ImmunityBio, Inc. (IBRX) experienced a severe market selloff on Tuesday, with its stock price collapsing by 21.1% to close at $7.42. The steep decline was triggered by the public release of a warning letter from the U.S. Food and Drug Administration (FDA), which accused the biotechnology company of disseminating false or misleading promotional materials for its flagship cancer immunotherapy, Anktiva.
FDA Alleges Overstated Claims
The regulatory action, dated March 13 and published on Tuesday, March 25, 2026, centers on a television commercial and an episode of a podcast hosted by Sean Spicer. According to the FDA, these promotional pieces suggested that Anktiva could "cure and even prevent all cancer," function as a standalone treatment, or serve as a cancer vaccine. The agency stated these claims constitute misbranding under federal law, as Anktiva is not approved for such broad indications.
Specifically, the FDA challenged the clinical evidence underpinning the marketing. It noted that the pivotal QUILT-3.032 trial failed to produce interpretable disease-free survival data, leaving uncertainty about how long patients remain cancer-free after treatment. The letter further emphasized that the agency is unaware of any substantiation supporting assertions that Anktiva can cure cancer.
Critical Revenue Driver at Stake
The warning strikes at the core of ImmunityBio's business. Anktiva is the company's primary commercial asset, accounting for nearly all of its product revenue. A February filing with the Securities and Exchange Commission revealed that the drug generated approximately $113 million of ImmunityBio's total $113.3 million in net product revenue for 2025. Analyst consensus compiled by LSEG projects 2026 sales to reach $217.6 million, highlighting the drug's critical growth trajectory.
Currently, Anktiva is FDA-approved in the United States for use in combination with BCG immunotherapy for the treatment of certain adults with non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ, with or without papillary tumors, who are unresponsive to BCG alone. The FDA explicitly clarified that Anktiva is not cleared for treating all cancer types, for use in lung cancer patients after checkpoint inhibitor failure, or for cancer prevention following radiation exposure.
Expansion Plans Amid Regulatory Scrutiny
The warning introduces significant uncertainty as ImmunityBio actively seeks to expand Anktiva's market. On March 9, the company announced it had resubmitted an application to the FDA to broaden the drug's label for use in papillary-only bladder cancer. Just days later, on March 20, ImmunityBio secured approval for Anktiva in Macau, marking its first entry into the Asian market and expanding its geographic footprint to 34 countries and territories.
The FDA noted in its letter that it had previously sent untitled letters to the company in September 2025 and January 2026 concerning similar promotional presentations for Anktiva. While the agency did not specify if these prior communications would impact the pending label-expansion application, the history deepens the regulatory overhang on the company's key strategic initiatives.
Competitive and Analyst Perspectives
ImmunityBio faces established competition in the broader bladder cancer market from therapies like Merck's (MRK) Keytruda and Janssen's Inlexzo, both of which hold FDA approvals. The company's challenge is to effectively commercialize Anktiva and expand its reach against this backdrop.
In response to the warning, an ImmunityBio spokesperson stated the company is reviewing the letter and plans to respond within the mandated 15-working-day timeframe, adding, "We take the warning very seriously and will work cooperatively with the agency to address it." Analyst Edward Tenthoff of Piper Sandler expressed a measured view, indicating he expects the company to resolve the FDA's concerns and is not adjusting his revenue forecast for Anktiva at this time.
The sharp market reaction underscores the high stakes for ImmunityBio, whose financial health is almost entirely tethered to the successful commercialization and regulatory standing of a single product. The resolution of this FDA matter will be closely watched by investors as a key determinant of the company's near-term stability and long-term growth potential.
