11 March 2020 - - US-based immunotherapy company ImmunityBio, Inc has released results from studies evaluating N-803, an IL-15 superagonist, alone and in combination with anti-HIV broadly neutralising antibodies (bNAbs), in SHIV-infected, antiretroviral therapy-suppressed rhesus macaques at the Annual Conference on Retroviruses and Opportunistic Infections.

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 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

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 out of hiding, providing a novel "shock-and-kill" therapy for HIV cure research.

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 neutralising antibodies undertaken by the AIDS Clinical Trial Group (IND 147995, Protocol A5386), sponsored by the National Institute of Allergy and Infectious Diseases (NIAID).

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 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 US Food and Drug Administration 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