ImmunityBio, Inc. (NASDAQ: IBRX) shares fell 7.25% to $9.27 on Friday, a decline of $0.73, even as the company reported significant progress in treating bladder cancer. The drop unfolded during a volatile session in which a sharp mid-morning selloff pushed prices lower. The selling came despite the release of new long-term clinical results showing durable treatment responses among patients with difficult-to-treat bladder cancer.

Stock Slides as Long-Term Trial Data Are Published

ImmunityBio shares faced selling pressure on October 16 despite the company's announcement of encouraging clinical findings. The stock declined throughout the session, and a sharp drop in mid-morning trading accelerated its losses. The selloff contrasted with new evidence the company reported in support of ANKTIVA, its immunotherapy for non-muscle invasive bladder cancer.

The company announced the publication of long-term findings from its Phase 2/3 QUILT-3.032 clinical trial in The Journal of Urology. The study covered 100 patients with BCG-unresponsive bladder cancer — a form of the disease that persists or returns despite prior treatment with BCG, the long-standing immunotherapy instilled directly into the bladder — and tracked responses over a multi-year follow-up period. Researchers evaluated ANKTIVA in combination with Bacillus Calmette-Guérin therapy in patients with carcinoma in situ and certain papillary tumors. Carcinoma in situ is a flat lesion confined to the bladder lining, while papillary tumors grow as protruding, finger-like growths.

The study recorded a 71% complete response rate among patients who received the combination treatment. Researchers also reported a median complete response duration of 26.6 months, with some responses exceeding 53 months. The findings provide further evidence of sustained treatment benefits for patients who have limited options.

Trial Shows Durable Responses and Strong Survival Rates

The clinical results showed that 63.8% of responding patients maintained complete responses for at least 12 months. A further 52.3% held their responses at 24 months, while 44.2% reached the 36-month milestone. Among responders in the FDA-reviewed population, more than maintained complete responses beyond 45 months.

Survival data were similarly detailed. The trial recorded 84% cystectomy-free survival among responders at 36 months, meaning patients avoided surgical removal of the bladder — a closely watched measure because cystectomy has traditionally been the standard next step for patients once BCG therapy fails. Disease-specific survival reached 98.2% after three years, while progression-free survival stood at 80.9%. Among patients whose cancer never responded to previous BCG treatment, researchers observed a 66% complete response rate.

Safety findings supported the treatment's clinical profile throughout the extended follow-up period. Researchers reported Grade 3 treatment-related adverse events in 4% of patients, with no Grade 4 or Grade 5 events. Most adverse reactions involved mild or moderate bladder symptoms associated with treatment delivery.

FDA Approvals Underpin Expanded Use of ANKTIVA

ImmunityBio secured its initial FDA approval for ANKTIVA in 2024, establishing an additional treatment option for certain bladder cancer patients. The approval covered adults with BCG-unresponsive non-muscle invasive bladder cancer involving carcinoma in situ. In October 2026, roughly two years later, the FDA expanded the treatment's approved indication to include patients with papillary-only disease, giving the therapy its broadest approved use to date.

ANKTIVA activates natural killer cells and T cells, which help the immune system recognize and attack cancer cells. The therapy uses an interleukin-15 receptor agonist to strengthen immune activity and support lasting treatment responses. ImmunityBio administers the medicine directly into the bladder alongside BCG rather than through intravenous or subcutaneous injection.

According to the prescribing information, treatment delays can create serious risks when patients require surgical removal of the bladder. The guidance advises doctors to reconsider cystectomy when patients fail to respond after a second induction course.

Despite the latest clinical progress, ImmunityBio shares remained under pressure on Friday, underscoring the contrast between the company's treatment developments and its market performance.