X003: A One-Time Treatment for Beta-Thalassemia

A one-time gene therapy for transfusion-dependent beta-thalassemia.

X003 restores natural hemoglobin production, freeing patients from lifelong transfusions.

Blood stem cells are collected from the patient through a simple apheresis procedure.

A functional β-globin gene is added to the collected cells using a precise vector.

Each batch is carefully tested for safety and quality before infusion.

The modified stem cells are infused back into the patient to restore healthy blood production.

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4. What is X003?

X003 is designed to address the root cause of β-thalassemia, not just manage its symptoms.

Using the patient’s own blood stem cells, X003 introduces a functional β-globin gene that enables the body to produce healthy hemoglobin independently. This reduces — and in many cases, eliminates — the need for ongoing blood transfusions.

Unlike lifelong transfusion regimens that can lead to iron overload and other complications, X003 offers a one-time, potentially curative treatment.

It allows patients to achieve stable hemoglobin levels and reclaim a more normal, transfusion-free life.

Important Safety Information

As with any medical procedure, treatment with X003 may involve potential side effects and complications. Most are temporary and manageable under close medical supervision. All steps of the process, from cell collection to infusion, are conducted in GMP-compliant facilities to ensure the highest safety and quality standards.

Commonly Observed Side Effects

The main risks are related to myeloablative conditioning (Busulfan), a standard preparatory treatment given before infusion.
These may include:

Hematological effects: lowered white blood cell count (78–83%), decreased neutrophil count (78–83%), and decreased platelet count (25–78%)
Non-hematological effects: hypokalemia (33–67%), vomiting (56–58%), oral mucositis, and febrile neutropenia (44–67%)

Most reactions are Grade 1–2 in severity and respond well to standard medical care.
Grade 3 or higher reactions are rare and manageable with appropriate interventions.

Serious Adverse Events

To date, no insertional mutagenesis, clonal expansion, or replication-competent retrovirus (RCL)–related events have been observed in patients treated with X003.

Safety Monitoring

Safety is monitored continuously throughout the treatment process to ensure that every patient is provided with the most adequate care.

Risk Mitigation

To minimize risks, patients are:

Carefully screened and prepared before treatment
Closely monitored during hospitalization
Supported by an experienced medical team throughout recovery

If You Experience Symptoms After Treatment

Patients should promptly contact their care team if they experience:

Persistent fever or fatigue
Unusual bleeding or bruising
Infection symptoms (e.g., sore throat, upper-respiratory infection)
Severe nausea, vomiting, or diarrhea

Long-Term Outlook

In clinical and real-world data, most patients experienced stable recovery of blood counts within weeks of infusion.
The median engraftment time for neutrophils was 13 days (range: 8–16), and for platelets 14 days (range: 10–21).

A one-time gene therapy for transfusion-dependent beta-thalassemia. ​

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