Understanding Ph+ ALL

What is Ph+ ALL?

What is Ph+ ALL? Philadelphia Chromosome Positive, Acute (the cancer grows quickly), Lymphoblastic (the cancer affects young white blood cells called lymphoblasts), Leukemia.

As you may know, Ph+ ALL stands for:

Ph+ Philadelphia chromosome positive
A Acute (the cancer grows quickly)
L Lymphoblastic (the cancer affects young white blood cells called lymphoblasts)
L Leukemia

Ph+ ALL (or Philadelphia-positive ALL) is a type of blood cancer that grows quickly. It starts in young white blood cells called lymphoblasts or blast cells.

In people with Ph+ ALL, a change, or mutation, in their DNA creates the “Philadelphia” (Ph) chromosome. When the Ph chromosome is present in cells, a protein known as BCR-ABL is produced. This protein activates the bone marrow to make too many lymphoblasts, which leads to leukemia.

Man and woman walking.

Not actual patients

Treating Ph+ ALL

Doctors treat Ph+ ALL with chemotherapy, corticosteroids, and TKIs. People with more advanced stages of the disease may receive other treatments as well. Your doctor will determine the treatment that is right for you.

Monitoring your response to treatment for Ph+ ALL

Throughout treatment, your doctor will monitor how well your body is responding. To do this, your doctor may perform 2 types of tests.



Cytogenetic testing helps detect the presence of altered chromosomes (such as the Philadelphia chromosome) in the body.



Molecular testing measures the levels of BCR-ABL in the body. One type of molecular test is called qPCR, and it can be used to determine how well treatment is working.

Determining if your current treatment is working

When evaluating these test results, your doctor will look for:


The goal of treatment is complete remission, which means:

  • Your blood count is normal

  • Your disease symptoms are gone

  • Your doctor cannot see any leukemia cells in a sample of your bone marrow using a microscope

Even if you have complete remission, there may still be a small number of leukemia cells left behind. This is called minimal residual disease. It can only be detected with sensitive laboratory tests.


Your doctor may monitor the levels of BCR-ABL in your blood. BCR-ABL is a protein that helps make leukemia cells.

Why your doctor may change your treatment

Some people will need to change their TKI treatment over time. There are 2 main reasons why a person may need to change their TKI treatment—resistance and/or intolerance.


If your Ph+ ALL no longer responds to a TKI treatment, this is called resistance. A number of factors can cause your cancer to become resistant to treatment, including if your Ph+ ALL develops a mutation. Resistance is one reason your doctor may recommend changing to a different TKI.


Another reason your doctor may recommend changing TKIs is intolerance to side effects caused by your current treatment.

Mutations may affect treatments

In Ph+ ALL, changes called mutations can appear in the BCR‑ABL protein during treatment with a TKI. Mutations may impact your condition and cause your treatment to stop working. So, it’s important for your doctor to test regularly for mutations.

If you develop a mutation while on your current TKI, your doctor may recommend that you change to a different TKI that may work better against the mutation.

T315I is a type of mutation that can occur in Ph+ ALL. ICLUSIG is the only TKI that is approved to treat people with Ph+ ALL who have the T315I mutation.

Doctor discussion guide

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How ICLUSIG works

Find out more about ICLUSIG and how it works