Who may be eligible for the Mirdametinib in Histiocytic Disorders trial?

Inclusion Criteria: 1. Subjects must be ≥ 2 years of age AND have a diagnosis of a histiocytic disorder that requires systemic therapy * If patient has had a diagnostic biopsy, biopsy must be reviewed and confirmed by CCHMC pathologist as feasible * If patient has had a biopsy but has not had molecular testing done, must have tissue available for mutational analysis * If patient has isolated pituitary/CNS disease or situations where biopsy is not feasible, positive ddPCR blood test for mutation associated with histiocytic neoplasm with clinical features of histiocytosis is sufficient 2. Must have measurable disease on PET scan or brain MRI 3. Subjects must demonstrate adequate organ function as defined: * Renal: maximum serum creatinine 2x the upper limit of normal (ULN) OR a creatinine clearance or radioisotope GFR ≥ 70ml/min/1.73 m2 * Liver: ALT ≤ 3x ULN AND normal INR (≤ 1.5) * Hematologic: Hematology: Albumin ≥ 2.8 g/dL; Absolute neutrophil count ≥ 1.5 x 109/L; Platelets ≥ 100 x 109/L; Hemoglobin ≥ 9.0 g/dL * Patients with organ function abnormalities outside of these thresholds deemed to be the result of histiocytic disease will be considered eligible Exclusion Criteria: 1. Prior therapy with stipulations as described: * Myelosuppressive Chemotherapy: Must not have received any cytotoxic chemotherapy which impacts the growth and development of cells in the bone marrow within 14 days of enrollment onto this study (i.e. cytarabine, cladribine, clofarabine, mercaptopurine, methotrexate, vinblastine) * MEK Inhibitors: Must not have received a MEK inhibitor within 30 days (or 5 half-lives, whichever is longer) of enrollment, NOR have had disease progression on MEK inhibitor * Steroids: Due to the increased risk of an ocular event, the use of systemic oral, inhaled, or ocular glucocorticoid therapy is prohibited within 14 days prior to first dose of mirdametinib. Throughout the treatment period, short term glucocorticoid treatment (30 days or less) is permitted. Any patients requiring long-term steroid use (more than 30 consecutive days) are not eligible. The exception to this rule is subjects with endocrine deficiencies who require physiologic steroids * Radiation: Must not have received radiation within 14 days of study enrollment or have received radiation to the orbit at any time 2. Risk factors for retinal vein occlusion (RVO) are listed. Exclusion should be considered by clinical discretion if they have any of the following risk factors for RVO at screening: * Intraocular pressure (IOP) \> 21 mmHg; if IOP is unable to be obtained (eg age, cooperation, tolerability), ophthalmologist's exam findings and overall assessment will be utilized. If in the ophthalmologist's assessment there are no signs of raised IOP, the subject will be considered eligible for this parameter * Glaucoma or any significant abnormality (≥ grade 2) on ophthalmologic exam that is uncontrolled with intervention * Serum cholesterol \> 300 mg/dL * Serum triglycerides \> 300 mg/dL * Hyperglycemia (either fasting blood glucose \> 125 mg/dL OR random blood glucose \> 200 mg/dL) * Uncontrolled hypertension (participants ≤ 12 years of age with a blood pressure ≥ 95th percentile for age + 12 mmHg; participants ≥ 13 years of age with a blood pressure ≥ 140/90 mm Hg) unresolved on repeat measurement 3. LVEF \< 55% at screening OR history of clinically significant cardiac disease, unless deemed to be the direct result of disease 4. Subjects who are pregnant or breastfeeding, or are at risk of pregnancy or fathering a baby and are unable to use acceptable methods of birth control during the length of the study

ClinicalTrials.gov record NCT06153173

Mirdametinib in Histiocytic Disorders

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Jul 27, 2026

A Phase II Trial of the MEK Inhibitor Mirdametinib in Histiocytic Disorders

About this page. This page shows the study's official ClinicalTrials.gov record ↗, with added help to make it easier to understand. We explain medical terms, highlight key details in plain language, and suggest questions you may want to ask the study team.

The record is periodically copied from ClinicalTrials.gov and may lag behind changes. AI summaries are checked by software, not a clinician.Read moreShow less

The official record is written by the study sponsor and published on ClinicalTrials.gov. It may not always reflect the latest changes. Before making any decisions, please confirm important information with the study team and your own healthcare team.

Where you see "AI summary", AI was used to create a plain-language explanation and software checked it against the source. It has not been reviewed by a clinician, so it may contain mistakes or leave out important details.

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.

Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.

PhasePhase 2A study that tests whether a treatment has the intended effect and continues to check safety, usually in a larger group than phase 1.

Age2 years old and older

SexAll

LocationUnited States

AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This is an open-label Phase II trial testing oral mirdametinib in people aged 2 and older with LCH or other histiocytic disorders who require systemic therapy. Participants take mirdametinib by mouth twice daily in continuous 4-week cycles (dose based on body surface area, with a set maximum). The main outcome is response on PET or MRI after 13 cycles (about 1 year); other outcomes include duration of response and blood drug measurements.

What it is studying. The study is testing whether oral mirdametinib produces measurable disease responses on PET or MRI in people with LCH, JXG, RDD, or other histiocytic disorders. It also measures how long any responses last and characterizes drug levels in the blood.

What the researchers hope to learn. To determine the best overall response rate to mirdametinib after 13 four-week cycles (1 year), to measure duration of response up to 2 years, and to collect pharmacokinetic data (Cmax, Tmax, AUC).

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

The purpose of this study is to see if treatment with mirdametinib in patients with Langerhans cell histiocytosis (LCH) or other histiocytic disorders will be better than current treatments and with fewer side effects.

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Drug: Mirdametinib

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

Subjects must be ≥ 2 years of age AND have a diagnosis of a histiocytic disorder that requires systemic therapy
If patient has had a diagnostic biopsy, biopsy must be reviewed and confirmed by CCHMC pathologist as feasible
If patient has had a biopsy but has not had molecular testing done, must have tissue available for mutational analysis
If patient has isolated pituitary/CNS disease or situations where biopsy is not feasible, positive ddPCR blood test for mutation associated with histiocytic neoplasm with clinical features of histiocytosis is sufficient
Must have measurable disease on PET scan or brain MRI
Subjects must demonstrate adequate organ function as defined:
Renal: maximum serum creatinine 2x the upper limit of normal (ULN) OR a creatinine clearance or radioisotope GFR ≥ 70ml/min/1.73 m2
Liver: ALT ≤ 3x ULN AND normal INR (≤ 1.5)
Hematologic: Hematology: Albumin ≥ 2.8 g/dL; Absolute neutrophil count ≥ 1.5 x 109/L; Platelets ≥ 100 x 109/L; Hemoglobin ≥ 9.0 g/dL
Patients with organ function abnormalities outside of these thresholds deemed to be the result of histiocytic disease will be considered eligible

Exclusion criteria

Prior therapy with stipulations as described:
Myelosuppressive Chemotherapy: Must not have received any cytotoxic chemotherapy which impacts the growth and development of cells in the bone marrow within 14 days of enrollment onto this study (i.e. cytarabine, cladribine, clofarabine, mercaptopurine, methotrexate, vinblastine)
MEK Inhibitors: Must not have received a MEK inhibitor within 30 days (or 5 half-lives, whichever is longer) of enrollment, NOR have had disease progression on MEK inhibitor
Steroids: Due to the increased risk of an ocular event, the use of systemic oral, inhaled, or ocular glucocorticoid therapy is prohibited within 14 days prior to first dose of mirdametinib. Throughout the treatment period, short term glucocorticoid treatment (30 days or less) is permitted. Any patients requiring long-term steroid use (more than 30 consecutive days) are not eligible. The exception to this rule is subjects with endocrine deficiencies who require physiologic steroids
Radiation: Must not have received radiation within 14 days of study enrollment or have received radiation to the orbit at any time
Risk factors for retinal vein occlusion (RVO) are listed. Exclusion should be considered by clinical discretion if they have any of the following risk factors for RVO at screening:
Intraocular pressure (IOP) > 21 mmHg; if IOP is unable to be obtained (eg age, cooperation, tolerability), ophthalmologist's exam findings and overall assessment will be utilized. If in the ophthalmologist's assessment there are no signs of raised IOP, the subject will be considered eligible for this parameter
Glaucoma or any significant abnormality (≥ grade 2) on ophthalmologic exam that is uncontrolled with intervention
Serum cholesterol > 300 mg/dL
Serum triglycerides > 300 mg/dL
Hyperglycemia (either fasting blood glucose > 125 mg/dL OR random blood glucose > 200 mg/dL)
Uncontrolled hypertension (participants ≤ 12 years of age with a blood pressure ≥ 95th percentile for age + 12 mmHg; participants ≥ 13 years of age with a blood pressure ≥ 140/90 mm Hg) unresolved on repeat measurement
LVEF < 55% at screening OR history of clinically significant cardiac disease, unless deemed to be the direct result of disease
Subjects who are pregnant or breastfeeding, or are at risk of pregnancy or fathering a baby and are unable to use acceptable methods of birth control during the length of the study

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Detailed description from the registry

Langerhans cell histiocytosis (LCH) is a rare blood disorder. Though affecting all ages, LCH occurs more often in children, with an increased incidence in children less than 1 year of age. The disease presents in various ways, with most children suffering bony lesions, and skin rashes. In some patients, LCH affects vital organs such as liver, spleen, bone marrow, and the central nervous system. This group of patients are at significant risk of serious illness and death and are thus said to have risk-organ-positive (RO+) LCH. Current treatments for LCH consist of chemotherapy combined with other medications. However, many patients, especially those with RO+ disease, do not respond to therapy. Of the patients that do respond, many suffer progression of disease after an initial response to therapy, or recurrence of disease after completion of therapy. The purpose of this study is to see if treatment with mirdametinib in patients with LCH or other histiocytic disorders will be better than current treatments and with fewer side effects.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Take oral mirdametinib twice daily on a continuous schedule in 4‑week cycles with dose based on body surface area. Undergo screening and regular monitoring including PET scans or brain MRI to assess disease, blood tests for organ function and drug levels (pharmacokinetics), eye exams and cardiac checks, and routine safety labs. Provide tumor tissue for mutation testing if available (or a positive ddPCR blood test for pituitary/CNS cases where biopsy isn't feasible), and complete pregnancy testing and contraception requirements if applicable.

How the study is structured. Single-group, open-label Phase II interventional study: all participants receive oral mirdametinib twice daily (continuous 4-week cycles). Response is assessed by PET or brain MRI after 13 cycles (1 year); participants have additional follow-up (including imaging) for duration of response and have blood samples taken early in treatment for pharmacokinetics. The study is non-randomized and not masked.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

The listed sites are in United States. Is any of them reachable for me, and does the study help with travel?
Which of the eligibility criteria would need to be checked with tests before I could join?

More on Langerhans cell histiocytosis

Clinical trials20 trials listed for Langerhans cell histiocytosisEvery trial the registry lists for Langerhans cell histiocytosis, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in Langerhans cell histiocytosis researchLatest monthly update: September 2026. Includes: Adult routine care. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start: Feb 5, 2024
Primary completion: March 2030 (estimated)
Study completion: March 2031 (estimated)
Target enrollment: 40 participants (estimated)
Last updated on registry: Sep 21, 2026
Data verified: Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor: Children's Hospital Medical Center, Cincinnati

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Monica Trapp 📞 (513) 803-8574 ✉ monica.trapp@cchmc.org
Caitlin Cottrell 📞 (513) 803-7039 ✉ Caitlin.Cottrell@cchmc.org

Participating sites (1)

Cincinnati Children's Hospital Medical CenterRecruiting
Cincinnati, Ohio, 45229 · United States
- Monica Trapp · Monica.Trapp@cchmc.org
- Caitlin Cottrell · caitlin.cottrell@cchmc.org
- Ashish Kumar, MD, PhD

Terms used on this page · explanations by MedicalUpdates.ai

biopsy: Removal of a small piece of tissue so it can be examined under a microscope. 'Biopsy-proven' or 'histologically confirmed' means the diagnosis was confirmed by examining tissue under a microscope.
PET scan: A scan in which a small amount of a radioactive tracer is injected so that activity in tissues can be seen. Often combined with a CT or MRI scan.
MRI: A scan that uses magnets and radio waves, not X-rays, to make detailed pictures of the inside of the body. Some implants and metal objects mean a person cannot have one.
upper limit of normal: The highest value of a blood test that a laboratory considers normal. Criteria such as '≤ 3 × ULN' mean the result must be no more than three times that value.
creatinine clearance: A measure of kidney function, calculated from a blood creatinine level together with age, weight and sex.
GFR: A blood-test estimate of how well the kidneys are filtering. Lower numbers mean reduced kidney function; many studies set a minimum value.
Absolute neutrophil count: The number of neutrophils, a type of white blood cell that fights infection, in a blood sample. Studies often require it to be above a set level.
Prior therapy: Treatment a person has already had for the condition. A 'line of therapy' is one course of treatment; studies often require, or limit, the number of prior lines.
enrollment: The number of participants a study plans to include, or has included. 'Estimated' means the planned number; 'actual' means the number who joined.
5 half-lives: The time it takes for the amount of a drug in the body to fall by half. 'Five half-lives' is often used as the point at which a previous drug has essentially left the body.
glucocorticoid: Steroid medicines, such as prednisone, that reduce inflammation. Studies often require a stable dose at entry or measure whether the study treatment allows the dose to be reduced.
at screening: The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
Inclusion Criteria: The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria: The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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