Alecensa (alectinib) is a tyrosine kinase inhibitor (TKI) that works specifically on a protein called anaplastic lymphoma kinase (ALK protein). Tyrosine kinases (TK) help to determine processes such as growth, differentiation, metabolism, and cell death, and are involved in signaling pathways – these are pathways that control and regulate the flow of information between cells and their outside environment. Research has linked abnormal TK activity or mutations to various cancers – one of these is non-small cell lung cancer. Anaplastic lymphoma kinase (ALK) mutations are present in approximately 5% of NSCLC cases, and by inhibiting this protein, Alecensa reduces the growth of ALK-positive metastatic NSCLC. Alecensa is only used in metastatic NSCLC that has been tested and confirmed to be ALK-positive.