In the news ... 2006 archive

GSK Puts the Brakes on Brecanavir

December 18, 2006

Citing “insurmountable issues regarding formulation”, pharmaceutical giant GlaxoSmithKline (GSK) has announced it is stopping the development of its experimental protease inhibitor, brecanavir.

This is the third drug in a row that GSK has stopped during the clinical development process. In 2005 they halted the CCR5 antagonist, aplaviroc, due to liver toxicity. This followed stopping their work on an integrase inhibitor that they were developing alongside the Japanese company Shionogi.

Although the unsuccessful development of a new HIV drug is generally discouraging, some activists—including Project Inform—have openly questioned the need for yet another Norvir-boosted protease inhibitor. Currently, eight are in wide use. Norvir boosting, while effective at increasing the amount of certain HIV drugs circulating in the blood, brings some significant problems of its own, including unwanted drug interactions and side effects. (Read this article for more information on Norvir boosting.)

GSK hasn’t successfully developed a new drug to treat HIV since Agenerase (amprenavir) in 1999 and has slipped from its long-held position as the number one seller of HIV drugs in the US. GSK has successfully introduced several new products to treat HIV during this time, including fixed dose combinations like Epzicom and Combivir and a new formulation of amprenavir called Lexiva (fosamprenavir).

GSK has an active HIV drug development program, including a second integrase inhibitor called GSK364735—also co-developed with Shionogi. The discontinuation of brecanavir will likely shift GSK’s focus to this integrase inhibitor, which is currently in Phase I safely studies.