Real-world Study of Darafenib or Trametinib and Clofarabine for High-risk/Recurrent/Refractory Langerhans Cell Histiocytosis in Children

A Real-world Investigation of the Combination of Darafenib or Trametinib and Clofarabine in the Treatment of High-risk, Recurrent, or Refractory Pediatric Patients With Langerhans Cell Histiocytosis.

Real-world Study of Darafenib or Trametinib and Clofarabine for High-risk/Recurrent/Refractory Langerhans Cell Histiocytosis in Children (NCT07022834) is a Phase 2 interventional studying Langerhans Cell Histiocytosis (LCH), sponsored by West China Second University Hospital. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

Langerhans cell histiocytosis (LCH) is the most common histiocytosis in children, with an incidence of 2.6-8.9 per million. It is an inflammatory myeloid tumor with varied symptoms. Mild cases often resolve spontaneously, while severe cases can affect multiple organs and be life-threatening. LCH affecting the liver, spleen, or hematopoietic system has a poor prognosis and is high-risk group. The LCH-III study showed that low-risk children respond well to prednisone and vinblastine, with nearly 100% survival, but high-risk children's survival is about 80%, with a 30% reactivation rate.Long-term studies reveal that about 50% of patients are resistant to prednisone and vinblastine, leading to progression and recurrence. Except combination of prednisone and vinblastine, cladribine (introduced in 1998) and MAPK inhibitors (introduced in 2014), have lowered the mortality rate of LCH in children. Cladribine, a nucleoside analogue, is used for treating recurrent acute myeloid leukemia in children by disrupting DNA synthesis. In the LCH-98-S regimen, low-risk children with LCH responded well to moderate doses of cladribine, but 44% of high-risk children still faced disease progression. Later studies showed that high-dose cladribine with medium-dose cytarabine increased survival in refractory LCH from 30% to 85%, but also raised chemotherapy toxicity, with some cases experiencing severe hematological toxicity and half of the deaths resulting from chemotherapy complications. Clofarabine, a nucleoside analogue, inhibits ribonucleotide reductase and DNA polymerase, offering stronger anti-tumor effects and fewer side effects than cladribine and fludarabine in treating refractory leukemia. Case reports show that LCH patients unresponsive to cladribine improve with clofarabine treatment at moderate doses (25mg/m2/day). A retrospective study of 58 LCH patients using clofarabine (25mg/m2/day) showed an 87% progression-free survival rate after one year. While the main side effect was grade 3 or higher hematological toxicity, 98.3% of patients tolerated it and completed treatment. Further prospective studies are needed to determine the optimal dose, duration, long-term efficacy, and complications of clofarabine in children with LCH. Research indicates that childhood LCH is often linked to mutations in MAPK pathway genes, with over half of cases involving BRAFV600E mutations. MAPK inhibitors, like vemurafenib, dabrafenib and trametinib, are effective for relapsed and refractory LCH, but they don't eliminate malignant clones, leading to disease reactivation after stopping treatment. Some BRAF-deficient mutation LCH patients resist vemurafenib and dabrafenib, but trametinib can manage the disease in these cases. Activation of the MAPK pathway increases BCL2L1 expression in LCH cells, and rapamycin fails to induce apoptosis in BRAFV600E+ LCH cells, enhancing resistance to cell death. MAPK inhibitors combined with chemotherapy are theoretically more effective at inducing apoptosis in LCH cells and resetting the immune environment to eliminate malignant clones. Two clinical studies confirm their safety and efficacy in treating refractory recurrent LCH. In a follow-up of 10 LCH cases treated with nucleotide analogues and MAPK inhibitors, only 2 patients relapsed after a short treatment duration. Additionally, 19 children with BRAFV600E mutation LCH were treated with cladribine, cytarabine, and vemurafenib, achieving a 100% response rate. Nearly 80% completed treatment without recurrence, and no increase in side effects was observed. Since 2020, our center treated nearly 40 LCH patients with MAPK inhibitors, including 14 combined with LCH-III chemotherapy. Follow-ups show no severe toxic side effects, aligning with literature. However, most high-risk patients, especially those who stopped oral MAPK inhibitors, had disease reactivation. Two high-risk patients with liver involvement achieved complete liver lesion regression with cladribine. This clinical study aims to assess the efficacy and safety of dabrafenib or trametinib and clofarabine for high-risk/recurrent/refractory LCH in children.

What Stage of Research Is This?

Phase 2 trials evaluate whether a treatment actually works against Langerhans Cell Histiocytosis (LCH) and continue monitoring side effects. Phase 2 enrolls larger groups (typically 100–300 patients) and produces the first real efficacy signal. A successful Phase 2 readout is what unlocks the much larger Phase 3 confirmatory trials needed for FDA approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

With a target enrollment of 20 participants, this is a small study — typical of early-phase research, rare-disease trials, or pilot studies designed to generate preliminary signal before a larger study is launched.

Who May Be Eligible (Plain English)

Who May Qualify: 1. Children aged 0-18 with LCH (CD1a+/CD207+); 2. Initial LCH diagnosis with hematopoietic, liver, or spleen involvement; 3. LCH patients with disease progression or reactivation after chemotherapy (e.g., prednisone, vincristine, cytarabine, clarithromycin) or targeted therapy; 4. Consent to treatment and follow-up; 5. ECOG score ≥ 2, Lansky score ≥ 50, organ function suitable for chemotherapy. Who Should NOT Join This Trial: 1. Other underlying diseases (e.g., primary weakened immune system, heart/kidney failure, hepatitis, HIV, organ transplant); 2. Secondary tumor; 3. Recent chemotherapy, radiotherapy, or MAPK inhibitor use with lingering adverse effects; 4. Ongoing nephrotoxic drug use; 5. Refusal to consent. Exit Criteria: 1. Allergies to dabrafenib or trametinib and clofarabine； 2. Disease progression after 3 months on dabrafenib or trametinib； 3. Severe toxic side effects from clofarabine (grade 4 non-infectious non-hematological toxicity, SIRS, capillary leak syndrome)； 4）The doctor recommends halting the current treatment plan for the patient's benefit. Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: 1. Children aged 0-18 with LCH (CD1a+/CD207+); 2. Initial LCH diagnosis with hematopoietic, liver, or spleen involvement; 3. LCH patients with disease progression or reactivation after chemotherapy (e.g., prednisone, vincristine, cytarabine, clarithromycin) or targeted therapy; 4. Consent to treatment and follow-up; 5. ECOG score ≥ 2, Lansky score ≥ 50, organ function suitable for chemotherapy. Exclusion Criteria: 1. Other underlying diseases (e.g., primary immunodeficiency, heart/kidney failure, hepatitis, HIV, organ transplant); 2. Secondary tumor; 3. Recent chemotherapy, radiotherapy, or MAPK inhibitor use with lingering adverse effects; 4. Ongoing nephrotoxic drug use; 5. Refusal to consent. Exit Criteria: 1. Allergies to dabrafenib or trametinib and clofarabine； 2. Disease progression after 3 months on dabrafenib or trametinib； 3. Severe toxic side effects from clofarabine (grade 4 non-infectious non-hematological toxicity, SIRS, capillary leak syndrome)； 4）The doctor recommends halting the current treatment plan for the patient's benefit.

Treatments Being Tested

DRUG

Dabrafenib or Trametinib and Clofarabine

Drug: Dabrafenib or Trametinib Dabrafenib: 3-5 mg/kg/day; Trametinib: 0.025mg/kg/day Drug: Clofarabine Consolidation therapy: 25 mg/m2/d, days 1-5 Maintenance therapy: 25 mg/m2/d, days 1-2

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Department of Pediatric Hematology and Oncology, West China Second University Hospital, Sichuan University, Chengdu, China

Chengdu, Sichuan, China

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT07022834), the sponsor (West China Second University Hospital), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT07022834 clinical trial studying?

Who can participate in NCT07022834?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT07022834?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT07022834. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT07022834. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.