On February 1, 2006, the U.S. Court of Appeals for the Federal Circuit reversed its earlier decision to invalidate a multi-billion dollar pharmaceutical patent, and remanded the case to the district court to consider the invalidity issue anew. The decision was a major victory for the Washington Legal Foundation (WLF), which filed a brief in the case last summer, urging the three-judge appeals court panel to reverse its prior decision. Particularly gratifying to WLF was that the panel reversed itself based on the precise arguments raised by WLF in its brief. The case now returns to the U.S. District Court for the Southern District of New York for reconsideration of the patent invalidity issue. Based on guidance provided by the appeals court regarding how the issue should be resolved, WLF attorneys said that it was likely that the district court will ultimately uphold the patent, which covers OxyContin, a powerful pain relief medication.