Shares of ImmunityBio Inc. (NASDAQ:IBRX) tumbled 15% on Tuesday following the arrival of a warning letter from the U.S. Food and Drug Administration concerning promotional content for the company’s bladder cancer therapy ANKTIVA.
In its review, the FDA’s Office of Prescription Drug Promotion determined that a television advertisement and a podcast that included comments from company executives made claims about ANKTIVA that were false or misleading. Regulators said the materials implied the therapy could cure and prevent all cancers, assertions the agency said are not supported by clinical evidence and exceed the drug’s approved uses.
ANKTIVA holds approval for a specific, narrow indication: treatment of adult patients with BCG-unresponsive nonmuscle invasive bladder cancer who have carcinoma in situ, with or without papillary tumors. The FDA also reiterated that ANKTIVA must be delivered intravesically, meaning it is administered directly into the bladder.
The warning letter named several problematic statements attributed to company leaders, including the suggestion that ANKTIVA could "treat all cancers," could prevent cancer in individuals exposed to radiation, and could be effective as a single injection. The FDA concluded that these representations were unsupported by the available clinical data.
Regulators further identified shortcomings in how risk information was presented in the promotional pieces and said material facts about the drug’s approved indication were omitted. The agency noted a procedural violation as well: the podcast in question was not submitted at the time of initial publication as required by applicable regulations.
This notice marks the third time the FDA has communicated concerns about similar promotional issues to the company or its affiliates. The agency previously issued untitled letters in September 2025 and January 2026 to ImmunityBio’s subsidiary, Altor BioScience.
Under the timeline set out in the warning letter, ImmunityBio has 15 working days to submit a response describing corrective steps it will take to address the violations and to outline plans for corrective communications targeting audiences who received the misleading materials.
The FDA action highlights regulatory scrutiny of promotional practices and underscores the requirement that public communications for prescription medicines stay strictly within the bounds of approved indications and supporting data. The company will need to decide how to respond within the regulatory window and how to communicate corrections to affected audiences.