MedPath

Study of XP-8121 For the Treatment of Adult Subjects With Hypothyroidism

Phase 2
Completed
Conditions
Hypothyroidism
Interventions
Registration Number
NCT05823012
Lead Sponsor
Xeris Pharmaceuticals
Brief Summary

This is a non-randomized, open-label, single arm, self-controlled study of XP-8121 (levothyroxine sodium) to determine a target dose conversion factor from stably dosed oral levothyroxine to XP-8121 (levothyroxine sodium) in patients with hypothyroidism and to assess the safety and tolerability of XP-8121(levothyroxine sodium) after once weekly subcutaneous injections. This study includes the following periods: Screening, Titration Period, and Maintenance Period. The study will conclude with an End of Maintenance Visit or Early Termination (ET) Visit.

Detailed Description

This is a non-randomized, open-label, single arm, self-controlled study of XP-8121 (levothyroxine sodium) to determine a target dose conversion factor from stably dosed oral levothyroxine to XP-8121 (levothyroxine sodium) in patients with hypothyroidism and to assess the safety and tolerability of XP-8121 (levothyroxine sodium) after once weekly subcutaneous injections. This study includes the following periods: Screening, Titration Period (2 to 8 weeks), and Maintenance Period (4 weeks). A pharmacokinetic substudy will be conducted for a subset of participants during the Maintenance Period. The study will conclude with an End of Maintenance Visit or Early Termination (ET) Visit.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
46
Inclusion Criteria
  • Provide written informed consent.
  • Male or female between the ages of 18 and 65 years (inclusive) at Screening, with chronic hypothyroidism and on a stable dose of oral levothyroxine (Synthroid or an FDA-approved generic equivalent to Synthroid) or, if in the pharmacokinetic substudy, Synthroid only for at least 3 months.
  • Thyroid stimulating hormone (TSH) within the normal range at Screening (central laboratory) and at least 3 months prior to Screening (documented by local laboratory).
  • Free thyroxine within the normal range at Screening (central laboratory).
Exclusion Criteria
  • History of hypersensitivity to levothyroxine (any formulation).
  • Current dose of oral levothyroxine, based on body weight >2 μg/kg/day.
  • Current levothyroxine total daily dose either <50 μg or >375 μg.
  • Current use of combined thyroid treatment (i.e., Synthroid plus liothyronine or Synthroid plus Armour Thyroid) and/or any other levothyroxine aside from those used in the study.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
XP-8121levothyroxine sodiumXP-8121 100 to 1500 μg subcutaneous injection
Primary Outcome Measures
NameTimeMethod
Dose Conversion FactorDay 29 of the Maintenance Period

Geometric mean ratio of the weekly dose of XP-8121 to the daily dose of oral levothyroxine (aka dose conversion factor), where the XP-8121 dose corresponds to the administration immediately preceding collection of blood TSH used to determine normalization at the end of Maintenance Period. The dose conversion factor was assessed by comparing the natural log-transformed final XP-8121 dose in μg that maintained normalized TSH throughout the Maintenance Period to the natural log-transformed daily oral levothyroxine dose the participant was taking before the study, using a linear mixed effects model with treatment as the fixed effect and subject as the random effect. Geometric least square means (LSMs) were calculated by exponentiating the LSM from the ANOVA. The geometric mean ratio and the corresponding 90% CI was found by exponentiating the differences of log-transformed LSM and 90% confidence interval (CI) of the difference.

Tolerability Assessment: Modified Draize Scale - ErythemaWeek 1 Dosing in Titration Period through Day 22 Dosing in Maintenance Period

The Modified Draize Scale assessment of erythema and edema was conducted 30 (+/-5) minutes after each dosing. The Modified Draize Scale is a 5-point scale: 0-none, 1-very slight, 2-slight, 3-moderate, 4-severe.

Tolerability Assessments: Injection Site Discomfort EvaluationWeek 1 dosing in the Titration Period through Day 22 dosing in the Maintenance Period

Injection site discomfort was assessed by each participant at 10 (+/-2) minutes post-injection.

Tolerability Assessment: Modified Draize Scale - EdemaWeek 1 Dosing in Titration Period through Day 22 Dosing in Maintenance Period

The Modified Draize Scale assessment of erythema and edema was conducted 30 (+/-5) minutes after each dosing. The Modified Draize Scale is a 5-point scale: 0-none, 1-very slight, 2-slight, 3-moderate, 4-severe.

Secondary Outcome Measures
NameTimeMethod
Thyroid Hormone Concentrations: Free Thyroxine (fT4)Up to Day 29 of the Maintenance Period

Thyroid hormone concentrations (total thyroxine, free protein-unbound thyroxine (fT4), and TSH) following the first dose of XP-8121 during the Titration Period and Maintenance Periods

Proportion of Participants With Normalized TSH at End of Maintenance PeriodDay 29 of the Maintenance Period

Proportion of participants enrolled with normalized TSH at the end of the Maintenance Period.

Thyroid Hormone Concentrations: Total ThyroxineUp to Day 29 of the Maintenance Period

Thyroid hormone concentrations (total thyroxine, free protein-unbound thyroxine (fT4), and TSH) following the first dose of XP-8121 during the Titration Period and Maintenance Periods

Proportion of Participants With Normalized TSH Throughout the Maintenance PeriodDay 29 of the Maintenance Period

Proportion of participants enrolled with normalized TSH throughout the Maintenance Period

Thyroid Hormone Concentrations: Thyroid Stimulating Hormone (TSH)Up to Day 29 of the Maintenance Period

Thyroid hormone concentrations (total thyroxine, free protein-unbound thyroxine (fT4), and TSH) following the first dose of XP-8121 during the Titration Period and Maintenance Periods

Trial Locations

Locations (6)

ProSciento, Inc.

🇺🇸

Chula Vista, California, United States

Catalina Research Institute, L.L.C.

🇺🇸

Montclair, California, United States

Panax Clinical Research, LLC

🇺🇸

Miami Lakes, Florida, United States

American Research Corporation

🇺🇸

San Antonio, Texas, United States

Mt. Olympus Medical Research, LLC

🇺🇸

Sugar Land, Texas, United States

Rainier Clinical Research Center

🇺🇸

Renton, Washington, United States

ProSciento, Inc.
🇺🇸Chula Vista, California, United States

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