Clinical Trials & Registries

What is a Clinical Trial?

According to, a clinical study [trial] involves research using human volunteers (also called participants) that is intended to add to medical knowledge.

There are 2 types: observational studies and clinical trials.

What is a Registry?

According to the National Institutes of Health (NIH), a patient registry is a collection—for one or more purposes—of standardized information about a group of patients who share a condition or experience. The use of “patient” in patient registries is often used to distinguish the focus of the data set on health information.

Participation in research is important and is one way that patients and families can make a difference for the future. This can include participating in a clinical trial for a treatment which could potentially aid it in achieving milestones including FDA approval or enrolling in a registry or survey to share aspects of your histio journey, or possibly volunteering time as a patient advocate for a study or registry to ensure the patient perspective and voice is included. You can ask your physician for more information about potential opportunities or explore our website for more information; it is recommended that you consult your physician if you have questions about eligibility for a particular study, trial, or registry.

You can learn more about clinical trials, registries, and studies from the trusted sources below. You can also explore this page for more information about genomic studies, patient registries by histiocytic disorder and bone marrow transplant resources. If you have questions, or if you are aware of a study, registry, or trial that is not listed, please contact us at or call us at (856) 589-6606. is a database of privately and publicly funded clinical studies conducted around the world. It is run by the United States National Library of Medicine (NLM) at the National Institutes of Health (NIH). The site currently contains over 443,400 research studies in all 50 states and in 221 countries.

Be The Match Jason Carter
Clinical Trials Search and Support

This program makes it easier to find and join clinical trials. The program offers one-on-one support, an online search tool, educational resources, and financial assistance for travel.

Clinical Trials Support

Are you an HLH or LCH patient or caregiver looking for help finding a clinical trial or paying for travel arrangements to participate in one? The Be The Match Jason Carter Clinical Trials Search and Support may be able to help! They offer travel grants to help get you to clinical trials and can help you navigate the process along the way.

Learn more at

Clinical Trial & Study Opportunities for Histiocytic Disorders

North American Consortium for Histiocytosis (NACHO)

NACHO was formed in July 2014 by clinicians and scientists from twelve institutions dedicated to developing a research infrastructure to effectively implement clinical and translational studies and conduct biological research of histiocytic diseases. Their mission is to cure all patients with histiocytic diseases and optimize outcomes through innovative and collaborative research. Learn more, here!

Clinical Trials: the below list are trials that are currently available across multiple NACHO sites within North America.  Use this interactive map to search for a specific trial site near you! The searchable map is powered by the Histiocytosis Association through the generosity of CytoSorbents.


Other Available Studies


The Swiss-based company AB2 Bio is conducting a clinical study in North America (U.S.A. and Canada) and Germany, and recruiting patients in several regions. The aim of this Phase III study is to assess the efficacy and safety of Tadekinig alfa in pediatric and adult patients with monogenic, interleukin-18 driven autoinflammation caused by NLRC4-MAS mutation or XIAP deficiency. This study is no longer enrolling patients, however the PIs welcome contact by physicians to learn more. Learn more at Read the Study Information Sheet here.

Testing for Children & Young Adults With Relapsed or Refractory Histiocytosis

Phase II Clinical Trial testing cancer genes to choose treatments for children and young adults with histiocytosis that has come back (relapsed) or has not gotten better with treatment (refractory. There are 162 sites participating in this clinical study within the United States. Learn more about this trial, here.

ELA026 for Secondary HLH

Secondary hemophagocytic lymphohistiocytosis (or simply “sHLH”) is a severe, but rare, inflammatory syndrome that is triggered by an underlying disease such as cancer, an infection, or autoimmune disease. People with sHLH produce too many inflammatory white blood cells that then cause organ damage, and it is often fatal. There is no standard way to treat sHLH. Some cancer drugs are used to control the disease, but new treatments are needed. ELA026 may represent a new way to target the abnormal white blood cells that cause sHLH. How it works: ELA026 is an antibody that attaches to the abnormal inflammatory cells and causes them to break apart. By breaking down these cells, it is believed that the signs and symptoms of sHLH and other inflammatory diseases can be controlled. ELA026 is currently in a clinical trial in Europe, including the UK, Spain, Austria, Italy, and the Netherlands; study sites opened in the United States in September 2022, starting with MD Anderson, Texas Children’s and Georgetown. In order to be eligible for the trial, patients must have sHLH and be at least 12 years of age; a full list of eligibility criteria can be seen on the study sites linked; you should discuss with your care team if this study is right for you. US study information; EU study information.

Open Study Sites:

  • Medical University (Vienna, Austria)
  • Medical University Innsbruck (Innsbruck, Austria)
  • Ospedale Pediatrico Bambino Gesù, IRCCS (Rome, Italy)
  • Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico (Milano, Italy)
  • Hospital La Fe (Valencia, Spain)
  • Hospital 12 de Octubre (Madrid, Spain)
  • Hospital Ramón y Cajal, (Madrid, Spain)
  • Erasmus Medical Center (Rotterdam, Netherlands)
  • University College London Hospitals (London, UK)
  • Georgetown (Washington D.C., USA)
  • MD Anderson (Houston, Texas)
  • Texas Children’s Hospital (Houston, Texas)

Registries & Gene Therapies

You've learned more about clinical trials and studies, but what about Registries and Gene Therapies? Our friends at the National Organization for Rare Disorders (NORD) explain all about registries, gene therapies and more in the videos below. Find more information and videos at

Learn more about the registries the Histiocytosis Association supports in our Grants Awarded directory.

Click an image below to view the video on NORD's YouTube channel.

Registries for Histiocytosis

Histiocytosis Follow Up Study

The Histiocytosis Association, in partnership with Dr. Gaurav Goyal at the University of Alabama at Birmingham, together are conducting a research study to learn about the health of people with histiocytic disorders. The study is interested in understanding the risk (chance) of long-term side effects from the disease and treatments. The information collected will be used to make recommendations for the treatment and follow-up of future patients who are diagnosed with histiocytic disorders.

Read more and find out how to participate, here: Histiocytosis Follow Up Study.

Hemophagocytic lymphohistiocytosis (HLH)

Adult HLH Registry - Europe: A register database was established at the Jena University Hospital for the systematic collection of patient cases with HLH in adults. This web-based register database was created in cooperation between the Jena Center for Clinical Studies and the Department of Hematology and Oncology at the Jena University Hospital. Clinical and laboratory chemical data are registered in an anonymous form.

INTO-HLH Registry: (Insight into the Natural history and Treatment Outcomes of Hemophagocytic Lymphohistiocytosis) will enroll pediatric and adult patients with HLH. The proposed study, a collaboration between Cincinnati Children's Hospital Medical Center (CCHMC), Texas Children's Hospital, the North American Consortium for Histiocytosis (NACHO), and Sobi Inc. aims to establish a robust registry that will enable investigators to better define the natural history of HLH. FAQs for the study can be found here, and the page, here. Visit the study website:

Histiocyte Society (HS) and European Society of Immunodeficiencies (ESID) HLH Registry: The HLH Registry is a database implemented as a collaborative project of the HS and ESID in collaboration with the Inborn Errors Working Party (IEWP) of the European Bone Marrow Transplantation Group (EBMT) but is not limited to formal members as participants worldwide are encouraged to contribute to this effort. This international HLH Registry is aimed to collect and analyze clinical, epidemiological, immunological, genetic, treatment and survival data for assessment of feasibility and design of future interventional studies on the treatment of HLH.

*If you have already enrolled in one of the above studies, you are welcome to enroll in the others, so long as you meet the eligibility criteria. You can also ask your physician or the registry's team if enrolling in one automatically enrolls you in another. Multiple registries exist due to the need to focus on a particular set of information, such as geographic location (i.e., Europe v North America). The registry information or team will inform you about collaborative efforts with other existing registries or studies.*

International Rare Histiocytic Disorders Registry (IRHDR)

The Division of Haematology and Oncology at the Hospital for Sick Children is conducting a research study. This research study is being done to build up a registry of patients with rare histiocytic disorders in order to learn more about these disorders and what types of treatments are being used. The histiocytic disorders included in this registry are the Juvenile xanthogranuloma family, Erdheim-Chester disease, Multifocal Reticulohistiocytosis, Rosai-Dorfman disease and the Malignant Histiocytoses. This study does not involve any additional tests and it will not impact your/your child’s current treatment. If you/your child would like to participate or have any questions, please email:

Read the Study Introduction Letter here.

Erdheim-Chester Disease

Memorial Sloan Kettering Cancer Center has created a registry for patients with Erdheim-Chester Disease (ECD). The purpose of a patient registry is to create a database of medical information on patients with ECD. The focus of the registry is on understanding the ongoing health challenges, challenges that occur with treatment, and the many ways that ECD affects individuals impacted. With this information, the investigators hope to advance the knowledge that is known on ECD, its treatments, and what is best for patients.

Read the study information here.  Participate in the registry online, here.

Visit the ECD Global Alliance for additional information about the history and data generated so far from the registry.

Free Genomic Profiling

According to, genomic profiling is "a laboratory method that is used to learn about all the genes in a person or in a specific cell type, and the way those genes interact with each other and with the environment." For histiocytic disorders, genetic testing to look for genetic mutations may be suggested by your physician, or you may want to discuss this as a possibility if it has not been suggested. Upon identifying whether or not a person diagnosed with histiocytosis has a genetic mutation, decisions can be made about course of treatment; other members of the family may also consider genetic testing. Many time insurance companies will cover this testing and your hospital may be able to perform the test on their own. In cases where it is not covered or a second opinion is being sought, you can try these other resources below.


The Memorial Sloan Kettering Make-an-IMPACT Initiative is a rare-cancer global outreach initiative that provides free genomic profiling for patients with Langerhans Cell Histiocytosis (LCH), Erdheim-Chester Disease (ECD), Rosai-Dorfman Disease (RDD), Juvenile Xanthogranuloma (JXG), and Histiocytic Sarcoma (HS). Genomic profiling with world class, next-generation sequencing technology developed at Memorial Sloan Kettering Cancer Center aims to identify genetic mutations in these tumors. These tumors often harbor mutations in BRAF or related family of genes and may respond to drugs that target these genetic alterations. Patients who were diagnosed or treated for LCH, RDD, ECD, JX, or HS within 2 years with current active disease may be eligible to participate. If you would like to learn more, please visit the Make-an-IMPACT site or reach out to the Make-an-IMPACT team: If you are eligible and would like to participate, please complete the volunteer form.

National Institutes of Health (NIH)

The Hematopathology Section of the National Institutes of Health provides consultation in selected cases of diagnostic difficulty and is pleased to assist patients with the diagnosis of histiocytosis, or suspected histiocytosis. Relevant diagnoses include Erdheim-Chester disease, Langerhans cell histiocytosis, Juvenile Xanthogranuloma, ALK-positive histiocytosis, Rosai-Dorfman disease, and Indeterminate cell histiocytosis. Other histiocytic neoplasms, histiocytic sarcoma, are accepted. View and/or download this list of instructions regarding cases to be submitted in consultation: Histiocytosis Registry And Genomic Studies; please share this with your physician.

*Patients should speak with their medical and caregiving teams about any trial or study you may be interested in prior to enrolling.*