In this case, a federal district court certified a class of consumers and health insurance plans that claimed that they were victims of an antitrust conspiracy by the makers of the prescription drug Asacol to exclude generic competitors from the market. A panel of the U.S. Court of Appeals for the First Circuit reversed, holding that the class could not be certified because a small minority of class members (estimated to be about 10%) would have willingly paid a higher price to the name-brand drug even if identical, lower-cost generic versions were available. The court held that the plaintiffs were required to propose a manageable mechanism for excluding these uninjured members from the class before trial, and that the use of affidavits to establish injury in a claims process following determinations of liability and aggregate damages was not an acceptable method of weeding out uninjured members. The plaintiffs filed a petition for rehearing en banc, and Public Citizen filed an amicus brief supporting the petition. The brief argues that the panel’s decision conflicts with a prior First Circuit decision, In re Nexium, as well as a U.S. Supreme Court decision, Tyson Foods v. Bouaphakeo; that it will cause confusion and uncertainty for lower courts and litigants, and that it threatens to prevent certification of classes in a wide range of cases where small numbers of class members have not suffered compensable damages. The court denied rehearing in January 2019.