GlaxoSmithKline will not participate in Human Genome Sciences’ strategic alternatives review process and will instead commence a tender offer this week to acquire all outstanding shares of HGS for $13.00 per share in cash.

GSK’s offer represents a premium of 81% to HGS’s closing share price of $7.17 on April 18, the last trading day before HGS publicly disclosed GSK’s private offer.

GSK says it believes 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 promises of Benlysta, albiglutide and darapladib. GSK says it values the long relationship it has with HGS and prefers a friendly transaction in a timely fashion. GSK remains willing to meet and review its offer with HGS at any time.

GSK’s decision not to participate in HGS’s strategic alternatives review process and to take its offer directly to HGS shareholders reflects a number of factors, including:

• GSK’s participation in the process is unnecessary as its offer is not conditioned on due diligence or financing and can be completed expeditiously

• It is important for HGS shareholders to understand that GSK is committed to proceeding with its offer

• There is clear strategic and financial logic to this combination and HGS shareholders should have the opportunity to decide for themselves on the merits of the offer

• GSK believes that the four weeks that have passed since its offer made on April 11, together with the additional 20 business days that GSK’s tender offer must remain open following its commencement, provides a reasonable amount of time for HGS to complete its review of alternatives

GSK continues to believe it has made a full and fair offer which is in the interest of shareholders of both companies. The transaction is aligned with 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, according to GSK.