Takeda has become the latest major drugmaker to explore the potential of RNA interference by signing a deal with Alnylam Pharma of the USA that could be worth over $1 billion.

The agreement will see the Japanese firm pay $100 million upfront and $50 million in near-term technology transfer payments covering non-exclusive licences in two RNAi treatment fields, oncology and metabolic diseases. Takeda may opt to expand their partnership to include additional therapeutic areas, for $50 million each.

In return, Alnylam is also eligible to receive R&D funding and may get up to $171 million in development and commercial milestone payments and royalties for each product. The whole five-year deal could add up to more than $1 billion and sees Takeda becomes the only Asian company to receive right of first refusal to develop and market Alnylam RNAi therapies for the Asian market.

In addition, Alnylam receives the option to co-develop and co-market Takeda RNAi drug programmes in the US market on a 50-50 basis. However the firms noted that the alliance excludes ALN-RSV01, Alnylam’s most advanced programme which is in Phase II trials for the treatment of respiratory syncytial virus infection.

The deal is more good news for Alynam which was founded in 2002 and has its headquarters in Cambridge, Massachusetts. Less than a year ago it signed a collaboration with Roche which could also be worth over $1 billion to develop RNAi therapeutics covering oncology, as well as respiratory, metabolic and liver diseases. It also has deals in place with Novartis, Biogen Idec and Medtronic.

The deal is the latest example of Takeda’s determination to reduce its reliance in the future on the multibillion-dollar diabetes drug Actos (pioglitazone) which faces patent expiries in 2011. It also highlights its desire to become a major player in oncology and comes just as the Tokyo-based firm completed its $8.8 billion acquisition of Millennium Pharmaceuticals, giving it access to the multiple myeloma drug Velcade (bortezomib).

RNAi is considered to be one of the hottest new areas of drug research and resulted in the 2006 Nobel Prize in medicine for the two discoverers of the technology, Andrew Fire and Craig Mello. It is a naturally-occurring mechanism within cells and potentially forms the basis for a new class of drugs that can selectively silence the inappropriate activity of specific genes within the cell.