A Study to Assess the Safety and Efficacy of Oral Armour Thyroid Compared to Synthetic T4 for the Treatment of Primary Hypothyroidism in Adult Participants

Phase 2

Recruiting

• Conditions: Hypothyroidism
• Interventions: Drug: Armour Thyroid; Drug: Levothyroxine

• Registration Number: NCT06345339
• Lead Sponsor: AbbVie

Brief Summary

This study will evaluate the efficacy and safety of Armour Thyroid treatment compared with synthetic T4 in subjects who have primary hypothyroidism and are currently stabilized (i.e., in-range thyroid-stimulating hormone \[TSH\]) on synthetic T4 treatment. This study will also therefore evaluate the efficacy and safety of dose conversion from synthetic T4 therapy to Armour Thyroid therapy.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2024-03-27
• Study First Submitted QC: 2024-03-27
• Study First Posted: 2024-04-03
• Study Start: 2024-04-26
• Status Verified: 2025-06
• Last Update Submitted: 2025-06-06
• Last Update Posted: 2025-06-10
• Primary Completion: 2027-09
• Study Completion: 2028-06

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 2800

Inclusion Criteria

• Have a diagnosis of primary hypothyroidism made >= 12 months prior to Screening.
• Be on continuous thyroid replacement therapy of synthetic T4 for primary hypothyroidism for at least 12 months immediately prior to the Screening Visit.
• Be on a stable FDA-approved daily dose of synthetic T4 prior to the Screening visit, and must be taking synthetic T4 dose of at least 25 mcg at Screening visit. Must enter the study using the same stable dose to determine dose conversion.
• Documentation of 1 in-range thyroid-stimulating hormone (TSH) (i.e., within 0.45 - 4.12 mIU/L, inclusive) at Screening and at least 1 additional in range TSH (i.e., within 0.45 - 4.12 mIU/L, inclusive) taken at a minimum of 6 weeks and a maximum of 12 months prior to Screening.

Exclusion Criteria

• Any clinical condition or previous surgery that might affect the absorption, distribution, biotransformation, or excretion of Armour Thyroid or synthetic T4.
• History of alcohol or other substance abuse within the previous 6 months prior to the Screening.
• Known or suspected allergy or intolerance to any ingredients of Armour Thyroid, including its excipients, synthetic T4, other thyroid replacement medications, or pork products.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Group 1	Armour Thyroid	Participants will receive Armour Thyroid for up to 81 weeks.
Group 2	Armour Thyroid	Participants will alternate between Armour Thyroid and synthetic T4 for up to 81 weeks.
Group 2	Levothyroxine	Participants will alternate between Armour Thyroid and synthetic T4 for up to 81 weeks.

Primary Outcome Measures

Name	Time	Method
Percentage of Participants who Achieve Thyroid-Stimulating Hormone (TSH) Response	Week 55	TSH response is defined as TSH values falling within 0.45 to 4.12 mIU/L (inclusive). TSH response will be determined at Week 55 and at a prior visit with no out-of-range TSH values in between (response rate is tested against a specified non-inferiority margin).
Number of Participants with Adverse Events (AEs)	Up to approximately 90 weeks	An AE is defined as any untoward medical occurrence in a patient or clinical investigation in which a participant is administered a pharmaceutical product which does not necessarily have a causal relationship with this treatment.

Secondary Outcome Measures

Name	Time	Method
Percentage of Participants who Achieve TSH Response	Week 55	TSH response is defined as TSH values falling within 0.45 to 4.12 mIU/L. TSH response will be determined at Week 55 and at a prior visit with no out-of-range TSH values in between (response rate is tested against a specified non-inferiority margin \[stricter than the one used in the Primary Outcome Measure\]).
Frequency of Dose Titrations During the Double-Blind (DB) Period Among Participants who Achieved TSH Response at the End of the DB Period	Week 55	Frequency of dose titrations (0,1,2...) during the DB period among participants who achieved TSH response at the end of the DB period.
Number of Participants Needing Altered Dose Conversion from Synthetic T4 to Armour Thyroid	Up to approximately 29 weeks	Number of participants needing altered dose conversion from synthetic T4 to Armour Thyroid.

Trial Locations

Locations (138)

Central Research Associates /ID# 255719; 🇺🇸 Birmingham, Alabama, United States

UAB Hospital /ID# 262565; 🇺🇸 Birmingham, Alabama, United States

Kaiser San Diego Dept Endocrinology, SCPMG /ID# 262552; 🇺🇸 Bonita, California, United States

Facey Medical Foundation - Burbank /ID# 262104; 🇺🇸 Burbank, California, United States

John Muir Medical Center /ID# 257103; 🇺🇸 Concord, California, United States

Diagnamics Inc. /ID# 262680; 🇺🇸 Encinitas, California, United States

Providence - St. Jude Medical Center /ID# 256520; 🇺🇸 Fullerton, California, United States

NorCal Medical Research /ID# 256512; 🇺🇸 Greenbrae, California, United States

Velocity Clinical Research - Huntington Park /ID# 259044; 🇺🇸 Huntington Park, California, United States

Scripps Whittier Diabetes Institute /ID# 259215; 🇺🇸 La Jolla, California, United States

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