Press Release

CULVER CITY, Calif.--(BUSINESS WIRE)--Jan. 23, 2017-- NantKwest Inc. (Nasdaq:NK), a pioneering, next-generation, clinical-stage immunotherapy company focused on harnessing the unique power of the immune system using natural killer (NK) cells to treat cancer, infectious diseases, and inflammatory diseases, today announced that the U.S. Food and Drug Administration (FDA) has authorized the company's Investigational New Drug Application (IND) for its first-in-human, high-affinity natural killer (haNK) cell therapy Phase I clinical study.

The company plans to promptly initiate this trial, which is believed to be the first ever clinical evaluation of a genetically engineered, allogenic, off-the-shelf, natural killer cell for the treatment of patients with cancer.

"We are thrilled to have received notification from the FDA that our first haNK cell therapy program has been authorized to proceed into Phase I clinical trials and are focused on moving swiftly to begin this study," said Patrick Soon-Shiong, MD, Chairman and CEO of NantKwest. "The FDA's authorization to initiate this clinical trial achieves a significant milestone for NantKwest as we begin clinical investigation of the use of haNK cell therapy for the treatment of cancer in a wide range of cancer types."

haNK Cell Therapy Platform

NantKwest's haNK cell therapy platform, developed to be an allogeneic, off-the-shelf therapy, is focused on optimizing the key role that natural killer cells play in mediating innate immunity, enhancing adaptive immune responses, and, specifically in the case of haNK, improving anti-tumor responses via antibody-dependent cell-mediated cytotoxicity (ADCC).

To achieve this objective, haNK cells have been engineered to express IL-2 and the high-affinity variant of the CD16 receptor (V158 FcγRIIIa). In preclinical studies, the addition of haNK to a variety of therapeutic antibodies has led to increased tumor cell killing when compared to the antibody alone. Thus, this first-in-human clinical study is designed to provide the necessary safety data to rapidly transition to haNK-antibody combination trials.

Dr. Soon-Shiong added, "As only about 10% of patients are born with the high affinity CD16 receptor, we believe the potential for haNK cell therapy to improve patient outcomes for the other 90% of the patient population and become part of the standard-of-care for cancer patients is very compelling."

Study Background

The primary objective of the study is to determine the safety of haNK cell monotherapy administered intravenously once per week in up to 16 patients with metastatic or locally advanced solid tumors. Other objectives include determination of objective response rate, progression-free survival, overall survival, and any correlations between tumor molecular profiles (based on genomics, transcriptomics, and quantitative proteomics) and patient outcomes.

For additional information, including exclusion and inclusion criteria, contact information and other details, please visit www.clinicaltrials.gov, QUILT trial #3.028.

About NantKwest

NantKwest (Nasdaq:NK) is a pioneering, next generation, clinical-stage immunotherapy company focused on harnessing the unique power of our immune system using natural killer (NK) cells to treat cancer, infectious diseases and inflammatory diseases. NK cells are the body's first line of defense due to the innate ability of NK cells to rapidly identify and destroy cells under stress, such as cancer or virally-infected cells.

NantKwest's unique NK cell-based platform, with the capacity to grow active killer cells as a biological cancer therapy, has been designed to induce cell death against cancer or infected cells by three different modes of action: (1) Direct killing using activated NK cells (aNK) that release toxic granules directly into the cell through cell to cell contact, (2) Antibody-mediated killing using haNKs, which are NK cells engineered to incorporate a high affinity receptor that binds to an administered antibody, enhancing the cancer cell killing effect of that antibody, and (3) Targeted activated killing using taNKs, which are NK cells engineered to incorporate chimeric antigen receptors (CARs) to target tumor-specific antigens found on the surface of cancer cells.

Our aNK, haNK and taNK platform addresses certain limitations of T cell therapies including the reduction of risk of serious "cytokine storms" reported after T cell therapy. As an "off-the-shelf" therapy, NantKwest's NK cells do not rely on a patient's own often compromised immune system. In Phase 1 clinical trials in patients with late stage cancer, NantKwest's NK cells have been successfully administered as an outpatient infusion therapy without any reported severe side effects, even at doses of 10 billion cells.

By leveraging an integrated and extensive genomics and transcriptomics discovery and development engine, together with a pipeline of multiple, clinical-stage, immuno-oncology programs that include a Phase 2 trial for a rare form of melanoma and the planned initiation of a clinical trial of NK cells targeted to breast cancer, we believe NantKwest is uniquely positioned to be the premier immunotherapy company and transform medicine by delivering living drugs in a bag and bringing novel NK cell-based therapies to routine clinical care. For more information, please visit www.nantkwest.com.

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Source: NantKwest Inc.

NantKwest Inc.
Jen Hodson, Public Relations Director
Cell: 562-397-3639
jhodson@nantworks.com