Gilead Sciences has signed an antibodies pact with MacroGenics which could be worth over $1 billion to the latter.

Gilead has secured a licence to get access to MacroGenics' Dual-Affinity Re-Targeting (DART) technology to be directed at up to four undisclosed targets. DART is a bi-specific antibody platform in which a single recombinant molecule is able to target two different antigens.

Cashwise, MacroGenics is getting up to $30 million in license fees and $85 million in pre-clinical milestones. Gilead will fully fund the firm's research activities and MacroGenics could also receive up to $1 billion in clinical, regulatory and commercialisation payments "if all four programmes achieve the requisite milestones". Gilead will also pay out tiered (up to low double-digit) royalties on future sales.

Roy Baynes, head of oncology and inflammation therapeutics at Gilead, said that "we look forward to building a long-term collaboration with MacroGenics, a leader in the development of bi-specific antibodies, which represents a promising new area of research".

The Rockville, Maryland-headquartered, privately-held biotech already has three major collaborations in place surrounding the DART platform, signed in the past two years. They are with Pfizer, Boehringer Ingelheim and Servier.

Gilead lines up hep C filings

Meantime, Gilead  has given an update on its hepatitis C development programme at the JPMorgan Healthcare Conference in San Francisco, specifically concerning the once-daily nucleotide analogue polymerase inhibitor sofosbuvir and the firm's NS5A inhibitor GS-5885.

Head of R&D Norbert Bischofberger noted that since the acquisition of Pharmasset only a year ago, Gilead has fully enrolled four Phase III studies of sofosbuvir and during the first quarter of this year will have initiated two Phase II trials of the a sofosbuvir/GS-5885 fixed-dose combination. He added that "we are on track to submit the initial regulatory filing for sofosbuvir by mid-2013" and to file for approval of the combo in 2014.