A Study to Evaluate the Efficacy and Safety of LASN01 in Patients With Thyroid Eye Disease

February 17, 2026 updated by: Lassen Therapeutics Inc.

A Phase 2, Proof-of-Concept, Randomized, Double-Masked, Placebo-Controlled Study to Determine the Efficacy and Safety of LASN01 in Patients With Thyroid Eye Disease

LASN01 is a novel, fully human antibody directed against the human IL-11 receptor being developed for treatment of patients with thyroid eye disease (TED).

The primary and secondary objectives of this study are to evaluate the treatment effect, safety, and pharmacokinetics of LASN01 administered IV in patients with TED with no prior anti-IGF-1R treatment or in patients with TED who have previously received teprotumumab treatment.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This clinical trial (LASN01-CL-2201) comprises a multiple-dose design in 3 parallel treatment arms for patients with TED with no prior anti-IGF-1R treatment, and a 4th treatment arm for patients with TED who have previously received teprotumumab treatment.

Study Type

Interventional

Enrollment (Actual)

41

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

  • Spain
      • Córdoba, Spain, 14012
        • Site 302
      • Seville, Spain, 41009
        • Site 301
  • United Kingdom
      • London, United Kingdom, EC1V 2PD
        • Site 201
      • London, United Kingdom, NW1 5QH
        • Site 206
      • Newcastle upon Tyne, United Kingdom, NE1 4LP
        • Site 204
  • United States
    • California
      • Beverly Hills, California, United States, 90210
        • Site 111
      • Palo Alto, California, United States, 94303
        • Site 105
      • San Diego, California, United States, 92093
        • Site 101
    • Florida
      • Miami, Florida, United States, 33136
        • Site 103
    • Michigan
      • Livonia, Michigan, United States, 48152
        • Site 108
    • Nevada
      • Las Vegas, Nevada, United States, 89144
        • Site 112
    • North Carolina
      • Wilmington, North Carolina, United States, 28403
        • Site 110
    • Texas
      • Houston, Texas, United States, 77030
        • Site 106
      • Houston, Texas, United States, 77401
        • Site 104
    • Washington
      • Seattle, Washington, United States, 98104
        • Site 109

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Male or female patients ≥18 years of age at the time of Screening
  2. Clinical diagnosis of Graves' disease associated with active TED
  3. Moderate-to-severe active TED
  4. Female patients must be nonpregnant, nonlactating, surgically sterile for ≥6 months, or agree to use a highly effective method of contraception. Males must be surgically sterile or agree to use a highly effective method of contraception.

  5. No previous:

    1. Medical treatment for TED, with the exception of:

      • Local supportive measures;
      • Mycophenolate, and oral or injectable steroids;
      • Immunomodulating therapies
      • For the open-label treatment arm only: Previous treatment with teprotumumab is required.
    2. Orbital surgery
    3. Orbital radiation

  6. Patients

    • Without prior anti-IGF-1R treatment: less than 15 months from onset of TED symptoms
    • With prior teprotumumab treatment: depending on time of diagnosis or reactivation of disease

Exclusion Criteria:

  1. Patients with 2 mm proptosis decrease between Screening and Day 1, or a 1-point decrease on the CAS 7-point scale between Screening and Day 1
  2. Patients with a known decreased best corrected visual acuity due to optic neuropathy as defined by a decrease in vision of 3 lines on the Snellen chart, new visual field defect, or color defect secondary to optic nerve involvement within the last 6 months before Screening; or any known optic neuropathy or compression or any neurologic or neuro-ophthalmologic condition that may result in visual field loss.
  3. Previous or any planned orbital irradiation/radiotherapy or orbital surgery for TED during the study period (ie, treatment and FU)
  4. Use of oral and/or IV corticosteroid for conditions other than TED in the 6 weeks before Day 1 (topical steroids for conditions other than TED are allowed)
  5. Active autoimmune disorder(s) requiring or likely to require treatment (other than Grave's disease and TED) that would interfere with study assessments, as determined by the PI or designee
  6. Any previous use of anti-IGF-1R monoclonal antibody (eg, teprotumumab) at any time, with exception to the open-label post-teprotumumab treatment arm where prior use of teprotumumab is required
  7. Use of selenium within 3 weeks before Day 1 or expected use during the clinical trial (multivitamins that include selenium are allowed in usual doses)
  8. Use or expected use of biotin (including multivitamins that include biotin) within 2 days before any laboratory collection

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: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Randomized low-dose LASN01 (anti-IGF-1R-naïve TED)
Drug: LASN01
Low dose of LASN01 will be administered intravenously.
Other Names:
  • Low-dose LASN01
Drug: LASN01
High dose of LASN01 will be administered intravenously.
Other Names:
  • High-dose LASN01
Experimental: Randomized high-dose LASN01 (anti-IGF-1R-naïve TED)
Drug: LASN01
Low dose of LASN01 will be administered intravenously.
Other Names:
  • Low-dose LASN01
Drug: LASN01
High dose of LASN01 will be administered intravenously.
Other Names:
  • High-dose LASN01
Placebo Comparator: Randomized placebo (anti-IGF-1R-naïve TED)
Drug: Placebo
Placebo will be administered intravenously.
Other Names:
  • Placebo to match
Experimental: Open-label high dose LASN01 (post-teprotumumab, US only)
Drug: LASN01
Low dose of LASN01 will be administered intravenously.
Other Names:
  • Low-dose LASN01
Drug: LASN01
High dose of LASN01 will be administered intravenously.
Other Names:
  • High-dose LASN01

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of Participants Showing a Response in Proptosis Measured Using Hertel Exophthalmometer (≥2 mm Decrease From Baseline) in the Study Eye and Separately in Either Eye Without Increased Proptosis (≥2 mm Increase) in the Other Eye
Time Frame: Day 1-Day 253
Day 1-Day 253
For Randomized Treatment Arms: Number of Participants With Adverse Events Receiving LASN01 Compared to Placebo
Time Frame: Day 1-Day 393
Pooled analysis of 300 and 600 mg Q4W as compared with placebo.
Day 1-Day 393
For Open-label Treatment Arm: Number of Participants With Adverse Events Receiving LASN01
Time Frame: Day 1-Day 393
Day 1-Day 393

Secondary Outcome Measures

Outcome Measure
Time Frame
Percentage of Participants Showing a Response in Clinical Activity Score (CAS) in the Study Eye Compared to Baseline as Assessed by CAS Evaluation
Time Frame: Day 1-Day 253
Day 1-Day 253

Collaborators and Investigators

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

Sponsor

Lassen Therapeutics Inc.

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)

March 5, 2024

Primary Completion (Actual)

April 22, 2025

Study Completion (Actual)

April 22, 2025

Study Registration Dates

First Submitted

December 14, 2023

First Submitted That Met QC Criteria

January 23, 2024

First Posted (Actual)

January 26, 2024

Study Record Updates

Last Update Posted (Actual)

March 9, 2026

Last Update Submitted That Met QC Criteria

February 17, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • LASN01-CL-2201

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.

Clinical Trials on Eye Diseases

Clinical Trials on Placebo

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in France

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe