Sanofi-Aventis says that it has re-acquired the Japanese rights to its top-selling super-aspirin, Plavix (clopidogrel) from partner, Daiichi Pharmaceutical.

No-one from the firm was available for comment at the time of going to press, so it is not know what the rationale behind the move is, or what the cost implications will be. However, Daiichi, which is in the process of being bought by fellow Japanese company Sankyo in an $8 billion dollar deal [[25/02/05a]], already has a strong foothold in the market for anti-clotting drugs. It currently sells Panaldine (ticlopidine) – one of the widely used clot-busters on the market – and Sankyo and partner Eli Lilly are is currently conducting Phase III trials of their own such offering, prasugrel [[26/10/04i]].

Both Sanofi-Aventis and Daiichi have agreed to collaborate in the future in the areas of manufacturing and co-promotion to ensure the success of Plavix in Japan, where it is currently under regulatory review.

The Japanese drug market could be an important one for Plavix if Sanofi-Aventis proves unsuccessful in its bid to defend the drug’s patent in the all-important US market, where it is facing challenges from Canadian company, Apotex, and India’s Dr Reddy’s Laboratories [[10/05/05d]].