The attraction between Biogen Idec and Isis remains strong; the pair have partnered up yet again, this time under a a broad, multi-year collaboration to advance the treatment of neurological diseases with antisense technology. 

Marking the fourth alliance between the groups in just two years, the move combines Biogen's expertise in neurology with Isis' leadership in antisense technology with the aim of developing novel therapies for such disorders. 

In a partnership spanning six years, Biogen has gained exclusive rights to use Isis' antisense technology - designed to alter a gene's function, silencing a mutation or activating a gene to compensate for an underlying genetic defect - to develop potential neurological therapies.

In return, the group will make an upfront payment of $100 million to Isis, a majority of which will be reflected as R&D expense in Biogen's third quarter financial results.

Isis is also eligible to receive milestone payments, license fees and royalty payments for all treatments developed through the alliance.

Under the terms of the deal, Isis will be primarily responsible for drug discovery and early development of antisense therapies, while Biogen will be responsible for the creation and development of small molecule treatments and biologics.