Recombinant blood factors with improved therapeutic properties will be researched and developed under a new partnership between Biogen Idec (Nasdaq: BIIB) and California biotechnology company Amunix.

The partnership combines Mountain View, California-based Amunix's expertise in protein pharmaceuticals with Biogen Idec's capabilities working with recombinant blood factors for hemophilia. Biogen Idec, headquartered in Weston, Massachusetts, maintains major biologics R&D and manufacturing operations in Research Triangle Park, North Carolina.

The exclusive, worldwide research collaboration agreement calls for both companies to jointly conduct preclinical research. Biogen Idec will also be responsible for clinical development, manufacturing and commercialization of therapeutic candidates selected for further development.

The deal calls for Amunix to receive an initial upfront payment in addition to R&D funding. Future milestone and royalty payments are also possible if Biogen Idec selects therapeutic candidates from the partnership for further development. The companies declined to disclose any additional details about the financial terms of the agreement. Increasingly, such deals between large pharma companies and small biotechs offer the biotechs small upfront payments with the payoff coming in royalties if a commercialized product results from the partnership.

Privately held Amunix focuses on the discovery and development of novel therapeutics with improved dosing frequency and administration. The company's patented platform technology, XTEN, extends the half-life of protein, which results in therapies that require less frequent injection. Amunix has licensing agreements with other partners for its lead candidates. Versartis is in early stage clinical trials on product candidate VRS-317 for growth hormone deficiency; Diartis Pharmaceuticals is in phase 1 trials for VRS-859, which targets type 2 diabetes mellitus.