Press Release

Cambridge, MA, March 25, 2004 -- GlaxoSmithKline (GSK) and Vertex Pharmaceuticals Incorporated (Nasdaq: VRTX) announced today that they have received a positive opinion from the European Committee for Proprietary Medicinal Products (CPMP) for Telzir(R) (fosamprenavir) for the treatment of HIV infection in adults in combination with other antiretroviral medications.

Telzir, when combined with low-dose ritonavir and other antiretroviral agents, has demonstrated its ability to reduce the concentrations of HIV in plasma in both antiretroviral therapy naive and experienced patients. For antiretroviral naive and experienced patients, the recommended dose is one 700mg tablet of Telzir twice daily and one 100mg capsule of ritonavir twice daily with other antiretroviral medicinal products. The low number of tablets and the fact that Telzir with low-dose ritonavir may be taken with or without food may help HIV-infected patients' long-term adherence to therapy and improve overall outcome.

Telzir was co-discovered by GlaxoSmithKline and Vertex Pharmaceuticals and is currently marketed in the United States under the brand name Lexiva(TM).

GlaxoSmithKline is one of the world's leading research-based pharmaceutical and healthcare companies and an industry leader in HIV research and therapies. The company is engaged in basic research programs designed to investigate new targets to treat HIV.

About Vertex
Vertex Pharmaceuticals Incorporated is a global biotechnology company committed to the discovery and development of breakthrough small molecule drugs for serious diseases. The Company's strategy is to commercialize its products both independently and in collaboration with major pharmaceutical partners. Vertex's product pipeline is principally focused on viral diseases, inflammation, autoimmune diseases and cancer. Vertex co-promotes the new HIV protease inhibitor Lexiva(TM) with GlaxoSmithKline.

Vertex Safe Harbor Statement
This press release may contain forward-looking statements. While management makes its best efforts to be accurate in making forward-looking statements, such statements are subject to risks and uncertainties that could cause Vertex's actual results to vary materially. These risks and uncertainties include those risks listed under Risk Factors in Vertex's form 10-K filed with the Securities and Exchange Commission on March 15, 2004.

Vertex Contacts:
Michael Partridge, Director, Corporate Communications, (617) 444-6108
Lora Pike, Manager, Investor Relations, (617) 444-6755

GlaxoSmithKline Contacts:
Martin Sutton, 011-44-208-047-5502 (Media)
Duncan Learmouth, 011-44-208-047-5540 (Investors)