This presentation contains forward-looking statements relating to the proposed transaction involving NantKwest, Inc. ("NantKwest") and ImmunityBio, Inc. ("ImmunityBio"), including financial estimates and statements as to

39th Annual JP Morgan Healthcare

Conference January 13, 2021 Exhibit 99.1

This presentation contains forward-looking

statements relating to the proposed transaction involving NantKwest, Inc. ("NantKwest") and ImmunityBio, Inc. ("ImmunityBio"), including financial estimates and statements as to the expected timing, completion and effects of

the proposed transaction and statements relating to NantKwest and ImmunityBio's future success in improving the treatment of various diseases and illnesses, including, but not limited to COVID-19 and cancer. Statements in this communication

that are not statements of historical fact are considered forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the "Securities Act"), and Section 21E of the Securities Exchange Act of

1934, as amended (the "Exchange Act"), which are usually identified by the use of words such as "anticipates," "believes," "continues", "could", "estimates,"

"expects," "intends," "may," "plans," "potential", "predicts", "projects," "seeks," "should," "will," and variations of such

words or similar expressions. These forward-looking statements are neither forecasts, promises nor guarantees, and are based on the current beliefs of NantKwest's management and ImmunityBio's management as well as assumptions made by and

information currently available to NantKwest and ImmunityBio. Such statements reflect the current views of NantKwest and ImmunityBio with respect to future events and are subject to known and unknown risks, including business, regulatory, economic

and competitive risks, uncertainties, contingencies and assumptions about NantKwest and ImmunityBio, including, without limitation, (i) inability to complete the proposed transaction because, among other reasons, conditions to the closing of the

proposed transaction may not be satisfied or waived, (ii) uncertainty as to the timing of completion of the proposed transaction, (iii) potential adverse effects or changes to relationships with employees, suppliers or other parties resulting from

the announcement or completion of the proposed transaction, (iv) the outcome of any legal proceedings that may be instituted against the parties and others related to the potential transaction between NantKwest and ImmunityBio, (v) possible

disruptions from the proposed transaction that could harm NantKwest's or ImmunityBio's respective business, including current plans and operations, (vi) unexpected costs, charges or expenses resulting from the proposed transaction, (vii)

uncertainty of the expected financial performance of the combined company following completion of the proposed transaction, including the possibility that the expected synergies and value creation from the proposed transaction will not be realized

or will not be realized within the expected time period, (viii) the ability of each of NantKwest or ImmunityBio to continue its planned preclinical and clinical development of its respective development programs, and the timing and success of any

such continued preclinical and clinical development and planned regulatory submissions, (ix) inability to retain and hire key personnel, and (x) the unknown future impact of the COVID-19 pandemic delay on certain clinical trial milestones and/or

NantKwest's or ImmunityBio's operations or operating expenses. More details about these and other risks that may impact NantKwest's business are described under the heading "Risk Factors" in NantKwest's most

recent Quarterly Report on Form 10-Q and Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission ("SEC") and in subsequent filings made by NantKwest with the SEC, which are available on the SEC's website

at www.sec.gov. NantKwest and ImmunityBio caution you not to place undue reliance on any forward-looking statements, which speak only as of the date hereof. NantKwest and ImmunityBio do not undertake any duty to update any forward-looking statement

or other information in this communication, except to the extent required by law. No representation is made as to the safety or effectiveness of these product candidates for the therapeutic use for which such product candidates are being studied.

Certain information contained in this presentation relates to or is based on studies, publications, surveys and other data obtained from third-party sources and NantKwest's and ImmunityBio's own internal estimates and research. While

NantKwest and ImmunityBio believe these third-party sources to be reliable as of the date of this communication, it has not independently verified, and makes no representation as to the adequacy, fairness, accuracy or completeness of, any

information obtained from third-party sources. In addition, all of the market data included in this communication involves a number of assumptions and limitations, and there can be no guarantee as to the accuracy or reliability of such assumptions.

Finally, while NantKwest and ImmunityBio each believes its own internal research is reliable, such research has not verified by any independent source. No Offer or Solicitation This presentation is not intended to and does not constitute an

offer to sell or the solicitation of an offer to buy, sell or solicit any securities or any proxy, vote or approval in any jurisdiction pursuant to or in connection with the proposed transaction or otherwise, nor shall there be any sale of

securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offer of securities shall be deemed to be made except by means

of a prospectus meeting the requirements of Section 10 of the Securities Act. Additional Information and Where to Find It In connection with the proposed transaction, NantKwest intends to file a registration statement on Form S-4 with the

SEC, which will include a prospectus and joint proxy / solicitation statement of NantKwest and ImmunityBio (the "solicitation statement/prospectus"). NantKwest may also file other documents regarding the proposed transaction with the

SEC. This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval. This communication is not intended to be, and is not, a substitute for such filings or for

any other document that NantKwest may file with the SEC in connection with the proposed transaction. BEFORE MAKING ANY VOTING OR INVESTMENT DECISION, INVESTORS AND SECURITY HOLDERS ARE URGED TO CAREFULLY READ THE ENTIRE REGISTRATION STATEMENT AND

SOLICITATION STATEMENT / PROSPECTUS, WHEN THEY BECOME AVAILABLE, AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY BECAUSE THEY WILL CONTAIN IMPORTANT

INFORMATION ABOUT THE PROPOSED TRANSACTION. Investors and security holders will be able to obtain free copies of the registration statement and solicitation statement/prospectus and other documents filed with the SEC by NantKwest through the website

maintained by the SEC at www.sec.gov. In addition, investors and security holders will be able to obtain free copies of the prospectus and other documents filed with the SEC on NantKwest's website at www.ir.nantkwest.com. Participants

in the Solicitation NantKwest and certain of its respective directors and executive officers may be deemed to be participants in the solicitation of proxies from stockholders of NantKwest in connection with the proposed transaction under the rules

of the SEC. Investors may obtain information regarding the names, affiliations and interests of directors and executive officers of NantKwest in NantKwest's proxy statement for its 2020 annual meeting of stockholders, which was filed with the

SEC on April 24, 2020, as well as its other filings with the SEC. Other information regarding the participants in the proxy solicitation and a description of their direct and indirect interests, by security holdings or otherwise, will be included in

the registration statement, solicitation statement / prospectus and other relevant materials to be filed with the SEC by NantKwest regarding the proposed transaction (if and when they become available). You may obtain free copies of these documents

at the SEC's website at www.sec.gov. Copies of documents filed with the SEC will also be available free of charge from NantKwest using the sources indicated above. Forward-Looking Statements

An immunotherapy leader focused on treating

cancer and infectious diseases by orchestrating the innate (NK) and adaptive (T cell) immune system Combined Immunotherapy Platforms Better Positioned to Treat Patients Immunotherapy Portfolio Pipeline Clinical Updates Closing 13 first-in-human

molecules in clinical trials 11 in Phase 2 to 3 development Strong global intellectual property portfolio of over 400 issued and pending worldwide patent applications with patent life extending to 2035 and beyond GMP large scale manufacturing

capacity Breakthrough Designation of lead fusion protein MergeCo Late-Stage Pipeline in NK Cell Therapy & Fusion Proteins Proprietary Natural Killer (NK) cell platforms spanning off-the-shelf NK-92 cell line & autologous & allogeneic

stem cell products Phase 2 clinical trials Proprietary manufacturing processes and GMP large scale facilities NASDAQ: NK Broad range immunotherapy products spanning antibody fusion proteins, immune-modulators and adenovirus platforms Phase 2 / 3

stage Breakthrough Designation Deep pipeline spanning infectious disease and oncology Privately Held Proposed NASDAQ: IBRX +

NantKwest: Clinically Advanced NK Cell

Platform Immunotherapy Portfolio Pipeline Clinical Updates Closing Proprietary Natural Killer (NK) cell platforms spanning off-the-shelf NK-92 cell line & autologous & allogeneic stem cell products Phase 2 clinical trials Proprietary

manufacturing processes and GMP large scale facilities NASDAQ: NK

NantKwest: Clinically Advanced NK Cell

Platform aNK (NK-92) haNK PD-L1 t-haNK CD-19 t-haNK HER2 t-haNK EGFR t-haNK Innate Immunity Without Major Inhibitory Receptors NKG2D NKG2D NKG2D NKG2D NKG2D NKG2D High-Affinity CD16 X CD16 CD16 CD16 CD16 CD16 erIL2 X erIL2 erIL2 erIL2 erIL2 erIL2

CAR Insertion(s) X CD16 PD-L1 CD19 HER2 EGFR Clinical Indication Core Cell Line Registrational Merkel Cell* Pancreatic* NSCLC Lymphoma Breast Head & Neck Current Status Universal NK Cell Line Phase II Jan 2019 Phase II June 2020 IND Authorized

IND Planned Q1 2021 IND Planned Q3 2021 *Registrational Intent Immunotherapy Portfolio Pipeline Clinical Updates Closing Proprietary Natural Killer (NK) cell platforms spanning off-the-shelf NK-92 cell line & autologous & allogeneic stem

cell products Phase 2 clinical trials Proprietary manufacturing processes and GMP large scale facilities NASDAQ: NK *Registrational Intent

NantKwest: Large Scale Cell Therapy

Manufacturing Capacity For haNK and PD-L1 t-haNK Immunotherapy Portfolio Pipeline Clinical Updates Closing Proprietary Natural Killer (NK) cell platforms spanning off-the-shelf NK-92 cell line & autologous & allogeneic stem cell products

Phase 2 clinical trials Proprietary manufacturing processes and GMP large scale facilities NASDAQ: NK GMP Large Scale Manufacturing Facilities Over 3 Trillion Cryopreserved NK Cells Manufactured and Stored 2017-2020

Next Generation GMP in a Box Biologic

Manufacturing Device for N=1 M-ceNK Cytokine Enriched Natural Killer Donor Derived NK GMP-in-a-Box NANT-001 NANT-XL Immunotherapy Portfolio Pipeline Clinical Updates Closing

Rationale for Cytokine Enriched Natural

Killer Cell (M-ceNK): Cytokine-Induced Memory-like Natural Killer Cells Exhibit Enhanced Responses Against Myeloid Leukemia in Pre-Clinical Models Abstract: Natural killer (NK) cells are an emerging cellular immunotherapy for patients with acute

myeloid leukemia (AML); however, the best approach to maximize NK cell antileukemia potential is unclear. Cytokine-induced memory-like NK cells differentiate after a brief preactivation with interleukin-12 (IL-12), IL-15, and IL-18 and exhibit

enhanced responses to cytokine or activating receptor restimulation for weeks to months after preactivation. We hypothesized that memory-like NK cells exhibit enhanced antileukemia functionality. We demonstrated that human memory-like NK cells have

enhanced interferon- production and cytotoxicity against leukemia cell lines or primary human AML blasts in vitro. Using mass cytometry, we found that memory-like NK cell functional responses were triggered against primary AML blasts,

regardless of killer cell immunoglobulin-like receptor (KIR) to KIR-ligand interactions. In addition, multidimensional analyses identified distinct phenotypes of control and memory-like NK cells from the same individuals. Human memory-like NK cells

xenografted into mice substantially reduced AML burden in vivo and improved overall survival. In the context of a first-in-human phase 1 clinical Immunotherapy Portfolio Pipeline Clinical Updates Closing

Autologous Apheresis Patient White Cell

Collection Day 1 Concentrate 0.3 - 1.0 x 109 NK Cells Day 17 Autologous & Allogeneic: M-ceNK Memory Cytokine Enhanced Natural Killer Cell Platform Aliquot One Bag into 10 Lots for Cryopreservation Single Aliquot For Enrichment Autologous

Apheresis White Cells Day 1 CD56 CD3 White Cells GMP-in-a-Box NK Cell Enrichment Cytokine Induced Proliferation NK Enrichment Day 1-16 CD56 CD3 Enhanced NK Cells Autologous Cytokine Enhanced Natural Killer Cells for Transfusion 0.3 - 1.0 x 109

NK Cells Day 17 CD56 CD3 Cytokine Enhanced NK Cells (M-ceNK) Day 1 Cryopreservation For Future Uses Immunotherapy Portfolio Pipeline Clinical Updates Closing

NantKwest Platforms: Memory Cytokine

Enriched Natural Killer Cells (M-ceNK) & Mesenchymal Stem Cells (MSC) MSC M-ceNK Autologous & Allogeneic Memory Cytokine Enriched Stem Cells Bone Marrow, Cord Tissue Peripheral Blood Cord Blood Cytokine Enriched Closed System GMP in a Box

CAR Insertion Potential Current Status Phase Ib IND Ready Q1 2021 Clinical Indication COVID-19 Solid & Liquid Tumors M-ceNK Cytokine Enriched Natural Killer Autologous & allogeneic Donors GMP-in-a-Box

Immunotherapy Portfolio Pipeline Clinical Updates Closing

ImmunityBio: NK, T Cell and Macrophage

Platforms Immunotherapy Portfolio Pipeline Clinical Updates Closing Broad range immunotherapy products spanning antibody fusion proteins, immune-modulators and adenovirus platforms Phase 2 / 3 stage Breakthrough Designation Deep pipeline spanning

infectious disease and oncology Privately Held Aldoxorubicin Anktiva (N-803) Adenovirus (hAd5) Antibody Cytokine Fusion Proteins Activating NK & T Cells Albumin-Bound Immuno-Modulators Tumoricidal Macrophages Vaccine Technologies Memory T Cells

Mechanism of Action Core Modalities Lead pH- Sensitive Hydrazine Linker Albumin-binding site Cytokine Cytokine Fusion Antibody (IgG1) Spike Protein Nucleocapsid (N) Protein

Unparalleled Combined Immunotherapy

Platforms Aldoxorubicin Anktiva (N-803) Adenovirus (hAd5) Antibody Cytokine Fusion Proteins Activating NK & T Cells Albumin-Bound Immuno-Modulators Tumoricidal Macrophages Vaccine Technologies Memory T Cells Mechanism of Action Core Modalities

Lead pH- Sensitive Hydrazine Linker Albumin-binding site Cytokine Cytokine Fusion Antibody (IgG1) Spike Protein Nucleocapsid (N) Protein Natural Killer (NK) Natural Killer Off-the-Shelf NK Cells Autologous Memory ceNK Immunotherapy Portfolio

Pipeline Clinical Updates Closing

Phase Target Indication Pre-clinical Ph

I Ph II Ph III Fusion Proteins Aldoxorubicin Adenovirus Natural Killer Late Stage Clinical Development: Anktiva Bladder II / III BCG Unresponsive NMIBC Carcinoma In-Situ (CIS) Disease Anktiva II BCG Unresponsive NMIBC Papillary Disease

Anktiva Lung III 1L Squamous & Non-Squamous Non-Small Cell Lung Cancer CPI Alone Anktiva III 1L Non-Small Cell Lung Cancer CPI + Concurrent Chemo Anktiva IIb 2L or Greater Checkpoint Relapsed Non-Small Cell Lung Cancer

Anktiva PD-L1 t-haNK Glioblastoma II Recurrent Glioblastoma Anktiva Aldox Pancreatic II 3L Metastatic Pancreatic Cancer Anktiva Aldox PD-L1 t-haNK II / III 1L / 2L Metastatic Pancreatic

Cancer Anktiva Aldox PD-L1 t-haNK Breast Ib / II 3L or Greater Triple Negative Breast Cancer Anktiva Aldox haNK III 3L or Greater Triple Negative Breast Cancer Anktiva PD-L1

t-haNK Merkel II Recurrent Merkel Cell Carcinoma Anktiva haNK Colon II 3L Metastatic Colon Cancer (NCI) hAd5-CEA Infectious Disease COVID-19 I COVID-19 Therapeutic Anktiva I COVID-19 Vaccine Trials: TCELLVACCINE

hAd5 S-Fusion + N-ETSD hAd5 S+N HIV I ACTG / NIAID: HIV Broadly Neutralizing Antibodies Anktiva II Thai Red Cross: Reducing HIV Persistence by IL-15 Anktiva Antibody Cytokine Fusion Proteins N-820 Pre-IND Liquid Tumors:

IL-15 Superagonist + Anti CD20 Fusion Protein IL-15 / CD20 N-809 Pre-IND Solid Tumors: IL-15 Superagonist + Anti PD-L1 Fusion Protein IL-15 / PD-L1 N-830 Pre-IND Solid Tumors: Tumor Necrosis Targeting (TNT) TNT + TGFb Trap Fusion

Protein TNT / TGFb N-812 Pre-IND Solid Tumors: Tumor Necrosis Targeting (TNT) TNT + IL-12 Fusion Protein TNT / IL-12 NK Platform CD19 t-haNK IND Auth Diffuse Large B Cell Lymphoma CD-19 t-haNK HER2 t-haNK Pre-IND HER2+

Breast Cancer / Gastric Cancer HER2 t-haNK EGFR t-haNK Pre-IND EGFR+ Squamous Cell Carcinoma EGFR t-haNK M-ceNK Pre-IND All Solid & Liquid Tumors M-ceNK Pre-Clinical Fast Track Breakthrough & Fast Track Clinical

Stage Unparalleled Combined Platforms Across Oncology and Infectious Disease ImmunityBio ImmunityBio ImmunityBio NantKwest Pipeline Immunotherapy Portfolio Clinical Updates Closing

Significant Market Opportunity for Lead

Programs SARS-CoV-2 COVID-19 Vaccine ~350mm Targeted patients in the U.S. BCG Unresponsive Non-Muscle Invasive Bladder Cancer ~18k Targeted patients in the U.S. ~81k Bladder cancer patients in the U.S. Non-Small Cell Lung Cancer 1L Squamous &

Non-Squamous NSCLC 2L or Greater Checkpoint Relapsed NSCLC ~106k Targeted 1L patients in the U.S. ~21k patients in the U.S. Pancreatic Cancer 3L Metastatic Pancreatic Cancer 1L/2L Metastatic Pancreatic Cancer ~31k Targeted 3L patients in the U.S.

~49k | ~39k Targeted 1L and 2L, respectively, patients in the U.S. Pipeline Immunotherapy Portfolio Clinical Updates Closing BLADDER LUNG PANCREAS COVID-19 ~4 billion Global Population Developing Countries

Selected Summary of Upcoming Catalysts

Ph Trial Clinical Update Anticipated Timing Bladder II / III BCG Unresponsive NMIBC Carcinoma In-Situ (CIS) 2L Full Accrual Initial Readout for FDA Anticipated BLA Filing Q4 2020 1H 2021 2H 2021 II BCG Unresponsive NMIBC Papillary 2L Full Accrual

Initial Readout Q4 2021 Q1 2022 Lung III Non-Small Cell Lung 1L CPI Chemo Free Activating Sites / Enrolling Patients Ongoing III Non-Small Cell Lung Cancer 1L CPI + Concurrent Chemo Activating Sites / Enrolling Patients Ongoing IIb Checkpoint

Relapsed Lung 2L or Greater Confirm Registrational Protocol Design Q2 2021 Pancreatic II / III Pancreatic Cancer 3L Confirm Registrational Protocol Design 2H 2021 Breast II Triple Negative Breast Cancer 3L or Greater Confirm Registrational Protocol