GSK extends tender offer for all outstanding shares of Human Genome Sciences

GlaxoSmithKline plc (LSE: GSK) today announced it has extended its tender offer to acquire all of the outstanding shares of Human Genome Sciences (NASDAQ: HGSI) for US$13.00 per share in cash to 5:00 pm New York City time on Friday 29 June 2012. The tender offer was previously scheduled to expire at 12:00 midnight New York City time, at the end of the day on 7 June 2012.

GSK’s offer represents a premium of 81 percent to HGS’s closing share price of US$7.17 on 18 April 2012, the last trading day before HGS publicly disclosed GSK’s private offer. GSK continues to believe its offer represents full and fair value and is in the best interests of both companies’ shareholders. It is well aligned to GSK’s long-term strategy of delivering sustainable growth, simplifying GSK’s business model, enhancing R&D returns, and deploying capital with discipline. For HGS shareholders, it provides immediate liquidity at a substantial premium while eliminating further exposure to the significant execution risk inherent in HGS achieving its future growth objectives. GSK’s offer reflects the value of Benlysta, darapladib, albiglutide, HGS’s operating and financial assets, and expected cost synergies of at least US$200 million.

GSK continues to believe that now is the appropriate time in the evolution of the GSK/HGS relationship for the companies to combine and that GSK is uniquely positioned to deliver on the opportunity of the combination.

The closing of the tender offer is subject to the terms and conditions detailed in the amended tender offer documents as filed on Schedule TO with the U.S. Securities and Exchange Commission on 10 May 2012 and 23 May 2012. Except for the extension of the tender offer expiration date, all other terms and conditions of the offer remain unchanged. As of 12:00 midnight New York City time at the end of the day on 7 June 2012, approximately 474,029 shares (including 24,856 shares subject to guarantees of delivery) had been tendered and not withdrawn, pursuant to the offer.

Lazard and Morgan Stanley are acting as financial advisors to GSK and Cleary Gottlieb Steen & Hamilton and Wachtell, Lipton, Rosen & Katz are providing legal advice.