IN212199 revoked under S.25 (2)

In a decision dated December 15, 2010, the Indian Patent Office revoked the Patent Number IN212199 issued to Novartis claiming single-pill combination of aliskiren and valsartan, marketed as Valturna. The Assistant Controller, B. Ahilan, revoked the patent after Novartis failed to defend the patent in a post-grant opposition filed by Sun Pharmaceuticals Ltd. The patent was issued on November 26, 2007 against the Application Number 724/CHENP/2003.

Aliskiren is the first in the class of orally effective direct renin inhibitors approved for the treatment of primary hypertension and marketed by Novartis under the brand name Tektuma. In contrast to conventional RAS blockers (ACE inhibitor and ARB), aliskiren blocks renin system by directly inhibiting plasma renin activity and preventing the formation of both angiotensin I and angiotensin II. Since aliskiren promising clinical results, Novartis began clinical studies on aliskiren combination with other hypertensive agents that included ACE inhibitors (enalapril, amlodipine and ramipril) and ARBs (valsartan and losartan) and HCTZ. The aliskiren-valsartan combination study yielded greater blood pressure reductions than either monotherapy or placebo, upon which the patent at issue is based.

Sun Pharmaceuticals filed the post-grant opposition appealing revocation of the patent under S.25 (2), particularly on the grounds of lack of inventive step, insufficient disclosure/lack of best method, not an invention and non-patentable under the Act.

During the post-grant opposition, Novartis proposed to amend the claims having narrowed scope than the issued claims which the Controller agreed and instructed that arguments will be made on the proposed claims. Sun argued that the specification disclosure lack enablement and best method requirements because none of examples exemplified the compositions of amended claims. Sun further argued that use of generic name ‘aliskiren’ in amended claim is not supported by the description. The Controller agreed with Sun’s arguments that amended claims lack enablement and best method requirements under S.10 (4) (a) and (b), also agreed that despite the compound represent by formula I of amended claim is aliskiren but use of generic name ‘aliskiren’ is not explicitly mentioned in the specification disclosure. He therefore concluded that the specification lack sufficiency of disclosure and best method requirements.

Sun further argued that amended claims are obvious because prior art documents described aliskiren a highly specific and potent for human renin (referred as D5) and also provided synergetic compositions comprising at least two therapeutic agents selected from the group consisting of a renin inhibitor, an ACE inhibitor and an angiotensin II antagonist (referred as D2). Responding to Sun’s obviousness arguments, Novartis tried to distinguish amended claims over the prior art documents and argued that renin inhibitor described in D2 is terlakiren and not relevant to amended claims. Considering D2 (combination of renin inhibitor with ACE inhibitor or AT1 antagonist) and D5 (aliskiren a highly potent renin inhibitor), the Controller held that the amended claims was obvious to try and lack inventive step.

Sun also argued that amended claims are not patentable under S.3 (d) because enhanced efficacy is not demonstrated over the prior art document D2. Agreeing with Sun’s arguments, the Controller concluded that amended claims are not patentable under S.3 (d).