A Study of Armour® Thyroid Compared to Synthetic T4 (Levothyroxine) in Previously Hypothyroid Participants

Phase 2

Completed

Conditions: Thyroid Disease
Euthyroid
Thyroid Gland
Thyroid Hormones
Hypothyroidism

Interventions: Drug: Armour® Thyroid
Drug: Levothyroxine

Registration Number: NCT04124705

Lead Sponsor: Allergan

Brief Summary: This study will evaluate the safe and effective dose conversion from levothyroxine (synthetic T4) therapy to Armour Thyroid therapy in participants who are on a stable dose of levothyroxine and have thyroid stimulating hormone (TSH) levels within the normal reference range.

Detailed Description: This study will include will include a Screening Period, double-blinded Titration Period (at least 18 weeks, up to 36 weeks), and a double-blinded Stabilization Period (12 weeks).

Participants will be randomized to receive either their same dose of levothyroxine or an approximately, matching dose of Armour Thyroid, using a dose-conversion chart based on the United States Pharmacopeia (USP) Drug Information 2000, which states that 1 grain of Armour Thyroid is equivalent to 100 mcg of levothyroxine.

During the Titration Period, Investigators will have the option to up-or down-titrate a participant's dose as needed based on the participant's TSH level (normal reference range 0.45 - 4.12 mIU/L, inclusive). At Week 18, if a participant's TSH levels are not within the normal reference range, the Investigator may up-or down-titrate the dose by continuing the Titration Period beyond Week 18 for up to a maximum of 3 additional titrations at 6-week intervals. Participants whose TSH levels have not normalized after the maximum 3 additional titrations will not enter the Stabilization Period.

At the end of the Titration Period, participants with TSH levels within normal reference range may enter the Stabilization Period. Depending on whether a participant requires additional dose titration after the Week 18 visit, the Stabilization Period may end at Week 30, 36, 42, or 48.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 284

Inclusion Criteria

Participants who have a diagnosis of primary hypothyroidism made ≥ 12 months before study entry (Visit 1).
Be on continuous thyroid replacement therapy with synthetic T4 for primary hypothyroidism for at least 12 months immediately prior to the Screening Visit (Visit 1).
Be on a stable Food and Drug Administration (FDA)-approved daily dose of synthetic T4 for a minimum of 3 months prior to the Screening Visit (Visit 1). Must enter the study on the same stable dose.
Have euthyroid status indicated by at least 1 documented TSH value within normal reference range (0.45 - 4.12 mIU/L, inclusive) at a minimum of 6 weeks and maximum of 12 months prior to the Screening Visit (Visit 1). Also have a confirmed TSH value within the normal reference range drawn at the Screening Visit (Visit 1).
Male and female participants willing to minimize the risk of inducing pregnancy for the duration of the clinical study and follow-up period (35 days after last dose of study intervention).

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 5 years.
Known or suspected allergy or intolerance to any ingredients of Armour Thyroid, including its excipients, levothyroxine (T4), other thyroid replacement medications, or pork products.
Have received active treatment with an investigational drug within 30 days or 5 half lives, whichever is longer, of Screening Visit (Visit 1).
Current enrollment in an investigational drug or device study or participation in such a study within 60 days of entry into this study.

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Armour® Thyroid	Armour® Thyroid	Participants were randomized to receive Armour Thyroid at a dose corresponding to their pre-randomized dose of synthetic T4. During the first 18 to 36 weeks (titration period) the dose of Armour Thyroid could be titrated based on levels of thyroid stimulating hormone (TSH), in order to achieve TSH levels within the normal reference range (0.45 - 4.12 mIU/L, inclusive). Once TSH levels were within the normal reference range, participants continued to receive a stable dose of Armour Thyroid for an additional 12 weeks (stabilization period).
Levothyroxine	Levothyroxine	Participants were randomized to receive levothyroxine at their pre-randomized dose. During the first 18 to 36 weeks (titration period) the dose of levothyroxine could be titrated based on levels of TSH in order to achieve TSH levels within the normal reference range (0.45-4.12 mIU/L, inclusive). Once TSH levels were within the normal reference range, participants continued to receive a stable dose of levothyroxine for an additional 12 weeks (stabilization period).

Primary Outcome Measures

Name	Time	Method
Percentage of Participants With a Sustained TSH Response	End of the titration period (Week 18, 24, 30, or 36) and end of the stabilization period (Week 30, 36, 42, or 48, depending on the length of the titration period).	Sustained TSH response is defined as TSH values that are within the normal reference range of 0.45 to 4.12 mIU/L, inclusive, at both the end of Titration Period and the end of the Stabilization Period.

Secondary Outcome Measures

Name	Time	Method
Percentage of Participants With a Titration TSH Response	End of the titration period (Week 18, 24, 30, or 36)	Titration TSH Response is defined as having a TSH value within the normal reference range of 0.45 to 4.12 mIU/L, inclusive, at the end of the Titration Period.

Trial Locations

Locations (28): Sponsor Site /ID# 235853
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Fort Lauderdale, Florida, United States
Sponsor Site /ID# 236809
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West Palm Beach, Florida, United States
Sponsor Site /ID# 235032
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Atlanta, Georgia, United States
Sponsor Site /ID# 238088
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Lawrenceville, Georgia, United States
Sponsor Site /ID# 237199
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Columbus, Georgia, United States
Sponsor Site/ID# 235204
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Greenville, North Carolina, United States
Sponsor Site/ID# 237652
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Dallas, Texas, United States
Sponsor Site /ID# 235870
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El Paso, Texas, United States
Sponsor Site /ID# 237986
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Little Rock, Arkansas, United States
Sponsor Site /ID# 235716
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Huntington Beach, California, United States
Sponsor Site /ID# 235210
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Greenbrae, California, United States
Sponsor Site /ID# 238258
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Van Nuys, California, United States
Sponsor Site/ID# 235866
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Denver, Colorado, United States
Sponsor Site /ID# 235714
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Lexington, Kentucky, United States
Sponsor Site /ID# 235202
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Asheville, North Carolina, United States
Sponsor Site /ID# 238026
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Santa Clarita, California, United States
Sponsor Site /ID# 235860
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Round Rock, Texas, United States
Sponsor Site /ID# 238023
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Hickory, North Carolina, United States
Sponsor Site /ID# 235211
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Renton, Washington, United States
Sponsor Site/ID# 237655
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Dallas, Texas, United States
Sponsor Site /ID# 235894
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San Antonio, Texas, United States
Sponsor Site /ID# 236022
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Spokane, Washington, United States
Sponsor Site/ID# 236977
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Tacoma, Washington, United States
Sponsor Site /ID# 237950
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Birmingham, Alabama, United States
Sponsor Site /ID# 238120
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Sacramento, California, United States
Sponsor Site /ID# 236701
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Louisville, Kentucky, United States
Sponsor Site /ID# 237137
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Austin, Texas, United States
Sponsor Site/ID# 238071
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Austin, Texas, United States