iMATRIX: This phase I/II trial is evaluating how safe and tolerable targeted therapy (alectinib) is in children and adolescents with Anaplastic Lymphoma Kinase (ALK) fusion-positive solid cancers or cancers of the brain or spinal cordA Phase I/II, Open-Label, Multicenter, Study Evaluating the Safety, Pharmacokinetics, and Efficacy of Alectinib in Pediatric Participants With ALK Fusion-Positive Solid or CNS Tumors for Whom Prior Treatment Has Proven to be Ineffective or for Whom There is No Satisfactory Treatment Available

Exclusion

• Medical history of: prior use of ALK inhibitors; diagnosis of Anaplastic Large Cell Lymphoma (ALCL); any gastrointestinal disorder that may affect absorption of oral medications, such as mal-absorption syndrome or status post-major bowel resection; history of organ transplant; stem cell infusions as defined by the protocol
• Substance abuse within 12 months prior to screening
• Familial or personal history of congenital bone disorders, bone metabolism alterations, or osteopenia
• Treatment with investigational therapy 28 days prior to initiation of study drug
• Liver or kidney disease as defined by the protocol
• National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) v5.0 grade >/=3 toxicities attributed to any prior therapy such as radiotherapy (excluding alopecia), which have not shown improvement and are strictly considered to interfere with alectinib
• Co-administration of anti-cancer therapies other than those administered in this study
• Active hepatitis B or C virus (HBV, HBC), or known HIV-positivity or AIDS-related illness
• Any clinically significant concomitant disease or condition that could interfere with, or for which the treatment might interfere with, the conduct of the study or the absorption of oral medications or that would, in the opinion of the Principal Investigator, pose an unacceptable risk to the participant in this study
• Any psychological, familial, sociological, or geographical condition potentially hampering compliance with the study protocol requirements and/or follow-up procedures; such conditions should be discussed with the participant before trial entry
• Planned procedure or surgery during the study except as permitted treatment as defined by the protocol
• Infection considered by the investigator to be clinically uncontrolled or of unacceptable risk to the participant upon induction of neutropenia, including participants who are, or should be, on antimicrobial agents for the treatment as active infection
• Pregnant or breastfeeding, or intending to become pregnant during the study or within 3 months after the final dose of alectinib