The US Court of Appeals has overturned a district court's dismissal of Xechem International's 2003 paclitaxel lawsuit against Bristol-Myers Squibb (BMS), enabling Xechem to reinstate its claims against BMS. Generics manufacturer Xechem alleged anticompetitive action by BMS in delaying competition of generic versions of the anticancer drug paclitaxel (marketed by BMS as Taxol). The lawsuit was initially dismissed by the District Court on the grounds that the statute of limitations barred the action. Xechem's antitrust suit against BMS seeks damages of US $150 million.

The Hatch–Waxman amendments to the Food and Drug Act entitle pharmaceutical companies that first bring a drug to market to a five-year period of exclusivity. BMS was first-to-market with paclitaxel, the exclusivity period of which was due to expire in July 1997. Shortly before its exclusivity was to end, BMS listed in the FDA's Orange Book (approved drugs and the patents which protect them) two patents covering the administration of paclitaxel. It sued all manufacturers that filed Abbreviated New Drug Applications (ANDA) for that drug, so the automatic 30-month deferral of generics manufacturing allowed by the amendment took effect. Courts ultimately determined that all the important claims of both patents are invalid. Just before the 30-month deferral was to expire, BMS listed a third patent in the Orange Book. This reset the 30-month clock, which continued to run until 17 January 2002, at which point BMS withdrew this listing after the third patent had also been declared invalid.

Xechem makes and sells paclitaxel all over the world, but not in the United States. The company began the antitrust suit in 2003, claiming that the activities described above excluded rivals and exposed consumers to elevated prices. The district court dismissed the complaint because Xechem did not file an ANDA in 1997, and also the four years allowed by the statute began in 1997 and therefore expired before Xechem's litigation started. The Appeals Court, however, explained that although it might be too late to complain in 2003 about what BMS did in 1997, it is not too late to complain about what they did in 2000 or 2002. Each discrete act with fresh adverse consequences starts its own period of limitations.