Desiccated Thyroid Extract Combined With Levothyroxine for TSH Suppression Therapy in DTC

Summary

The global incidence of Differentiated Thyroid Cancer (DTC) is rising. While surgery followed by TSH suppression is the standard of care, achieving target TSH levels with levothyroxine (L-T4) monotherapy remains challenging, with only 25-70% of intermediate/high-risk patients attaining it within 6-8 months. This therapeutic dilemma stems from three key issues: impaired T4-to-T3 conversion due to DIO2 polymorphisms, the non-physiological hormone ratio of T4 monotherapy, and L-T4's narrow therapeutic window. This often results in an "under- versus over-suppression" paradox, increasing risks of recurrence, atrial fibrillation, and osteoporosis. Combining L-T4 with desiccated thyroid extract (DTE; T4:T3 ≈ 4:1) may overcome these limitations by bypassing DIO2 defects and providing a more physiological hormone profile, thereby potentially improving TSH control while mitigating side effects. Supported by the 2023 Chinese guidelines and our promising pilot data (82% cumulative target attainment at a median of 1.4 months), we propose a two-stage national study: a multicenter cohort study followed by a randomized trial, to generate high-level evidence for this combination therapy in high-risk DTC.

Conditions

• Intermediate-to-High Risk Differentiated Thyroid Cancer

Interventions

DRUG

desiccated thyroid extract (DTE)+levothyroxine (L-T4)

Desiccated thyroid extract (DTE) is a dry preparation obtained from animal thyroid glands that contains both thyroxine (T4) and triiodothyronine (T3) in an approximately 4:1 ratio, closely matching the physiological hormone profile secreted by the human thyroid. Combining DTE with levothyroxine (L-T4) may overcome current therapeutic bottlenecks. First, L-T4 given in adequate doses provides the major T4-mediated TSH suppression, while the small amount of T3 supplied by DTE acts directly on pituitary thyrotrophs, bypassing impaired DIO2 conversion; this pharmacodynamic synergy yields tighter TSH control, steadier serum levels, and fewer thyrotoxic side-effects. Second, because thyroid-hormone receptor isoforms are differentially expressed across tissues and display distinct T4/T3 affinities, the combination allows finer tuning of thyroid hormone signaling-maintaining adequate tumor suppression while attenuating adverse cardiac and skeletal effects.

Sponsors & Collaborators

• West China Tianfu Hospital, Sichuan University

  collaborator UNKNOWN

• Shang Jin Hospital of West China Hospital,Sichuan University

  collaborator UNKNOWN

• Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, China

  collaborator UNKNOWN

• First Affiliated Hospital of Guangxi Medical University

  collaborator OTHER

• First Affiliated Hospital of Kunming Medical University

  collaborator OTHER

• Xijing Hospital of Airforce Medical University

  collaborator UNKNOWN

• Sir Run Run Shaw Hospital

  collaborator OTHER

• First Affiliated Hospital of Chongqing Medical University

  collaborator OTHER

• The Affiliated Hospital Of Guizhou Medical University

  collaborator OTHER

• The Second Affiliated Hospital of Kunming Medical University

  collaborator OTHER

• The Second Affiliated Hospital of Lanzhou University

  collaborator UNKNOWN

• The Fifth People's Hospital of Qinghai Province （Qinghai Province Cancer Hospital)

  collaborator UNKNOWN

• The Affiliated Hospital of Inner Mongolia Medical University

  collaborator OTHER

• The First Affiliated Hospital of Shanxi Medical University

  collaborator OTHER

• General Hospital of Ningxia Medical University

  collaborator OTHER

• Yantai Yuhuangding Hospital

  collaborator OTHER

• Sun Yat-sen University

  collaborator OTHER

• Zhongnan Hospital

  collaborator OTHER

• West China Hospital

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-11-30

Primary Completion

2027-11-30

Completion

2028-06-30