NantKwest Announces Achievement of End Point in Merkel Cell Carcinoma Phase II Trial With Evidence of Efficacy of Activated Natural Killer (aNK) Cells in Solid Tumors

Nov 14, 2016

Promising Clinically Meaningful Responses Seen Including a Radiological Complete Response in Early Data Analysis Presented at the 31st Annual Meeting of the Society for Immunotherapy of Cancer

CULVER CITY, Calif.–Nov. 14, 2016– 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, announced a presentation of early analysis of the Company’s ongoing Phase II Merkel cell carcinoma study at the 31st Annual Meeting of the Society for Immunotherapy of Cancer (SITC) held November 9-13, 2016 in National Harbor, Maryland.

NantKwest’s presentation on Friday, November 11th, Adoptive Cellular Therapy (ACT) With Allogeneic Activated Natural Killer (aNK) Cells in Patients With Advanced Merkel Cell Carcinoma (MCC): Preliminary Results of a Phase 2 Trial‎, highlighted interim results from the Company’s ongoing Phase II clinical study of the Company’s investigational aNK natural killer cell therapy in Merkel cell carcinoma. Dr Shailender Bhatia from Fred Hutchinson Cancer Research Center presented the first evidence of a radiological complete response following single agent aNK infusion in a patient with recurrent disease after multiple lines of therapy including relapse after checkpoint inhibitor therapy.

Merkel cell carcinoma is a rare and aggressive skin cancer that is increasing in incidence. Patients with metastatic or locally advanced Merkel cell carcinoma have an extremely poor prognosis with less than 20% of patients surviving longer than five years.

Commenting on the results, Patrick Soon-Shiong, MD, Chairman and CEO of NantKwest said the following: “We are encouraged to see, even in a heavily pretreated patient population, including patients who have failed checkpoint inhibitor therapy, that our aNK natural killer cell therapy exhibited clinically meaningful antitumor activity, including a promising radiological complete response in one patient, and we look forward to the rapid development of our aNK program in Merkel cell carcinoma. In addition, through our clinical development program, we strive to bring the potential for long-term survival to a broad range of cancer patients in a number of additional cancer indications.”

Dr. Soon-Shiong continued, “We believe this data, while a small data set, provides the foundation to submit to the FDA our plans to transition this trial to a pivotal study. Subject to FDA authorization, this transitional study will include our aNK cell therapy in combination with ALT-803, an investigational IL-15 superagonist complex shown to synergistically activate NK and T cells in human clinical trials and currently in development by Altor Biosciences. We believe this novel combination offers the potential to further improve response rates and bring NantKwest’s natural killer cell therapy one step closer to routine clinical cancer care in a patient population in urgent need of better treatment options.”

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 ‎

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