Skip to content
Clinical Trials – home
Not yet recruiting

Feasibility Study of AloCelyvir and Autologous Tumor‑Infiltrating T Lymphocytes in Children and Young Adults with High‑Risk Relapsed/Refractory Neuroblastoma

Verified siteInvestigational
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

A plain-language summary of the goals, design and what participants do

The study looks at children and young adults with advanced, high‑risk relapsed/refractory neuroblastoma, a cancer that starts in nerve tissue and often returns after standard treatment. The experimental approach combines two cell‑based products. The first product, called AloCelyvir, is made from donor bone‑marrow stem cells that have been genetically altered with a virus named ICOVIR-5 and grown in the laboratory before being given by an intravenous (into a vein) infusion. The second product uses the patient’s own tumor‑infiltrating tumor-infiltrating lymphocytes, which are immune cells taken from the tumor, expanded outside the body with the help of three immune‑boosting proteins: interleukin-7, interleukin-15, and interleukin-21. The main purpose of the study is to determine whether the combination of these two cell therapies can be administered safely.

Participants will first receive the stem‑cell product and, after a short interval, the expanded T‑cell product, each as a single intravenous infusion. After each infusion, patients will remain in the hospital for observation and will have regular check‑ups, blood tests, and physical examinations to look for any side effects or problems. The study will continue to follow each participant for several months, recording any changes in the cancer and overall health, with the goal of learning how the treatments are tolerated and whether they show any early signs of benefit.

The research process

The trial runs in 9 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Baseline assessments

    After enrollment, undergo a series of medical examinations, blood tests, and imaging studies to document the current condition of the neuroblastoma and overall health.

    These assessments are used to confirm that the patient meets the study criteria and to establish a reference point for future comparisons.

  2. Step 2

    Collection of tumor tissue

    A sample of tumor tissue is obtained through a scheduled biopsy or surgery.

    The tissue is sent to a specialized laboratory where autologous tumor‑infiltrating lymphocytes (tils) are isolated and prepared.

  3. Step 3

    Manufacturing of study cells

    The laboratory expands the patient’s own tils using interleukin‑7, interleukin‑15 and interleukin‑21, creating a cell suspension for injection.

    In parallel, allogeneic bone‑marrow‑derived mesenchymal stem cells are transduced with icovir‑5 and expanded to produce alocelyvir.

  4. Step 4

    First cell infusion (alocelyvir)

    The prepared alocelyvir product is administered intravenously as a bolus injection or infusion.

    The exact volume and rate are determined by the study protocol; no specific dose amount is listed in the trial description.

  5. Step 5

    Observation period after alocelyvir

    Following the infusion, the patient is monitored for any immediate side effects, including vital signs and laboratory values.

    This observation period helps identify any dose‑limiting toxicities, which are the primary safety focus of the trial.

  6. Step 6

    Second cell infusion (autologous tils)

    After the observation period, the expanded autologous tils are administered intravenously as a bolus injection or infusion.

    As with alocelyvir, the specific dose and infusion rate follow the study protocol and are not detailed in the provided information.

  7. Step 7

    Post‑infusion monitoring

    The patient continues to be observed for adverse events, with regular checks of vital signs, physical examinations, and laboratory tests.

    Any side effects are recorded and graded according to standard criteria.

  8. Step 8

    Follow‑up visits and assessments

    Periodic clinic visits are scheduled to evaluate the response of the neuroblastoma, using imaging and clinical examinations.

    These visits also include safety assessments such as blood work and monitoring for new or ongoing adverse events.

  9. Step 9

    Final evaluation

    At the end of the trial period, a comprehensive assessment is performed to determine overall response, progression‑free survival, and overall survival outcomes.

    The results contribute to the study’s objective of establishing the safety and tolerability of the sequential combination of alocelyvir and tils.

Who can join the trial?

10 criteria

  • Have neuroblastoma that has relapsed or is refractory (meaning it has come back or did not respond to previous treatments) and no known cure is available.
  • Give written informed consent (and assent if you are old enough) together with your parent or legal guardian to join the study.
  • Weigh at least 3 kg (about 6.6 lb).
  • Be between 1 month and 21 years old.
  • Have at least one tumor spot that can be seen on imaging (scans) or measurable bone‑marrow disease that can be examined under a microscope.
  • Be able to undergo an excisional biopsy to remove a small piece of tumor (about 2 cm × 2 cm) so that TILs (tumor‑infiltrating lymphocytes, a type of immune cell) can be collected.
  • Have a life expectancy longer than 14 weeks (about 3½ months) without the study treatment.
  • If you are a female who could become pregnant, you must have a negative serum or urine pregnancy test within the past 72 hours and agree to use acceptable birth‑control methods during the study and for at least 12 months after the lymphodepleting therapy (a treatment that lowers immune cells).
  • If you are a male who could father a child, you must agree to use condoms during the study and for at least 12 months after the lymphodepleting therapy.
  • Show adequate organ function (normal liver, kidney, heart, and other major organ health) before starting the treatment.

Who cannot join the trial?

12 criteria

  • You must not have received any systemic anticancer therapy (cancer‑fighting medicines that affect the whole body) within the last 14 days, or within a time equal to five times the drug’s half‑life (the period it takes for half of the drug to leave your body), whichever is shorter.
  • You cannot have an active infection with hepatitis B, hepatitis C, or HIV (viruses that affect the liver or immune system).
  • You cannot have a primary immunodeficiency (a condition you are born with that makes your immune system weak).
  • You cannot have an active autoimmune disease that requires immunosuppressive therapy (medicines that lower the activity of the immune system).
  • You must not have had a very strong chemotherapy called myeloablative therapy followed by a return of your own blood‑forming stem cells (autologous hematopoietic stem cell rescue) within the past 4 weeks.
  • You cannot have had a stem‑cell transplant from another person (allogeneic stem cell transplantation) within the past 3 months.
  • You must not have received radiotherapy (non‑palliative) (radiation treatment that is not only for comfort) within the last 14 days.
  • You cannot have had major surgery in the past 14 days.
  • You must not have any side‑effects from previous treatment that are Grade 3 toxicity (CTCAE) or higher (moderate to severe problems according to a standard grading system).
  • You cannot have brain tumors that are causing symptoms or that have not been treated (symptomatic or untreated brain metastases). Treated brain metastases may be considered only after special discussion.
  • You must not have had a severe immediate allergic reaction or intolerance to the drugs cyclophosphamide, fludarabine, aldesleukin, or any ingredient (called an excipient) in the lab‑grown immune cells (TILs).
  • You cannot have an active, uncontrolled infection caused by bacteria, viruses, fungi, or parasites.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Not yet recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

  • Autologous tumor-infiltrating T lymphocytes, ex vivo expanded with interleukin-7, interleukin-15 and interleukin-21

    are immune cells that are taken from the child’s own tumor. In the laboratory, these cells are grown with special proteins (interleukin‑7, interleukin‑15, and interleukin‑21) that help them multiply and become more active. After they are expanded, the cells are given back to the patient through an IV infusion. The goal is for these boosted T‑cells to recognize and destroy any remaining cancer cells in the body.

  • AloCelyvir

    is a therapy that uses stem cells taken from a donor’s bone marrow. These cells are genetically modified with a harmless virus called icovir‑5, which turns the stem cells into tiny “delivery trucks” that can travel to the tumor and release anti‑cancer signals. After being grown in the lab, the modified stem cells are infused into the patient’s bloodstream. The purpose is to help the immune system fight the neuroblastoma by targeting the cancer from a different angle.

What is already known about the treatment

  • Autologous tumor-infiltrating T lymphocytes, ex vivo expanded with interleukin-7, interleukin-15 and interleukin-21

    The product is given as a cell suspension that is injected into a vein as a short‑time infusion. It is an experimental therapy that is still being studied in clinical trials and is not yet approved for routine use. It is intended for children and young adults with high‑risk relapsed or refractory neuroblastoma. The cells are the patient’s own immune cells taken from the tumor, grown outside the body with three signaling proteins (IL‑7, IL‑15, IL‑21) to become more active, and then returned to the patient where they locate and kill cancer cells; it is classified as an adoptive cell immunotherapy.

  • AloCelyvir

    This medicine is also a cell suspension administered by intravenous infusion. It is an investigational product that is currently in early clinical testing and has not received market approval. It is designed to treat high‑risk relapsed or refractory neuroblastoma in children and young adults. The therapy uses donor‑derived stem cells that have been engineered to carry a modified virus (ICOVIR‑5); the stem cells deliver the virus to the tumor where it replicates, destroys cancer cells and stimulates the immune system, and it falls under the categories of cell‑based gene therapy and oncolytic virotherapy.

Investigated diseases

High‑risk relapsed/refractory neuroblastoma - Neuroblastoma is a cancer that arises from immature nerve‑cell precursors, most often in the adrenal glands or sympathetic nervous system. High‑risk disease shows rapid growth and often spreads to bone marrow, lymph nodes, and distant organs. When it relapses or becomes refractory, the tumor returns or does not respond to standard therapies, leading to continued progression.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase ITrial ID2025-522006-21-00Protocol codeACTIVEEstimated enrolment15 patientsSponsorFundacion Para La Investigacion Biomedica Del Hospital Universitario La Princesa

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

Legal notice · Published by CTIN POLAND sp. z o.o., ul. rtm. Witolda Pileckiego 67/109, 02-781 Warsaw, Poland · KRS 0001111334 · REGON 528919042 · NIP 9512598637

© 2026 Clinical Trials EU – European Clinical Trials Information Network

GDPR compliance, ISO 9001 and ISO 27001 certified (LL-C Certification)

On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).