Notifiable share interest in Theravance, Inc.

Notifiable Share Interest in Theravance, Inc.

GlaxoSmithKline plc ("GSK") announces that on 18 February 2011 GSK purchased 152,278 shares of Common Stock of Theravance, Inc. ("Theravance") at a price of $23.70 per share, for a total investment of $3,608,988.60. These shares were purchased from Theravance pursuant to GSK's right to acquire, on a quarterly basis, sufficient shares of common stock to maintain its ownership percentage in Theravance, taking into account the preceding quarter's net option exercise and equity vesting activity.

GSK's interest in Theravance now comprises 5,902,278 shares of Common Stock and 9,401,499 shares of Class A Common Stock, which together represent approximately 19.01% of Theravance's outstanding capital stock. The calculation is based on a total of 80,503,825 shares of Common Stock outstanding in Theravance. This purchase is disclosable and will be reported under the rules of the Securities and Exchange Commission.

Victoria Whyte

Company Secretary

21 February 2011