Anaplastic Lymphoma Kinase: Role in specific tumours, and development of small molecule inhibitors for cancer therapy

The Anaplastic Lymphoma Kinase (ALK) is a receptor tyrosine kinase first identified as the product of a gene rearrangement in Anaplastic Large Cell Lymphoma. ALK has subsequently been found to be rearranged, mutated, or amplified in a further series of tumours including neuroblastoma, and Non-Small Cell Lung Cancer. There is strong preclinical evidence that ALK is a driving force for oncogenesis in these cases, and that inhibition of ALK kinase activity results in anti-tumoural efficacy. These observations have sparked the development of small molecule kinase inhibitors, the most advanced of which is currently in clinical testing and which has shown promising preliminary activity in the subset of lung cancer patients whose tumours harbour activated ALK. In this review, we describe the various oncogenic forms of ALK, relevant clinical settings, and give a detailed overview of current drug discovery efforts in the field.