Safety and Dose-Response of Bletilla Formosana in Prediabetic Subjects

July 14, 2026 updated by: YUAN-CHIEH YEH, Chang Gung Memorial Hospital

A Phase I/II Randomized, Double-Blind, Placebo-Controlled Pilot Trial Evaluating the Safety and Dose-Response of Bletilla Formosana in Prediabetic Subjects

This study evaluates the safety and preliminary efficacy of Bletilla formosana (BF), a traditional herbal medicine, in adults with prediabetes. Prediabetes is a high-risk condition where blood sugar levels are elevated, often leading to type 2 diabetes. While lifestyle changes are the standard treatment, researchers are exploring herbal supplements as a complementary way to support metabolic health. Preclinical research has shown that BF possesses anti-inflammatory properties and may help regulate blood glucose. Participants in this study will be randomly assigned to receive either a high dose of BF, a low dose of BF, or a placebo (an inactive substance) for 12 weeks. The total study duration is approximately 24 weeks, involving four clinic visits for blood tests and safety monitoring to see how BF affects blood sugar markers and inflammation.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

This is a single-center, Phase I/II, randomized, double-blind, placebo-controlled, parallel-design trial. The primary goal is to translate robust preclinical findings-where BF extract was shown to inhibit neutrophil-driven inflammation and improve glycemic parameters in animal models-into clinical evidence.

A total of 94 prediabetic subjects (defined by FPG 100-125 mg/dL or HbA1c 5.7%-6.4%) will be enrolled.

Participants will be randomized in a 2:2:1 ratio into one of the following three arms:

High-dose group: 3g Bletilla formosana powder daily. Low-dose group: 1.5g Bletilla formosana powder plus 1.5g placebo daily. Placebo group: 3g inactive placebo powder daily.

The study consists of three distinct phases:

Screening Phase: Up to 2 weeks for eligibility confirmation. Treatment Phase: 12 weeks of oral administration. Follow-up Phase: 12 weeks post-treatment to evaluate sustained efficacy and safety outcomes.

Phase I objectives focus on safety and tolerability, with adverse events (AEs) and serious adverse events (SAEs) graded according to CTCAE v5.0.

Phase II objectives explore preliminary efficacy through changes in fasting plasma glucose (FPG), HbA1c, and HOMA-IR.

Secondary endpoints include assessment of inflammatory biomarkers (TNF-α, IL-6, and CRP) and lipid profiles.

Clinical assessments, including 12-lead ECG and comprehensive laboratory testing, are scheduled at Screening, Week 6, Week 12 (end of treatment), and Week 24 (end of study).

Study Type

Interventional

Enrollment (Estimated)

94

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Taiwan
      • Keelung, Taiwan, 204
        • Keelung Chang Gung Memorial Hospital
        • Contact:
        • Contact:
        • Principal Investigator:
          • Yuan-Chieh Yeh, MD
      • Taoyuan, Taiwan, 333
        • Taoyuan Chang Gung Memorial Hospital
        • Contact:
        • Contact:
      • Taoyuan, Taiwan, 333
        • Linkou Chang Gung Memorial Hospital
        • Contact:
        • Contact:
        • Principal Investigator:
          • Hsing-Yu Chen, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Adults aged 30-70 years.
  2. Prediabetes defined by any of the following:
  3. Fasting Plasma Glucose (FPG) of 100-125 mg/dL, or
  4. Glycated hemoglobin (HbA1c) of 5.7%-6.4%.
  5. Willingness to provide written informed consent and comply with study procedures.

Exclusion Criteria:

  1. Established type 1 or type 2 diabetes mellitus, or recent use of oral antidiabetic agents or insulin (within 3 months).
  2. Abnormal liver function, defined as Alanine aminotransferase (ALT) or Aspartate aminotransferase (AST) exceeding 2-fold the upper reference limit (≥2 × ULN) at screening.
  3. Abnormal renal function, defined as serum creatinine (Cr) >1.5 mg/dL or Estimated Glomerular Filtration Rate (eGFR) <60 mL/min/1.73 m².
  4. Gastrointestinal disorders that may affect drug absorption, such as gastrostomy, enterostomy, severe chronic diarrhea, or malabsorption syndrome.
  5. Severe comorbidities within the past 6 months, including major stroke, myocardial infarction, major trauma, or major surgery.
  6. Recent use of medications (within 1 month) that may significantly alter blood glucose or lipids, such as systemic corticosteroids or non-stable doses of lipid-lowering agents.
  7. Malignant tumor under active treatment, or immunodeficiency/autoimmune disorders requiring immunosuppressive therapy.
  8. Psychiatric disorders or cognitive impairment that may affect protocol compliance.
  9. Active use of other investigational drugs within 3 months prior to screening.
  10. Pregnancy or lactation.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: High-dose Bletilla formosana (BF)
Participants receive 3g of Bletilla formosana powder daily for 12 weeks. To maintain blinding, the total dose is divided into two 1.5g sachets (one in the morning and one in the evening).
Drug: Bletilla formosana (BF) powder
A traditional Chinese medicinal herb (Taiwanese ground orchid). The raw material is derived from the approved botanical species and medicinal part listed in the Taiwan Herbal Pharmacopoeia.
Experimental: Low-dose Bletilla formosana (BF)
Participants receive 1.5g of Bletilla formosana powder and 1.5g of placebo powder daily for 12 weeks. To maintain blinding, this is administered as one active sachet and one matching placebo sachet (one in the morning and one in the evening).
Drug: Bletilla formosana (BF) powder
A traditional Chinese medicinal herb (Taiwanese ground orchid). The raw material is derived from the approved botanical species and medicinal part listed in the Taiwan Herbal Pharmacopoeia.
Other: Placebo
An inactive powder matching the appearance and dosage form of the BF powder, consisting of starch and caramel coloring.
Placebo Comparator: Placebo
Participants receive 3g of inactive placebo powder daily for 12 weeks. To maintain blinding, this is administered as two matching placebo sachets (one in the morning and one in the evening).
Other: Placebo
An inactive powder matching the appearance and dosage form of the BF powder, consisting of starch and caramel coloring.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Participants with at Least One Treatment-Emergent Adverse Event (AE)
Time Frame: From baseline to Week 24.
Incidence of all adverse events (AEs) graded by CTCAE v5.0.
From baseline to Week 24.
Number of Participants with Serious Adverse Events (SAEs)
Time Frame: From baseline to Week 24
Number of participants experiencing life-threatening or fatal events according to ICH-GCP definitions.
From baseline to Week 24
Change from Baseline in Fasting Plasma Glucose (FPG) (mg/dL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Change in fasting blood sugar levels to assess the preliminary glycemic efficacy of Bletilla formosana.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in Glycated Hemoglobin (HbA1c) (%)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of average blood glucose control over time.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in Homeostatic Model Assessment for Insulin Resistance (HOMA-IR)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Calculated using fasting insulin and glucose levels to assess changes in insulin sensitivity.
Baseline, Week 6, Week 12, and Week 24.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change from Baseline in Tumor Necrosis Factor-alpha (TNF-α) (pg/mL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
To evaluate the anti-inflammatory effects of Bletilla formosana.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in Interleukin-6 (IL-6) (pg/mL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
To evaluate the anti-inflammatory effects of Bletilla formosana.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in C-reactive protein (CRP) (mg/dL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
To evaluate the anti-inflammatory effects of Bletilla formosana.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in Total Cholesterol (mg/dL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of lipid profiles using standard laboratory methods
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in High-Density Lipoprotein (HDL) (mg/dL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of lipid profiles using standard laboratory methods.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in Low-Density Lipoprotein (LDL) (mg/dL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of lipid profiles using standard laboratory methods.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in Triglycerides (TG) (mg/dL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of lipid profiles using standard laboratory methods.
Baseline, Week 6, Week 12, and Week 24.

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change from Baseline in Alanine Aminotransferase (ALT) (U/L)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of clinical laboratory safety tests to monitor hepatic, renal, and hematologic function.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in Aspartate Aminotransferase (AST) (U/L)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of clinical laboratory safety tests to monitor hepatic, renal, and hematologic function.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in Total Bilirubin (mg/dL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of clinical laboratory safety tests to monitor hepatic, renal, and hematologic function.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in Blood Urea Nitrogen (BUN) (mg/dL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of clinical laboratory safety tests to monitor hepatic, renal, and hematologic function.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in Serum Creatinine (mg/dL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of clinical laboratory safety tests to monitor hepatic, renal, and hematologic function.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in White Blood Cell Count (WBC) (10^3/μL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of clinical laboratory safety tests to monitor hepatic, renal, and hematologic function.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in Hemoglobin (Hb) (g/dL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of clinical laboratory safety tests to monitor hepatic, renal, and hematologic function.
Baseline, Week 6, Week 12, and Week 24.
Change from Baseline in Platelet Count (10^3/μL)
Time Frame: Baseline, Week 6, Week 12, and Week 24.
Assessment of clinical laboratory safety tests to monitor hepatic, renal, and hematologic function.
Baseline, Week 6, Week 12, and Week 24.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Chang Gung Memorial Hospital

Collaborators

National Science and Technology Council

Investigators

  • Principal Investigator: Yuan-Chieh Yeh, MD, Chang Gung Memorial Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

July 1, 2026

Primary Completion (Estimated)

July 1, 2027

Study Completion (Estimated)

August 1, 2027

Study Registration Dates

First Submitted

June 23, 2026

First Submitted That Met QC Criteria

July 14, 2026

First Posted (Actual)

July 15, 2026

Study Record Updates

Last Update Posted (Actual)

July 15, 2026

Last Update Submitted That Met QC Criteria

July 14, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 202500720A3C6002
  • NSTC 114-2321-B-255-001 (Other Grant/Funding Number: National Science and Technology Council)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

The study team does not have a plan to share individual participant data at this time to maintain participant confidentiality as stated in the informed consent.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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