An Australian multicenter observational study investigating the treatment free survival in unresectable advanced and metastatic melanoma patients who have received immune checkpoint inhibitors

Two treatments are used to treat metastatic or advanced melanoma; either combination CTLA4 inhibitor (ipilimumab) & PD-1 inhibitor (nivolumab) or single agent PD-1 inhibitor (pembrolizumab or nivolumab). Survival is improved with combination immunotherapy as compared to single agent immunotherapy. Mutations in BRAF are common in melanoma. Melanoma patients without BRAF mutation have a less pronounced benefit from combination immunotherapy compared to single agent. Combination immunotherapy, while improved efficacy, has increased side effects. Whether to give combination or single agent immunotherapy for a patient can be a complex decision. A new outcome measure coined treatment free survival has emerged to further support clinicians to determine the optimal immunotherapy pathway. Treatment free survival (TFS) denotes the amount of time patients spend with stable advanced melanoma after cessation of the first line treatment, before cancer progression prompts initiation of second line treatment, or death from progressive cancer. TFS was further divided into time spent on and off immunosuppression. Patients on combination immunotherapy have a longer TFS but also longer time on steroids. There are several factors that likely to change the TFS (both on and off steroids) in the real world Australian population. The aim of this study is to measure the TFS for an Australian cohort on combination immunotherapy and single agent immunotherapy. The TFS, both on and off immunosuppression, for the two Australian immunotherapy cohorts will be compared. Further aims are to compare the TFS of combination immunotherapy and single agent immunotherapy to the Keynote067/069 TFS data which coined the TFS. The study will be an analytical observation cohort study. Data will be extracted from the medical records program (iEMR/EMR). The data cohort will be gained from chemotherapy programs (MOSAIQ/CHARM) which will include any patient who received treatment during the proposed time period.