Herbs of rich-Iodine for Graves’ Hyperthyroidism Trial (the HIGHT trial): a study protocol for a randomized, double-blind, placebo-controlled, multicentre clinical trial

Background Graves' hyperthyroidism is one of the refractory diseases in endocrinology. Thionamides are known to be effective and its common side-effects are markedly reduced when starting with low dose. Iodine-rich Chinese herbal decoction (IRH) is a frequently prescribed Chinese herbal medicine in patients with Graves' hyperthyroidism. However, high quality clinical evidence is still very scarce, which made the Traditional Chinese Medical (TCM) management of Graves' hyperthyroidism remains controversial. The objective of this study is to prove that IRH might get faster and longer lasting remission and improved quality of life (QoL) in Graves' hyperthyroidism patients compared with methimazole (MMI) . Methods/design This study is a randomized, double-blind, placebo-controlled and multicentre clinical trial. We will recruit a total of 240 participants with Graves' hyperthyroidism who have any common ATD-associated side-effects. They will be randomized (1:1:1) to receive ((cid:0)) IRH plus MMI placebo, ((cid:0)) IRH placebo plus MMI and ((cid:0)) IRH plus MMI for 12 weeks. The primary outcome measures will be the serum free triiodothyronine (FT3), free thyroxine (FT4) levels and serum thyroid-stimulating hormone (TSH) level. Secondary outcome measures will include the level of thyroid stimulating hormone-receptor antibodies (TRAb), thyroid ultrasound (US) and Thyroid-specic Patient Reported Outcome(ThyPRO39). The outcomes of this study will provide new evidence for the ecacy and safety of IRH for the treatment of Graves' hyperthyroidism and will also guide physicians at clinics more clearly in prescribing IRH. The HIGHT trial: The Herbs of rich-Iodine for Graves’ Hyperthyroidism Trial; IRH: Iodine-rich Chinese herbal decoction; TCM: Traditional Chinese Medical; QoL: quality of life; ThyPRO39: Thyroid-specic Patient Reported Outcome; MMI: methimazole; FT3: free triiodothyronine; FT4: free thyroxine; TSH: thyroid-stimulating hormone; TSH-R-Ab: thyroid stimulating hormone-receptor antibodies; US: Ultrasound; ATD: Anti-thyroid drugs; PTU: propylthiouracil; RAI:radioactive iodine; KI: potassium iodide; SPIRIT: Standard Protocol Items: Recommendations for Interventional Trials; TRAb: TSH-receptor Antibody; TPOAb: Thyroid peroxidase antibody; TgAb: Thyroglobulin antibody; SAS: Statistics Analysis System; SAEs: serious adverse events; eCRFs: electronic case report forms; AEs: adverse events; SOP: standard operating procedures; ITT: Intention to treat; FAS: Full analysis set; PPS: Per-protocol set; SAS: Safety analysis set; LOCF: last observation carried forwar.

Secondary outcome measures will include the level of thyroid stimulating hormone-receptor antibodies (TRAb), thyroid ultrasound (US) and Thyroid-speci c Patient Reported Outcome(ThyPRO39).

Discussion
The outcomes of this study will provide new evidence for the e cacy and safety of IRH for the treatment of Graves' hyperthyroidism and will also guide physicians at clinics more clearly in prescribing IRH.
[6] The ATD treatment is usually lasts for a period of 12 to 18 months and then tapered off. The common side effects of ATD contain skin rash, urticaria, arthralgia, polyarthritis, fever and leukopenia [1]. Rare but major side effects include hepatitis, a lupus-like syndrome, and agranulocytosis (neutrophil count < 500/mL), which occurs in 0.1-1.0% of the Graves' hyperthyroidism patients [7][8][9]. The above mentioned side effects of ATD are the main reason for the withdrawal of ATD. In addition, patients with Graves' hyperthyroidism suffer from a wide range of symptoms and have major impairments in most areas of quality of life (QoL). Therefore, a better therapy is desperately needed.
The administration of stable iodide to hyperthyroid patients has been known to produce clinical bene t.
Plummer utilized 10 drops of Lugol's solution containing 5% I2 and 10% potassium iodide (KI), once or four times a day (approximately 80-320 mg iodine daily) to hyperthyroidism with good effect [10][11][12][13]. Starting from the 1930s, Thompson et al reported satisfactory results after giving hyperthyroid patients approximately 6 mg of iodine daily in 64% of the mild cases and 10% of the severe cases [14]. In recent years, treatment of Graves' hyperthyroidism with KI is widely accepted by Japanese thyroid specialists, and its e cacy has been reported in 2016 ATA guideline [15][16][17][18][19].
Currently, Traditional Chinese Medicine (TCM) is widely used to treat patients with Graves' hyperthyroidism in China and has accumulated rich experience [20][21][22]. Rich-Iodine herbs are those of their main representatives. The granules used in this trial contains eight Chinese herbs, algae, including kelp, spica prunellae, oldenlandia, and so on. Our studies have con rmed that the iodine content of algae and kelp are much higher than other herbs, therefore, we call them iodine-rich herbs [23][24][25]. Our small sample, iodine-rich Chinese herbal decoction (IRH) showed safety and effectiveness in patients with Graves' hyperthyroidism [26]. However, there have been few high-quality trials and more evidence is needed to prove the therapeutic effect of IRH.
We set up this study, which is a randomized, double-blind, placebo-controlled, multicentre clinical trial to clarify that IRH might get faster and longer lasting remission and improved QoL in Graves' hyperthyroidism patients compared with MMI, to provide high-quality data.

Methods/design
Objectives The aim of this trial is to assess the e cacy and safety of IRH in patients with Graves' hyperthyroidism who have any common ATD-associated side-effects.

Design
The HIGHT trial (Herbs of rich-iodine for Graves' Hyperthyroidism Trial) is a randomized, double-blind, placebo-controlled and multicentre clinical trial in patients with Graves' hyperthyroidism who have any common ATD-associated side-effects. The trial has a multi-arm design with 1:1:1 allocation to the  Figure 1 brie y shows the study ow chart, and the time-point of assessment is shown in Table 1. The development of the protocol of this study is per Standard Protocol Items: Recommendations for Intervention Trials (SPIRIT) guideline. [27]  All assessments must be made at the time points speci ed above. If the assessment is not possible at the speci ed time, the assessment shall still be conducted, and the time shall be noted in the electronic case report form (eCRF). Following this, deviations from the protocol can be assessed. ThyPRO39: Thyroid-speci c Patient Reported Outcome; FT3: free triiodothyronine; FT4: free thyroxine; TSH: levels and serum thyroid-stimulating hormone; TRAb: TSH-receptor Antibody; TPOAb: Thyroid peroxidase antibody; US: Ultrasound; TgAb: Thyroglobulin antibody. *Patients should be informed of potential side effects of ATD and the necessity of informing the physician promptly if they should develop jaundice, light-colored stools, dark urine, fever, pharyngitis, or cystitis. In patients taking ATD, a differential white blood cell count should be obtained during febrile illness and/or pharyngitis, and liver function should be assessed in those who experience jaundice, light-colored stools, or dark urine. Full Blood Count every week for 4 weeks and then every 4 weeks; Liver Function Tests (LFT) every 2 weeks for 4 weeks and then every 4 weeks. # Adverse reactions of former treatment of ATD. ## That is, thyroid surgery or RAI therapy. All assessments must be made at the time points speci ed above. If the assessment is not possible at the speci ed time, the assessment shall still be conducted, and the time shall be noted in the electronic case report form (eCRF). Following this, deviations from the protocol can be assessed. ThyPRO39: Thyroid-speci c Patient Reported Outcome; FT3: free triiodothyronine; FT4: free thyroxine; TSH: levels and serum thyroid-stimulating hormone; TRAb: TSH-receptor Antibody; TPOAb: Thyroid peroxidase antibody; US: Ultrasound; TgAb: Thyroglobulin antibody. *Patients should be informed of potential side effects of ATD and the necessity of informing the physician promptly if they should develop jaundice, light-colored stools, dark urine, fever, pharyngitis, or cystitis. In patients taking ATD, a differential white blood cell count should be obtained during febrile illness and/or pharyngitis, and liver function should be assessed in those who experience jaundice, light-colored stools, or dark urine. Full Blood Count every week for 4 weeks and then every 4 weeks; Liver Function Tests (LFT) every 2 weeks for 4 weeks and then every 4 weeks. # Adverse reactions of former treatment of ATD. ## That is, thyroid surgery or RAI therapy.  positive TRAb according to local laboratory results); 3. Intolerance to MMI or PTU (such as liver function injury, agranulocytosis, rash and urticaria and so on) and refuse thyroidectomy or RAI; 4. Willingness to provide written informed consent.
Exclusion criteria 1. Hyperthyroidism crisis; 2. Symptomatic compression or large goiter; 3. Those whose FT4 exceeds the measuring range, and/or TRAb exceeds the measuring range; 4. Subjects who allergy to the components in TCM and/or placebo; 5. Those who have thiocarbamides-associated major side effects including of severe hepatitis (elevation of AST or ALT more than double the normal upper limit), agranulocytosis (neutrophil count < 500/mL), severe exfoliative dermatitis; . Women who are pregnant or lactating, or preparing for pregnancy and lactating women; 7. Subjects with a history of alcohol abuse, drug abuse, or mental diseases; . Those who are in seriously unstable medical condition, such as cardiovascular disease, cerebrovascular disease, hepatobiliary disease, renal disease or problems in the urinary reproductive system, or neoplasms, or whose treatment with any medication potentially in uencing thyroid function (IFN-gama, amiodarone, lithium, corticosteroids, etc.); 9. Subjects who have taken other clinical trial drugs within 3 months; 10. Subjects who are thought to be inappropriate for this study.

Intervention
Study recruits receive respectively IRH plus placebo MMI (A group), placebo IRH plus MMI (B group), or IRH plus MMI (C group). Participants in three groups will take either IRH or the placebo IRH twice daily (10 g/packet at a time), plus either MMI or placebo MMI once daily (5-10 mg at a time) for 12 weeks.
The drugs will be distributed to Graves' hyperthyroidism patients per month.
Both IRH and placebo granules are manufactured by Jingyin Pharmaceutical (Jingyin, China) according to good manufacturing practice guidelines. Drugs will be prepared in the form of brown granules. The constituents of IRH are kelp, spica prunellae, oldenlandia, and so on. The placebo will consist of corn starch, lactose hydrate, citric acid, and caramel color. The placebo and IRH will have the same size, appearance, smell and taste. They are packaged in the same packet, labelled as trial-speci c Investigational Medicinal Products (IMPs) as the IRH granules, and then distributed to the 5 centres.
MMI tablets (Thyrozol, 10mg × 50) are produced by Merck KGaA, Germany. The placebo MMI tablets are made for the trial by Beijing Chengyou Pharmacy Manufacturing Unit in accordance with good manufacturing practice and exactly match the size, appearance, taste, smell of the active MMI tablets, which are removed from their blister-packs and re-packaged in the same bottles as the placebos. Both active and placebo drugs are then labeled as trial-speci c IMPs and distributed to the 5 centres.

Randomization and allocation concealment
Randomization using Statistics Analysis System (SAS) software will be performed by independent staff statisticians. Participants will be randomly assigned to either the A or B or C group in a 1:1:1 ratio. The study coordinator will be blinded to the group assignment and will give participants the numbered package of intervention according to their visiting time sequence at baseline visit. Thus, the allocation concealment will be maintained throughout the study. The allocation for each subject will be sealed in an opaque envelope and will not be disclosed until the clinical trial is completely over, unless serious adverse events (SAEs) happen.

Blindness
Double-blinding method is adopted in this study. Both participants and investigators will be blinded to the allocation until completion of the trial. The each placebo drug was con rmed in advance that the size, appearance, taste and avor were similar. According to the randomization sequence, drugs will be packed in the same form and will be delivered to the hospital. At the end of the study, the blinding codes will be revealed. In case of SAEs, an administrator will unblind the patient information as an emergency and provide relevant treatment.

Concomitant medication or treatment
The use of any traditional medicine designed to treat Graves' hyperthyroidism, except for the intervention of this trial, will be prohibited during the study. During the treatment, the clinician can decide whether to combine with β-adrenergic blocker, antihistamine agents, hepatoprotective agents and leukocytopoiesispromoting agents according to the speci c condition. All concomitant medication and treatment (that is, treatment drugs / treatment measures for other diseases) during the study period will be recorded in the combined medication table in detail.

Discontinuation
Participants may withdraw from the trial at any time for any reason, and the reason will be recorded in the electronic case report forms (eCRFs). In order to conduct intention-to-treat analyses with as few missing data as possible, the investigator may ask the participants which aspects of the trial, they wish to withdraw from.These can include the following: receipt of the trial intervention, participation in the remaining follow-up assessments, or use of already collected data in the data analyses. The investigators will discontinue a participant's taking of the trial intervention at any time, if the participant: experiences intolerable adverse reactions; is diagnosed with any of the exclusion criteria during the intervention period; is referred for ablative therapy (RAI or thyroid surgery) during the intervention period. In all three cases, the investigator and/or the treating physician will encourage the participant to continue with follow up assessment and to allow the use of collected data in the analyses.

Safety assessment
Safety will be assessed in terms of the routine physical examination consists of breath rate, heart rate, temperature, blood pressure, weight, and routine kidney function, liver function, blood, urine, and electrocardiogram test results obtained at 2, 4, 8 and 12 weeks of treatment, respectively. Adverse events, vital signs, and laboratory examinations will be recorded on eCRFs before and after patients take their medication at every visit. Adverse events (AEs) are de ned as any unexpected sign or symptom during the treatment period, and participants will be asked to inform clinicians about the occurrence of any AEs while taking their medication. The researchers will then comprehensively evaluate the relation between these AEs and the experimental drugs according to the records, including the occurrence time, duration, manifestation, cause, and treatment measures. If SAEs occur that may lead to death or require extended hospitalization, the participants will be asked to quit the clinical trial as soon as possible, and proper treatment will be provided.

Outcomes
Outcomes will be assessed four times during the trial.

Primary outcome
The primary outcome will be the change in serum FT3, FT4 levels and serum TSH level results from baseline to the end of the 12-week intervention.
Secondary outcomes 1. The proportion of euthyroidism participants at the study visits at 2, 4, 8 and 12 weeks of treatment, respectively; 2. The serum level of TRAb at 2, 4, 8 and 12 weeks of treatment, respectively; 3. The change in thyroid imaging (thyroid color Doppler ultrasound) from baseline to the end of the 12week intervention. 4. Proportion of participants who have been referred to ablative therapy (RAI or thyroid surgery) at some point during the entire intervention period; 5. Thyroid-speci c Patient Reported Outcome (ThyPRO39) and hyperthyroid symptoms during 12 weeks after randomization, and at the end of the intervention period. ThyPRO39 will be measured by the global score in the questionnaire; . Number of patients with ARs and / or SARs during the intervention period.

Data management and Monitoring
All researchers involved in the study will be quali ed physicians. All source documents, such as informed consent forms, signature of participants and questionnaires, will be collected and conserved in compliance with standard operating procedures (SOP). The data will be collected via an electronic data capture system through eCRFs using the OpenClinical EDC management system. The main data will be locked up until research completed. For the questions in the eCRFs, data manager should inquire the researchers through clinical supervisor and make data modi cation, a rmation and record according to the reply of researchers. The principal investigator will coordinate dissemination of data.
The administrators of the A liated Hospital of Liaoning Traditional Chinese Medicine University will visit each unit regularly (once a month) to con rm the quality of data collection and facilitate problem-solving and the Ethics Committee will monitor for protocol violations. The safety, progress, study integrity, and design aspects will be monitored by the research team involved in this study.

Statistical Analysis Plan
Analysis of data sets 1. Intention to treat (ITT): The ITT principle will include subjects who meet the full analysis set criteria, including subjects who had the primary outcome assessed once or more except for the baseline measures and who took the test drug at least once. 2. Full analysis set (FAS): According to the principle of analysis for ITT, participants will be rejected by smallest and reasonable method. 3. Per-protocol set (PPS): PPS should be used in the patients who satis ed with the following characters: case of completed observation; t with inclusion criteria; not using prohibited drugs. 4. Safety analysis set (SAS): All information of safety record will be assessed, including subjects who took the test drug at least once.
Statistical analysis method 1. All parameters will be analyzed by SPSS version 25.0 software package. 2. The signi cance level will be set to 0.05 in a two tailed test.
3. The last observation carried forward (LOCF) method will be used for the missing data supplement. 4. Dropping analysis: The chi-square test, or Fisher exact probability method. 5. The model will include baseline values and gender as covariates and treatment as a xed effect. The independent t test or Wilcoxon rank-sum test will be used for continuous variables, and the chisquare test or Fisher's exact test will be used for categorical variables.
. Comparison within each group: Student's t test or Wilcoxon's signed-rank test will be used to compare data before and after the treatment between the groups. Categorical data will be analyzed using the chi-square test or Fisher's exact test. 7. Comparison between groups: The chi-square test for enumeration data; Wilcoxon rank sum test for non-normal distribution of measurement data; Student's t-test for normal distribution of measurement data; ANOVA for repeated measurement data; Ridit test for ranked data. . CMH test for the center effect. 9. Compliance analysis: The incidence of SAEs and AEs related to the treatment will be analyzed. The percentage of subjects who experience one or more side effects during the study will be analyzed and presented using a descriptive analysis for each group.

Ethical considerations
The HIGHT trial will be conducted in accordance with the principles of the Declaration of Helsinki (2013 version). The trial design will follow the principles set out in the Good Clinical Practice guidelines for the appropriate clinical use of TCM. The trial is approved by the Ethics Committee of A liated Hospital of Liaoning Traditional Chinese Medicine University (H-4-2012-026). The trial was registered at the Chinese Clinical Trial Registry (ChiCTR2000032706). The trial will fully comply with the SPIRIT reporting guidelines. After the clinicians provide a complete explanation to the participants, written informed consent will be obtained from the participants before treatment intervention. The trial will help to demonstrate if IRH is effective and safe for patients with Graves' hyperthyroidism and the results will be published in peer-reviewed journals to ensure widespread dissemination. All protocol amendments will be approved by the Institutional Review Board prior to execution.

Discussion
This study is a randomized, double-blind, placebo-controlled multicentre clinical trial designed to prove that IRH might get faster and longer lasting remission and improved QoL compared with MMI in Graves' hyperthyroidism patients who have any common ATD-associated side-effects.
TCM is bene cial to Chinese thyroid patients for thousands of years. Our previous study have shown that IRH may be an alternative therapy for Graves' hyperthyroidism patients who suffer from common ATDassociated side-effects, but its quality is not enough [26]. In addition, we hope to establish a standard IRH scheme, given that there is, to date, no such consensus in Graves' hyperthyroidism patients. To the best of our knowledge, this is the rst randomized, double-blind, placebo-controlled multicentre clinical trial that will determine the e cacy and safety of IRH in the therapy of Graves' hyperthyroidism patients, which is why we intend to perform this study.
The strength of this study is the rigorous design, which is a randomized, double-blind, placebo-controlled multicentre clinical trial. The outcomes derived from this study include objective parameters, such as the serum FT3, FT4, TSH levels, TRAb, TgAb, TPOAb and thyroid imaging, as well as subjective parameters obtained from questionnaires (ThyPRO-39). To ensure the quality of this study and reach a reliable conclusion, the experimental design and study performance are under strict quality control. At each center, training sessions will be provided to explain the study protocol, and the standard operating procedures.
The short study period is the limitation of this study. Nevertheless, this study is reasonably well designed.
The results are expected to provide new evidence for the effectiveness and safety of IRH treatment in patients with Graves' hyperthyroidism and guide physicians more clearly in prescribing IRH. Figure 1