This study looks at a new way to prepare patients for a blood or bone marrow transplant. The plan uses three drugs: **treosulfan**, **fludarabine**, and **rabbit antithymocyte globulin (rATG)**. Treosulfan is a chemotherapy drug that helps stop unwanted cell growth. Fludarabine works by blocking enzymes the body needs to grow cancer cells. **rATG** helps lower the body’s immune response, which can help the bone marrow work better. Together, these drugs may cause fewer problems after a transplant.

• The study lasts for about one year and includes regular follow-ups after the transplant.
• Patients may take part if they are older than 1 year but younger than 50 years.
• Patients receive treosulfan and fludarabine by IV (intravenous) and undergo several tests.

There are some risks and not everyone can join; for example, those with prior transplants or certain infections are not eligible. Compensation is not mentioned in the study details. Participants will need to sign a consent form before starting the treatment. You might want to discuss with a doctor if this is the right choice for you.