacy in their use as a medicament following storage when compared with the di-HCL salts disclosed in the prior art reference. But IPAB dismissed the argument and said improved moisture absorption property and hence stability of ditosylate salt cannot be considered as enhanced efficacy as per recent supreme case judgement.

 

Obviousness:

By citing F. Hoffman-La Roche Ltd v. Cipla Ltd IPAB stated it was obvious to try for person skilled in the art to choose from different salts disclosed in Exhibit B ie. substance patent of Lapatinib. Out of 19 salts disclosed in Exhibit B, two sulphonyl salts include ditosylate salts. It was submitted that when the problem to be solved was hygroscopicity, it was obvious for a person skilled in the art to try the salts disclosed in Exhibit B which would give the desired result.

Exhibit C teaches the salt of a different active ingredient which is analgesic. Once there is a suggestion that tosylate salt would solve the problem of hygroscopicity, there is definitely an encouragement to try it.

IPAB further explained that in the present case there is a clear indication in Ex.B of the tosylate compound. There is no doubt that zooming in on a correct salt is not easy, if the choice could only have been made by testing each compound one after the other with no clue available. But Ex.C gives a clue. It was reasonable to hope it might, it would not have been a blindman’s buff choice. So we are of the opinion that to the Person Skilled in The Art taught by Exhibits B and C the invention was obvious.

S.8 disclosure and non-compliance:

IPAB gave elaborated explanation for the section 8 requirement and stated that one must carefully apply the provision. S.8 of the Act is not intended to be a bonanza for all those who want an inconvenient patent removed.

The Ayyangar Report makes it clear that the purpose for introducing this provision was to ensure that it would be an advantage for our Patent Office to know the objections raised by the patent offices outside India regarding the patentablity of the invention and the amendment if any made or to be made. It also says that it would be of great use for the proper examination to know if the invention was anticipated.

IPAB also remanded patent office and said that It is unfortunate that the office has failed to understand the importance of the S.8 requirement and leaves it to the Patentee to decide what he will give. IPAB also requested patent office and Controller General to educate and instruct the officers regarding the requirements of law.

Finally IPAB rejected S. 8 ground and stated that In the present case we are rejecting the S.8 objection only because the applicant has not made out the grounds of attack by stating the facts. In this case in the Revocation application, the applicant has merely stated that S.8 has not been complied with and foreign filing particulars have not been given. Nothing more is stated. In the petition filed for receiving additional documents, the affidavit filed by the applicant merely lists the documents were downloaded. We do not think that is sufficient.

If you wish to see the whole decision, you can access the same on IPAB site at http://www.ipab.tn.nic.in/