Part I: IPAB revokes Allergan’s patent on eye drugs Ganfort and Combigan

Crying their eyes out?

This two part post is about the recently revoked patents owned by Allergan Inc (USA). The patents covered the drugs Ganfort and Combigan, and were used in the treatment for Glaucoma. The drugs essentially reduced pressure in the eyes. The revocation applications were filed by Ajanta Pharma Ltd, a leading Indian drugmaker. Both applications applied for a revocation on  the grounds of obviousness and non-compliance of S. 8, and were successful on the same.  The Board consistently held that non-compliance of S. 8 will attract invalidation of the patent. The decisions were pronounced by Justice Sridevan (alongwith DPS Parmar) on her last day as the Chairman of the IPAB. Ajanta Pharma previously lost a trademark infringement suit to US drugmaker Alcon in 2008, in relation to similar brand-names of drugs used in treatment of Glaucoma. 

Patent I [ORA/20/2011/PT/KOL]

Ajanta Pharma Ltd filed a revocation application against Allergan’s patented eye drug to cure Ocular Hypertension(Glaucoma). Allergan had claimed to achieve enhanced treatment of ocular hypertension with reduced side effects. The IPAB revoked the patent without costs. The invention was titled “Hypotensive Lipid (prostaglandin derivatives) and Timolol composition and methods of using same” [Patent No.212695] and, covered the drugs Ganfort and Combigan. The revocation application was filed on the grounds of non-compliance of s. 8 and obviousness of the invention. 


The applicants stated that the respondents had a duty to disclose information as per the requirements of s. 8 and the respondents did not disclose application numbers of the patent grant applications pending in various countries to the Indian Patent Office, despite providing undertakings for the same. 
The impugned patent was a fixed combination of Bimatoprost and Timolol. The only issue which the applicants focused on was whether the combination was obvious in view of simultaneous (five minute gap) administration of these known drugs referred to as serial or adjunct monothrapy. A number of citations were relied on but the obviousness argument principally rested on the previous combined fixed dose containing Latanoprost and Timolol, each disclosed by prior publication.    The counsel  submitted that the combination of Bimatoprost [US 5688819] and Timolol[US W09730710]  was obvious because it was only a matter of conventional and routine experimentation, to arrive at the claimed combination. The applicants stated that in absence of data that compares the claimed combination to combinations known in prior art, specifically, closest prior art combinations employing Timolol and a prostaglandin analog i.e. Latanoprost, there was no inventive merit or enhanced treatment that was exhibited.  In the present matter, it was obvious that a combination of a prostaglandin analog and a beta blocker, specifically Timolol, would result in an additive enhanced effect. This motivation with a reasonable expectation of success was sufficient to render the impugned patent obvious and devoid of inventive merit.
Respondents contended that the revocation application was time barred because the patent had been granted in 2007, and the revocation application was filed only in 2011.

The respondents attempted to prove that the therapy was an unexpected result. According to the learned counsel the structural similarities between bimatoprost and latanoprost were overemphasized by the applicants.There were many chemical compounds that are as close structurally to latanoprost as bimatoprost is, and there is no reason why one of skill in the art would have considered bimatoprost alone as the best compound for modification of a latanoprost composition.
The IPAB held that the application was not time barred. The right to revoke patent any time after the grant of patent under section 64 cannot be extinguished by applying limitation of three years under Article 137 of the Limitation Act. This will run contrary to the scheme of the patent law and the application for revocation can be filed before Appellate Board any time after the grant of a patent.

The IPAB found that Latanoprost and Bimatoprost were analogs of Dinoprost.  Latanoprost, sold as Xalatan and Bimatoprost as Lumigan, both widely recognized in the treatment for glaucoma. Prior art taught use of Timolo and Latanoprost combination. . The Board categorically held that “We do not agree with the respondent that ‘no comparison was required as Latanoprost is different from Bimatoprost and a comparison of combinations comprising the two would be akin to comparing apples to oranges, as we find both are ‘oranges’ Bimatoprost [akin to seedless orange] better than latanprost [akin to orange with seeds] to lower the IOP.”   The respondents may have been easily led to believe by prior art teachings that Bimatoprost like Latanoprost is capable of producing the same result if not better.  Therfore, the choice of Bimatoprost to replace Latanoprost was obvious use of a material generally available in the market and suitable for purpose. 

With respect to S. 8, yet again, the IPAB pointed out the unpleasant term ‘settled’ used in communication between the Controller and the respondents in respect of settling for submission of prosecution details of any one of the major Patent Offices internationally. The Board sincerely hoped that the practice dies a natural death. The Board held that in this case there was non compliance of S. 8(2) as no information relating to
prosecution of same application in other countries was provided even when the respondent agreed to do so as whenever it became available. “In the present case the ground of the violation of section 8 has been clearly made out and we have no hesitation say applicant succeeds on this ground of revocation”

The patent was revoked. No order was made regarding costs. 

Anubha Sinha

Anubha Sinha - @anubhasinha_ on Twitter — is a graduate of Dr. RML National Law University, Lucknow, and presently works at the Centre for Internet and Society. She also blogs on

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