imatinib

The first-line medication for Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML), both in adults and children.

The Philadelphia chromosome is a specific genetic abnormality in chromosome 22 of leukemia cancer cells (particularly, CML cells) due to t(9;22)(q34;q11), reciprocal translocation between chromosomes 9 and 22, and contains the BCR-ABL1 (Breakpoint Cluster Region-ABelson Leukemia 1) gene, a fusion gene coding for a hybrid protein, a tyrosine kinase signaling protein, that is "always on", causing the cell to divide uncontrollably by interrupting the stability of the genome and impairing various signaling pathways governing the cell cycle.

It is a 2-phenyl amino pyrimidine derivative that functions as an inhibitor targeting multiple tyrosine kinases such as CSF1R, ABL, c-KIT, FLT3, and PDGFR-β.
It works by stopping the BCR-ABL tyrosine-kinase, leading to slow growth or programmed cell death of certain types of cancer cells.

In many cases, it can induce a complete cytogenetic response and major molecular response.
However, it is not a cure for leukemia. Instead, it is a "chronic therapy" that helps to control the disease and prevent it from progressing. Some patients may need to continue taking it for an extended period of time to maintain remission, and others may eventually require additional treatment options.

(Indications)
• chronic myelogenous leukemia (CML)
• acute lymphocytic leukemia (ALL)
• chronic eosinophilic leukemia
• gastrointestinal stromal tumors
• hypereosinophilic syndrome
• dermatofibrosarcoma protuberans
• myelodysplastic/myeloproliferative diseases
• aggressive systemic mastocytosis

(Side effects)
Common:
• vomiting
• diarrhea
• muscle pain
• headache
• visual disturbances
• itchy rash
Severe:
• fluid retention
• gastrointestinal bleeding
• bone marrow suppression
• liver problems
• heart failure
• growth stunting in children or adolescents
During pregnancy:
• risk of embryo-fetal toxicity