TMI: Your Formulation Is Showing

A recent citizen petition provides a cautionary tale for those who might be tempted to include confidential information in a notice letter. On November 2, 2026, AstraZeneca submitted a citizen petition asking the FDA not to approve Cipla’s ANDA for a generic olaparib product referencing Lynparza.¹ AstraZeneca appended two of Cipla’s Paragraph IV (“PIV”) notice letters as exhibits to its petition, which were then publicly posted on the Regulations.gov docket. The letters, marked “Highly Confidential,” disclose certain details about Cipla’s (allegedly noninfringing) formulation. 

Pharmaceutical companies generally treat their formulations as closely guarded confidential information, the disclosure of which may invite serious consequences. ² But content of a PIV notice letter is not necessarily protected from public disclosure. ³ ANDA filers are required under 21 U.S.C. § 355(j)(2)(B)(iv)(II) to articulate “the factual and legal basis” of their invalidity or noninfringement