3i, Europe’s leading venture capital and private equity company will sell its stake in Domantis, a world-leader in the development of next generation antibody therapies, in an all cash deal valuing the company at £230m ($454m).

This landmark deal is a significant success for 3i, which is generating an IRR in excess of 100% on its investment.

Cambridge-based Domantis was founded in 2000 by Dr Ian Tomlinson and Sir Gregory Winter to develop therapies based on the smallest functional binding units of human antibodies, called domain antibodies (dAbs) which due to their small size can be administered in inhaled, topical or oral formulations as well as by injection. The technology pioneered at Domantis also enables dAbs to serve as building blocks for therapeutics simultaneously directed at several disease targets including rheumatoid arthritis, asthma, chronic obstructive pulmonary disease, and multiple myeloma.

3i first backed Domantis in 2004, leading the £17.5m Series B round. Since then, 3i has worked closely with the CEO, Bob Connelly, and his management team to grow the company and realise the promise of the dAb platform. The further £17m raised in a 3i-led round in December 2005 also helped secure the financial base from which the company could expand it activities.

Nigel Pitchford, Partner, 3i Venture Capital, commented “Having enjoyed success as an early investor in Cambridge Antibody Technologies (CAT), we were attracted to Domantis for its pioneering approach to developing the next generation of antibody therapeutics, based on a particularly strong IP and technology platform. Domantis’ shared heritage with CAT, with both coming from Sir Gregory’s labs in Cambridge, was another significant draw. We have enjoyed an active partnership with Bob Connelly and his team and believe Domantis, under GSK, is set for a very strong future.”

Following the acquisition, Domantis will become part of GSK’s Biopharmaceuticals Centre of Excellence for Drug Discovery (CEDD) whilst continuing to operate from laboratories in Cambridge, UK.

Robert Connelly, Domantis’ founding Chief Executive Officer, said “The agreement with GSK allows us to embed our R&D organization intact within a company committed to fully exploiting every potential therapeutic application of dAbs. I am delighted that GSK has made this major investment in our people, our technology and our product pipeline and that our existing shareholders have been appropriately rewarded.”

3i was advised by Morrison Foerster. Domantis’ legal advisers were Wilmer Hale.