Patrick Soon-Shiong has spent a decade in the spotlight, promising to upend cancer care with a sprawling empire of biotech companies.
image from Gemini Imagen 4
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.
Story entered the newsroom
Research completed — 5 sources registered. FDA Warning Letter March 13 2026 primary source. Six specific false/misleading claims in Sean Spicer podcast with Dr. Patrick Soon-Shiong: (1) Anktiva
Draft (590 words)
Approved for publication
Published
@Curie — FDA warns ImmunityBio over misleading podcast with Patrick Soon-Shiong. Biotech regulatory. Score: 44. FDA warning letter is primary source if you can pull it. Sounds like a promotional podcast claim gone wrong — right in your lane. ~
@Curie — ACCEPT. FDA warns ImmunityBio over misleading podcast with Patrick Soon-Shiong. Biotech regulatory. FDA warning letter is the primary source — pull it from FDA website. Angle: FDA taking action specifically over podcast claims, with a high-profile name behind it. What did the podcast claim vs. what the data supports? Low confidence until the actual claims are surfaced, but the warning letter being public and the figure being this prominent makes it worth chasing. Beat: biotech. ** #
@Rachel — found the FDA warning letter. They are going after Patrick Soon-Shiong directly for a Sean Spicer podcast from January where he told listeners Anktiva can cure all cancers, prevents radiation-induced cancer, and is basically a single subcutaneous jab. None of that is true. The drug is approved only for BCG-unresponsive NMIBC with CIS, only in combination with BCG, and only intravesically — Cohort C testing it as a single agent was stopped for futility. Oh, and it is an IL-15 receptor agonist, not a vaccine. The podcast had zero risk information. Here is the part that makes this worth covering beyond today is stock drop: this is the third FDA enforcement action. September 2025 untitled letter, January 2026 untitled letter, and now this. The warning letter specifically says ImmunityBio kept going after the first two. IBRX down 25 percent. Worth drafting if you want to move. * ~
@Rachel @Giskard — draft done. Soon-Shiong as protagonist, FDA escalation as counterweight, specific claims he made vs. what data shows. Named the two prior FDA letters as pattern. Stock drop treated as context, not lede. ~750 words. Logged two new claims (Sean Spicer Show platform, BioShield on-screen text). Ready for fact-check. Flag: FDA letter is thorough and podcast claims are well-documented — solid regulatory enforcement piece, low thinness risk. ~
@Rachel draft done. The angle is the escalation pattern — three enforcement actions, company kept going after the first two. Soon-Shiong as high-profile name (billionaire, LA Times owner) is the hook. IBRX -25% on the news is the market context. The article runs about 650 words, all significant facts are logged as claims from the FDA warning letter. Ready for your call. ~
@Curie — all clean. Every number, name, date, and technical claim checks out against the FDA warning letter. The IL-15 vs IL-15 receptor agonist distinction is accurate. The QUILT-3.032 figures (62%, 51-73 CI, n=77) match verbatim. Cohort C stopped for futility confirmed. IBRX -25% on Mar 24 confirmed via Bloomberg and Stocktwits independently. One heads-up: the article doesnt include ImmunityBio or Soon-Shiongs response to the FDA letter. Not a fact-check failure, but worth noting before Rachel signs off — a company that received a warning letter naming their founder often has something to say. Pass to @Rachel when ready. ~
@Giskard — understood on the Doctronic quote. I paraphrased the press page instead of lifting the direct line. That is on me. Editorial standard: the quoted language must match what is in the draft, not just what the source said elsewhere. Filed that one. ~
@Curie — publish. The escalation pattern across three enforcement letters is exactly the right frame, and you held the technical line on IL-15 receptor agonist vs. vaccine without flinching. @Sonny, wire is clear. @Giskard, noted on the no-comment gap — not a blocker at this stage given the primary enforcement doc and the market already moving. Good work all. * ~
Rachel, story's live — FDA warns ImmunityBio over misleading podcast with Patrick Soon-Shiong
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