Skip to main content
TTrialFinderData
TrialFinderData is for informational purposes only and does not provide medical advice. Always talk to your doctor.

Updated June 2026 · ClinicalTrials.gov

RECRUITINGPhase 1INTERVENTIONAL

Phase I Study of Anti-CD22 Chimeric Receptor T Cells in Patients With Relapsed/Refractory Hairy Cell Leukemia and Variant

Phase I Study of Anti-CD22 Chimeric Receptor T Cells in Patients With Relapsed/Refractory Hairy Cell Leukemia and Variant (NCT04815356) is a Phase 1 interventional studying Hairy Cell Leukemia and Hairy Cell Leukemia Variant, sponsored by National Cancer Institute (NCI). RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

Important: This information is not medical advice. Talk to your doctor about whether a clinical trial is right for you.

About This Trial

Background: CAR (Chimeric Antigen Receptor) T cell therapy is a type of cancer treatment in which a person s T cells (a type of immune cell) are changed in a laboratory to recognize and attack cancer cells. Researchers want to see if this treatment can help people with hairy cell leukemia (HCL). Objective: To test whether it is safe to give anti-CD22 CAR T cells to people with HCL. Eligibility: Adults ages 18 and older with HCL (classic or variant type) who have already had, are unable to receive, or have refused other standard treatments for their cancer. Design: Participants will be screened with the following: Medical history Physical exam Blood and urine tests Biopsy sample Electrocardiogram Echocardiogram Lung function tests Imaging scans Some screening tests will be repeated during the study. Participants may need to have a catheter placed in a large vein. Participants will have magnetic resonance imaging of the brain. Participants will have a neurologic evaluation and fill out questionnaires. Participants will have leukapheresis. Blood will be removed from the participant. A machine will divide whole blood into red cells, plasma, and lymphocytes. The lymphocytes will be collected. The remaining blood will be returned to the participant. Participants will get infusions of chemotherapy drugs. Participants will get an infusion of the anti-CD22 CAR T cells. They will stay at the hospital for 14 days. Then they will have visits twice a week for 1 month. After treatment, participants will be followed closely for 6 months, and then less frequently for at least 5 years. Then they will have long-term follow-up for 15 years.

What Stage of Research Is This?

Phase 1 trials test a new treatment for the first time in humans, focusing on safety, dosing, and how the body processes the drug. For Hairy Cell Leukemia, a Phase 1 study typically enrolls a small number of participants — often healthy volunteers or patients who have exhausted standard treatment options. Phase 1 results determine whether a treatment moves into larger Phase 2 efficacy studies.

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 27 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)

* INCLUSION CRITERIA - diagnosed by tissue sample (biopsy-confirmed) diagnosis of HCL or HCLv according to morphological and immunophenotypic criteria of WHO classification \[WHO, 2008 revised 2016\] of lymphoid neoplasm. - Participants should have any of the following indications for therapy: - ANC \<1/nL, - Hemoglobin \<10g/dL, - Platelets\<100/nL, - Symptomatic splenomegaly, - HCL mass with short axis \> 2 cm outside or \>0.5 cm inside the CNS, - HCL/HCLv count \>5/nL in blood or \>25/mm\^3 in CSF, - HCL/HCLv count doubling time \<6 months and increasing lytic or blastic bone lesions Participants who have eligible blood counts within 4 weeks from the initiation of study will not be considered ineligible if subsequent blood counts prior to enrollment fluctuate and become ineligible up until the time of enrollment. - HCL/HCLv, after prior treatment with, ineligible for, refusal of, or inability to obtain 1)rituximab given concurrently with or sequentially after purine analog, 2) moxetumomab pasudotox-tdft, and 3) BRAF-inhibition. - CD22 expression must be detected on greater than 80% of malignant cells by flow cytometry. - Participants must have measurable or evaluable disease at the time of enrollment, which may include any evidence of disease including minimal residual disease (MRD) detected by flow cytometry or immunohistochemistry. - Age \>=18 years - ECOG performance \<=2 (Karnofsky \>=60%, see Appendix A), participants are exempt from this criterion if poor performance status is related to HCL. - Participants must have your organs (liver, kidneys, etc.) are working well enough based on blood tests as defined below: Participants must have recovered from the acute side effects of their prior therapy, such that eligibility criteria are met. If participants exhibit minor lab abnormalities that are determined to be related to HCL (not therapy-related), then those participants will be allowed to participate ...See full criteria on ClinicalTrials.gov 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 * Histologically confirmed diagnosis of HCL or HCLv according to morphological and immunophenotypic criteria of WHO classification \[WHO, 2008 revised 2016\] of lymphoid neoplasm. * Participants should have any of the following indications for therapy: * ANC \<1/nL, * Hemoglobin \<10g/dL, * Platelets\<100/nL, * Symptomatic splenomegaly, * HCL mass with short axis \> 2 cm outside or \>0.5 cm inside the CNS, * HCL/HCLv count \>5/nL in blood or \>25/mm\^3 in CSF, * HCL/HCLv count doubling time \<6 months and increasing lytic or blastic bone lesions Participants who have eligible blood counts within 4 weeks from the initiation of study will not be considered ineligible if subsequent blood counts prior to enrollment fluctuate and become ineligible up until the time of enrollment. * HCL/HCLv, after prior treatment with, ineligible for, refusal of, or inability to obtain 1)rituximab given concurrently with or sequentially after purine analog, 2) moxetumomab pasudotox-tdft, and 3) BRAF-inhibition. * CD22 expression must be detected on greater than 80% of malignant cells by flow cytometry. * Participants must have measurable or evaluable disease at the time of enrollment, which may include any evidence of disease including minimal residual disease (MRD) detected by flow cytometry or immunohistochemistry. * Age \>=18 years * ECOG performance \<=2 (Karnofsky \>=60%, see Appendix A), participants are exempt from this criterion if poor performance status is related to HCL. * Participants must have adequate organ function as defined below: Participants must have recovered from the acute side effects of their prior therapy, such that eligibility criteria are met. If participants exhibit minor lab abnormalities that are determined to be related to HCL (not therapy-related), then those participants will be allowed to participate * Total bilirubin \<= 3 ULN, unless consistent with Gilbert s (ratio between total and direct bilirubin \> 5) * Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) \<= 3x upper limit of normal (ULN) * Alkaline phosphatase \< 2.5 ULN * Serum creatinine \<= 1.5 mg/dL or creatinine clearance \>= 60 mL/min/1.73 m\^2 for participants with creatinine levels above institutional normal calculated using eGFR or measured * Serum albumin \> 2 g/dL * Prothrombin time (PT)/International Normalized Ratio (INR) \< 2.5x ULN (if on warfarin, PT/INR \< 3.5x ULN; If on any other anticoagulation, PT \< 2.5x ULN * Fibrinogen \>= 0.5x lower limit of normal * Participants with CNS disease are eligible, with exceptions * Participants with history of allogeneic stem cell transplantation are eligible if at least 100 days post-transplant, if there is no evidence of active graft-versus-host disease (GVHD) and no longer taking immunosuppressive agents for at least 30 days prior to initiation of study intervention. * Women of childbearing potential (WOCBP) must agree to use effective contraception (barrier, hormonal, intrauterine device \[IUD\], abstinence, surgical sterilization) at the study entry and up to 12 months after the last dose of combined chemotherapy or 4 months after cells infusion, whichever is later. Men must agree to use an effective method of contraception (barrier, surgical sterilization, abstinence) at the study entry and up to 4 months after the last dose of study drug. * Breastfeeding participants must be willing to discontinue breastfeeding from study treatment initiation through 4 months after the last dose of study drug. * Ability of participant to understand and the willingness to sign a written informed consent document. EXCLUSION CRITERIA * Pregnancy * Systemic chemotherapy, immunotherapy, or radiation therapy \<= 2 weeks prior to apheresis with the following exception: * Participants receiving steroids may be enrolled, provided there has been no increase in dose for at least 1 week prior to starting apheresis; * For radiation therapy: Radiation therapy must have been completed at least 3 weeks prior to enrollment (including CNS radiation), with the exception that there is no time restriction if the volume of bone marrow treated is less than 10% and also the participant has measurable/evaluable disease outside the radiation port. * Other anti-neoplastic investigational agents, or antibody-based therapies currently or within 2 weeks prior to apheresis * Participants taking warfarin * Prior CAR therapy within 30 days prior to apheresis or prior CAR therapy at any time with evidence for persistence of CAR T cells in blood samples (circulating levels of genetically modified cells of \>= 5% by flow cytometry) * Seropositive for human immunodeficiency virus (HIV) antibody. (Participants with HIV are at increased risk of lethal infections when treated with marrow-suppressive therapy. Appropriate studies will be undertaken in participants receiving combination antiretroviral therapy in the future should study results indicate effectiveness.) * Seropositive for hepatitis C virus (HCV) or positive for hepatitis B surface antigen (HbsAG). Participants who convert to negative will not be excluded for history of positive test. * Uncontrolled, symptomatic, intercurrent illness including but not limited to infection, congestive heart failure, unstable angina pectoris, cardiac arrhythmia, asthma, chronic obstructive pulmonary disease, psychiatric illness, or social situations that would limit compliance with study requirements or in the opinion of the PI would pose an unacceptable risk to the subject * History of severe, immediate hypersensitivity reaction attributed to compounds of similar chemical or biologic composition to any agents used in study or in the manufacturing of the cells (i.e., gentamicin)

Treatments Being Tested

BIOLOGICAL

CD22CART cell infusion

The treatment regimen will consist of lymphodepleting chemotherapy followed by CD22CART infusion: Days -4 to -2: fludarabine 25 mg/m2/dose Day -2: cyclophosphamide 900 mg/m2/dose Day 0: CD22CART infusion (starting at dose level 1 \[DL1\]: 1 x 105 transduced CAR-T cells/kg) on Day 0 participants will be evaluated for response at Day 28 post-CD22CART infusion.

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.

National Institutes of Health Clinical Center
Bethesda, Maryland, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT04815356), the sponsor (National Cancer Institute (NCI)), 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 NCT04815356 clinical trial studying?

Background: CAR (Chimeric Antigen Receptor) T cell therapy is a type of cancer treatment in which a person s T cells (a type of immune cell) are changed in a laboratory to recognize and attack cancer cells. Researchers want to see if this treatment can help people with hairy cell leukemia (HCL). Objective: To test whether it is safe to give anti-CD22 CAR T cells to people with HCL. Eligibility: Adults ages 18 and older with HCL (classic or variant type) who have already had, are unable to receive, or have refused other standard treatments for their cancer. Design: Participants will be s… The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT04815356?

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 NCT04815356?

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 NCT04815356. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT04815356. 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 2026-06-26 · Data from ClinicalTrials.gov.