Evaluating Atezolizumab in Adults, Children, and Young Adults with Rare or Common Cancers That Have High Tumor Mutational Burden, High Microsatellite Instability, or Constitutional Mismatch Repair Deficiency

What this Trial Is About

Researchers are evaluating the drug atezolizumab in a clinical trial for adult, pediatric, and teenageyoung adult patients with rare cancers or common cancers showing specific genetic changes called high tumor mutational burden TMB, high microsatellite instability MSI, or proven constitutional mismatch repair deficiency CMMRD. Atezolizumab is already approved for several cancer types, and this trial aims to see if it can be useful for other cancers with these genetic features. This trial is part of the DETERMINE program, which studies targeted therapies for rare cancers or cancers with specific mutations. Participants who qualify will receive atezolizumab treatment, given intravenously every 21 days. Adults receive 1200 mg per dose, while pediatric patients receive 15 mgkg up to 1200 mg. Treatment continues until the cancer progresses without benefit, unacceptable side effects occur, or the patient chooses to stop. Before treatment, patients undergo biopsy and blood sample collection. Blood samples are also collected during treatment and at the end of treatment. After treatment ends, patients will be followed up every 3 months for 2 years. During the study, patients will have regular disease assessments, including scans every two treatment cycles each cycle is 21 days and at the end of treatment, with less frequent assessments after 24 weeks. Quality of life questionnaires will be completed regularly. Researchers will monitor treatment response, duration of response, survival, and any serious side effects. Follow-up for survival and safety continues for up to 2 years after treatment ends, with some safety monitoring extending up to 5 years. The trial aims to provide evidence to support wider access to this treatment through the NHS if results are positive.

DETERMINE Trial Treatment Arm 02: Atezolizumab in Adult, Paediatric and Teenage/Young Adult Patients With Cancers With High Tumour Mutational Burden (TMB) or Microsatellite Instability-high (MSI-high) or Proven Constitutional Mismatch Repair Deficiency (CMMRD) Disposition