ImmunityBio Announces Durable Virus Control of SHIV Without Anti-Retroviral Therapy by Activating NK and Memory T Cells with N-803, an IL-15 Superagonist

Mar 10, 2020

ImmunityBio Announces Durable Virus Control of SHIV Without Anti-Retroviral Therapy by Activating NK and Memory T Cells with N-803, an IL-15 Superagonist

First demonstration of durable control of viremia without antiviral therapy in 9 of 13 SHIV-infected monkeys receiving combination therapy with N-803 and broadly neutralizing antibodies; Study results presented at the Conference on Retroviruses and Opportunistic Infections

Positive preclinical study followed by Phase 1 trials

CULVER CITY, Calif., March 10, 2020 – ImmunityBio, Inc., a privately held immunotherapy company, today announced results from studies evaluating N-803, an IL-15 superagonist, alone and in combination with anti-HIV broadly neutralizing antibodies (bNAbs), in SHIV-infected, antiretroviral therapy-suppressed rhesus macaques (RM) at the Annual Conference on Retroviruses and Opportunistic Infections (CROI). The presented data provide evidence that repeated co-dosing of N-803 in combination with bNABs may facilitate long-term viral remission in the absence of antiretroviral therapy.

Key findings of the studies presented by James B. Whitney, Ph.D., Assistant Professor of Medicine at Harvard Medical School in an oral presentation titled, “Combination IL-15 Therapy in a SHIV NHP Model”, include:

  • 9 of 13 antiretroviral therapy (ART) suppressed RMs treated with N-803 in combination with one or two bNAbs (10-1074 and 3BNC-117) exhibited durable control of viremia following ART removal, with durability observed beyond 25 weeks 
  • NK cells in the blood showed peak activation at 48 hours post N-803 administration throughout the dosing period
  • Memory T cells were preferentially activated by N-803, and CD8+ memory T cells demonstrated more robust expansion during the dosing period
  • N-803 dosing was well-tolerated

“Almost 40 years after the HIV virus was discovered, it continues to claim more than a million lives worldwide annually,” said Dr. Patrick Soon-Shiong, Chairman and CEO of ImmunityBio, Inc. “While antiretrovirals have improved patient outcomes and significantly decreased morbidity and mortality, there is neither a vaccine nor a cure for HIV infection. ImmunityBio is therefore searching for a solution that will impact the HIV reservoir.  Thesetudies demonstrate that combination therapy with N-803, ImmunityBio’s IL-15 superagonist, which activates NK and DC8 T cells together with broadly neutralizing antibodies, may stimulate the immune system to enable immune control of HIV in the absence of antiretroviral treatment.”  

In addition to these studies, recently published data in Nature reports that N-803 induces robust and persistent SIV reactivation in the context of CD8 T cell depletion, stimulating simian immunodeficiency virus (SIV) out of hiding, providing a novel “shock-and-kill” therapy for HIV cure research.1. Taken together, these findings provide the potential of new strategies to overcome HIV through a sequential action of shocking viral reservoirs out of hiding with N-803 and then killing these infected cells through the powerful immune response of Natural Killer, CD8 and Memory T cells activated by the IL-15 superagonist, to potentially enable long term viral control. 

On the basis of these positive preclinical results, two clinical trials have been initiated in patients with HIV.  A Phase 1 study of N-803 as a single agent in HIV-infected patients has been completed (NCT02191098). This will be followed by a second trial combining N-803 with neutralizing antibodies undertaken by the AIDS Clinical Trial Group (IND 147995, Protocol A5386), sponsored by the National Institute of Allergy and Infectious Diseases (NIAID).  

About ImmunityBio

ImmunityBio, Inc. is a privately held immunotherapy company with a broad portfolio of biological molecules at clinical stages of development. The Company’s goals are to employ this portfolio to activate endogenous Natural Killer (NK) and CD8+ T cells in the fields of cancer and infectious disease. Specifically, in regards to cancer, ImmunityBio’s goal is to develop a memory T-cell cancer vaccine to combat multiple tumor types—without the use of high-dose chemotherapy. Regarding infectious disease, the Company is addressing HIV, influenza, and the coronavirus.

The Company’s first-in-human platform of technologies has enabled it to achieve one of the most comprehensive, late-stage clinical pipelines, activating both the innate (natural killer cell) and the adaptive immune systems. The product pipeline includes an albumin-linked chemotherapeutic (Aldoxorubicin), a novel IL-15 cytokine superagonist (N-803), checkpoint inhibitors, macrophage polarizing peptides, bi-specific fusion proteins targeting TGFb and IL-12, adenovirus, and yeast vaccine therapies targeting tumor associated antigens and neoepitopes.

In December 2019, the U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy Designation to N-803 for BCG-unresponsive CIS non-muscle invasive bladder cancer (NMIBC). Other indications currently at registration-stage trials include BCG-unresponsive papillary bladder cancer, first and second-line lung cancer, and metastatic pancreatic cancer. 

In the field of infectious disease, ImmunityBio’s goal is to develop therapies, including vaccines, for the prevention and treatment of HIV, influenza, and the coronavirus SARS-CoV-2.

  1. McBrien, J.B., Mavigner, M., Franchitti, L. et al. Robust and persistent reactivation of SIV and HIV by N-803 and depletion of CD8+ cells. Nature 578, 154–159 (2020).

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements include statements concerning or implying that ImmunityBio will be successful in improving the treatment of HIV. Risks and uncertainties related to this endeavor include, but are not limited to, obtaining FDA approval of ImmunityBio’s N-803 product candidate.

Forward-looking statements are based on management’s current expectations and are subject to various risks and uncertainties that could cause actual results to differ materially and adversely from those expressed or implied by such forward-looking statements. Accordingly, these forward-looking statements do not constitute guarantees of future performance, and you are cautioned not to place undue reliance on these forward-looking statements.  These forward-looking statements speak only as of the date hereof, and we disclaim any obligation to update these statements except as may be required by law.

Contact us at

+1-844-MY NK CELLS (+1-844-696-5235)

How Can ImmunityBio Help You?

Solutions for Patients

Many cancer therapies, including radiation therapy, chemotherapy, CAR-T therapy, and B-cell immunotherapy, severely weaken the immune system—the human body’s most important natural disease-fighting weapon. But ImmunityBio creates targeted, personalized immunotherapies that are designed to strengthen the immune system and enable it to outsmart your disease.

Opportunities for Trial Investigators

The broad therapeutic potential and demonstrated safety of ImmunityBio’s immune-enhancing IL-15 superagonist Anktiva (N-803), engineered NK-92® cell-based therapies, and our next-generation adenovirus-vectored anti-cancer vaccines make them appealing therapeutics for testing by trial investigators who want to make a contribution to clinical cancer research. Interested clinicians and other are encouraged to contact ImmunityBio to find out how they may support discovery of future cancer treatments.

Tools for Research Scientists

Our NK-92® easy-to-maintain and highly cytotoxic natural killer cell line provides a versatile bioanalytical testing tool that can help researchers develop functional killing assays that are more consistent and reliable than donor blood and reporter gene assays.

ImmunityBio is continuously pursuing new immunotherapies designed to attack disease by enhancing the patient’s immune system, not weakening it.