Leukemias
Philadelphia-positive B-cell acute lymphoblastic leukemia
Also called: Ph+ B-ALL · BCR-ABL1 B-ALL · Ph-positive ALL · acute lymphoblastic leukemia · Ph+ ALL · ALL · Philadelphia chromosome-positive B-ALL · B acute lymphoblastic leukaemia with BCR::ABL1 fusion
Classified by the World Health Organization as B-lymphoblastic leukaemia/lymphoma with BCR::ABL1 fusion.
What a donor has to do with this
For some people with this condition, a transplant using blood stem cells from an unrelated donor is part of the treatment guidelines. When a transplant is the right route and no one in the family matches, that donor comes from a registry. Not everyone with this condition has a transplant, and many never need one.
This is our reading of published transplant guidelines for this condition, not a measurement of how many people need a donor. Where a source actually counted donors, the figure and the people it counted are shown further down. Where none did, we say so rather than estimate.
What the evidence says
- Who it affects
- Typically diagnosed in adulthood, with BCR::ABL1 markedly more common as age rises and uncommon in childhood B-ALL. Source population/region/year: international adult ALL evidence synthesized in the EBMT Handbook, published 2024.
- Treatments other than a transplant
- Tyrosine-kinase inhibitor plus ALL therapy, blinatumomab-based regimens, and CD19 CAR-T in relapsed/refractory CD19-positive disease; post-CAR-T allo-HCT remains individualized
- If a transplant is used, the cells come from
- Allogeneic peripheral blood or bone marrow; cord blood and haploidentical grafts are alternatives when matched related/unrelated donors are unavailable; dominant source not reported in the opened disease-specific sources
- How often the donor was unrelated
- Not reported. No source we could read states this for this condition, so we do not give a number. An estimate here would be a guess dressed as evidence.
Where this gets complicated
Modern TKI/blinatumomab regimens may reduce CR1 transplant use in selected deep responders, but EBMT 2025 still states the aggregate standard; practice is evolving.
“allo-HCT represents the standard of care in Ph+ALL”
It describes what teams consider in general. It cannot say what applies to any one person. Read the source.
People with this condition need donors
Joining a registry is a cheek swab and a short health form. You are contacted only if you turn out to be a possible match for someone, and you can ask questions and decline before anything else happens.
Related conditions
Others in leukemias. They are genuinely different diseases with different treatments — the group name is not a diagnosis.
Where this came from
- WHO Classification of Haematolymphoid Tumours, 5th edition — final table of contents — WHO/IARC, final print volume 2024; online classification introduced 2022
- Indications for haematopoietic cell transplantation and CAR-T: 2025 EBMT practice recommendations — EBMT / Bone Marrow Transplantation, 2025-09-09
- Adult Acute Lymphoblastic Leukemia Treatment (PDQ)—Health Professional Version — NCI, 2025-03-17
- Acute Lymphoblastic Leukemia in Adults — Springer / EBMT Handbook, 2024-04-11