RESPONSE ORIENTED MAINTENANCE THERAPY IN ADVANCED FOLLICULAR LYMPHOMA. RESULTS OF THE INTERIM ANALYSIS OF THE FOLL12 TRIAL CONDUCTED BY THE FONDAZIONE ITALIANA LINFOMI.

PET-based staging, PFS24 may not be a robust surrogate endpoint for OS. The improved outcomes in PET-staged patients with early progression may be associated with identification and exclusion of patients with transformed disease at time of therapy. Patients with early progression are at risk for early death. In contrast, patients with early progression and no evidence of transformation have an extended OS, suggesting aggressive upfront therapies may not be warranted in these patients.