FDA warns ImmunityBio over misleading podcast with Patrick Soon-Shiong

Patrick Soon-Shiong has spent a decade in the spotlight, promising to upend cancer care with a sprawling empire of biotech companies. On March 13, the FDA sent him a reminder that one approved drug does not a revolution make.

The agency issued a warning letter to ImmunityBio CEO Richard Adcock, but it named Soon-Shiong by name — an unusual move for a formal enforcement action. The citation: a January podcast in which Soon-Shiong, the executive chairman and global chief scientific and medical officer of ImmunityBio, told listeners that Anktiva, his company's sole approved drug, could treat all cancers, was on the path to curing cancer, and could prevent cancer in people exposed to radiation. The podcast aired on The Sean Spicer Show, a platform more known for political commentary than oncology discussions.

The FDA called every one of those claims false and misleading.

Anktiva holds a single approved indication: BCG-unresponsive nonmuscle invasive bladder cancer with carcinoma in situ, used in combination with BCG and delivered directly into the bladder via catheter. That approval, granted in April 2024, was based on the QUILT-3.032 trial, a single-arm study of 77 patients that showed a 62 percent complete response rate with a 95 percent confidence interval of 51 to 73. Among responders, 58 percent maintained that response for at least 12 months and 40 percent for at least 24 months. Those are real numbers. They are also narrow numbers — one disease, one combination, no comparator arm. The FDA noted that without a randomized control group, the trial cannot isolate what role Anktiva itself played in those outcomes.

The podcast claimed something different. Soon-Shiong described Anktiva as a subcutaneous injection — a single jab — that could treat all cancers. The FDA warning letter states flatly: For Intravesical Use Only. Do NOT administer by subcutaneous, intravenous, or intramuscular routes. The agency also identified a separate cohort of the same trial, Cohort C, testing Anktiva as a single agent, which was stopped early for futility. The single-agent arm did not hold up. The single-jab framing is doubly false.

Soon-Shiong also told listeners that IL-15 was the most important molecule that could cure cancer, and that Anktiva was that molecule. Anktiva is an IL-15 receptor agonist — it binds to receptors on immune cells and triggers proliferation of NK cells, CD8+ T cells, and memory T cells. It is not IL-15 itself, and the FDA stated it is not aware of data showing Anktiva prevents cancer in people who have not been diagnosed with the disease, including people exposed to radiation. The agency also said Anktiva is not a vaccine. On the podcast screen, text read ANKTIVA BioShield alongside a patient brochure, which the FDA called a false prevention claim.

This is not the first time the FDA has written to ImmunityBio or its subsidiary about these claims. Untitled letters — a lower tier of enforcement — went to Altor BioScience on September 9, 2025 and January 7, 2026, addressing similar misleading presentations of Anktiva. The company continued. The warning letter is a higher level of enforcement, and the agency explicitly flagged the pattern. ImmunityBio has 15 working days to respond with a corrective communications plan.

Soon-Shiong is also the owner of the Los Angeles Times, acquired in 2018, which means he controls a newsroom that covers the same pharmaceutical ecosystem where his own companies operate. The warning letter does not mention the LA Times, but the conflict is not abstract.

ImmunityBio shares fell roughly 25 percent on March 24 following news of the warning letter. That is the market pricing in credibility. The more durable signal is the escalation: three enforcement actions, two of them ignored, and now a warning letter that names the scientist behind the claims. The FDA has drawn a line. Whether Soon-Shiong crosses it again will be the more interesting question.