GlaxoSmithKline plc announced the successful completion of the tender offer by its wholly-owned subsidiary Fountain Acquisition Corporation (FAC) for shares of common stock of Sirtris Pharmaceuticals, Inc.

The depositary for the offer has advised GSK and FAC that stockholders of Sirtris have now tendered a total of approximately 28,931,756 Sirtris shares (including shares tendered through notice of guaranteed delivery), representing approximately 97 per cent of the outstanding common stock of Sirtris. FAC has accepted for payment all Sirtris shares tendered in the offer.

FAC's ownership of the common stock of Sirtris exceeds the 90 per cent required to effect a short-form merger of FAC with and into Sirtris under Delaware law. FAC expects to effect the short-form merger later this week, without the need for a meeting of Sirtris stockholders. In the merger, FAC will acquire all other Sirtris shares (other than those as to which holders properly exercise appraisal rights) at the same $22.50 per share price, without interest and less any required withholding taxes, that was paid in the tender offer. As a result of the merger, Sirtris will become a wholly-owned subsidiary of GSK.

Sirtris Pharmaceuticals, Inc. is a biopharmaceutical company focused on discovering and developing proprietary, orally available, small molecule drugs with the potential to treat diseases associated with ageing, including metabolic diseases such as type II diabetes.