GlaxoSmithKline’s Patent on Retrovir Expires; Generic Versions of AZT Expected To Be Available Soon

The patent on azidothymidine, or AZT -- the main ingredient in GlaxoSmithKline's antiretroviral drug Retrovir -- expired on Saturday, paving the way for lower-cost generic versions to be made available for millions of HIV-positive people in developing countries and thousands in the U.S., the Raleigh News & Observer reports (Vollmer [1], Raleigh News & Observer, 9/18). In the U.S., AZT currently is available only as Retrovir; however, drug companies in China, India and some African countries in July began preparing to make generic AZT. Generic versions could cost about $105 for an annual supply, roughly 20% less than the least expensive AZT currently available worldwide (Vollmer [2], Raleigh News & Observer, 9/18). When FDA first approved Retrovir in 1987, it cost up to $10,000 per person annually, but by 1989 the price was lowered to about $2,200 for an annual supply (Raleigh News & Observer [1], 9/18). GSK does not expect its revenue to be affected by the patent expiration because it will not affect the price of Combivir and Trizivir, its newest drugs containing AZT, which in 2004 brought in combined sales of $1.6 billion (Raleigh News & Observer [2], 9/18).