Cizotinib is inhibitor of which receptor ?
**Core Concept**
Cizotinib is a tyrosine kinase inhibitor used in the treatment of non-small cell lung cancer (NSCLC) and other cancers. It targets specific receptors involved in the signaling pathways that promote cell growth and division.
**Why the Correct Answer is Right**
Cizotinib specifically inhibits the anaplastic lymphoma kinase (ALK) receptor tyrosine kinase, which is involved in the signaling pathway that promotes cell growth and division. This inhibition prevents the proliferation of cancer cells that have an overactive ALK pathway. Cizotinib also has a weak inhibitory effect on the epidermal growth factor receptor (EGFR) tyrosine kinase, but its primary mechanism of action is through ALK inhibition.
**Why Each Wrong Option is Incorrect**
**Option A:** MET is a receptor tyrosine kinase, but it is not the primary target of cizotinib. Cizotinib does have some inhibitory effect on MET, but it is not its primary mechanism of action.
**Option B:** VEGFR is a receptor tyrosine kinase involved in angiogenesis, but it is not the target of cizotinib. Cizotinib's primary mechanism of action is through ALK inhibition, not VEGFR inhibition.
**Option C:** HER2 is a receptor tyrosine kinase involved in the signaling pathway that promotes cell growth and division, but it is not the target of cizotinib. Cizotinib's primary mechanism of action is through ALK inhibition, not HER2 inhibition.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that cizotinib is a targeted therapy that specifically inhibits the ALK receptor tyrosine kinase, making it a valuable treatment option for patients with NSCLC and other cancers that have an overactive ALK pathway.
**Correct Answer: C. ALK**