Major Molecular Response (MMR) is not a type of leukemia. Instead, it is a term used to describe a deep level of remission in patients with chronic myeloid leukemia (CML), specifically related to the BCR::ABL1 gene.
Here's a breakdown of what MMR means within the context of CML treatment:
Understanding Chronic Myeloid Leukemia (CML)
CML is a type of blood cancer caused by an abnormal gene called BCR::ABL1. This gene produces a protein that causes the bone marrow to make too many white blood cells.
What is Major Molecular Response (MMR)?
- Targeting BCR::ABL1: Treatment for CML usually involves tyrosine kinase inhibitors (TKIs), which specifically target the BCR::ABL1 protein.
- Measuring Treatment Success: Instead of just counting cancer cells in the blood, doctors use a highly sensitive lab test to measure the level of BCR::ABL1 mRNA, which is the genetic material that carries the instructions for making the BCR::ABL1 protein.
- MMR Defined: MMR is achieved when there is a significant reduction in the amount of BCR::ABL1 mRNA in the patient's blood. This indicates a very low level of leukemia cells are present. It's a much deeper response than just seeing the cell count go down.
Here’s a table summarizing the concept:
| Term | Meaning | Significance in CML |
|---|---|---|
| BCR::ABL1 | Abnormal gene causing CML | Target for Treatment |
| TKIs | Drugs targeting the BCR::ABL1 protein | Treatment for CML |
| Major Molecular Response (MMR) | Significant reduction of BCR::ABL1 mRNA | Deep Remission |
Why is MMR Important?
Achieving MMR is a crucial goal for CML patients because:
- Lower Progression Risk: It’s associated with a lower risk of the disease progressing to a more advanced phase.
- Higher TFR Chance: Patients who achieve MMR are more likely to be able to eventually stop TKI treatment and remain in remission, which is known as treatment-free remission (TFR).
Therefore, while "MMR leukemia" is not a correct term, achieving MMR is a key indicator of successful treatment and an improved prognosis for people with CML. It's not a disease itself but a desirable treatment outcome.
