GlaxoSmithKline plc is requesting the U.S. Food and Drug Administration (FDA) to remove three patents related to the antidepressant Paxil (paroxetine hydrochloride) from the register of pharmaceutical patents maintained by the FDA and known as the "Orange Book".

The action follows the FDA's release on 12 June of new regulations concerning, among other matters, the listing of patents in the Orange Book. Although the new regulations do not specifically apply to patents already listed, FDA did provide new criteria for listing certain types of patents in the future. GSK is voluntarily seeking the delisting of three product-by-process patents -- U.S. Patent No. 6,172,233 ("the '233 patent"); U.S. Patent No. 6,080,759 and U.S. Patent No. 6,063,927 -- to proactively align with the new criteria.

GSK's delisting does not affect the validity of these patents. The company continues to pursue patent infringement claims in litigation in Philadelphia against Apotex Corp. and other generic companies under these and other patents. No trial date has been set in the Philadelphia litigation.

Delisting the '233 patent from the Orange Book removes the related Hatch-Waxman Act stay on final FDA approval of Apotex's abbreviated new drug application (ANDA) for paroxetine hydrochloride, although the litigation against Apotex continues. The Apotex stay was set to expire on 19 September 2003.

Timing of the launch of generic Paxil remains unclear; consequently GSK's published business performance earnings per share guidance for 2003 remains as previously stated.