title: Regulatory T Cell Responses in Participants with Type 1 Diabetes after a Single Dose of Interleukin-2: A Non-Randomised, Open Label, Adaptive Dose-Finding Trial.
abstract: BACKGROUND
  Interleukin-2 (IL-2) has an essential role in the expansion and function of CD4+ regulatory T cells (Tregs). Tregs reduce tissue damage by limiting the immune response following infection and regulate autoreactive CD4+ effector T cells (Teffs) to prevent autoimmune diseases, such as type 1 diabetes (T1D). Genetic susceptibility to T1D causes alterations in the IL-2 pathway, a finding that supports Tregs as a cellular therapeutic target. Aldesleukin (Proleukin; recombinant human IL-2), which is administered at high doses to activate the immune system in cancer immunotherapy, is now being repositioned to treat inflammatory and autoimmune disorders at lower doses by targeting Tregs.
  
  
  RESULTS
  To define the aldesleukin dose response for Tregs and to find doses that increase Tregs physiologically for treatment of T1D, a statistical and systematic approach was taken by analysing the pharmacokinetics and pharmacodynamics of single doses of subcutaneous aldesleukin in the Adaptive Study of IL-2 Dose on Regulatory T Cells in Type 1 Diabetes (DILT1D), a single centre, non-randomised, open label, adaptive dose-finding trial with 40 adult participants with recently diagnosed T1D. The primary endpoint was the maximum percentage increase in Tregs (defined as CD3+CD4+CD25highCD127low) from the baseline frequency in each participant measured over the 7 d following treatment. There was an initial learning phase with five pairs of participants, each pair receiving one of five pre-assigned single doses from 0.04 × 106 to 1.5 × 106 IU/m2, in order to model the dose-response curve. Results from each participant were then incorporated into interim statistical modelling to target the two doses most likely to induce 10% and 20% increases in Treg frequencies. Primary analysis of the evaluable population (n = 39) found that the optimal doses of aldesleukin to induce 10% and 20% increases in Tregs were 0.101 × 106 IU/m2 (standard error [SE] = 0.078, 95% CI = -0.052, 0.254) and 0.497 × 106 IU/m2 (SE = 0.092, 95% CI = 0.316, 0.678), respectively. On analysis of secondary outcomes, using a highly sensitive IL-2 assay, the observed plasma concentrations of the drug at 90 min exceeded the hypothetical Treg-specific therapeutic window determined in vitro (0.015-0.24 IU/ml), even at the lowest doses (0.040 × 106 and 0.045 × 106 IU/m2) administered. A rapid decrease in Treg frequency in the circulation was observed at 90 min and at day 1, which was dose dependent (mean decrease 11.6%, SE = 2.3%, range 10.0%-48.2%, n = 37), rebounding at day 2 and increasing to frequencies above baseline over 7 d. Teffs, natural killer cells, and eosinophils also responded, with their frequencies rapidly and dose-dependently decreased in the blood, then returning to, or exceeding, pretreatment levels. Furthermore, there was a dose-dependent down modulation of one of the two signalling subunits of the IL-2 receptor, the β chain (CD122) (mean decrease = 58.0%, SE = 2.8%, range 9.8%-85.5%, n = 33), on Tregs and a reduction in their sensitivity to aldesleukin at 90 min and day 1 and 2 post-treatment. Due to blood volume requirements as well as ethical and practical considerations, the study was limited to adults and to analysis of peripheral blood only.
  
  
  CONCLUSIONS
  The DILT1D trial results, most notably the early altered trafficking and desensitisation of Tregs induced by a single ultra-low dose of aldesleukin that resolves within 2-3 d, inform the design of the next trial to determine a repeat dosing regimen aimed at establishing a steady-state Treg frequency increase of 20%-50%, with the eventual goal of preventing T1D.
  
  
  BACKGROUND
  ISRCTN Registry ISRCTN27852285; ClinicalTrials.gov NCT01827735.
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: John A
authors.initials: JA
authors.lastname: Todd
authors.affiliation: Department of Mathematics, Imperial College London, London, United Kingdom.
authors.forename: Marina
authors.identifier: http://orcid.org/0000-0003-0789-8944
authors.initials: M
authors.lastname: Evangelou
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Antony J
authors.initials: AJ
authors.lastname: Cutler
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Marcin L
authors.initials: ML
authors.lastname: Pekalski
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Neil M
authors.initials: NM
authors.lastname: Walker
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Helen E
authors.initials: HE
authors.lastname: Stevens
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Linsey
authors.initials: L
authors.lastname: Porter
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Smyth
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Rainbow
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Ricardo C
authors.initials: RC
authors.lastname: Ferreira
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Laura
authors.identifier: http://orcid.org/0000-0003-3246-7855
authors.initials: L
authors.lastname: Esposito
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Kara M D
authors.identifier: http://orcid.org/0000-0002-8089-0693
authors.initials: KM
authors.lastname: Hunter
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Kevin
authors.identifier: http://orcid.org/0000-0001-9055-6894
authors.initials: K
authors.lastname: Loudon
authors.affiliation: National Institute for Health Research Cambridge Clinical Trials Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, United Kingdom.
authors.forename: Kathryn
authors.identifier: http://orcid.org/0000-0002-7843-7080
authors.initials: K
authors.lastname: Irons
authors.affiliation: Department of Immunobiology, Faculty of Life Sciences & Medicine, King's College London, National Institute of Health Research Biomedical Research Centre, Guy's and St Thomas' National Health Service Foundation Trust and King's College London, London, United Kingdom.
authors.forename: Jennie H
authors.initials: JH
authors.lastname: Yang
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Charles J M
authors.initials: CJ
authors.lastname: Bell
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Helen
authors.initials: H
authors.lastname: Schuilenburg
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: James
authors.identifier: http://orcid.org/0000-0002-2499-3663
authors.initials: J
authors.lastname: Heywood
authors.affiliation: Wellcome Trust/MRC Institute of Metabolic Science, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, Cambridge, United Kingdom.
authors.forename: Ben
authors.initials: B
authors.lastname: Challis
authors.affiliation: Wellcome Trust/MRC Institute of Metabolic Science, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, Cambridge, United Kingdom.
authors.forename: Sankalpa
authors.identifier: http://orcid.org/0000-0001-9519-0940
authors.initials: S
authors.lastname: Neupane
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Pamela
authors.initials: P
authors.lastname: Clarke
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Gillian
authors.initials: G
authors.lastname: Coleman
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Sarah
authors.initials: S
authors.lastname: Dawson
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Donna
authors.initials: D
authors.lastname: Goymer
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Katerina
authors.identifier: http://orcid.org/0000-0002-9533-100X
authors.initials: K
authors.lastname: Anselmiova
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Jane
authors.initials: J
authors.lastname: Kennet
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Judy
authors.initials: J
authors.lastname: Brown
authors.affiliation: Division of Virology, Department of Pathology, Addenbrooke's Hospital, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Sarah L
authors.identifier: http://orcid.org/0000-0002-9790-7420
authors.initials: SL
authors.lastname: Caddy
authors.affiliation: Division of Virology, Department of Pathology, Addenbrooke's Hospital, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Jia
authors.identifier: http://orcid.org/0000-0003-3995-324X
authors.initials: J
authors.lastname: Lu
authors.affiliation: Public Health England, Clinical Microbiology and Public Health Laboratory, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, United Kingdom.
authors.forename: Jane
authors.initials: J
authors.lastname: Greatorex
authors.affiliation: Division of Virology, Department of Pathology, Addenbrooke's Hospital, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Ian
authors.initials: I
authors.lastname: Goodfellow
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.|MRC Biostatistics Unit Hub for Trials Methodology Research, Cambridge Institute of Public Health, Cambridge Biomedical Campus, Cambridge, United Kingdom.
authors.forename: Chris
authors.identifier: http://orcid.org/0000-0001-9755-1703
authors.initials: C
authors.lastname: Wallace
authors.affiliation: Department of Immunobiology, Faculty of Life Sciences & Medicine, King's College London, National Institute of Health Research Biomedical Research Centre, Guy's and St Thomas' National Health Service Foundation Trust and King's College London, London, United Kingdom.
authors.forename: Tim I
authors.identifier: http://orcid.org/0000-0002-6973-5377
authors.initials: TI
authors.lastname: Tree
authors.affiliation: Wellcome Trust/MRC Institute of Metabolic Science, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, Cambridge, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Evans
authors.affiliation: MRC Biostatistics Unit Hub for Trials Methodology Research, Cambridge Institute of Public Health, Cambridge Biomedical Campus, Cambridge, United Kingdom.
authors.forename: Adrian P
authors.initials: AP
authors.lastname: Mander
authors.affiliation: National Institute for Health Research Cambridge Clinical Trials Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, United Kingdom.|MRC Biostatistics Unit Hub for Trials Methodology Research, Cambridge Institute of Public Health, Cambridge Biomedical Campus, Cambridge, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Bond
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Linda S
authors.initials: LS
authors.lastname: Wicker
authors.affiliation: JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Frank
authors.identifier: http://orcid.org/0000-0002-0597-4328
authors.initials: F
authors.lastname: Waldron-Lynch
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers; D018925:Chemokines / Q000096:biosynthesis; D003922:Diabetes Mellitus, Type 1 / Q000517:prevention & control*; D004305:Dose-Response Relationship, Drug; D004804:Eosinophils / Q000187:drug effects; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D018836:Inflammation Mediators / Q000378:metabolism; D007376:Interleukin-2 / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins / Q000009:adverse effects / Q000494:pharmacology; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D018925:Chemokines; D018836:Inflammation Mediators; D007376:Interleukin-2; D011994:Recombinant Proteins; C082598:aldesleukin