Natural Killer-cell Therapy for Acute Myeloid Leukemia

Study Overview
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Brief Summary
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This study investigates an innovative treatment for relapsed or refractory acute myeloid leukemia exploiting administration of ex vivo-generated allogeneic natural killer (NK) cells with preceding non-myeloablative conditioning chemotherapy with or without subsequent in vivo IL-2 cytokine support.

Detailed Description
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This study investigates an innovative treatment for relapsed or refractory acute myeloid leukemia (AML) exploiting administration of ex vivo-generated allogeneic natural killer (NK) cells with preceding non-myeloablative conditioning chemotherapy with or without subsequent in vivo IL-2 cytokine support. This is a prospective phase I/IIa study. The first phase is a IL-2 dose-escalating safety study in twelve patients. The second phase of the study is designed as a Simon's optimal two-stage single-arm phase IIa study, comprising seventeen patients. Prior to NK cell infusion, all patients will receive cyclophosphamide and fludarabine (Cy/Flu) based lymphodepleting chemotherapy. On day 0, all patients will receive a fixed dose of 1.0-3.0 x 10^9 allogeneic umbilical cord blood-derived NK cells (UCB-NK cells). These cells are generated ex vivo from CD34+ hematopoietic progenitor cells obtained from an allogeneic UCB unit. In phase I of the study patients will receive UCB-NK cells without subcutaneous (SC) IL-2, with lower dose SC IL-2 or with higher dose SC IL-2 (n=3 per treatment group, n=6 in the highest tolerable dose). After establishing the safety of UCB-NK cells combined with SC IL-2, we will continue with phase IIa of the study, with ten patients in the first stage (including the six patients from phase I with comparable IL-2 dose) and if clinical efficacy is achieved an additional seven patients in the second stage.

Official Title
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Infusion of ex Vivo-generated Allogeneic Natural Killer Cells in Combination With Subcutaneous IL-2 in Patients With Acute Myeloid Leukemia: a Phase I/IIa Study

Conditions
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Acute Myeloid Leukemia Refractory, Acute Myeloid Leukemia, Relapsed, Adult

Intervention / Treatment
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* Biological: UCB-NK cells
* Drug: IL-2


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: AML patients (de novo and secondary) or patients with MDS excess blasts-2 according to WHO criteria 2016, who have stable disease or non-rapidly progressive disease with or without disease controlling medication who are (at time of inclusion) ineligible for allo-SCT. Patients may belong to any of the following categories: Relapsed/refractory disease after treatment with intensive chemotherapy, hypomethylating agents, targeted agents, autologous or allo-SCT (at least 6 months ago) and DLI Newly diagnosed, untreated patients ineligible for allo-SCT Other inclusion criteria: Age ≥ 18 years WHO performance 0-2 Life expectancy of > 4 months Written informed consent Hydrea is allowed as pre-treatment to control blast count until day -3 Other disease controlling medication is allowed until day -7 Exclusion Criteria: Progressive disease according to ELN criteria in case of previous therapy Patients on immunosuppressive drugs or active GvHD Patients with active infections (viral, bacterial or fungal); acute anti-infectious therapy must have been completed within 14 days prior to study treatment Severe cardiovascular disease (CTCAE III-IV) Severe pulmonary dysfunction (CTCAE III-IV) Severe renal dysfunction (CTCAE III-IV) Severe hepatic dysfunction (CTCAE III-IV) Severe neurological or psychiatric dysfunction (CTCAE III-IV) Patients on concurrent chemotherapy or interferon-alpha treatment Pregnancy or breastfeeding

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The study is divided in two phases. In phase I, we will determine the safety of our UCB-NK cell product with or without sc IL-2, following a non-myeloablative immunosuppressive conditioning regimen in patients with AML. Three patients will receive NK cells without IL-2. If no dose limiting toxicities occur another three patients will receiving NK cells with a low dose IL-2, and if safe, another six patients will receive NK cells with a higher dose IL-2. The primary objective of phase IIa of the study is to evaluate the effect of UCB-NK cell adoptive immunotherapy in combination with SC IL-2 following a non-myeloablative immunosuppressive conditioning regime on disease activity in patients with AML. Therefore 17 patients will be evaluated using a Simon's optimal two-stage single-arm study design, with 10 patients in the first stage and an additional 7 patients in the second stage. These patients will receive NK cells with the highest tolerable dose IL-2, established after phase I.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: NK cells without IL-2<br>On day 0, patients will receive a fixed dose of 1.0-3.0 x 10^9 allogeneic UCB-NK cells. Prior to NK cell infusion, patients will receive cyclophosphamide and fludarabine (Cy/Flu) based lymphodepleting chemotherapy. NK cells administration will not be followed by sc IL-2. N=3. | Biological: UCB-NK cells<br>* Natural killer cells generated from CD34+ hematopoietic progenitor cells derived from an allogeneic umbilical cord blood<br>|
| Active Comparator: NK cells with low dose IL-2<br>On day 0, patients will receive a fixed dose of 1.0-3.0 x 10^9 allogeneic UCB-NK cells. Prior to NK cell infusion, patients will receive cyclophosphamide and fludarabine (Cy/Flu) based lymphodepleting chemotherapy. IL-2 will be administered in a fixed dose of 3.0 x 10^6 units starting 4 hours after NK cell infusion and given every other day for 6 doses in total. N=3 | Biological: UCB-NK cells<br>* Natural killer cells generated from CD34+ hematopoietic progenitor cells derived from an allogeneic umbilical cord blood<br>Drug: IL-2<br>* In vivo cytokine support<br>* Other names: Aldesleukin;|
| Active Comparator: NK cells with higher dose IL-2<br>On day 0, patients will receive a fixed dose of 1.0-3.0 x 10^9 allogeneic UCB-NK cells. Prior to NK cell infusion, patients will receive cyclophosphamide and fludarabine (Cy/Flu) based lymphodepleting chemotherapy. IL-2 will be administered in a fixed dose of 6.0 x 10^6 units starting 4 hours after NK cell infusion and given every other day for 6 doses in total. N=6 | Biological: UCB-NK cells<br>* Natural killer cells generated from CD34+ hematopoietic progenitor cells derived from an allogeneic umbilical cord blood<br>Drug: IL-2<br>* In vivo cytokine support<br>* Other names: Aldesleukin;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Phase I: Evaluate Safety and Toxicity using the CTCAE toxicity criteria | Patients will be evaluated intensively using the CTCAE toxicity criteria and graft versus host disease (GvHD) classification criteria, defining dose limiting toxicities (DLTs): 1. Any treatment-emergent non-hematologic grade 3 toxicity lasting >72 hours, except for transient constitutional symptoms, diarrhea, fatigue or skin rash not requiring systemic steroid therapy. 2. Acute GvHD >grade 2 within 6 weeks of the first IL-2 dose. If in any of the three patients of each individual cohort of the phase I study a DLT occurs, the cohort will be extended to 6 patients. If 2 patients experience DLT within a cohort of 3 or 6 patients the study will be stopped in case the patients were only receiving NK cells or the study will be continued without IL-2 or the lower dose of IL-2 in case the patients were receiving NK cells in combination with IL-2. Serious, life threatening adverse events or grade 4 toxicity will be a reason to terminate the study or continue without IL-2 cytokine support. | 28 days | 
| Phase IIa: % blasts or % minimal residual disease (MRD) in the bone marrow | The primary objective of phase IIa of the study is to evaluate the effect of UCB-NK cell adoptive immunotherapy in combination with SC IL-2 following a non-myeloablative immunosuppressive conditioning regime on disease activity in patients with AML. At day 28 a bone marrow biopsy will be performed to evaluate % blasts or % minimal residual disease (MRD) in the bone marrow. A complete remission is defined as BM blasts <5%; marrow should not be merely 'aplastic': at least 200 cells should be enumerated or cellularity should be at least 10%. MRD will be evaluated by flow cytometry (leukemia associated phenotypes (LAPs)) and/or molecular quantification of patient specific mutations (PCR). For phase IIa of the study the clinical evaluation data (% blasts and % MRD positivity) will be translated in a clinical response (stable disease, partial remission, complete remission) and quantitative presented. | 28 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of the in vivo lifespan and expansion potential of the NK cells following adoptive transfer and IL-2 administration. | We will determine the percentage and absolute number of donor-derived NK cells in peripheral blood and bone marrow after infusion using flow cytometry and DNA chimerism analysis. A positive expansion rate of the infused NK cells requires an absolute number of ≥100 donor-derived NK cells per μl blood at day +7 and/or +14. | 28 days | 
| Exploration of the functional activity of the donor NK cells in PB and BM, with or without SC IL-2 administration. | NK cells from peripheral blood and bone marrow will be obtained. These cells will be stimulated in vitro for 4 hours and subsequently the degranulation marker CD107a and immunoregulatory marker IFNy will be measured by flow cytometry. These results can be compared between patients that did receive IL-2 or did not. | 28 days | 
| Evaluation of plasma cytokine concentrations (IL-2, IL-15, IL-7, IFN-γ, TNFα, IL-6) pre- and post-infusion of IL-2. | This will be correlated with absolute lymphocyte count and in vivo NK cell persistence and expansion. | 28 days | 
| Number of patients eligible for allo-SCT based on hematologic response | Only in Phase IIa. | 28 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Natural Killer cells, Acute Myeloid Leukemia, Cellular Immunotherapy