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CompletedNCT05823012Updated Jul 3, 2025Results posted

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

A Phase 2 interventional study of levothyroxine sodium in Hypothyroidism, sponsored by Xeris Pharmaceuticals. Completed at 6 sites in United States. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2025-07-03.

Sponsored by Xeris Pharmaceuticals · Phase 2, Interventional, and Treatment

Phase
Phase 2
Study type
Interventional
Enrollment
46
Allocation
Not applicable
Ages
18 Years to 65 Years
Sex
All
01

Study 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.

Read the 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.

02

Conditions studied

  • Hypothyroidism

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03

Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
No

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

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.
04

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
46 participants (actual)

Study arms

  • Experimental
    XP-8121

    XP-8121 100 to 1500 μg subcutaneous injection

    Drug: levothyroxine sodium

Interventions

  • Druglevothyroxine sodium

    Levothyroxine sodium 10 mg/mL

    Also known as: XP-8121

05

What researchers measure

Primary outcomes

  1. Dose Conversion Factor

    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.

    Time frame: Day 29 of the Maintenance Period

  2. Tolerability Assessment: Modified Draize Scale - Erythema

    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.

    Time frame: Week 1 Dosing in Titration Period through Day 22 Dosing in Maintenance Period

  3. Tolerability Assessment: Modified Draize Scale - Edema

    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.

    Time frame: Week 1 Dosing in Titration Period through Day 22 Dosing in Maintenance Period

  4. Tolerability Assessments: Injection Site Discomfort Evaluation

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

    Time frame: Week 1 dosing in the Titration Period through Day 22 dosing in the Maintenance Period

Secondary outcomes

  1. Proportion of Participants With Normalized TSH Throughout the Maintenance Period

    Proportion of participants enrolled with normalized TSH throughout the Maintenance Period

    Time frame: Day 29 of the Maintenance Period

  2. Proportion of Participants With Normalized TSH at End of Maintenance Period

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

    Time frame: Day 29 of the Maintenance Period

  3. Thyroid Hormone Concentrations: Total Thyroxine

    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

    Time frame: Up to Day 29 of the Maintenance Period

  4. Thyroid Hormone Concentrations: Free Thyroxine (fT4)

    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

    Time frame: Up to Day 29 of the Maintenance Period

  5. Thyroid Hormone Concentrations: Thyroid Stimulating Hormone (TSH)

    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

    Time frame: Up to Day 29 of the Maintenance Period

06

Results

Posted Jul 3, 2025

Participant flow

Participants were recruited over an approximate 7.5 month period at medical research centers with experience in hypothyroidism.

Titration Period
Participant flow — Titration Period
MilestoneXP-8121
Started46
Completed42
Not completed4
Withdrew: Adverse event1
Withdrew: Inability to achieve a tolerable replacement dosage3
Maintenance Period
Participant flow — Maintenance Period
MilestoneXP-8121
Started42
Completed39
Not completed3
Withdrew: Adverse event1
Withdrew: Inability to achieve a tolerable replacement dosage1
Withdrew: Inability to achieve an adequate replacement dosage1

Outcome measures

PrimaryDose Conversion Factor

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.

Time frame:
Day 29 of the Maintenance Period
Reported as:
Geometric least squares mean · Ratio
Dose Conversion Factor
RatioXP-8121
Dose Conversion Factor4.24 (4.06 to 4.42)
PrimaryTolerability Assessment: Modified Draize Scale - Erythema

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.

Time frame:
Week 1 Dosing in Titration Period through Day 22 Dosing in Maintenance Period
Reported as:
Count of participants · Participants
Tolerability Assessment: Modified Draize Scale - Erythema
ParticipantsXP-8121
Titration Period: Week 1 Dosing — 0 - None43
Titration Period: Week 1 Dosing — 1 - Very Slight3
Titration Period: Week 1 Dosing — 2 - Slight0
Titration Period: Week 1 Dosing — 3 - Moderate0
Titration Period: Week 1 Dosing — 4 - Severe0
Titration Period: Week 2 Dosing — 0 - None41
Titration Period: Week 2 Dosing — 1 - Very Slight2
Titration Period: Week 2 Dosing — 2 - Slight0
Titration Period: Week 2 Dosing — 3 - Moderate0
Titration Period: Week 2 Dosing — 4 - Severe0
Titration Period: Week 3 Dosing — 0 - None41
Titration Period: Week 3 Dosing — 1 - Very Slight2
Titration Period: Week 3 Dosing — 2 - Slight0
Titration Period: Week 3 Dosing — 3 - Moderate0
Titration Period: Week 3 Dosing — 4 - Severe0
Titration Period: Week 4 Dosing — 0 - None37
Titration Period: Week 4 Dosing — 1 - Very Slight5
Titration Period: Week 4 Dosing — 2 - Slight0
Titration Period: Week 4 Dosing — 3 - Moderate0
Titration Period: Week 4 Dosing — 4 - Severe0
Titration Period: Week 5 Dosing — 0 - None38
Titration Period: Week 5 Dosing — 1 - Very Slight4
Titration Period: Week 5 Dosing — 2 - Slight0
Titration Period: Week 5 Dosing — 3 - Moderate0
Titration Period: Week 5 Dosing — 4 - Severe0
Titration Period: Week 6 Dosing — 0 - None38
Titration Period: Week 6 Dosing — 1 - Very Slight3
Titration Period: Week 6 Dosing — 2 - Slight0
Titration Period: Week 6 Dosing — 3 - Moderate0
Titration Period: Week 6 Dosing — 4 - Severe0
Titration Period: Week 7 Dosing — 0 - None12
Titration Period: Week 7 Dosing — 1 - Very Slight1
Titration Period: Week 7 Dosing — 2 - Slight0
Titration Period: Week 7 Dosing — 3 - Moderate0
Titration Period: Week 7 Dosing — 4 - Severe0
Titration Period: Week 8 Dosing — 0 - None12
Titration Period: Week 8 Dosing — 1 - Very Slight0
Titration Period: Week 8 Dosing — 2 - Slight0
Titration Period: Week 8 Dosing — 3 - Moderate0
Titration Period: Week 8 Dosing — 4 - Severe0
Maintenance Period: Day 1 Dosing — 0 - None40
Maintenance Period: Day 1 Dosing — 1 - Very Slight2
Maintenance Period: Day 1 Dosing — 2 - Slight0
Maintenance Period: Day 1 Dosing — 3 - Moderate0
Maintenance Period: Day 1 Dosing — 4 - Severe0
Maintenance Period: Day 8 Dosing — 0 - None40
Maintenance Period: Day 8 Dosing — 1 - Very Slight2
Maintenance Period: Day 8 Dosing — 2 - Slight0
Maintenance Period: Day 8 Dosing — 3 - Moderate0
Maintenance Period: Day 8 Dosing — 4 - Severe0
Maintenance Period: Day 15 Dosing — 0 - None39
Maintenance Period: Day 15 Dosing — 1 - Very Slight1
Maintenance Period: Day 15 Dosing — 2 - Slight1
Maintenance Period: Day 15 Dosing — 3 - Moderate0
Maintenance Period: Day 15 Dosing — 4 - Severe0
Maintenance Period: Day 22 Dosing — 0 - None37
Maintenance Period: Day 22 Dosing — 1 - Very Slight2
Maintenance Period: Day 22 Dosing — 2 - Slight0
Maintenance Period: Day 22 Dosing — 3 - Moderate0
Maintenance Period: Day 22 Dosing — 4 - Severe0
PrimaryTolerability Assessment: Modified Draize Scale - Edema

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.

Time frame:
Week 1 Dosing in Titration Period through Day 22 Dosing in Maintenance Period
Reported as:
Count of participants · Participants
Tolerability Assessment: Modified Draize Scale - Edema
ParticipantsXP-8121
Titration Period: Week 1 Dosing — 0 - None44
Titration Period: Week 1 Dosing — 1 - Very Slight2
Titration Period: Week 1 Dosing — 2 - Slight0
Titration Period: Week 1 Dosing — 3 - Moderate0
Titration Period: Week 1 Dosing — 4 - Severe0
Titration Period: Week 2 Dosing — 0 - None43
Titration Period: Week 2 Dosing — 1 - Very Slight0
Titration Period: Week 2 Dosing — 2 - Slight0
Titration Period: Week 2 Dosing — 3 - Moderate0
Titration Period: Week 2 Dosing — 4 - Severe0
Titration Period: Week 3 Dosing — 0 - None43
Titration Period: Week 3 Dosing — 1 - Very Slight0
Titration Period: Week 3 Dosing — 2 - Slight0
Titration Period: Week 3 Dosing — 3 - Moderate0
Titration Period: Week 3 Dosing — 4 - Severe0
Titration Period: Week 4 Dosing — 0 - None41
Titration Period: Week 4 Dosing — 1 - Very Slight1
Titration Period: Week 4 Dosing — 2 - Slight0
Titration Period: Week 4 Dosing — 3 - Moderate0
Titration Period: Week 4 Dosing — 4 - Severe0
Titration Period: Week 5 Dosing — 0 - None42
Titration Period: Week 5 Dosing — 1 - Very Slight0
Titration Period: Week 5 Dosing — 2 - Slight0
Titration Period: Week 5 Dosing — 3 - Moderate0
Titration Period: Week 5 Dosing — 4 - Severe0
Titration Period: Week 6 Dosing — 0 - None41
Titration Period: Week 6 Dosing — 1 - Very Slight0
Titration Period: Week 6 Dosing — 2 - Slight0
Titration Period: Week 6 Dosing — 3 - Moderate0
Titration Period: Week 6 Dosing — 4 - Severe0
Titration Period: Week 7 Dosing — 0 - None11
Titration Period: Week 7 Dosing — 1 - Very Slight1
Titration Period: Week 7 Dosing — 2 - Slight1
Titration Period: Week 7 Dosing — 3 - Moderate0
Titration Period: Week 7 Dosing — 4 - Severe0
Titration Period: Week 8 Dosing — 0 - None12
Titration Period: Week 8 Dosing — 1 - Very Slight0
Titration Period: Week 8 Dosing — 2 - Slight0
Titration Period: Week 8 Dosing — 3 - Moderate0
Titration Period: Week 8 Dosing — 4 - Severe0
Maintenance Period: Day 1 Dosing — 0 - None42
Maintenance Period: Day 1 Dosing — 1 - Very Slight0
Maintenance Period: Day 1 Dosing — 2 - Slight0
Maintenance Period: Day 1 Dosing — 3 - Moderate0
Maintenance Period: Day 1 Dosing — 4 - Severe0
Maintenance Period: Day 8 Dosing — 0 - None42
Maintenance Period: Day 8 Dosing — 1 - Very Slight0
Maintenance Period: Day 8 Dosing — 2 - Slight0
Maintenance Period: Day 8 Dosing — 3 - Moderate0
Maintenance Period: Day 8 Dosing — 4 - Severe0
Maintenance Period: Day 15 Dosing — 0 - None40
Maintenance Period: Day 15 Dosing — 1 - Very Slight0
Maintenance Period: Day 15 Dosing — 2 - Slight1
Maintenance Period: Day 15 Dosing — 3 - Moderate0
Maintenance Period: Day 15 Dosing — 4 - Severe0
Maintenance Period: Day 22 Dosing — 0 - None39
Maintenance Period: Day 22 Dosing — 1 - Very Slight0
Maintenance Period: Day 22 Dosing — 2 - Slight0
Maintenance Period: Day 22 Dosing — 3 - Moderate0
Maintenance Period: Day 22 Dosing — 4 - Severe0
PrimaryTolerability Assessments: Injection Site Discomfort Evaluation

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

Time frame:
Week 1 dosing in the Titration Period through Day 22 dosing in the Maintenance Period
Reported as:
Count of participants · Participants
Tolerability Assessments: Injection Site Discomfort Evaluation
ParticipantsXP-8121
Titration Period: Week 1 Dosing — Yes14
Titration Period: Week 1 Dosing — No32
Titration Period: Week 2 Dosing — Yes9
Titration Period: Week 2 Dosing — No34
Titration Period: Week 3 Dosing — Yes12
Titration Period: Week 3 Dosing — No31
Titration Period: Week 4 Dosing — Yes10
Titration Period: Week 4 Dosing — No32
Titration Period: Week 5 Dosing — Yes12
Titration Period: Week 5 Dosing — No30
Titration Period: Week 6 Dosing — Yes9
Titration Period: Week 6 Dosing — No32
Titration Period: Week 7 Dosing — Yes6
Titration Period: Week 7 Dosing — No7
Titration Period: Week 8 Dosing — Yes2
Titration Period: Week 8 Dosing — No10
Maintenance Period: Day 1 Dosing — Yes13
Maintenance Period: Day 1 Dosing — No29
Maintenance Period: Day 8 Dosing — Yes12
Maintenance Period: Day 8 Dosing — No30
Maintenance Period: Day 15 Dosing — Yes8
Maintenance Period: Day 15 Dosing — No33
Maintenance Period: Day 22 Dosing — Yes6
Maintenance Period: Day 22 Dosing — No33
SecondaryProportion of Participants With Normalized TSH Throughout the Maintenance Period

Proportion of participants enrolled with normalized TSH throughout the Maintenance Period

Time frame:
Day 29 of the Maintenance Period
Reported as:
Count of participants · Participants
Proportion of Participants With Normalized TSH Throughout the Maintenance Period
ParticipantsAll ParticipantsParticipants Who Entered the Maintenance Period
Proportion of Participants With Normalized TSH Throughout the Maintenance Period2727
SecondaryProportion of Participants With Normalized TSH at End of Maintenance Period

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

Time frame:
Day 29 of the Maintenance Period
Reported as:
Count of participants · Participants
Proportion of Participants With Normalized TSH at End of Maintenance Period
ParticipantsAll ParticipantsParticipants Who Entered Maintenance Period
Proportion of Participants With Normalized TSH at End of Maintenance Period3131
SecondaryThyroid Hormone Concentrations: Total Thyroxine

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

Time frame:
Up to Day 29 of the Maintenance Period
Reported as:
Mean · nmol/L
Thyroid Hormone Concentrations: Total Thyroxine
nmol/LXP-8121
Titration Period: Baseline103.68 ± 27.278
Titration Period: Week 2 Dosing88.17 ± 23.019
Titration Period: Week 3 Dosing89.68 ± 23.019
Titration Period: Week 4 Dosing92.44 ± 24.104
Titration Period: Week 5 Dosing94.26 ± 22.059
Titration Period: Week 6 Dosing97.38 ± 22.056
Titration Period: Week 7 Dosing90.29 ± 18.867
Titration Period: Week 8 Dosing88.58 ± 25.032
Maintenance Period: Day 1 Dosing (Baseline)103.45 ± 24.970
Maintenance Period: Day 8 Dosing102.24 ± 23.704
Maintenance Period: Day 15 Dosing103.35 ± 23.508
Maintenance Period: Day 22 Dosing104.67 ± 19.389
Maintenance Period: Day 29101.97 ± 24.532
SecondaryThyroid Hormone Concentrations: Free Thyroxine (fT4)

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

Time frame:
Up to Day 29 of the Maintenance Period
Reported as:
Mean · pmol/L
Thyroid Hormone Concentrations: Free Thyroxine (fT4)
pmol/LXP-8121
Titration Period: Baseline14.60 ± 2.713
Titration Period: Week 2 Dosing12.09 ± 2.209
Titration Period: Week 3 Dosing11.69 ± 2.494
Titration Period: Week 4 Dosing12.47 ± 2.668
Titration Period: Week 5 Dosing12.84 ± 2.417
Titration Period: Week 6 Dosing12.88 ± 1.977
Titration Period: Week 7 Dosing12.32 ± 1.814
Titration Period: Week 8 Dosing13.26 ± 1.840
Maintenance Period: Day 1 Dosing (Baseline)14.50 ± 2.411
Maintenance Period: Day 8 Dosing14.36 ± 2.319
Maintenance Period: Day 15 Dosing14.24 ± 2.147
Maintenance Period: Day 22 Dosing14.27 ± 1.917
Maintenance Period: Day 2914.14 ± 1.796
SecondaryThyroid Hormone Concentrations: Thyroid Stimulating Hormone (TSH)

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

Time frame:
Up to Day 29 of the Maintenance Period
Reported as:
Mean · mIU/L
Thyroid Hormone Concentrations: Thyroid Stimulating Hormone (TSH)
mIU/LXP-8121
Titration Period: Baseline1.958 ± 1.0778
Titration Period: Week 2 Dosing3.942 ± 2.8299
Titration Period: Week 3 Dosing6.534 ± 8.2589
Titration Period: Week 4 Dosing6.162 ± 8.8632
Titration Period: Week 5 Dosing6.397 ± 9.8016
Titration Period: Week 6 Dosing5.506 ± 7.1427
Titration Period: Week 7 Dosing8.326 ± 8.5120
Titration Period: Week 8 Dosing5.752 ± 5.3967
Maintenance Period: Day 1 Dosing (Baseline)2.967 ± 2.1827
Maintenance Period: Day 8 Dosing2.920 ± 2.7009
Maintenance Period: Day 15 Dosing2.739 ± 2.8858
Maintenance Period: Day 22 Dosing2.494 ± 2.0766
Maintenance Period: Day 292.493 ± 1.5087

Adverse events

Collected over From Screening through the End of Maintenance Visit (Day 29) or up to 14 (+/-2 days) after last dose of XP-8121 for participants who withdrew prematurely. Non-serious events are listed at a 3% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Titration Period0/46 (0%)0/46 (0%)19/46 (41.3%)
Maintenance Period0/42 (0%)0/42 (0%)4/42 (9.5%)
Overall0/46 (0%)0/46 (0%)22/46 (47.8%)
Most frequent other events
Most frequent other events
EventTitration PeriodMaintenance PeriodOverall
FatigueGeneral disorders10/460/4210/46
Injection site painGeneral disorders3/462/425/46
HeadacheNervous system disorders4/460/424/46
Urinary tract infectionInfections and infestations3/460/423/46
Temperature intoleranceGeneral disorders2/460/422/46
Weight increasedInvestigations1/461/422/46
AnxietyPsychiatric disorders1/461/422/46
EcchymosisSkin and subcutaneous tissue disorders1/461/422/46
PruritisSkin and subcutaneous tissue disorders2/460/422/46

Baseline characteristics

Age, Continuous
Age, Continuous(years)XP-8121
Median54.5 (33 to 65)
Sex: Female, Male
Sex: Female, Male(Participants)XP-8121
Female37
Male9
Race (NIH/OMB)
Race (NIH/OMB)(Participants)XP-8121
American Indian or Alaska Native0
Asian1
Native Hawaiian or Other Pacific Islander0
Black or African American0
White44
More than one race1
Unknown or Not Reported0
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)XP-8121
Hispanic or Latino29
Not Hispanic or Latino17
Unknown or Not Reported0
Baseline Body Mass Index
Baseline Body Mass Index(kg/m^2)XP-8121
Median29.50 (23.1 to 39.9)
Primary Hypothyroidism History
Primary Hypothyroidism History(Participants)XP-8121
Count of participants46
Prior Daily Oral Levothyroxine Brand
Prior Daily Oral Levothyroxine Brand(Participants)XP-8121
Synthroid9
Other Brand or Generic37
Prior Daily Oral Levothyroxine Dose
Prior Daily Oral Levothyroxine Dose(Participants)XP-8121
50 micrograms14
75 micrograms12
88 micrograms3
100 micrograms8
112 micrograms3
125 micrograms3
150 micrograms2
175 micrograms1
07

Study locations

6 sites
  • ProSciento, Inc.
    Chula Vista, California 91911, United States
  • Catalina Research Institute, L.L.C.
    Montclair, California 91763, United States
  • Panax Clinical Research, LLC
    Miami Lakes, Florida 33014, United States
  • American Research Corporation
    San Antonio, Texas 78215, United States
  • Mt. Olympus Medical Research, LLC
    Sugar Land, Texas 77479, United States
  • Rainier Clinical Research Center
    Renton, Washington 98057, United States
08

References and documents

Study documents

  • Study protocol · May 7, 2023
  • Statistical analysis plan · Apr 4, 2024

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No

09

Registry details

Key details

Study ID
NCT05823012
Lead sponsor
Xeris Pharmaceuticals
Responsible party
Sponsor
First posted
Apr 21, 2023
Start date
May 15, 2023
Primary completion
Feb 22, 2024
Completion
Feb 22, 2024
Results posted
Jul 3, 2025
Last update
Jul 3, 2025

Study contacts

Valentina Conoscenti, MD
study director · Xeris Pharmaceuticals, Inc.

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
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