Elan Corp has moved swiftly to cure “an unintended breach" in the company's existing partnership with Biogen Idec over Tysabri and revised its proposed link-up with Johnson & Johnson which will see the firm receive $115 million less from the US healthcare giant than was originally agreed.

In July, the Irish company announced plans to sell an 18.4% stake and the rights to its portfolio of Alzheimer’s disease investigational drugs to J&J in return for $1 billion. However that agreement also gave the latter an option to acquire the 50% stake held in Tysabri (natalizumab) by Biogen if control of that company changes hands.

Biogen sued, saying that represented a material breach of the Tysabri deal and earlier this month a US judge agreed with the US biotechnology major. In order not to forfeit its own rights to the MS blockbuster and complete the deal with J&J, Elan was therefore forced to revise its pact with the latter.

Under the revised terms of the transaction, J&J will now invest $885 million in Elan, rather than the original $1 billion agreed, in exchange for the same 18.4% stake. Elan noted that J&J will still commit up to $500 million to acquire “substantially all“ of the Dublin-headquartered group’s Alzheimer's Immunotherapy Programme (of which Elan still holds 49.9%), including bapineuzumab.

The companies hope to finalise the transaction "as promptly as possible," Elan added. The news went down well with analysts and Ian Hunter at Irish broker Goodbody said that “investors will receive comfort from the fact that there will be no further dilution in Elan's stake of the API programme and no loss of Tysabri rights”.