Clausen, Michael Roost

Abstract A short diagnosis-to-treatment interval independently predicts inferior outcomes in follicular lymphoma. Using international discovery and validation cohorts, we demonstrate its prognostic value beyond established prognostic indices, with implications for risk stratification, clinical trial design, and interpretation.

PURPOSE Although most patients with follicular lymphoma (FL) can expect an indolent course, progressive lymphoma remains the primary cause of death during the first decade after diagnosis. Progression of disease within 24 months (POD24) of starting first-line (1L) immunochemotherapy defines a high-risk population with poor survival, but better risk stratification at diagnosis is needed. METHODS The FLIPI24 model was developed and internally validated to predict 24-month event rates using individual data from 4,485 patients treated with 1L immunochemotherapy from 10 observational cohorts of FL. Overall and cause-specific survival was further evaluated in FLIPI24 risk groups. External validation in the 1L immunochemotherapy setting was performed using the prospective observational Lymphoma Epidemiology of Outcomes (LEO) cohort (N = 565) and three randomized phase III trials (N = 3,192); extension to all patients with FL (any 1L therapy) was performed in the LEO cohort (N = 1,445) and its Molecular Epidemiology Resource subcohort (N = 1,074). RESULTS The FLIPI24 model uses age and four blood-based variables (hemoglobin, lactate dehydrogenase, beta-2 microglobulin, and WBC count). FLIPI24 showed consistent performance across validation and extension data sets, which was superior to existing prognostic tools. Across the four external immunochemotherapy validation data sets, patients with high-risk FLIPI24 (23%-32% of patients) had significantly higher 24-month event rates (22%-35%) and inferior 5-year overall survival (77%-83%) compared with patients with low-risk FLIPI24 (29%-31% of patients, 24-month event rates: 10%-12%; 5-year OS: 96%-97%). Results were consistent when evaluating lymphoma-related death and when extended to all patients with FL. CONCLUSION The FLIPI24 model robustly stratifies, at diagnosis, patients with FL at increased risk of lymphoma-related death versus patients with very low lymphoma-related mortality during the first decade after diagnosis. FLIPI24 can be used to enrich future clinical trial designs in newly diagnosed FL.

ABSTRACTThe development of new first‐line treatments for patients with follicular lymphoma (FL) is becoming increasingly challenging due to already excellent survival outcomes. The present study investigated the outcomes of patients with FL who underwent contemporary first‐line therapies but would not have been eligible for inclusion in recent trials and explored how commonly used in/exclusion criteria impacted their survival outcomes. This study included adult patients diagnosed with FL in the period 2000–2018 registered in the Danish Lymphoma Registry. Through searches on ClinicalTrials.gov, four recent 1st line phase 3 randomized controlled trials with R‐Bendamustine, R‐CVP, and/or R‐CHOP as control or experimental arms were included. Inclusion and exclusion criteria for each trial were retrieved and categorized. Patients were then divided into trial‐eligible and ineligible groups according to blood test results correlated to organ function and ECOG performance score (PS). Survival outcomes were significantly worse among trial‐ineligible patients, with adjusted differences between trial‐eligible and ineligible patients of 12%–20% in five‐year overall survival (OS) overall. Inclusion criteria based on PS and renal function were the main drivers of OS differences. More inclusive trials will lead to faster recruitment and secure focus on developing medicines for the group of patients with the worst outcomes.

Key PointsPatients who received R-chemo followed by MR had an improved 5-year PFS and OS independent of prognostic factors. A reduction of the risk of HT was observed among the MR patients of the training, but not of the validation, cohort.