Initially Launching a Novel, High-Affinity BCMA CAR Targeting NK Cell Development Candidate For Multiple Myeloma, With An Option For Up To Five Additional CAR Targeting Sequences? San Diego, CA,??NantKwest, Inc. (Nasdaq:NK), a leading clinical-stage Natural Killer (NK) cell based therapeutics company, and ProMab Biotechnologies today announced the establishment of a worldwide license to a B-Cell Maturation Antigen (BCMA) targeted antibody sequence for multiple myeloma along with an option for up to five undisclosed targeting sequences for exclusive use in the development of chimeric antigen receptor (CAR) based NK cell therapies. ?We are pleased to announce this collaboration with ProMab Biotechnologies, marking another milestone for NantKwest in the development of targeted, next generation, NK cell therapeutics against multiple myeloma and other cancers,? said Dr. Patrick Soon-Shiong, CEO of NantKwest. ?With an estimated five-year survival rate of around 49% and accounting for 10% of all hematological malignancies, patients with multiple myeloma are in critical need for more effective treatment options. We believe, NantKwest?s CAR-based NK cell therapy may represent a much needed new treatment option for these patients. We eagerly anticipate growing our relationship with ProMab and accelerate the development of these new and innovative, next-generation off-the shelf, CAR-based NK cell therapies.? ?ProMab?s strategic focus is on the development of?monoclonal antibodies and?their application in cell therapy?through the integration of next generation sequencing, bioinformatics, high-throughput screening technologies, and novel in vitro in vivo validation tools. This new partnership allows NantKwest to leverage the breadth of our monoclonal antibody generation and validation platform, our human antibody library screening capabilities, together with NantKwest?s strong NK cell engineering, manufacturing, and clinical expertise.? said John Wu, President and CEO of ProMab Biotechnologies. ?We look forward to working together with the NantKwest team to more rapidly bring new NK cell therapeutics into the clinic?. Multiple Myeloma Multiple myeloma is a debilitating blood cancer that while treatable is usually considered incurable, resulting in over 100,000 deaths annually on a worldwide basis. Representing a significant unmet medical need, without treatment, survival is typically less than one year. Even with treatment, which typically involves the use of chemotherapy, steroids, targeted therapy, and in some cases, stem cell transplant, survival often can only be extended to 4 to 5 years. The BCMA protein is important in B cell development and preferentially expressed in mature B lymphocytes. BCMA protein is also believed to be involved in the development of multiple myeloma and other blood cancers and is an important target for drug development. About NantKwest Inc.? 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 has 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 living cancer therapy, our NK cells have been designed to induce cell death against cancers and virally infected cells by several mechanisms, including: 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; 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. 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 300 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. For additional information, please visit www.nantkwest.com About ProMab Biotechnologies ProMab Biotechnologies is a biotechnology company?located in Richmond? California,?that?focuses to?develop and commercialize?mouse, rabbit, human monoclonal antibodies as well as chimeric antigen receptor-T Cell (CAR-T) products.?ProMab?s CAR-T platform covers both hematological and solid cancers with intensive in vitro and in vivo pre-clinical validation designed for safer and better?treatment. As a CRO in the immunology field for 18 years, ProMab offers standard laboratory procedures and animal studies for the antibody discovery through the integration of the newest techniques in antibody library construction, next generation sequencing, unique humanization modeling, high-throughput screening, and artificial intelligence analysis systems.?ProMab aims to out-license antibodies validated in CAR-T therapy or bring the CAR-T technologies to the early stage market of clinical study. ProMab has partnered with top biotechnology startups, medical institutions, and pharmaceuticals to advance the development of cell therapies as well as bispecific antibodies across multiple cancers. For more information, visit?www.promab.com. 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 the Company 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 our 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 our business are described in detail in our Securities and Exchange Commission filings, including in our Quarterly Report on Form 10-Q for the quarter ended September 30, 2018. ?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. For additional information please contact either of the individuals below: Media Contact: Jen Hodson 562-397-3639 Jen@nant.com