NantKwest Announces Durable Complete Responses in Multiple Advanced-Stage Solid Tumor Cancers Following Off-the-Shelf NK Cell Therapy in First 35 Patients

Jun 4, 2019

5 out of 35 Durable Complete Responses Observed in Patients with Relapsed Third-Line Advanced Solid Tumors with Duration Ranging 4 to 24 Months

Culver City, CA.- June 4, 2019– Patrick Soon-Shiong, MD, Chairman and CEO of NantKwest (Nasdaq:NK), a leading clinical-stage, natural killer cell based therapeutics company today presented a clinical data update in patients who have received off-the-shelf aNK and/or haNK natural killer cell therapy in combination with immunotherapeutic agents in advanced solid tumors. These results demonstrated durable complete responses in 5 out of 35 patients with highly refractory late stage cancers across multiple tumor types.

Data presented at the Jefferies Healthcare Conference demonstrated complete responses across phase I combination studies of aNK/haNK with or without N-803, ImmunityBio, Inc.’s IL-15 fusion superagonist in solid tumor cancer patients with highly refractory disease.  ImmunityBio, Inc. (formerly known as NantCell, Inc.) is an affiliated company of NantKwest.  These combinations enhance NK and T cell activity and proliferation, and resulted in 14% complete responses across multiple indications, while demonstrating positive safety profiles. In patients with highly refractory and relapsed diseases who have failed multiple rounds of standard-of-care therapy, the responses were durable. 

All five patients with complete responses remain alive to date, ranging from 4 to 24 months from the onset of response.

“We are excited by the durable complete responses seen in patients with highly refractory disease safely treated with off-the-shelf haNK or aNK — to date over 511 infusions of haNK cell therapy have been administered, without any patient requiring hospitalization or resulting in cytokine release syndrome,” said Patrick Soon-Shiong, M.D. “These early signals of efficacy have now provided us a pathway to the development of registration trials across triple negative breast cell and Merkel cell carcinoma.” 

In addition, Dr. Soon-Shiong also announced the FDA authorization of a trial utilizing the first in class CD19 T-haNK for treatment of refractory diffuse large B-Cell Lymphoma and the IND filing of the first in class PD-L1 T-haNK for refractory solid tumors.

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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



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