OP437 Use Of Real-World Evidence In Survival Analysis Adjusting For Treatment Crossover In Cutaneous T-Cell Lymphoma

Real-World Evidence is useful for validating crossover adjustment approaches, particularly when the required because a trial does not accurately reflect health technology assessment (HTA)-relevant population. We use MAVORIC advanced stage mycosis fungoides and Sézary syndrome cutaneous T-cell lymphoma population data from Hospital Episodes Statistics to explore validate methods. Introduction The compared mogamulizumab vorinostat in patients with (MF) or (SS), subtypes of lymphoma. However, treatment comparison within may represent an HTA relevant UK perspective: (i) 72.6 percent randomized switched (ii) used current clinical practice UK. This study explores methods adjust effect estimates using different Evidence. medicine subject additional monitoring. will allow quick identification new safety information. See www.mhra.gov.uk/yellowcard how report side effects. Methods An (stage ≥IIB MF all SS) was included. Three were considered adjustment. A synthetic control arm created (HES) dataset. Predicted survival arm, post-crossover adjustment, HES inform selection appropriate direct between (reweighted distribution MF/SS HES) also conducted. Results Following inverse probability censoring weighting method, overall (OS) hazard ratio (HR) estimate vs. 0.45 (95% confidence interval (CI): 0.19, 1.07). method most based on assumptions OS adjusted data. HR reweighted 0.33 (CI: 0.21, 0.50). Conclusions Real World database can be better both support each other.