Why ImmunityBio Stock Slumped on Monday

By Eric Volkman – Apr 6, 2026 at 7:41PM ESTKey PointsIt sent the company a warning letter about a TV ad and a podcast episode about Anktiva.ImmunityBio sounded a contrite note in response.Cancer-focused biotech ImmunityBio (IBRX 2.81%) hasn't been in the good graces of a top regulator lately, and the latest development in that story on Monday was discouraging for investors. Numerous shareholders sold out of the stock to sink it by slightly over 3% that trading session. Peeved about promotional materials That regulator is the U.S. Food and Drug Administration (FDA). In mid-March, it sent ImmunityBio a warning letter stating that the biotech's recent promotional materials for cancer immunotherapy drug Anktiva were "false or misleading." Image source: Getty Images. Specifically, the FDA's warning covers a TV ad, in addition to a podcast episode rather provocatively titled "Is the FDA BLOCKING Life Saving Cancer Treatments?" The main subject of both is, of course, Anktiva. Despite what has to be considered the accusatory title of the podcast, the FDA approved Anktiva as a treatment for adults with BCG-unresponsive, non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS) nearly two years ago. On Monday, ImmunityBio said it filed a formal response to the warning letter. It stressed that the TV ad was never aired or otherwise publicly disseminated. Further, the company said, it has taken concrete measures to satisfy the regulator's concerns, "including the removal of the identified podcast from its corporate website and requesting its removal from third-party platforms." ExpandNASDAQ: IBRXImmunityBioToday's Change(-2.81%) $-0.20Current Price$7.09Key Data PointsMarket Cap$7.5BDay's Range$6.99 - $7.6252wk Range$1.83 - $12.43Volume282KAvg Vol39MGross Margin85.63% Someone made a misstep That dampened investor sentiment for two reasons. First, it made ImmunityBio look rash and sensationalistic, particularly with that podcast title. Second, it indicated a near-complete retreat in the face of the regulator's warning; this move felt weak to begin with and made the promotional campaign seem ill-considered and a waste of always-precious company time and resources. Every management team makes mistakes, so I don't think it's right to overly punish ImmunityBio for this clear misfire. Still, I'd keep a cautious eye on how the company manages its marketing going forward. It's never wise or useful to get on the wrong side of a regulator, particular if it's green-lighted one of your products in the recent past.Read NextMar 24, 2026 •By James BrumleyWhy ImmunityBio Stock Is Down More Than 20% TodayMar 23, 2026 •By James BrumleyWhy ImmunityBio Stock Is Up More Than 11% TodayApr 6, 2026 •By Eric VolkmanWhy Biogen Stock Got Mashed on MondayApr 6, 2026 •By Josh Kohn-LindquistStock Market Today, April 6: Soleno Therapeutics Climbs After $2.9 Billion All-Cash Buyout AgreementApr 6, 2026 •By Eric VolkmanWhy Soleno Therapeutics Stock Rocketed Higher on MondayApr 6, 2026 •By Reuben Gregg BrewerIs Valero Energy One of the Best Oil Stocks to Buy Right Now?About the AuthorEric Volkman is a contributing Motley Fool finance and stock market analyst. Previously, Eric was an equities analyst at European investment bank Raiffeisen Capital and Investment. He’s also been a freelance finance writer since 1995. He studied at Susquehanna University.TMFVolkmanStocks MentionedImmunityBioNASDAQ: IBRX$7.10(-2.81%)-$0.21*Average returns of all recommendations since inception. Cost basis and return based on previous market day close.