ClinicalTrials.gg
RecruitingNCT05968768Updated Oct 7, 2026

To Evaluate the Efficacy and Safety of Naxitamab in Patients With Refractory Ewing's Sarcoma (Butterfly)

A Phase 2 interventional study of Naxitamab in Ewing Sarcoma, sponsored by Anna Raciborska. Recruiting at 2 sites in Poland. Open to participants aged 2 Years to 21 Years. Per ClinicalTrials.gov, last updated 2026-10-07.

Sponsored by Anna Raciborska · Phase 2, Interventional, and Treatment

From the registry’s dates

  • Started Oct 2023; still recruiting 3 years later.
Phase
Phase 2
Study type
Interventional
Enrollment
24
Allocation
Randomized
Ages
2 Years to 21 Years
Sex
All
01

Study summary

Prospective, interventional, open, randomized, national, multicenter, non-commercial trial

Read the detailed description

The study includes:

  1. Biology screening: to estimate expression on GD2 on Ewing sarcoma cells from tumor tissue from archival material. Availability of tumor tissue is required for pre-screening testing to determine GD2 expression. To be screened for potential enrollment into the study patients or their legal representatives must have signed the pre-screening informed consent form (ICF) to consent to using their archival tumor sample to test the expression of GD2 in their tumor. The expression level of GD2 will be characterized in tumor tissue by immunohistochemistry (IHC) at a local and a central diagnostic testing laboratory.
  2. Standard stratifying diagnostic tests (laboratory assessment: morphology, blood chemistry including ALT, AST, eGFR, creatinine, sodium, potassium, coagulation, urine analysis including pH, blood, protein, leukocytes, glucose, urobilinogen, bilirubin, ketones, nitrites, specific gravity, vital signs (body temperature, systolic and diastolic blood pressure, and pulse rate), ECG, cardiac function test, imaging test: CT/MRI scan).
  3. Patients with GD2 expression will be randomized in proportions (2:1) to the experimental (D) and control groups (S). The cohort D will consist of 16 subjects, the cohort S 8 subjects. The exploratory cohort D will receive the experimental regimen in 3-week cycles consisting of irinotecan given intravenously (iv) 50 mg/m2 after oral temozolomide 100 mg/m2 on days 1-5 and naxitamab administered iv 2.25 mg/kg/day over 30 - 60 minutes, days 2, 4, 8 and 10 (up to 150 mg/day; total 9 mg/kg per cycle), and GM-CSF 250 mg/m2/day subcutaneously, days 6-10. Patients randomized to arm S will receive IT alone. Treatment cycles will be repeated every 21 days summary to 6 cycles or until disease progression, or subsequent relapsed, or occurrence of intolerable toxicity, or any event making impossible treatment continuation, or investigator's judgment, or withdrawal of consent. All activities are presented in Schedule of Assessments (SoA) at the end of the study synopsis.
  4. Patients will be recalculated according to the intent to treat (ITT) rule.
  5. The study will be conducted in accordance to GCP and after EC approval of the protocol.
02

Conditions studied

  • Ewing Sarcoma

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Keywords

  • Ewing Sarcoma
03

In context

Sarcoma, Ewing

250 studies on the registry are indexed under Sarcoma, Ewing; 69 are open to participants now.

This study's planned enrollment of 24 is below the median of 36 across 204 interventional studies indexed under Sarcoma, Ewing.

Browse Sarcoma, Ewing studies →

Lead sponsor

Anna Raciborska is the lead sponsor of 5 studies on the registry; 2 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
2 Years to 21 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. proven Ewing sarcoma of the bone or soft tissues.
  2. Subject's (formalin-fixed, paraffin-embedded; FFPE) available for evaluation of GD2 expression.
  3. Documented disease progression (during or after completion of at least one line treatment) or any subsequent recurrence.
  4. GD2 positive tumor assessed by IHC.
  5. Age ≥ 2 years and ≤ 21 years.
  6. of at least 12 weeks from the time was signed.
  7. Previous systemic anticancer treatment completed ≥ 3 weeks, major surgery ≥ 2 weeks, and radiation therapy ≥ 4 weeks prior to study enrollment.
  8. Recovered from adverse effects of prior surgery, radiotherapy, or Clinical trial protocol BUTTERFLY version 1.0 of 30.09.2022 r.anti-neoplastic therapy at the discretion of the investigator.
  9. Signing of informed consent for trial participation (including for naxitamab treatment) according with current legal regulations.
  10. Consent to the use of effective throughout the period of the study and a minimum of 1 year after discontinuation of study treatment in patients at puberty and sexual maturity

Exclusion criteria

Exclusion Criteria:

  1. Failure to meet any of the inclusion criteria.
  2. Not eligible to IT.
  3. Previous treatment with an anti-GD2 antibody.
  4. to the study drugs or any of their ingredients (covers IT and naxitamab).
  5. Simultaneous treatment with other drugs which might interact with naxitamab or IT regimen.
  6. Persistent toxicity related to prior therapy, making it impossible to treat with naxitamab.
  7. Significant cardiac conduction abnormalities, including known familial prolonged syndrome, or screening corrected QT interval (QTc) >480 msec.
  8. Symptoms of congestive heart failure or \<50%.
  9. Inadequate pulmonary function defined as evidence of dyspnea at rest, exercise intolerance, and/or chronic oxygen requirement. In addition, room air pulse oximetry \< 94% and/or abnormal pulmonary function tests if these assessments are clinically indicated.
  10. Requirement, or likely requirement, for at doses >10 mg prednisolone (or equivalent) per day or other agents.
  11. Diagnosis of other before study inclusion.
  12. Planning to become pregnant (while being treated with IT or naxitamab), pregnancy or breastfeeding.
  13. Other acute or persistent disorders, behaviors or abnormal laboratory test results, which might increase the risk related to the participation in this clinical trial or to taking the study drug, or which might influence the interpretation of the study results, or which, in the investigator's opinion, disqualify a patient from participating in the tri
Terms in these criteria, in plain language(11)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Histologically or cytologically confirmed

The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).

Your pathology report is the document that shows this.

Biopsy and archival tissue

A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.

Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.

Life expectancy

The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

QT and QTc

On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.

The study may name a correction formula and a limit in milliseconds, often around 450–480.

LVEF (left ventricular ejection fraction)

The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
24 participants (estimated)

Study arms

  • Experimental
    Experimental - Naxitamab Arm

    Treatment with naxitamab will be continued no longer than 6 cycles a year or until disease progression, patient consent, unacceptable toxicities, or study closure

    Drug: Naxitamab

  • No intervention
    Control Group - standard treatment

    The control group - will receive only standard treatment.

Interventions

  • Naxitamab will be used only in a hospital setting and must be administered under the supervision of a doctor with experience in the use of oncological therapies. The medicinal product must be administered by a healthcare professional prepared to deal appropriately with severe allergic reactions, including anaphylaxis, in an environment that provides immediate, full access to resuscitation. The patient should have 2 well-functioning IV accesses before any naxitamab treatment is initiated. The solution should be administered through a peripheral or central intravenous catheter. Other concomitant intravenous medicinal products should be administered through separate intravenous access. Before the start of each infusion, premedication will be carried out.

    Also known as: danyelza

06

What researchers measure

Primary outcomes

  1. Safety assessment of the addition of naxitamab to standard 3-week chemotherapy (CHT) in patients with refractory Ewing's sarcoma (ES)

    Safety will be assessed by number of serious adverse events (SAE), by the number of adverse events (AE), by medical examination with the analysis of recorded vital signs, laboratory abnormalities according to NCI CTCAE v5.0

    Time frame: up to 240 days

Secondary outcomes

  1. Event-Free Survival (EFS )

    Will be measured from randomization to death, disease progression or recurrence, or secondary malignancy, whichever comes first

    Time frame: 3 years

  2. Progression-Free Survival (PFS)

    from randomization to progression of the disease

    Time frame: 1 year

  3. Overall Response Rate (ORR)

    Defined as the proportion of patients with a best overall response of complete response (CR) or partial response (PR),

    Time frame: 126 days

  4. Overall Survival (OS)

    Will be measured from randomization to subject's death

    Time frame: 3 years

07

Study locations

1 of 2 sites recruiting
08

References and documents

Publications

  • Nakajima M, Guo HF, Hoseini SS, Suzuki M, Xu H, Cheung NV. Potent antitumor effect of T cells armed with anti-GD2 bispecific antibody. Pediatr Blood Cancer. 2021 Jul;68(7):e28971. doi: 10.1002/pbc.28971. Epub 2021 Apr 12. PubMed 33844437 ↗
  • Chan GC, Chan CM. Anti-GD2 Directed Immunotherapy for High-Risk and Metastatic Neuroblastoma. Biomolecules. 2022 Feb 24;12(3):358. doi: 10.3390/biom12030358. PubMed 35327550 ↗
  • Musumeci F, Cianciusi A, D'Agostino I, Grossi G, Carbone A, Schenone S. Synthetic Heterocyclic Derivatives as Kinase Inhibitors Tested for the Treatment of Neuroblastoma. Molecules. 2021 Nov 23;26(23):7069. doi: 10.3390/molecules26237069. PubMed 34885651 ↗
  • Wingerter A, El Malki K, Sandhoff R, Seidmann L, Wagner DC, Lehmann N, Vewinger N, Frauenknecht KBM, Sommer CJ, Traub F, Kindler T, Russo A, Otto H, Lollert A, Staatz G, Roth L, Paret C, Faber J. Exploiting Gangliosides for the Therapy of Ewing's Sarcoma and H3K27M-Mutant Diffuse Midline Glioma. Cancers (Basel). 2021 Jan 29;13(3):520. doi: 10.3390/cancers13030520. PubMed 33572900 ↗
  • Nazha B, Inal C, Owonikoko TK. Disialoganglioside GD2 Expression in Solid Tumors and Role as a Target for Cancer Therapy. Front Oncol. 2020 Jul 7;10:1000. doi: 10.3389/fonc.2020.01000. eCollection 2020. PubMed 32733795 ↗
  • Hensel J, Metts J, Gupta A, Ladle BH, Pilon-Thomas S, Mullinax J. Adoptive Cellular Therapy for Pediatric Solid Tumors: Beyond Chimeric Antigen Receptor-T Cell Therapy. Cancer J. 2022 Jul-Aug 01;28(4):322-327. doi: 10.1097/PPO.0000000000000603. PubMed 35880942 ↗
  • Mora J. Autologous Stem-Cell Transplantation for High-Risk Neuroblastoma: Historical and Critical Review. Cancers (Basel). 2022 May 24;14(11):2572. doi: 10.3390/cancers14112572. PubMed 35681553 ↗
09

Updates

1 registry update since Sep 25, 2026
Minor edits
Nothing that changes what the study is or who can join. Edited: verification date
1 update, last Oct 7, 2026
Show all 1 update
  1. Oct 7, 2026
    Minor edits only
    + 1 other change: verification date

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT05968768
Lead sponsor
Anna Raciborska
Collaborators
Wroclaw Medical University
Responsible party
Anna Raciborska (Prof Ass, Institute of Mother and Child, Warsaw, Poland) — Sponsor-investigator
First posted
Aug 1, 2023
Start date
Oct 24, 2023
Primary completion
May 1, 2027 (estimated)
Completion
Jul 31, 2028 (estimated)
Last update
Oct 7, 2026

Study contacts

Anna Raciborska, Prof.
Contact
klinika.onkologii@imid.med.pl
+48 22 32 77 205
Anna Raciborska, Prof.
principal investigator · the Institue of Mother and Child

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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