The investment is a sign of growth within Amgen's product pipeline particularly in areas such as cancer, bone health and inflammation. Amgen, the world's biggest biotech company by market capitalisation ($94.7 billion(€78.6 billion)), recently announced an increase in R&D spending by as much as 40 per cent for 2006.
Dr Jeremy Haigh, Amgen's European Head of R&D, told DrugResearcher.com: "One of the key focuses co-ordinated from the UK will be denosumab, which is currently being studied for its potential in a broad range of conditions associated with high bone turnover, including osteoporosis."
"Another promising product is panitumumab which has shown to improve progression free survival in phase 3 trials for colorectal cancer."
Amgen's recent delay in disclosing the latest data on this colon-cancer treatment, disappointed many analysts and investors, who were eager to see how Amgen would fit into a market crowded with competition from Genentech, Avastin and ImClone Systems.
Amgen are pinning its hope on panitumumab as its next blockbuster opportunity - a factor made more critical by the competition its other best seller Epogen faces from follow-on biologics, the biotech industry's equivalent of generic drugs.
Follow-on versions of Epogen, an anaemic treatment could start appearing in Europe later this year.
Meanwhile, Denosumab, an upcoming treatment for osteoporosis is not expected to hit the market for a few years yet. However, Amgen is already building momentum against Merck' Fosamax - its nearest rival.
Because of harsh side effects, 70 per cent of patients who start taking Fosamax drop it within a year. As demonstrated by early clinical data, denosumab could be much easier to tolerate.
Amgen expects to launch 54 new clinical trials of drugs in its pipeline, an impressive figure that could well explain the need to expand its R&D facilities.
Amgen's choice reinforces an emerging trend within the biotechnology community that has seen a clutch of companies set up operations with the British Isles.
Commenting on why the UK has been chosen for such a critical role, Amgen highlighted access to talent and good communications as key drivers:
"Uxbridge is located in the heart of the biopharmaceutical community to the West of London and has excellent links with California where our headquarters are based," the company said.
"Cambridge has a longstanding commitment to science and remains one of Europe's most important biotechnology clusters. Amgen has had a presence in Cambridge for 15 years where we have recruited more than 100 people here in the last 12 months alone."
The new site in Uxbridge, London has room to accommodate 300 additional staff forming a key part of a global R&D expansion for Amgen, effectively doubling current UK-based R&D capacity.
Over £100 million will be invested into Amgen's UK R&D operations with Amgen planning to add to the existing facilities in Cambridge by taking on a third building at the Cambridge Science Park.
Amgen has also announced plans to further strengthen its presence in Europe by locating a production plant in Cork, Ireland, and making Zug, Switzerland, the headquarters for all commercial operations outside the United States, Canada and Japan.
Cork has remained popular with biotechnology companies due to its thriving biotechnology community, infrastructure to support biologics manufacturing and attractive business climate.
By 2010, Amgen expects to employ more than 1,100 people at the new Irish manufacturing facility.