Amprenavir is an oral, non-peptidic
HIV-protease inhibitor undergoing phase III trials for the treatment of HIV and
AIDS. In October 1998, Glaxo Wellcome submitted a new
drug application (NDA) for
amprenavir (
Agenerase) in the US and Canada for which there is an April 1999 review deadline and in November 1998, filed an application for market approval in Europe. This product has been designated for fast-track approval. Merrill Lynch anticipates product launch in mid-1999 and estimates that
Agenerase will reach peak sales of $500M after its launch.
Amprenavir is a small molecule with significant aqueous solubility designed to combine
antiviral potency with good oral bioavailability. The compound is a potent and specific inhibitor of isolated
HIV-1 protease and of HIV-1 replication in T-cells and shows good absorption after oral dosage in man. The plasma half-life of
amprenavir is approximately 10 h, allowing for twice daily dosing. The
drug appears to cross the blood-brain barrier which may be an important feature in long-term treatment.
Amprenavir selects for a unique mutation in the
HIV-1 protease gene in vitro, and shows no or limited cross-resistance to other
protease inhibitors. In January 1999 Paribas predicted Glaxo sales of pound sterling 75 million in 1999 rising to pound sterling 400 million in 2003.