A Study Evaluation the Safety and Efficacy of Hormone Replacement Therapy With North Star Compared to Levothyroxine in Patients With Primary Hypothyroidism

February 16, 2026 updated by: Neuvosyn Laboratories, LLC

A Randomized, Double-blind, Dose-Conversion Study to Evaluate the Safety and Efficacy of Hormone Replacement Therapy With North Star Compared to Levothyroxine in Subjects With Primary Hypothyroidism Who Are Euthyroid on Levothyroxine Replacement Therapy

The North Star study is a multi-center, Phase 2, double-blind, randomized, parallel group clinical study to evaluate the safe and effective dose conversion from Levothyroxine to North Star therapy.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

303

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35209
        • Neuvosyn Investigational Site
    • California
      • Canoga Park, California, United States, 91304
        • Neuvosyn Investigational Site
      • Greenbrae, California, United States, 94904
        • Neuvosyn Investigational Site
      • Toluca Lake, California, United States, 91602
        • Neuvosyn Investigational Site
    • Connecticut
      • Farmington, Connecticut, United States, 06030
        • Neuvosyn Investigational Site
    • Florida
      • Boca Raton, Florida, United States, 33434
        • Neuvosyn Investigational Site
      • Miami, Florida, United States, 33144
        • Neuvosyn Investigational Site
      • Miami, Florida, United States, 33145
        • Neuvosyn Investigational Site
      • Miami, Florida, United States, 33155
        • Neuvosyn Investigational Site
      • Miami, Florida, United States, 33174
        • Neuvosyn Investigational Site
      • Miami, Florida, United States, 33179
        • Neuvosyn Investigational Site
      • Sunrise, Florida, United States, 33351
        • Neuvosyn Investigational Site
    • Georgia
      • Acworth, Georgia, United States, 30101
        • Neuvosyn Investigational Site
      • Atlanta, Georgia, United States, 30318
        • Neuvosyn Investigational Site
      • Columbus, Georgia, United States, 31904
        • Neuvosyn Investigational Site
      • Sugar Hill, Georgia, United States, 30024
        • Neuvosyn Investigational Site
    • Michigan
      • Saginaw, Michigan, United States, 48602
        • Neuvosyn Investigational Site
    • Missouri
      • Gladstone, Missouri, United States, 64118
        • Neuvosyn Investigational Site
    • New York
      • Williamsville, New York, United States, 14221
        • Neuvosyn Investigational Site
    • North Carolina
      • Denver, North Carolina, United States, 28037
        • Neuvosyn Investigational Site
      • Winston-Salem, North Carolina, United States, 27103
        • Neuvosyn Investigational Site
    • Ohio
      • Beavercreek, Ohio, United States, 45440
        • Neuvosyn Investigational Site
      • Columbus, Ohio, United States, 31904
        • Neuvosyn Investigational Site
    • Texas
      • Georgetown, Texas, United States, 78628
        • Neuvosyn Investigational Site
      • Houston, Texas, United States, 77040
        • Neuvosyn Investigational Site
      • Katy, Texas, United States, 77450
        • Neuvosyn Investigational Site
      • Katy, Texas, United States, 77494
        • Neuvosyn Investigational Site
      • Lewisville, Texas, United States, 75067
        • Neuvosyn Investigational Site
      • Paris, Texas, United States, 75462
        • Neuvosyn Investigational Site
      • Pearland, Texas, United States, 77584
        • Neuvosyn Investigational Site
      • Stafford, Texas, United States, 77477
        • Neuvosyn Investigational Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Diagnosed with primary hypothyroidism
  • On continuous thyroid replacement therapy for at least 6 months before Study Entry
  • On a stable daily dose of LT4 for a minimum of 12 weeks prior to Screening
  • Agree to practice a method of contraception
  • Female patients not pregnant or lactating at Screening
  • Agree to practice a method of contraception of greater than 90% reliability
  • Willing to give written informed consent for the Study
  • Provide written authorization for use and disclosure of protected health information

Exclusion Criteria:

  • Any clinical condition or previous surgery that might affect the absorption, distribution, biotransformation or excretion of North Star or levothyroxine
  • Hospitalization for a major illness within 4 weeks prior to Screening
  • Anticipated initiation or change in concomitant medications
  • Concomitant use of prohibited medications or supplements
  • Participated in another investigational new drug study within 30 days or 5 half-lives of the IMP, whichever is longer, prior to the first study drug administration.
  • For female subjects, be pregnant, nursing or planning to become pregnant during the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Levothyroxine
Drug: Levothyroxine
Levothyroxine
Experimental: North Star
Drug: North Star
North Star

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
The ratio of the LT4 dose (mcg/day) at screening to North Star (mg/day) at the end of the treatment period required to achieve and maintain serum thyroid-stimulating hormone (TSH) levels within the normal reference range.
Time Frame: Week 30
Week 30

Secondary Outcome Measures

Outcome Measure
Time Frame
Proportion of subjects who are euthyroid as determined by serum TSH level within the normal reference range at the end of the treatment period.
Time Frame: Week 30
Week 30

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Neuvosyn Laboratories, LLC

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 28, 2023

Primary Completion (Actual)

May 5, 2025

Study Completion (Actual)

September 18, 2025

Study Registration Dates

First Submitted

January 18, 2023

First Submitted That Met QC Criteria

January 25, 2023

First Posted (Actual)

February 3, 2023

Study Record Updates

Last Update Posted (Actual)

February 18, 2026

Last Update Submitted That Met QC Criteria

February 16, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • NorthStar-02-001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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