First engineered, GMP-grade, cryopreserved, off-the-shelf, bi-specific NK cell therapy to enter human clinical trials targeting CD16 and CD19 in patients with lymphoma

Culver City, California, June 3, 2019- NantKwest Inc. (Nasdaq:NK), 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 other diseases, today announced that the company’s t-haNK investigational new drug application (IND) has cleared FDA review and the program has now transitioned to a first-in-human clinical trial targeting CD19 t-haNK in advanced B-cell lymphoma.

CD19  is a transmembrane protein expressed in B cells and overexpressed in a large percentage of advanced leukemia and lymphoma representing a well validated therapeutic target. The CD19 t-haNK cell therapy is a novel, NK cell based immuno-oncology therapy that includes a CD19-based Chimeric Antigen Receptor (CAR) that has been engineered to create an NK cell that includes the high affinity CD16 (Fc receptor), which enhances an NK cell’s ability to bind and enhance monoclonal antibody activity. Use of a targeted, bi-specific NK cell is intended to enhance the cancer cell killing ability of this novel NK cell therapy.

“Based on extensive and encouraging preclinical results, we have enhanced our ability to modularly combine this proprietary off-the-shelf t-haNK-based therapy with a wide range of monoclonal antibodies using this multi-targeted approach,” commented Dr. Patrick Soon-Shiong, Chairman and CEO of NantKwest. Dr. Soon-Shiong continued, “We are now ready to transition this innovation in NK cell based therapeutics to a Phase I human clinical trials designed to assess the safety, tolerability and efficacy of CD19 t-haNK cell therapy in advanced b-cell lymphoma. Upon completion of the safety phase, NantKwest intends to combine this CD19 t-haNK cell therapy with other synergistic, immunomodulatory agents as part of an integrative, combination therapy approach that we describe as the NANT Cancer Vaccine to further enhance the synergistic effectiveness of this novel therapeutic intervention.”

CD19 t-haNK

NantKwest’s CD19-t-haNK cell therapy is designed to provide precise tumor-cell specificity through the use of a CAR construct that utilizes a CD19-specific scFv (single chain antibody fragment) engineered into the company’s proprietary NK cell that includes the CD16 (Fc high affinity receptor)..

In pre-clinical studies, cytotoxicity of these GMP-grade, cryopreserved CD19 t-haNK cells were comprehensively evaluated against a panel of cancer cell lines with different levels of CD19 expression in vitro and in vivo, with these studies showing increased activity and selective cytotoxicity towards CD19-expressing tumor cells of various b-cell origins including leukemia.

To better inform routine patient care, these clinical trials will incorporate a state-of-the-art, biomarker analysis using GPS Cancer™, which is an integrated, multi-omics, whole genome, transcriptomic platform, both provided by NantHealth, an affiliated company. These comprehensive molecular analysis tools are designed to provide critical information to the clinical study team regarding the unique molecular alterations associated with the patient’s cancer and response rates, potentially enhancing patient management.

Additional information regarding the CD19 t-haNK clinical study can be found at www.nantkwest.com or www.clinicaltrials.gov

About NantKwest 

NantKwest, a member of the NantWorks ecosystem of companies, is an innovative clinical-stage immunotherapy company focused on harnessing the power of the innate immune system by using the natural killer cell to treat cancer and virally induced infectious diseases.

NantKwest is uniquely positioned to implement precision cancer medicine, with the potential to change the current paradigm of cancer care. Natural Killer (NK) cells are a safeguard in the human body designed to recognize and detect cells under stress due to cancer or viral infection. NantKwest’s “off-the-shelf” activated NK cell platform is designed to destroy cancer and virally infected cells from the body. The safety of our NK cells as well as their activity against a broad range of cancers have been tested in phase I clinical trials in Canada and Europe as well as in multiple phase I and II clinical trials in the United States. In addition to being a universal cell-based therapy that does not require individualized patient sourcing or matching, our NK cell products have been largely administered in the outpatient setting as an “off-the-shelf” living drug.

With the capacity to grow active killer cells as a cancer therapy, our NK cells have been designed to induce cell death against cancers and virally infected cells by several mechanisms, including: (i) innate killing, whereby all of our NK platforms recognize the stress proteins typically found on cancer cells, which, upon binding, release toxic granules to immediately kill their targets; (ii) antibody-mediated killing with our haNK® platform, which are NK cells engineered to express antibody receptors that can bind to therapeutic antibody products, thereby enhancing the cancer cell killing effect of that antibody; and (iii) Chimeric Antigen Receptor directed killing using the taNK® platform, which includes NK cells engineered to incorporate chimeric antigen receptors (CARs) to target tumor-specific antigens found on the surface of cancer cells. All three modes of killing (innate, antibody-mediated, and CAR directed killing) are employed by our t-haNK™ platform, which is an innovative combination of our aNK, haNK® and taNK® platforms in a single product.

Our haNK®, and t-haNK™ platforms have been designed to address certain limitations of CAR T-cell therapy including the capability to infuse cell therapy in an outpatient setting which allows for potential reduction of risk for serious cytokine storms and protracted serious adverse events. In Phase I and II clinical trials in patients with late stage cancer, our NK cells have been administered as an investigational outpatient infusion safely with greater than 500 infusions to date at a dose of 2 billion cells per infusion.

By leveraging an integrated and extensive genomics and transcriptomics discovery and development engine, together with a pipeline of multiple, clinical-stage, immuno-oncology programs, 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.

NK-92, aNK, haNK, taNK, and t-haNK are trademarks of NantKwest, Inc.

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 NantKwest will be successful in improving the treatment of cancer. Risks and uncertainties related to this endeavor include, but are not limited to, obtaining FDA approval of NantKwest’s NK cells as well as other therapeutics as part of the NANT Cancer Vaccine platform as a cancer treatment.

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 and other risks regarding NantKwest’s business are described in detail in its Securities and Exchange Commission filings, including in NantKwest’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2019. 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.

Media Contact:

Jen Hodson

562-397-3639

Jen@nant.com