SNUH Immune Checkpoint Inhibitor-induced Hypothyroidism Recovery Trial

Seoul National University Bundang Hospital107 enrolled

Overview

The goal of this study is to find out whether hypothyroidism caused by immune checkpoint inhibitors (ICIs) can recover after stopping the ICIs. The study also aims to identify factors that can help predict which patients will be able to stop taking thyroid hormone replacement. The main questions the study will answer are: * What percentage of patients recover normal thyroid function and can stop levothyroxine after stopping ICIs? * What clinical or laboratory factors can predict successful withdrawal of levothyroxine? Participants will: * Be adult cancer patients who developed hypothyroidism during ICI treatment and are currently taking levothyroxine * Have already stopped ICI therapy * Gradually reduce their levothyroxine dose every 3 months if their thyroid function remains normal * Stop levothyroxine if thyroid function remains normal at low doses (≤0.025 mg) * Be monitored with thyroid function tests and clinical symptoms at each visit

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

107

Conditions

Hypothyroidism

Interventions

Participants will undergo a gradual dose reduction of levothyroxine according to a standardized tapering protocol. The levothyroxine dose will be reduced every 3 months based on thyroid function test results. If thyroid function remains stable, the dose will be decreased by 0.025 mg (±0.0125 mg). If thyroid function remains stable at a low dose (≤0.025 mg), levothyroxine will be discontinued.

Eligibility

Sex: ALLMin age: 19 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Adults aged 19 years or older. * Patients with a history of treatment with immune checkpoint inhibitors (ICIs). * Developed hypothyroidism during ICI treatment and initiated levothyroxine after starting ICI therapy. * Discontinued ICI therapy prior to study enrollment. Exclusion Criteria: * Use of levothyroxine or antithyroid medications within 3 months prior to initiating ICI therapy. * History of thyroid surgery, radioactive iodine therapy, or neck radiation therapy. * Current levothyroxine dose ≥0.1 mg at the time of enrollment.

Outcomes

Primary Outcomes

Proportion of participants who maintain discontinuation of levothyroxine for at least 6 months

The number and proportion of participants who are able to remain off levothyroxine for at least 6 consecutive months without requiring re-initiation of treatment due to abnormal thyroid function (serum TSH level ≥10 μIU/mL).

Time frame: Up to 6 months after levothyroxine discontinuation

Secondary Outcomes

Proportion of participants who can discontinue levothyroxine

The number and proportion of participants who were able to discontinue levothyroxine after dose reduction during the study follow-up period, regardless of whether the discontinuation was sustained. This includes any participant who temporarily stopped levothyroxine for any duration, even if the medication was later resumed.

Time frame: up to 3 years after study enrollment

Proportion of participants who maintain discontinuation of levothyroxine for at least 12 months

The number and proportion of participants who are able to remain off levothyroxine for at least 12 consecutive months without requiring re-initiation of treatment due to abnormal thyroid function (serum TSH level ≥10 μIU/mL).

Time frame: Up to 12 months after levothyroxine discontinuation

Proportion of participants who maintain discontinuation of levothyroxine for at least 36 months

The number and proportion of participants who are able to remain off levothyroxine for at least 36 consecutive months without requiring re-initiation of treatment due to abnormal thyroid function (serum TSH level ≥10 μIU/mL).

Time frame: Up to 36 months after levothyroxine discontinuation