SuperGen of the USA has announced plans to merge with the UK's Astex Therapeutics in a deal they say will create "a financially strong international oncology company".

Under the terms of the agreement, SuperGen will purchase Astex for $25 million in cash, plus stock representing 35% of the total post-closing float. The California-headquartered company will also pay an additional $30 million to the privately-held, Cambridge-based firm's backers, in either shares or cash, over a 30-month period.

The combined entity, to be named Astex Pharmaceuticals, will have $120 million in cash and equivalents and says it plans to leverage a revenue stream from SuperGen's Dacogen (decitabine) for myelodysplastic syndrome. The drug is marketed in North America by Eisai and in the rest of the world by Johnson & Johnson.

The combined company’s clinical pipeline will include seven drugs, four of which are currently in or entering into Phase II and three which are currently partnered with big pharma; these include GlaxoSmithKline, Novartis and AstraZeneca, as well as Eisai and J&J.

The new Astex says its partnered pipeline is potentially worth $2 billion in potential future milestone revenues, plus royalties. It will be headed by SuperGen chief executive James Manuso, who said "the outstanding pipeline and highly regarded drug discovery platform of Astex, coupled with the product candidates, development expertise and capital resources of SuperGen, are expected to give rise to a powerful new entity capable of delivering valuable cancer therapies".

The merger is expected to be completed in July.