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Diabetes and endocrinology
Protocol
Phase III, randomised, double-blind, placebo-controlled, multicentre trial to evaluate the efficacy and safety of rhGAD65 to preserve endogenous beta cell function in adolescents and adults with recently diagnosed type 1 diabetes, carrying the genetic HLA DR3-DQ2 haplotype: the DIAGNODE-3 study protocol
  1. Johnny Ludvigsson1,2,
  2. Linnea Eriksson3,
  3. Christoph Nowak3,4,
  4. Pedro F Teixeira3,
  5. Martina Widman3,
  6. Anton Lindqvist3,
  7. Rosaura Casas1,
  8. Marcus Lind5,6,
  9. Ulf Hannelius3
  1. 1Division of Pediatrics, Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
  2. 2Crown Princess Victoria Children's Hospital, Linköping, Sweden
  3. 3Diamyd Medical AB, Stockholm, Sweden
  4. 4Department of Neurobiology, Care Sciences and Society, Karolinska Institute, Stockholm, Sweden
  5. 5Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden
  6. 6NU-Hospital Group and the Sahlgrenska University Hospital, Uddevalla and Gothenburg, Sweden
  1. Correspondence to Professor Johnny Ludvigsson; johnny.ludvigsson{at}liu.se

Abstract

Introduction Type 1 diabetes (T1D) is an autoimmune disease leading to the destruction of the insulin-producing beta cells resulting in insulin deficiency and hyperglycaemic. Today, no approved therapy exists to halt this detrimental immunologic process. In a recent phase 2b study, intralymphatic administration of recombinant human glutamic acid decarboxylase 65 kDa (rhGAD65) adsorbed to Alhydrogel adjuvant to individuals recently diagnosed with T1D and carrying the HLA DR3-DQ2 haplotype showed promising results in preserving endogenous insulin secretion, confirming the results of a large meta-analysis of three randomised placebo-controlled trials of subcutaneous rhGAD65. The aim of the current precision medicine phase 3 study is to determine whether intralymphatic administration of rhGAD65 preserves insulin secretion and improves glycaemic control in presumed responder individuals with recently diagnosed T1D carrying HLA DR3-DQ2.

Methods and analysis Individuals ≥12 and <29 years recently diagnosed with T1D (<6 months) will be screened for the HLA DR3-DQ2 haplotype, endogenous insulin production estimated by fasting C-peptide and presence of GAD65 antibodies. 330 patients are planned to be randomised to 3 monthly intralymphatic injections of rhGAD65 or placebo (both accompanied by oral vitamin D supplementation), followed by 22 months of follow-up. The study is powered to detect a treatment effect in the two coprimary endpoints; change from baseline in AUC(0-120min) C-peptide levels during a mixed meal tolerance test, and change from baseline in glycaemic control estimated by haemoglobin A1c at 24 months. Secondary endpoints include effects on glucose patterns collected by masked continuous glucose monitoring, proportion of patients in partial remission and number of episodes of severe hypoglycaemia and/or diabetic ketoacidosis.

Ethics and dissemination The trial is approved by Ethics Committees in Poland (124/2021), the Netherlands (R21.089), Sweden (2021-05063), Czech Republic (EK-1144/21), Germany (2021361) and Spain (21/2021). Results will be published in international peer-reviewed scientific journals and presented at national and international conferences.

Trial registration number EudraCT identifier: 2021-002731-32, NCT identifier: NCT05018585.

  • General diabetes
  • IMMUNOLOGY
  • Clinical trials
http://creativecommons.org/licenses/by-nc/4.0/

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.

https://doi.org/10.1136/bmjopen-2022-061776

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    STRENGTHS AND LIMITATIONS OF THIS STUDY

    • The current study is a large, international, multicentre, randomised double-blind placebo-controlled trial.

    • The study is adequately powered to detect a treatment effect on two clinically important coprimary endpoints; preservation of beta cell function and glycaemic control (haemoglobin A1c).

    • The total study duration of 24 months should allay concerns about confounding from the so-called honeymoon period in recently diagnosed type 1 diabetes (T1D).

    • This is the first phase 3 trial in T1D using a precision medicine approach, limiting recruitment to the identified HLA DR3-DQ2 responder population to recombinant human glutamic acid decarboxylase 65 kDa treatment.

    • To fully understand the magnitude of a possible beneficial treatment effect, additional follow-up over several years might be needed to see the benefits of even minimum residual beta cell function.

    Introduction

    Type 1 diabetes (T1D) is an autoimmune disorder in which the immune system attacks the insulin producing beta cells in the pancreas. By the time an individual is diagnosed with T1D, 70%–90% of beta cell function has generally been lost. The destruction of the pancreatic beta cells in T1D is associated with cellular immune responses towards the pancreatic islet cells.1 Autoantibodies directed against glutamic acid decarboxylase (GAD) with a molecular mass 65 kDa (GAD65A), insulinoma-associated protein 2 (IA-2A), insulin (IAA) or zinc transporter antigen T8 (ZnT8A) precede the clinical onset of the disease.1

    T1D treatment consists of lifelong administration of exogenous insulin, which does not satisfactorily prevent neither acute nor long-term complications. The disease has a devastating impact on the quality of life (QoL) of the affected person and their family due to the constant stress of adjusting blood sugar and the common acute and life-threatening consequences of imperfect control—diabetic ketoacidosis (DKA) and severe hypoglycaemia.2–4 In addition, many individuals with T1D experience over the long term both macrovascular and microvascular complications affecting the heart, nerves, eyes and kidneys, putting them at risk of blindness, kidney failure and myocardial ischaemia.5 6 A recent article7 concluded that patients who received their diagnosis before the age of 10 years had a shortened lifespan by 14 years for males and 18 years for females. Early-onset T1D was also found to be associated with 30 times increased risk of serious cardiovascular outcomes and for women, this risk was 90 times higher compared with non-diabetic control persons.7 Even with good long-term blood glucose control (haemoglobin A1c, HbA1c ≤52 mmol/mol), the risk of premature death for any T1D patient is found to be twice as high as for healthy individuals and up to eight times higher for patients with poor glycaemic control.8

    There is currently no approved treatment preventing the destruction of beta cells. Insulin replacement therapy is the standard-of-care treatment, and despite the development of new insulins, new technologies for insulin administration and blood glucose diagnostics, patient targets for long-term blood glucose are currently met less frequently than 5 years ago in some populations in the USA.9 Any intervention which can stop or delay the loss of beta cell function would likely provide protection against hypoglycaemia and ketoacidosis, improve metabolic control, decrease blood glucose fluctuations, facilitate treatment and delay and/or reduce microvascular and macrovascular complications of diabetes.10–13 In addition, decreasing the autoimmune destruction of beta cells could allow for beta cell replenishment, either through regeneration or transplantation.

    The most efficient immune therapy for preservation of beta cell function is so far treatment with anti-CD3 monoclonal antibodies (teplizumab).14 15 TNF-alfa inhibitors,16 anti-thymocyte globulin,17 alefacept18 and rituximab19 have also demonstrated some efficacy in preserving beta cell function, but often these therapies have adverse events (AEs), serious risks and impose a heavy treatment burden, including, for example, several days of intravenous infusions. An alternative approach is treatment with autoantigen immunotherapies, even though most clinical trials with autoantigen immunotherapies have failed to meet their primary endpoints or shown inconclusive results.20–23

    Over the last two decades, however, an important development in the field has meant a shift away from a one-size-fits-all approach to T1D pathophysiology towards a more individualised, precision medicine approach that recognises inter-individual heterogeneity in T1D.24 The concept of disease heterogeneity has recently been extended to the concept of endotypes; that is, subtypes of T1D with distinct underlying pathobiological mechanisms, which should be considered in the design of clinical trials.25 For instance, the appearance of GAD65 autoantibodies (GADA) as the first autoantibody is linked to the juman leucocyte antigen (HLA) DR3-DQ2 haplotype, while the emergence of insulin autoantibodies as the first antibody is linked to HLA DR4-DQ8.25 26 As a consequence, applying the same intervention targeting a specific pathophysiological mechanism across an entire population ignores the fact that subgroups of patients whose disease is driven by the targeted mechanism may respond particularly well, while others show no response, resulting in apparently absent treatment effects across the entire population.

    GAD antigen-specific immunotherapy to preserve endogenous insulin secretion

    GAD65 is a major autoantigen in autoimmune diabetes, and clinical administration of purified recombinant human GAD65 rhGAD65 aims to intervene in the autoimmune process in T1D. The rhGAD65 is adsorbed to Alhydrogel (aluminium hydroxide particles) and formulated in phosphate buffer with mannitol. The intended mode of action is to slow or prevent autoimmune destruction of pancreatic beta cells by modulation of immune responses to GAD65. Inconsistent results observed in trials testing subcutaneous administration of rhGAD65 spurred the evaluation of alternative approach to improve treatment efficacy.20–22 27 DIAGNODE-1,28 29 a phase 1/2a open-label pilot combination trial evaluated an alternative administration route, with three doses of 4 µg rhGAD65 administered directly into inguinal lymph nodes, in combination with oral vitamin D in 12 patients (12–30 years of age) recently diagnosed with T1D. All patients were followed for 30 months. The positive results of the DIAGNODE-1 trial29 supported further development in a Phase 2b trial (DIAGNODE-2), a randomised and placebo-controlled trial testing the intralymphatic administration in 109 patients (12–24 years of age) recently diagnosed with T1D. Importantly, based on the concept of heterogeneity of disease mechanism, a meta-analysis of three previous Randomized Control Trials testing subcutaneous rhGAD65 was performed. The analysis showed that clinical efficacy is mainly seen in patients with HLA DR3-DQ2, and an even more pronounced treatment effect was seen in those individuals with HLA DR3DQ2 without HLA DR4-DQ8 though no clinical efficacy was observed in the full population.30 Due to the identification of HLA DR3-DQ2 patients as the responder population, the statistical analysis plan of the then ongoing DIAGNODE-2 study was amended before database lock to include analyses of the primary and secondary endpoints in the HLA DR3-DQ2 subgroup in the topline results. At 15 months of follow-up in DIAGNODE-2, rhGAD65 treatment showed a significant positive treatment effect in the prespecified genetic subgroup of patients positive for HLA DR3-DQ2 of 55.7% (p=0.0078), that is, that on average, the primary end point stimulated C-peptide secretion Area Under the Curve (AUC)mean 0-120 min declined by 55.7% less in patients treated with rhGAD65 compared with patients treated with placebo. For patients positive for HLA DR3-DQ2, C-peptide AUCmean 0-120 min declined approximately 28% over 15 months in the rhGAD65 group compared with about 58% for placebo.31 There were corresponding trends, though not statistically significant, in improvement in the secondary efficacy variables HbA1c, IDAA1c and exogenous insulin use after 15 months in the HLA DR3-DQ2-positive patients treated with rhGAD65 when compared with placebo.

    Results from an updated meta-analysis (manuscript in preparation) which added data from DIAGNODE-2 to the previous meta-analysis30 showed that in patients carrying the HLA DR3-DQ2-haplotype, a statistically significant treatment effect on change in AUC C-peptide of 48.3% for the subjects receiving 3 or 4 injections of rhGAD65 (p<0.0001) and 36.1% for the 2–4 injections (p=0.0316) . In addition to this, a statistically significant treatment effect on change in HbA1c of −4.789 mmol/mol for the subjects receiving 3 or 4 injections of rhGAD65 (p=0.0044) and −3.120 mol/mol for subjects receiving 2–4 injections (p=0.032). The data also reconfirmed previous findings that an even more pronounced treatment effect (on both change in AUC C-peptide and HbA1c) was seen in those individuals with HLA DR3DQ2 without HLA DR4-DQ8. Intralymphatic rhGAD65 injections were well tolerated and considered safe, consistent with prior clinical trial findings.31

    Objectives

    The primary objective is to evaluate the effect of three doses of rhGAD65 compared with placebo in terms of1 beta cell function; and2 glycaemic control in adolescents and adults recently diagnosed with T1D, who carry the HLA DR3-DQ2 haplotype. Secondary objectives are to compare the effect of rhGAD65 to placebo treatment with respect to the effects on other diabetes disease management indicators and long-term safety.

    Method and analysis

    Overall study design

    DIAGNODE-3 is a phase III randomised, double-blind, placebo-controlled, international, multicentre, parallel-arm, 24-month trial in adolescents and adults with recently diagnosed T1D, carrying the HLA DR3-DQ2 haplotype. Overall study design is shown in figure 1. The study is registered on Clinicaltrials.gov (NCT05018585). The study is expected to take 4.5 years to complete. This includes an intervention with follow-up for 24 months.

    Figure 1
    Figure 1

    Schematic overview of the study design.

    Throughout the study duration, all patients will receive standard-of-care routine treatment for their diabetes according to ADA guidelines (amended as appropriate to reflect local standard of care).

    Screening and run-in period

    Patients deemed eligible and/or their parent(s)/legal guardian(s) will have the study explained to them and will receive written patient information. After having had the time to review the study, they will have the opportunity to ask questions to the investigational team. After this, if the patient agrees to participate, they will sign and date the written informed consent form and for patients who are minors, both age-appropriate assent (according to local regulations) and parent’s/caregiver’s consent is collected. Patients and their parent(s)/legal guardian(s), when applicable, will provide written informed consent before any study-related procedures are performed. The patient and/or their parent(s)/legal guardian(s) will then receive a copy of the signed and dated patient information. Detailed study assessments are shown in table 1. HLA genotyping of the patient is performed at the first screening visit after preliminary eligibility is confirmed. If the patient is carrying the HLA DR3-DQ2 haplotype, the patient will attend the second screening visit (visit 1B) to perform the remaining screening procedures. After screening, patients deemed eligible will proceed to the run-in period (beginning at visit 1C) undergo masked CGM for 14 days, receive diabetes education and collect self-reported diabetes information in their eDiary.

    View this table:
    Table 1

    Schedule of assessments in diagnode-3

    Patients with a screening vitamin D level <100 nmol/L (40 ng/mL) will start oral vitamin D supplementation (2000 IU daily) beginning at visit 1C, 30 days prior to randomiszation. During the period of supplementation, vitamin D should be discontinued temporarily if the level exceeds 125 nmol/L (50 ng/mL) and may be resumed when levels are <100 nmol/L (40 ng/mL).

    Double-blind treatment period and long-term follow-up

    At visit 2, patients will be randomised 2:1 to one of the following two treatment groups:

    View this table:

    Randomisation will be performed by an Interactive Web Response Systems and stratified by HLA subgroup (presence or absence of HLA DR4-DQ8) and by region. The maximum number of adults (>18 years) recruited into the trial is 160. rhGAD65 or placebo injections will be administered in the inguinal lymph node by qualified personnel with the help of ultrasound. Vitamin D levels will be monitored throughout the trial. Vitamin D oral supplementation (2000 IU daily) will be administered from day −30 (Visit 1C) to day 90 for a total of 120 days for patients with a level<100 nmol/L (40 ng/mL) atscreening. All patients will continue to receive intensive insulin therapy via multiple daily injections or via CSII. Safety will be assessed via physical examinations, neurological assessments, vital signs, clinical laboratory assessments, injection site reactions and AEs. After the double blinded treatment period of 2 months, patients will be followed in a blinded manner for 22 months. An independent DSMB will be appointed to review unblinded safety data (at least twice a year).

    Study population

    Individuals between ≥12 and <29 years old, will be eligible for enrollment if they have been diagnosed with T1D within the previous 6 months at the time of screening, positive for the HLA DR3-DQ2 haplotype, fasting C-peptide is ≥0.12 nmol/L (0.36 ng/mL) and seropositive for GADA. Full list of inclusion and exclusion criteria is shown in tables 2 and 3.

    View this table:
    Table 2

    Inclusion criteria in the diagnode-3 study

    View this table:
    Table 3

    Exclusion criteria in the diagnode-3 study

    Study assessments

    Demographics and study procedures

    Demographics, baseline data medical history and family history of T1D will be collected at screening. Medical examinations (ie, physical, neurological and vital signs) will be performed at all on site visits. Patients will also be provided with an eDiary to collect self-reported data on daily insulin dose, injection site reactions, significant glucose events (mild/moderate/severe hypoglycaemic events and DKAs), as well as mealtimes and physical activity. Patients and caregivers (if applicable) will answer the Paediatric Quality of Life Inventory questionnaires at four visits between baseline and month 24 to assess QoL. Timings of all assessment can be found in table 1.

    Clinical laboratory assessments

    Laboratory assessments of diabetes status

    The timing of all study assessments is presented in table 1 All laboratory parameters will be analysed at a central laboratory. A 2-hour mixed meal tolerance test (MMTT) following an overnight fast (>10 hours) will be performed at baseline and at month 6, month 15 and month 24. Meal stimulated plasma glucose and C-peptide levels will be assessed throughout the MMTT.32

    Patients should come to the study site following an overnight fast (>10 hours) and have a plasma glucose level between 3.5 and 12 mmol/L (63–216 mg/dL) at home in the morning. Patients are allowed to take basal-insulin day/night before, but not in the morning before the MMTT. Patients should also not administer any short/direct acting insulin within 6 hours before the MMTT. Patients with CSII (insulin pump) must continue with their basal dose insulin, but not add any bolus dose during the last 6 hours before the MMTT.

    Samples for HbA1c will be analysed at a National Glycohemoglobin Standardization Program (NGSP) certified central laboratory. Results will be reported in both International Federation of Clinical Chemistry (mmol HbA1c/mol Hb) and NGSP (% HbA1c) units. Serum samples for fasting glucose and fasting C-peptide levels will also be collected and analysed throughout the trial.

    Safety and other laboratory assessments

    All patients will undergo HLA class II genotyping to assess the presence of HLA haplotypes DR3-DQ2 and DR4-DQ8 during the screening procedure. Samples will also be collected for clinical chemistry, haematology, urinalysis, lipids (total cholesterol, LDL-C, HDL-C and triglycerides), vitamin D, thyroid stimulating hormone, thyroid peroxidase antibody, transglutaminase antibody, IA-2 antibody, GAD65 antibody, SARS-CoV-2 antibody and for females; human chorionic gonadotropin, follicle stimulating hormone and luteinising hormone. Timing of the assessments can be found in table 1 and all samples will be analysed at a central laboratory.

    Immunology assessments

    Timing of immunological assessments is indicated in table 1. GAD65 antibody titres will be measured at a central laboratory. Additional variables to evaluate the influence of treatment on the immune system include GAD65 antibody isotypes, IA-2 antibodies and cell-mediated immune response by proliferation and cytokine secretion on GAD65 stimulation of PBMC.

    Continuous glucose monitoring

    CGM will be performed for 14 days during the run-in period (following visit 1C) and at three other timepoints during the trial. The timing of the distribution of the glucose monitoring system and assessments is presented in table 1. The FreeStyle Libre Pro/Pro iQ devices are intended for use only by healthcare professionals, with the patients being blinded to the CGM sensor readings. The devices will be used for data collection during the clinical trial, but not to inform decisions on diabetes management and therapy adjustments. Patients will be allowed to use an unblinded CGM device to manage their diabetes and adjust the therapy based on the glucose levels registered.

    Time period and frequency for collecting AE and serious AE information

    Any worsening in the patient’s condition after administration of study drug and up to the end of study or early termination visit should be considered an AE. All AEs will be collected throughout the whole study period (starting from visit 1C), reviewed and assessed for causality by the investigators at the time points specified in table 1. Injection site reactions will be collected during the 7 days following study drug injections (visits 2, 3 and 4), starting the day after the injection. Injection site reactions persisting after 7 days should be reported as an AE.

    Statistical considerations

    Sample size and power

    The primary efficacy analysis will be performed in the full analysis set. The primary efficacy variables will be (1) change from baseline to Month 24 in log-transformed C-peptide AUCmean 0-120 min during an MMTT and (2) change from baseline to Month 24 in mean HbA1c. The coprimary endpoints will be tested in both the overall population and in the subgroup of patients who carry the HLA DR3-DQ2 haplotype and simultaneously do not carry the DR4-DQ8 haplotype (hereafter the HLA DR4-DQ8-negative subgroup). The overall two-sided 5% type I error rate will be controlled using a fallback procedure. A two-sided 4% alpha will be assigned to the primary efficacy analysis in the overall population. The remaining 1% alpha will be assigned to the primary efficacy analysis in the HLA DR4-DQ8-negative subgroup.

    A total sample size of 288 patients is planned for a 2:1 randomisation to the rhGAD65 and placebo arms, respectively. This achieves 90% power to detect a clinically relevant difference of 40% in geometric mean ratio C-peptide (AUCmean 0-120 min) during an MMTT at month 24 between the rhGAD65 arm and placebo arm using a two-sided test at the 4% significance level. This is based on a t-test employing natural log transformation of C-peptide (AUCmean 0-120 min) during an MMTT at month 24 and assumed CV of 0.95 based on simulations of EoS (month 15) results in the placebo group of the phase 2b study DIAGNODE-2. Allowing for 12% drop-out to month 24, approximately 330 patients will be randomised.

    Statistical analyses

    Primary efficacy analysis

    Change from baseline in the coprimary endpoints will be analysed using a restricted maximum likelihood-based repeated measures approach (MMRM). The model for analysis will include fixed, categorical effects of such as for treatment and stratification variables, as well as interactions effects such as between baseline value-by-visit and the fixed continuous covariates, such as baseline age. Patient identification number will be included as a categorical random effect. An unstructured covariance matrix will be assumed. If this analysis fails to converge, compound symmetry will be tested. The (co)variance structure converging to the best fit, as determined by Akaike’s information criterion, will be used as the primary analysis. The Kenward-Roger approximation will be used to estimate denominator df. Additional methods of sensitivity analyses may be performed in the event that the proportion of missing values is greater than 5%. These analyses will compare the results from the MMRM model, which assumes that values are missing at random, with analyses assuming the values are missing not at random such as: return-to-baseline using multiple imputation and tipping point analysis. All sensitivity analyses will be regarded as exploratory, thus no formal adjustment for multiplicity will be performed.

    Negligible measurement error is expected, which is assumed to affect all patients, time points and treatment groups equally. The total variance used in the sample size calculation is constructed from the within-subject and the between-subject component of variation. Based on the assumption that the measurement error is the same for everyone, it is therefore accounted for in the total variance estimate.

    The coprimary endpoints will be tested sequentially, meaning that C-peptide is tested first, and, if significant, HbA1c is tested. Both co-primary endpoints need to meet the statistical significance criterion. The fallback procedure described by Wiens and Dmitrienko33 will be used to test the primary endpoints in the overall population and in the HLA DR4-DQ8-negative subgroup.

    If either of the coprimary endpoints is not statistically significant in the overall population at a two-sided significance level of 0.04, the coprimary endpoints in the HLA DR4-DQ8-negative subgroup will be tested sequentially at the 0.01 level of significance in an analogous manner to the primary analysis in the overall population. If both coprimary endpoints in the overall population are statistically significant at the two-sided 0.04 level, then the coprimary endpoints in the HLA DR4-DQ8-negative subgroup will be tested sequentially at the 0.05 level of significance in an analogous manner to the primary analysis in the overall population. The analysis of secondary and exploratory endpoints will be described in a statistical analysis plan (see online supplemental appendix 1) which will be finalised before the first patient is enrolled.

    Patient and public involvement

    Patients were not involved in the study design. Patients and Patient organisations (in Sweden Barndiabetesfonden) support recruitment through dissemination of information and participation in press conferences. Participating patients and caregivers will be informed about the outcome of the trial via webcast, letter and personal communication on the completion of the trial.

    Ethics and dissemination

    The trial will be performed in accordance with International Council for Harmonisation guidelines, Good Clinical Practice (GCP) and principles of the Declaration of Helsinki. The study has been approved by Ethics Committees in Poland (ref number: 124/2021), the Netherlands (ref number: R21.089), Sweden (Ref number: 2021-05063), Czech Republic (ref number: EK-1144/21) Germany (ref number: 2021361) and Spain (ref number: 21/2021). Recruitment of participants is planned to start during 2022. Once the trial is completed, results will be published in international peer-reviewed scientific journals and presented at national and international conferences. The main paper will include the primary and secondary outcomes. The manuscript will be submitted to an international peer-reviewed journal, and both positive, negative and inconclusive results will be published. The findings of the trial will be shared with participating sites and presented at national and international conferences. The results will be registered at ClinicalTrials.gov, in EudraCT and will be disseminated to the public.

    Ethics statements

    Patient consent for publication

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    Supplementary materials

    • Supplementary Data

      This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.

    Footnotes

    • Contributors JL conceived the idea and wrote the protocol for the DIAGNODE-1 trial on which the current trial is based . Thus, the design of DIAGNODE-3 is based on the ideas of JL, with further support from UH, MW and AL. The protocol is written by JL, UH, LE, CN, PFT, MW, AL. JL, UH, LE, CN, PFT, MW, AL, RC and ML have taken part in writing and reviewing the manuscript. All authors have approved the manuscript for publication.

    • Funding This trial is sponsored by Diamyd Medical AB. This protocol is based on previous protocols initially used in DIAGNODE-1 and DIAGNODE-2, studies supported by Barndiabetesfonden (The Swedish Child Diabetes Foundation), Diabetesfonden (the Swedish Diabetes Association), FORSS (Research Council of Southeast Sweden) and ALF/County Council Region Östergötland.

    • Competing interests JL has received unrestricted grants from Diamyd Medical, and honoraria as consultant from Dompé International and Provention Bio. ML has received research grants from Eli Lilly and NovoNordisk and been a consultant or received honoraria from Astra Zeneca, Boehringer Ingelheim, Eli Lilly and NovoNordisk. LE, CN, PFT, MW, AL and UH are all employees of Diamyd Medical. CN, PFT, MW and UH own shares in Diamyd Medical.

    • Patient and public involvement Patients and/or the public were involved in the design, or conduct, or reporting, or dissemination plans of this research. Refer to the Methods section for further details.

    • Provenance and peer review Not commissioned; externally peer reviewed.

    • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.