How do you define treatment success in MZL?

In this issue of Blood, Bommier et al have tested novel end points as surrogate markers for progression -free survival (PFS) in extranodal marginal zone lymphoma (MZL) treated with systemic therapy.1 Why is this important? Indolent non -Hodgkin lymphomas, such as follicular lymphoma (FL) and MZL, have a long natural history and favorable survival. As new and more effective therapies are developed to improve outcomes even further, investigators are faced with measuring and defining treatment success using surrogate end points (SEPs) to detect the benefit of a drug (see figure).