The litigation before the Delhi High Court can be traced to a commercial agreement between ‘Astellas’ and Mylan SAS for the supply of amoxicillin fast disintegrating tablets along with the sale of the requisite registration data in order for Mylan to be granted, regulatory approval for marketing the drug in France. This commercial arrangement which continued for at least a decade gradually lapsed and Mylan eventually entered into a commercial agreement with Micro-Labs for the supply of the same tablets which were previously being sourced from Astellas. Once Astellas learnt that they had been dumped by Mylan for Micro-Labs, they sued Mylan for patent infringement in France on the grounds that the tablets in question were covered by the claims of a European Patent bearing number 0910344. Mylan counter-sued by initiating legal proceedings for the revocation of the European Patent on grounds of invalidity etc. After several legal threats to Micro-Labs, Astellas filed the present patent infringement suit against Micro-Labs in May of 2011 for violation of the corresponding Indian patent granted by the Chennai Patent Office. However this suit before the Delhi High Court had been pre-empted by both Mylan and Micro-Labs filing separate revocation petitions against Astella’s Indian Patent before the IPAB on the ground of obviousness etc.
B. Indian Patent No: 234753
Astellas has filed the present infringement suit against Micro-Labs on the grounds that its Indian patent number 234753 was infringed. Claim no. 1 of the patent reads as follows:
1. A granulate for the preparation of fast-disintegrating and fast-dissolving compositions, containing an active ingredient, having a solubility in water of 1:>10, in admixture with a water dispersible cellulose, which is a microcrystalline cellulose and sodium carboxymethyl cellulose, characterized in that the water dispersible cellulose is present in an amount of < 15 wt%, the percentage based on the weight of the active ingredient. The remaining 9 claims are dependant claims.
The patent specification explains in the following manner, the problem sought to be solved by the present invention lay in providing a “composition or manufacturing method, which would be generally applicable to all kinds of active ingredients having a solubility in water of less than 10%, in order to obtain fast-disintegrating and fast dissolving compositions, containing a high amount of the active ingredient, while using conventional production equipment”.
The patent specification also explains that the prior art in the field has always contained a lower percentage of active ingredient than the claimed invention which has managed to maintain a higher percentage of active ingredient with the same rate of dissolution thereby not only increasing the bioavailability of the drug but also vastly improving the efficiency of the entire manufacturing process.
C. The defence put up by Micro-Labs in the Delhi law-suit
Since Micro-Labs had already received legal notices from Astellas regarding the alleged infringement, they had filed caveats in all relevant courts and were present in the Delhi High Court on the day Astellas suit came up for the first hearing. Micro-Labs has claimed the following defences in the infringement suit:
(a) Indian patent no. 234753 is anticipated by US Patent No: 5,455,049;
(b) Indian patent no. 234753 lacks inventive step in light of US Patent Nos: 3,539,365; 4,231,802 & 4,199,368 and WO 93/12768;
(c) Indian patent no. 234753 does not sufficiently and fairly describe the invention and the method by which it is to be performed;
(d) Indian patent no. 234753 was obtained on a false suggestion or representation.
(e) That the subject matter of the impugned patent is not patentable under Section 3(d) because it is a combination of known ingredients;
(f) That the claimed composition is not patentable within the meaning of Section 3(e);
(g) That the subject matter of the impugned patent lacks utility;
(h) That the Delhi High Court lacks jurisdiction to hear the matter because the principal office of Micro-Labs is located in Bangalore and not within the jurisdiction of the Delhi High Court.