Potential therapies for anaplastic lymphoma kinase-driven tumors in children: progress to date.

Anaplastic lymphoma kinase (ALK) is an oncogenic tyrosine kinase that is deregulated due to a variety of molecular mechanisms in pediatric cancer. They include chromosomal translocations, activation mutations, and gene amplifications. Since the initial discovery of ALK as an oncogenic tyrosine kinase involved in the chromosomal translocation t(2, 5)(p23;q35) in 1994, more than 20 translocation partners of ALK have been identified in various cancers. Furthermore, deregulation of ALK tyrosine kinase activity is critical for the pathogenesis of several other pediatric tumors, including neuroblastomas and inflammatory myofibroblastic tumors. The recent discovery of ALK translocations in adult lung cancer patients (non-small cell lung cancer) has accelerated the development of inhibitors of ALK tyrosine kinase as therapeutic agents. While excellent clinical response has been observed in many patients, the acquisition of clinical resistance to ALK inhibition highlights the need for development of second-generation ALK kinase inhibitors and/or combination therapies that target downstream signaling mediators or antibody drug conjugates. This article provides an update on the spectrum of ALK-driven tumors in the pediatric population and the potential therapies which target these tumors.