A Study Investigating the Change in Metabolism Phenotype in Paediatric, Adolescent & Young Adults With Hodgkin or Non-Hodgkin Lymphoma.

PEGASUS aims to test acceptability and feasibility of studying phenoconversion (the change in metabolism phenotype) using probe medications in a paediatric oncology patient population. The study will be conducted in patients (6-25 years of age) with Hodgkin lymphoma or non-Hodgkin lymphoma as exemplar cohort, but with the understanding that cancer-directed and supportive care medicines of the CYP3A4, CYP2C19, and CYP2D6 metabolic pathways are commonly utilised for the treatment of many paediatric, adolescent, young adult, and adult cancers. The study involves administration of the probe medication at timepoints which align with pre-determined hospital visits for the treatment of lymphoma and subsequent blood draws to measure the metabolism of the probe medications. The acceptability and feasibility of this study will inform future studies in phenoconversion within the paediatric cancer population to direct more personalised precision medicine.

Inclusion Criteria: * Age 6-25 years of age. * New diagnosis of Hodgkin Lymphoma or Non-Hodgkin Lymphoma. * Able to swallow and absorb oral or nasogastric tube (NGT) administration of probe drugs. * Able to provide written informed consent. Exclusion Criteria: * Failure to comply with inclusion criteria. * Has a known previous allergy to any of the probe medications (i.e., omeprazole or dextromethorphan). * Common Terminology Criteria for Adverse Events (CTCAE) Grade IV end organ dysfunction (i.e., hepatic, renal, gastrointestinal). * Had previous oncological treatment (not first cancer diagnosis). * Is a clinically unstable patient requiring intensive care admission in high-risk circumstances will not be considered eligible for consent. * Any patient requiring urgent initiation of anti-cancer treatment outside hours where a member of the study staff is unable to approach the parent/guardian or participant for consent prior to commencing anti-cancer therapy will be ineligible for consent. * Unable to provide written informed consent.