US biotechnology firm Biogen Idec bolstered its position in oncology by acquiring cancer specialist Conforma Therapeutics in a transaction valued at up to $250 million.

Biogen Idec has a stated ambition to invest hard cash to grow its pipeline and plug a gap caused by last year’s suspension from sale of multiple sclerosis drug Tysabri (natalizumab), as well as slowing growth for its flagship MS drug Avonex (interferon beta-1a), which forced it into a major restructuring involving significant staff cuts. Last August, the firm earmarked up to $660 million to license rights to several antibody drugs from Protein Design Labs, including two in Phase II trials.

Conforma has a portfolio of cancer drugs in preclinical and Phase I testing, so the acquisition is aimed more at boosting its medium- to long-term cancer portfolio, currently headed by Rituxan (rituximab) for non-Hodgkin’s lymphoma. Biogen Idec also sells a radiopharmaceutical drug, Zevalin (ibritumomab tiuxetan), and has a number of cancer drugs in development.

Founded in 1999, Conforma researches drugs that inhibit a type of protein molecule – heat shock protein 90 - that is thought to support the growth of cancer cells in a range of solid tumours and haematological cancers. Two drugs – CNF1010 and CNF2024 - have started clinical trials.

Biogen Idec will pay $150 million for all Conforma's outstanding shares, plus up to an additional $100 million based on certain milestones.

The deal does not include rights to Amrubicin, a synthetic compound that is already sold in Japan by Sumitomo to treat lung cancer and is in Phase II clinical trials in the USA. This drug will be retained by Conforma investors who plan to launch a company to develop it outside Japan.