On May 21, 2007, WLF wrote to DDMAC, calling on DDMAC to withdraw untitled letters sent on May 7 to Schering Corp. and GlaxoSmithKline, regarding their allegedly improper promotion of Nasonex and Flonase. DDMAC alleged that professional detail aids for those drugs were false and misleading because they made unsubstantiated superiority claims as well as claims that the products are more effective than FDA believes has been demonstrated. WLF responded that both DDMAC letters were inappropriate, because they characterized promotional materials as misleading without a sufficient empirical basis and faulted references to legitimate studies. Nasonex and Flonase are drug approved by FDA for treating allergies. WLF letter to DDMAC charged that DDMAC violates the First Amendment where, as here, it seeks to prohibit a manufacturer from saying anything about the results of comparison studies without first considering whether any tendency to mislead could be avoided by affixing disclaimers.