On April 8, 2005, the U.S. Court of Appeals for the Federal Circuit overturned one of its own decisions that had invalidated a significant pharmaceutical patent based on nothing more than a minor technicality. The latest ruling eliminates a worrisome patent law doctrine; WLF had been sufficiently concerned that it had filed a brief in the case, urging reversal. WLF’s brief warned that the initial decision would undermine confidence in the nation’s patent system as an effective means of protecting intellectual property rights. The initial decision had invalidated the patent because the drug company had begun a clinical trial of its drug’s effectiveness slightly more than a year before filing its patent application; the court held that that trial amounted to a “public use” of the drug — even though it was never offered for sale to anyone until seven years after the patent was applied for.