NKX101, Intravenous Allogeneic CAR NK Cells, in Adults With AML or MDS

A Phase 1 Study of NKX101, an Activating Chimeric Receptor Natural Killer Cell Therapy, in Subjects With Hematological Malignancies or Dysplasias

This is a single-arm, open-label, multi-center, Phase 1 study to determine safety and tolerability of an experimental therapy called NKX101 (allogeneic CAR NK cells targeting NKG2D ligands) in patients with relapsed/refractory AML or intermediate, high and very high risk relapsed/refractory MDS.

Study Overview

• Status: Active, not recruiting
• Conditions: MDS; AML, Adult; Relapsed/Refractory AML; Refractory Myelodysplastic Syndromes
• Intervention / Treatment: Biological: NKX101 - CAR NK cell therapy

Detailed Description

This is a dose-finding study of NKX101 and will be conducted in 2 parts:

Part 1: dose finding with two dosing regimens, utilizing modified "3+3" enrollment schema.

Part 2: dose expansion to further evaluate safety and tolerability, cellular kinetics, pharmacodynamics and anti-tumor response in expansion cohorts of patients with either AML or MDS.

• Study Type: Interventional
• Enrollment (Actual): 61
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Colorado
    • Denver, Colorado, United States, 80218
      • Colorado Blood Cancer Institute
  • Florida
    • Jacksonville, Florida, United States, 32224
      • Mayo Clinic Florida
  • Georgia
    • Atlanta, Georgia, United States, 30322
      • Winship Cancer Institute, Emory University
  • Illinois
    • Chicago, Illinois, United States, 60637
      • University of Chicago Medical Center
  • Ohio
    • Cleveland, Ohio, United States, 44195
      • The Cleveland Clinic - Taussig Cancer Institute
  • Tennessee
    • Nashville, Tennessee, United States, 37203
      • Sarah Cannon at TriStar Bone Marrow Transplant Center
  • Texas
    • Houston, Texas, United States, 77030
      • MD Anderson Cancer Center, University of Texas
    • San Antonio, Texas, United States, 78229
      • Methodist Healthcare System of San Antonio

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• General:

  • ECOG performance status ≤2

• Disease related:

  • For AML subjects:

    • Previously treated relapsed/refractory AML, including subjects with MRD+ disease
    • Received at most 3 lines of previous anti-leukemia therapy
    • For subjects with targetable fms-like tyrosine kinase 3 (FLT3)-mutated or isocitrate dehydrogenase (IDH)1/2 mutated disease, subjects must have received at least 1 prior respective targeted therapy and may receive up to 4 lines of prior therapy
    • White blood cell count of ≤25 × 10^9/L
    • For groups receiving NKX101 after lymphodepletion with fludarabine/cyclophosphamide +/- decitabine: Disease localized to the bone marrow, as evidenced by ≤ 5% peripheral blasts and no evidence of extramedullary disease
    • For groups receiving NKX101 after lymphodepletion with fludarabine/ cyclophosphamide +/- decitabine, group receiving NKX101 after lymphodepletion with fludarabine/ara-C: Additional subjects with specifically high-risk genetic mutations may be enrolled. High risk genetic mutation per ELN 2022 should be evaluated as per local assay and discussed with the Sponsor prior to study entry
    • For groups receiving NKX101 after lymphodepletion with fludarabine/cyclophosphamide +/- decitabine, group receiving NKX101 after lymphodepletion with fludarabine/ara-C: Additional subjects who have relapsed following HCT may be enrolled.

  • For MDS subjects:

    • Intermediate-, high-, or very high-risk MDS
    • Previously treated relapsed/refractory MDS
    • Received at least 1 and at most 3 lines of previous standard anti-MDS therapy
    • For groups receiving NKX101 after lymphodepletion with fludarabine/ cyclophosphamide +/- decitabine: Additional subjects with specifically high-risk disease may be enrolled. High-risk genetic mutation should be evaluated as per local assay
    • For group receiving lymphodepletion with fludarabine/cyclophosphamide +/- decitabine and NKX101: Additional subjects who have relapsed following HCT may be enrolled.
• Adequate Organ Function
• Platelet count ≥30,000/uL (platelet transfusions acceptable)

• Other:

  • Signed informed consent
  • Agree to use an effective barrier method of birth control

Exclusion Criteria:

• Disease related:

  • Acute promyelocytic leukemia with t(15;17) (q22;q12); or abnormal promyelocytic leukemia/retinoic acid receptor alpha (APML-RARA) and AML arising from chronic myelomonocytic leukemia (CMML)
  • Evidence of leukemic meningitis or known active central nervous system disease
  • Peripheral leukocytosis with ≥ 20,000 blasts/μL or other evidence of rapidly progressive disease that would preclude subject from completing at least 1 cycle of treatment
  • Use of any anti-AML/MDS chemotherapeutic or targeted small molecule drug within protocol specified window prior to the first dose of NKX101
  • Presence of residual non-hematologic toxicity from prior therapies that has not resolved to ≤ Grade 1
  • Any hematopoietic cell transplantation within 16 weeks
• Other comorbid conditions and concomitant medications prohibited as per study protocol

• Other:

  • Pregnant or lactating female

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: NKX101 - CAR NK cell therapy; All subjects in Part 1 will receive lymphodepletion with fludarabine/cyclophosphamide followed by 3 or 2 (Regimen A or B, respectively) weekly doses of NKX101. Subjects in Part 2 will receive lymphodepletion with either fludarabine/cyclophosphamide or fludarabine/cytarabine (ara-C), or if the optional arm is opened, lymphodepletion with fludarabine/cyclophosphamide and decitabine, followed by 3 weekly doses of NKX101. Part 2: unrelated off-the-shelf donor derived NKX101 will be used.

Biological: NKX101 - CAR NK cell therapy; NKX101 is an investigational allogeneic CAR NK product targeting NKG2D ligands on cancer cells. Part 2 will use the maximum tolerated dose (MTD) or recommended Phase 2 dose (RP2D) of NKX101 as determined in Part 1.; Other Names: Cyclophosphamide; Decitabine; Fludarabine; Cytarabine (ara-C)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability]	Incidence, nature, and severity of treatment related adverse events will be evaluated. An adverse event is any unfavorable and unintended sign including clinically significant abnormal laboratory findings, symptom or disease.	30 days after last dose of NKX101
Response rate to NKX101 (for Part 2)	Responses will be assessed per modified ELN criteria and will include complete and partial remission with and without varying degrees of hematologic recovery	28 days from first dose of NKX101

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of NKX101 half-life	Time required for 50% reduction from maximum amount of circulating NKX101	28 days from first dose of NKX101
NKX101 duration of persistence	Testing NKX101 in peripheral blood every 3 months after dosing to determine persistence	Followed up to 2 years after last dose of NKX101
Evaluation of host immune response against NKX101	Serum samples will be measured for antibodies against NKX101	Followed up to 2 years after last dose of NKX101
Response rate to NKX101	Time-to-first response, time-to-best response, duration of response, transfusion independent rate, bridge-to-transplant rate, event-free survival, progression-free survival (PFS), overall survival (OS) (for all subjects), and hematologic improvement rates (for subjects with myelodysplastic syndrome [MDS])	Primary assessment: 28 days after first dose of NKX101 followed up to 2 years after last dose of NKX101

Collaborators and Investigators

• Sponsor: Nkarta, Inc.
• Investigators: Study Director: David Shook, MD, Nkarta, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): September 21, 2020
• Primary Completion (Actual): October 2, 2024
• Study Completion (Estimated): July 1, 2039

Study Registration Dates

• First Submitted: September 25, 2020
• First Submitted That Met QC Criteria: November 9, 2020
• First Posted (Actual): November 10, 2020

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: December 20, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Keywords: Cell Therapy; Immunotherapy; Allogeneic; CAR; NK cell; NKG2D; IL15; Adoptive cell therapy; Off-the-shelf; ACR; Natural killer; NKX101; Interleukin 15; r/r AML
• Additional Relevant MeSH Terms: Hematologic Diseases; Bone Marrow Diseases; Myelodysplastic Syndromes; Anti-Infective Agents; Antineoplastic Agents; Immunosuppressive Agents; Immunologic Factors; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Enzyme Inhibitors; Antirheumatic Agents; Antimetabolites, Antineoplastic; Antimetabolites; Antiviral Agents; Antineoplastic Agents, Alkylating; Alkylating Agents; Myeloablative Agonists; Decitabine; Cyclophosphamide; Fludarabine; Cytarabine
• Other Study ID Numbers: NKX101-101

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No