Study objectives
The objective of this trial is to evaluate whether the effect of losartan potassium combined with KLX is superior to that of losartan potassium in DKD treatment and to obtain validated evidence for the application of KLX in the treatment of DKD.
Study design
This will be a double-blind randomized controlled trial to investigate the efficacy of KLX combined with losartan potassium compared with a placebo. The study will be conducted in eighteen centers in China: Guang’anmen Hospital of the China Academy of Chinese Medical Sciences, Dongzhimen Hospital of Beijing University of Chinese Medicine, the First Affiliated Hospital of Chengdu Medical College, Mianyang Central Hospital, the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine, Dazhou Central Hospital, Dezhou People’s Hospital, Linfen Central Hospital, the Affiliated Hospital of Liaoning University of Traditional Chinese Medicine, the First People’s Hospital of Luoyang, Shenzhen Hospital of Southern Medical University, Shanghai Shuguang Hospital, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, the Second Affiliated Hospital of Wannan Medical College, Nanyang City Central Hospital, the First Affiliated Hospital of Henan University of Chinese Medicine, Xinxiang Central Hospital, and Heze Municipal Hospital. Patients with DKD who want to participate in the study will undergo a standardized baseline evaluation before treatment including detailed history evaluation, physical examination, and laboratory testing. The enrolled participants will be randomly allocated to the KLX treatment and placebo control groups. The participants will be administered KLX or placebo in addition to losartan potassium for 24 weeks. Data will be collected during three visits to assess the efficacy of KLX and will be recorded on case report forms (CRFs). A flowchart of the study design is shown in Fig. 1, and the time points of assessment are shown in Table 1. The Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines [14] were followed during the development of the protocol of this study.
Table 1
Schedule of enrollment, intervention, and assessment
Study settings and recruitment
Assuming a 20% dropout rate, a total of 252 patients will be recruited from the eighteen centers mentioned above using posters, the hospitals’ websites, and networks from December 2019 to December 2020. Research assistants will manage the recruitment, and endocrinologists will diagnose the participants.
Participants
Subjects will be deemed eligible participants if they meet all of the listed inclusion criteria and none of the listed exclusion criteria.
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Diagnoses of type 2 diabetes and DKD;
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Diagnoses of TCM syndromes of qi and yin deficiency and blood stasis;
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A UACR ≥ 30 mg/g;
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An estimated glomerular filtration rate (eGFR, according the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation) ≥ 30 ml/min/1.73 m2 and ≤ 59 ml/min/1.73 m2;
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A fasting blood glucose level < 13.9 mmol/L and/or a 2 h postprandial blood glucose level < 16.6 mmol/L;
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A glycated hemoglobin (hemoglobin A1c, HbA1c) percentage ≤ 10%;
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An age between 35 and 75 years, male or female;
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Voluntary participation in this clinical study and provision of written informed consent.
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A diagnosis of type 1 diabetes;
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A lack of diagnosed diabetic retinopathy;
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A history of simple renal hematuria or proteinuria with hematuria; sudden onset of edema and mass proteinuria without abnormal renal function; significant renal tubular dysfunction; coexisting renal tubular abnormalities; primary glomerulonephritis or secondary nephritis except DKD; or acute or chronic infection of the urinary system;
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A hemoglobin (HGB) concentration < 90 g/L;
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An ALB concentration < 30 g/L;
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A diagnosis of renal artery stenosis;
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A serum potassium concentration > 5.5 mmol/L;
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A serum creatinine (Scr) concentration ≥ 3 mg/dL (256 µmol/L);
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A history of severe cardiovascular or cerebrovascular disease within three months before screening;
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Severe systemic primary disease or dysfunction;
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Severe liver dysfunction or ALT or AST levels higher than 2.5 times the normal range;
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Hypertension treated with more than 3 kinds of antihypertensive drugs, blood pressure that is poorly controlled after administration of drugs with a systolic blood pressure (SBP) ≥ 140 mmHg or a diastolic blood pressure (DBP) ≥ 90 mmHg, or hypotension with an SBP ≤ 90 mmHg or a DBP ≤ 60 mmHg (resting position);
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Chronic (for more than 3 weeks) or recurrent diarrhea (where diarrhea is defined as elimination of increased volumes of thin fecal matter with increased frequency (> 3 times/day));
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A history of active bleeding in the 3 months before screening;
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Coagulation disorders;
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Drug allergies or allergies to KLX or the active ingredient in losartan potassium;
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A history of alcohol or drug abuse or psychiatric disorders;
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Pregnancy, lactation or plans to become pregnant during the trial;
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A history of enrollment in other clinical studies in the past 3 months;
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Other circumstances under which the investigators considered it inappropriate to participate in this clinical study.
Randomization, allocation concealment, and blinding
The participants will be randomly assigned to either the KLX group or placebo group in a 1:1 ratio. Randomization will be performed using Statistics Analysis System (SAS) software by an independent statistical agency. The Institute of Data Management Center of Guang’anmen Hospital will be responsible for drug blinding and randomization concealment. The drug administrator will enroll patients at the 18 participating medical centers sequentially on the basis of screening order. Both the participants and the investigators will be kept blinded to the allocations until the trial is completed. In case of a severe adverse event, an administrator at the Data Management Center of Guang’anmen Hospital will unblind the patient information as an emergency measure and provide relevant treatment.
Intervention
All investigators will be trained before the start of the study according to an investigators’ brochure. The enrolled patients with DKD will be asked to take losartan potassium tablets (50 mg per day) as the basic treatment and will also be administered KLX or placebo. The subjects in the treatment group will take four capsules of KLX orally thrice a day for 24 weeks. The participants in the placebo control group will take the same amount of placebo for 24 weeks. Data from all the participants will be collected in four periods: on day 0 (V2), at 4 weeks ± 3 days (V3), at 12 weeks ± 5 days (V4), and at 24 weeks ± 5 days (V5).
The placebo is identical in appearance and properties to KLX capsule without any active ingredient. Both KLX and the placebo will be manufactured by Chengdu Kanghong Pharmaceutical Co., Ltd., at a dose of 500 mg. The placebo, whose appearance and properties will be identical to those of KLX, will contain no active ingredients. The placebo will be verified by the quality control department and will meet the standards of placebo preparation. The interventions should stop for a given participant if the creatinine doubles or ESRD is detected. The participants will be asked to refrain from taking any other treatment for diabetic nephropathy, including ACEI or ARB drugs other than losartan potassium tablets, calcium hydroxybenzenesulfonate, etc. as well as Chinese medicine that affect evaluation of qi and yin deficiency and blood stasis syndrome during the trial.
Outcome measures
The primary endpoint is the decline in the eGFR (ml/min/1.73 m2/year).
The secondary outcomes will include the incidence of Scr doubling, the incidence of ESRD, the proportion of subjects with a progressive decline in eGFR of > 30% from baseline within 24 weeks, the percent change in 24 h UTP, the change in UACR and the TCM syndrome scale scores.
To assess the safety of KLX treatment in patients with DKD, vital signs and some laboratory parameters will be measured and electrocardiography will be performed during the intervention period of the trial. In detail, the vital signs will include body temperature, blood pressure, respiratory rate and pulse rate. The biological indicators we will monitor will include routine blood indices (red blood cell count (RBCs), hemoglobin(HGB), white blood cell count (WBCs), and platelet count (PLTs)), routine urine and urine sediment parameters (assessed under microscopy), 24 h UTP levels, UACRs, liver function indices (alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (TBIL), and γ-glutamyl transferase (GGT)), renal function indices (eGFR and Scr), serum electrolytes (K+, Na+, and Cl−), blood lipid profile indices (total cholesterol (TC), triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C)), coagulatory function indices (prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen (FIB)), HbA1c levels, and fasting blood glucose levels. Moreover, detailed information about any adverse events will be recorded, including the severity, rate of incidence, and correlation with the treatment.
Follow-up
All included participants will be re-evaluated at 6 and 12 months through phone calls or as outpatients.
Statistics
This study will be a trial of a new therapeutic regimen of KLX treatment. The sample size was calculated using software PASS based on a similar study on a Chinese herbal medicinal supplement conducted previously [15]. Allowing for a 20% withdrawal rate, we plan to include 126 patients in this trial.
The independent researchers performing the biochemical tests, assessing the clinical outcomes, and analyzing the data will be kept blinded to the patients’ identities and grouping. All data will be analyzed using Statistical Package for the Social Sciences (SPSS) version 17.0 (SPSS, Inc., Chicago, IL) software. Comparisons will be made using chi-square tests for count data. Statistical significance will be considered for a p value < 0.05.
All researchers in this study will be qualified physicians and will receive training in standard operating procedures for trial execution, biological sample collection, and handling. Based on the initial observation records, all center investigators will complete the CRFs in an accurate and timely manner. The administrators of Guang’anmen Hospital will visit each center regularly to ensure the quality of data collection and to facilitate problem solving. All files will be properly classified and saved/archived under confidential conditions.