ImmunityBio Faces Investor Lawsuit Over Cancer Drug Claims

ImmunityBio stock plunged 21% after FDA warning. A consolidated class action lawsuit is underway, with a May 26, 2026, lead plaintiff deadline for shareholders.

A January 2026 podcast appearance by ImmunityBio's Executive Chairman, Patrick Soon-Shiong, has triggered significant legal and financial repercussions for the biotechnology firm. During the interview, Soon-Shiong asserted that the company's cancer drug, Anktiva, had the potential to treat "all cancers." This statement was subsequently deemed misleading by the U.S. Food and Drug Administration (FDA), leading to a single-day stock plunge of more than 21%.

The Legal Landscape Consolidates

In the wake of the sell-off, a consolidated class action lawsuit is moving forward. Seven major law firms are now actively recruiting lead plaintiffs, all aligned on a critical deadline: May 26, 2026. Pomerantz LLP was the latest to join the effort, announcing its investigation on April 2, 2026. The other firms involved are Rosen Law Firm, Levi & Korsinsky, Robbins Geller Rudman & Dowd, Kahn Swick & Foti, Faruqi & Faruqi, and Hagens Berman.

Shareholders who purchased ImmunityBio securities between January 19 and March 24, 2026, and suffered losses, are eligible to petition the court to serve as the lead plaintiff by the May deadline. The case is proceeding in the U.S. District Court for the Central District of California under the docket number Douglas v. ImmunityBio, Inc., No. 26-cv-03261.

Allegations of Material Misstatements

The core allegation in the litigation is that ImmunityBio and certain of its officers failed to disclose material information and made false and misleading statements during the class period. The FDA's action provides the foundation for these claims. On March 13, 2026, the agency issued a warning letter stating that the company's promotional materials created a misleading impression. While Anktiva is approved for a specific form of bladder cancer, the FDA concluded that the materials wrongly suggested the drug could cure and even prevent all types of cancer.

When this warning letter became public on March 24, 2026, the stock collapsed, erasing approximately $2 billion in market capitalization in a single session.

Clinical Development Continues Amid Litigation

Despite the legal challenges, ImmunityBio continues to advance its clinical pipeline. On March 9, 2026, the company submitted a supplemental Biologics License Application (sBLA) to the FDA for a combination of Anktiva and BCG for a specific bladder cancer indication. The agency acknowledged the submission and requested additional efficacy and long-term data, but did not mandate new clinical trials.

The ongoing QUILT-2.005 study is fully enrolled, and an independent data monitoring committee has confirmed the trial is adequately powered to measure its targeted difference in response rate. ImmunityBio has indicated plans for another BLA submission before the end of 2026.

While May 26, 2026, marks a procedural milestone for the lawsuit, the legal process is expected to extend far beyond this date. The selection of a lead plaintiff and the ultimate resolution of the allegations will likely take considerable additional time.