ImmunityBio is a clinical-stage biotechnology company focused on developing next-generation therapies that leverage the body’s own defense mechanisms to combat disease. The company’s primary mission involves bolstering the natural immune system to defeat both advanced cancers and infectious diseases. This approach centers on the belief that a robust, coordinated, and long-lasting immune response can be orchestrated for durable protection against a wide range of illnesses. ImmunityBio utilizes a vertically-integrated structure, which allows it to develop and manufacture its own novel immunotherapy and cell therapy platforms. These platforms are designed to work alone or in combination to drive and sustain an immune response, aiming for better outcomes than existing standards of care.
Core Scientific Approach: Natural Killer and T-Cell Activation
The foundational science behind ImmunityBio’s platform is the strategic activation of both the innate and adaptive arms of the immune system. The innate system’s first line of defense includes Natural Killer (NK) cells, which can rapidly identify and destroy abnormal cells without prior sensitization. The adaptive system, represented by T-cells, is responsible for a more specific, targeted, and long-term immunological memory.
The company’s strategy is often described as orchestrating a “triangle offense” against cancer cells, involving NK cells, and both CD4+ helper and CD8+ killer T-cells. Central to this approach is a proprietary molecule called Anktiva, also known as N-803, which functions as an interleukin-15 (IL-15) superagonist. This engineered cytokine complex selectively stimulates the proliferation and function of NK cells and CD8+ T-cells.
This selective stimulation is achieved by N-803’s unique structure, which binds to specific receptors on these immune cells. It avoids expanding T-regulatory cells, which are immune cells that suppress anti-tumor activity and can undermine cancer treatment effectiveness. By promoting the growth of these cancer-killing cells and memory T-cells, N-803 is designed to restore immune function for sustained tumor control. The activation of these cell types creates a coordinated, multi-pronged attack intended to eliminate existing disease and establish long-term immune memory to prevent recurrence.
Flagship Development: Anktiva and Bladder Cancer Treatment
ImmunityBio’s flagship development, Anktiva, has achieved its first regulatory approval as a combination therapy for a difficult-to-treat form of bladder cancer. Anktiva, when used with Bacillus Calmette-Guérin (BCG), is approved for adult patients with BCG-unresponsive non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS). NMIBC is a cancer that is confined to the bladder lining, and BCG is a standard intravesical immunotherapy that is instilled directly into the bladder.
The term “BCG-unresponsive” means the patient’s cancer has failed to respond to prior BCG treatment, leaving them with limited options, often leading to a radical cystectomy—the surgical removal of the bladder. The Anktiva combination is administered intravesically, meaning it is delivered directly to the bladder wall where the cancer resides. This localized delivery helps to concentrate the immune-activating molecules at the site of the tumor.
Clinical trial data, specifically from the pivotal QUILT-3.032 study, demonstrated the combination’s effectiveness, showing a complete response rate of 62% in the evaluable patient population. A complete response means all signs of cancer disappeared, and some of these responses were shown to be durable, lasting over 47 months in certain cases. The mechanism is believed to involve Anktiva acting as a boost, rescuing the efficacy of BCG by intensely amplifying the activated Natural Killer and T-cells that BCG initially primes. This durable response offers a meaningful alternative to the highly invasive surgery that these patients previously faced.
Expanding the Pipeline: Targeting Solid Tumors and Infectious Diseases
The core technology established with Anktiva is being applied across a broad clinical pipeline, demonstrating the platform’s versatility beyond bladder cancer. In the area of solid tumors, the company is investigating Anktiva in combination with other agents for cancers that have traditionally been difficult to treat. This includes studies in advanced metastatic pancreatic cancer and non-small cell lung cancer (NSCLC).
In these settings, Anktiva is being tested for its ability to reverse lymphopenia, which is a low count of lymphocytes (NK and T-cells) often caused by prior chemotherapy or the cancer itself. In patients with advanced NSCLC who had failed checkpoint inhibitor therapy, adding Anktiva has shown promising results by restoring lymphocyte levels and extending median overall survival. The company is also exploring combination therapies for other tumors, such as glioblastoma and ovarian cancer, often utilizing Anktiva alongside engineered Natural Killer cell therapies.
Beyond oncology, the company is using its immune-activating platform to address infectious diseases, particularly those that create persistent viral reservoirs. This includes work on HIV, where Anktiva is a component of a “kick-and-kill” strategy designed to flush out latent virus and allow the immune system to eliminate the infected cells. Furthermore, the IL-15 superagonist is being studied in clinical trials for conditions like Long COVID, aiming to restore immune function and enhance the body’s ability to clear the lingering viral components believed to contribute to the chronic symptoms of the condition.