Hyderabad-based Matrix Laboratories Ltd has been sued by the Tokyo-based Daiichi Sankyo in a patent infringement case. This was confirmed by the Nasdaq-listed Mylan Inc, which has a majority stake in Matrix. The company has been sued by Daiichi Sankyo in connection with Amlodipine Besylate/Olmesartan Medoxomil tablets in the capacities of 5 mg/20 mg, 10 mg/20 mg, 5 mg/40 mg, and 10 mg/40 mg, for its generic version of Daiichi Sankyo’s Azor tablets. These tablets are anti-hypertensive in nature and used in the treatment of angina.
Daiichi Sankyo filed a lawsuit on Tuesday in the US district court for the district of New Jersey, alleging infringement of the sole patent relating to Azor, which is listed in the “Orange Book” as US patent No 5,616,599. When contacted, the company officials were not available for comments. Mylan believes that Matrix is the first company to file a substantially complete Abbreviated New Drug Application (ANDA) containing a paragraph IV certification for the product. Matrix filed an ANDA with the US Food and Drug Administration in early 2008.
According to analysts, if Daichii Sankyo wins because of its first-to-file case, it will have a shared 180-exclusivity for marketing this product. As per estimates, Amlodipine tablets have a market size of around $2 billion. The product is currently the largest molecule, which has gone off-patent in Japan and represents the biggest generic opportunity so far in the Japanese generic market.